# Module:Citation/CS1

require ('strict');  

----------------------------< F O R W A R D D E C L A R A T I O N S >--------------------------------------  

each of these counts against the Lua upvalue limit  

local validation; -- functions in Module:Citation/CS1/Date_validation  

local utilities; -- functions in Module:Citation/CS1/Utilities  
local z = {}; -- table of tables in Module:Citation/CS1/Utilities  

local identifiers; -- functions and tables in Module:Citation/CS1/Identifiers  
local metadata; -- functions in Module:Citation/CS1/COinS  
local cfg = {}; -- table of configuration tables that are defined in Module:Citation/CS1/Configuration  
local whitelist = {}; -- table of tables listing valid template parameter names; defined in Module:Citation/CS1/Whitelist  

--------------------< P A G E S C O P E V A R I A B L E S >---------------  

declare variables here that have page-wide scope that are not brought in from  
other modules; that are created here and used here  

local added_deprecated_cat; -- Boolean flag so that the category is added only once  
local added_vanc_errs; -- Boolean flag so we only emit one Vancouver error / category  
local added_generic_name_errs; -- Boolean flag so we only emit one generic name error / category and stop testing names once an error is encountered  
local added_numeric_name_errs; -- Boolean flag so we only emit one numeric name error / category and stop testing names once an error is encountered  
local added_numeric_name_maint; -- Boolean flag so we only emit one numeric name maint category and stop testing names once a category has been emitted  
local Frame; -- holds the module's table  
local is_preview_mode; -- true when article is in preview mode; false when using 'Preview page with this template' (previewing the module)  
local is_sandbox; -- true when using sandbox modules to render citation  

----------------------------< F I R S T _ S E T >------------------------------------------------------------  

Locates and returns the first set value in a table of values where the order established in the table,  
-to- (or top-to-bottom), is the order in which the values are evaluated. Returns nil if are set.  

This version replaces the original 'for _, val in pairs do' and a similar version that used ipairs. With the pairs  
version the order of evaluation could not be guaranteed. With the ipairs version, a nil value would terminate  
the for-loop before it reached the actual end of the list.  

local function first_set (list, count)  
local i = 1;  
while i <= count do -- loop through all items in list  
if utilities.is_set( list[i] ) then  
return list[i]; -- return the first set list member  
end  
i = i + 1; -- point to next  
end  
end  

----------------------------< A D D _ V A N C _ E R R O R >----------------------------------------------------  

Adds a single Vancouver system error message to the template's output regardless of how many error actually exist.  
To prevent duplication, added_vanc_errs is nil until an error message is emitted.  

added_vanc_errs is a Boolean declared in page scope variables above  

local function add_vanc_error (source, position)  
if added_vanc_errs then return end  

added_vanc_errs = true; -- note that we've added this category  
utilities.set_message ('err_vancouver', {source, position});  
end  

----------------------------< I S _ S C H E M E >------------------------------------------------------------  

does this thing that purports to be a URI scheme seem to be a valid scheme? The scheme is checked to see if it  
is in agreement with http://tools.ietf.org/html/std66#section-3.1 which says:  
Scheme names consist of a sequence of characters beginning with a  
letter and followed by any combination of letters, digits, plus  
("+"), period ("."), or hyphen ("-").  

returns true if it does, else false  

local function is_scheme (scheme)  
return scheme and scheme:match ('^%a[%a%d%+%.%-]*:'); -- true if scheme is set and matches the pattern  
end  

--[=[-------------------------< I S _ D O M A I N _ N A M E >--------------------------------------------------  

Does this thing that purports to be a domain name seem to be a valid domain name?  

Syntax defined here: http://tools.ietf.org/html/rfc1034#section-3.5  
BNF defined here: https://tools.ietf.org/html/rfc4234  
Single character names are generally reserved; see https://tools.ietf.org/html/draft-ietf-dnsind-iana-dns-01#page-15;  
see also Single-letter second-level domain  
list of TLDs: https://www.iana.org/domains/root/db  

RFC 952 (modified by RFC 1123) requires the first and last character of a hostname to be a letter or a digit. Between  
the first and last characters the name may use letters, digits, and the hyphen.  

Also allowed are IPv4 addresses. IPv6 not supported  

domain is expected to be stripped of any path so that the last character in the last character of the TLD. tld  
is two or more alpha characters. Any preceding '//' (from splitting a URL with a scheme) will be stripped  
here. Perhaps not necessary but retained in case it is necessary for IPv4 dot decimal.  

There are several tests:  
the first character of the whole domain name including subdomains must be a letter or a digit  
internationalized domain name (ASCII characters with .xn-- ASCII Compatible Encoding (ACE) prefix xn-- in the TLD) see https://tools.ietf.org/html/rfc3490  
single-letter/digit second-level domains in the .org, .cash, and .today TLDs  
q, x, and z SL domains in the .com TLD  
i and q SL domains in the .net TLD  
single-letter SL domains in the ccTLDs (where the ccTLD is two letters)  
two-character SL domains in gTLDs (where the gTLD is two or more letters)  
three-plus-character SL domains in gTLDs (where the gTLD is two or more letters)  
IPv4 dot-decimal address format; TLD not allowed  

returns true if domain appears to be a proper name and TLD or IPv4 address, else false  

]=]  

local function is_domain_name (domain)  
if not domain then  
return false; -- if not set, abandon  
end  

domain = domain:gsub ('^//', ''); -- strip '//' from domain name if present; done here so we only have to do it once  

if not domain:match ('^[%w]') then -- first character must be letter or digit  
return false;  
end  

if domain:match ('^%a+:') then -- hack to detect things that look like s:Page:Title where Page: is namespace at Wikisource  
return false;  
end  

local patterns = { -- patterns that look like URLs  
'%f[%w][%w][%w%-]+[%w]%.%a%a+$', -- three or more character hostname.hostname or hostname.tld  
'%f[%w][%w][%w%-]+[%w]%.xn%-%-[%w]+$', -- internationalized domain name with ACE prefix  
'%f[%a][qxz]%.com$', -- assigned one character .com hostname (x.com times out 2015-12-10)  
'%f[%a][iq]%.net$', -- assigned one character .net hostname (q.net registered but not active 2015-12-10)  
'%f[%w][%w]%.%a%a$', -- one character hostname and ccTLD (2 chars)  
'%f[%w][%w][%w]%.%a%a+$', -- two character hostname and TLD  
'^%d%d?%d?%.%d%d?%d?%.%d%d?%d?%.%d%d?%d?', -- IPv4 address  
'[%a%d]+%:?' -- IPv6 address  
}  

for _, pattern in ipairs (patterns) do -- loop through the patterns list  
if domain:match (pattern) then  
return true; -- if a match then we think that this thing that purports to be a URL is a URL  
end  
end  

for _, d in ipairs (cfg.single_letter_2nd_lvl_domains_t) do -- look for single letter second level domain names for these top level domains  
if domain:match ('%f[%w][%w]%.' .. d) then  
return true  
end  
end  
return false; -- no matches, we don't know what this thing is  
end  

----------------------------< I S _ U R L >------------------------------------------------------------------  

returns true if the scheme and domain parts of a URL appear to be a valid URL; else false.  

This function is the last step in the validation process. This function is separate because there are cases that  
are not covered by split_url, for example is_parameter_ext_wikilink which is looking for bracketted external  
wikilinks.  

local function is_url (scheme, domain)  
if utilities.is_set (scheme) then -- if scheme is set check it and domain  
return is_scheme (scheme) and is_domain_name (domain);  
else  
return is_domain_name (domain); -- scheme not set when URL is protocol-relative  
end  
end  

----------------------------< S P L I T _ U R L >------------------------------------------------------------  

Split a URL into a scheme, authority indicator, and domain.  

First remove Fully Qualified Domain Name terminator (a dot following TLD) (if any) and any path(/), query(?) or fragment(#).  

If protocol-relative URL, return nil scheme and domain else return nil for both scheme and domain.  

When not protocol-relative, get scheme, authority indicator, and domain. If there is an authority indicator (one  
or more '/' characters immediately following the scheme's colon), make sure that there are only 2.  

Any URL that does not have news: scheme must have authority indicator (//). TODO: are there other common schemes  
like news: that don't use authority indicator?  

Strip off any port and path;  

local function split_url (url_str)  
local scheme, authority, domain;  

url_str = url_str:gsub ('([%a%d])%.?[/%?#].*$', '%1'); -- strip FQDN terminator and path(/), query(?), fragment (#) (the capture prevents false replacement of '//')  

if url_str:match ('^//%S*') then -- if there is what appears to be a protocol-relative URL  
domain = url_str:match ('^//(%S*)')  
elseif url_str:match ('%S-:/*%S+') then -- if there is what appears to be a scheme, optional authority indicator, and domain name  
scheme, authority, domain = url_str:match ('(%S-:)(/*)(%S+)'); -- extract the scheme, authority indicator, and domain portions  
if utilities.is_set (authority) then  
authority = authority:gsub ('//', '', 1); -- replace place 1 pair of '/' with nothing;  
if utilities.is_set(authority) then -- if anything (1 or 3+ '/' where authority should be) then  
return scheme; -- return scheme only making domain nil which will cause an error message  
end  
else  
if not scheme:match ('^news:') then -- except for news:..., MediaWiki won't link URLs that do not have authority indicator; TODO: a better way to do this test?  
return scheme; -- return scheme only making domain nil which will cause an error message  
end  
end  
domain = domain:gsub ('(%a):%d+', '%1'); -- strip port number if present  
end  

return scheme, domain;  
end  

--[[--------------------------< L I N K _ P A R A M _ O K >---------------------------------------------------  

checks the content of |title-link=, |series-link=, |author-link=, etc. for properly formatted content: no wikilinks, no URLs  

Link parameters are to hold the title of a Wikipedia article, so of the WP:TITLESPECIALCHARACTERS are allowed:  
1. < > [ ] | { } _
except the underscore which is used as a space in wiki URLs and # which is used for section links  

returns false when the value contains any of these characters.  

When there are no illegal characters, this function returns TRUE if value DOES NOT appear to be a valid URL (the  
|<param>-link= parameter is ok); else false when value appears to be a valid URL (the |<param>-link= parameter is NOT ok).  


local function link_param_ok (value)  
local scheme, domain;  
if value:find ('[<>%[%]|{}]') then -- if any prohibited characters  
return false;  
end  

scheme, domain = split_url (value); -- get scheme or nil and domain or nil from URL;  
return not is_url (scheme, domain); -- return true if value DOES NOT appear to be a valid URL  
end  

--<param>-link= value and its matching |<title>= value.  

|<title>= may be wiki-linked but not when |<param>-link= has a value. This function emits an error message when  
that condition exists  

check <link> for inter-language interwiki-link prefix. prefix must be a MediaWiki-recognized language  
code and must begin with a colon.  

local function link_title_ok (link, lorig, title, torig)  
local orig;  
if utilities.is_set (link) then -- don't bother if <param>-link doesn't have a value  
if not link_param_ok (link) then -- check |<param>-link= markup  
orig = lorig; -- identify the failing link parameter  
elseif title:find ('%[%[') then -- check |title= for wikilink markup  
orig = torig; -- identify the failing |title= parameter  
elseif link:match ('^%a+:') then -- if the link is what looks like an interwiki  
local prefix = link:match ('^(%a+):'):lower; -- get the interwiki prefix  

if cfg.inter_wiki_map[prefix] then -- if prefix is in the map, must have preceding colon  
orig = lorig; -- flag as error  
end  
end  
end  

if utilities.is_set (orig) then  
link = ''; -- unset  
utilities.set_message ('err_bad_paramlink', orig); -- URL or wikilink in |title= with |title-link=;  
end  

return link; -- link if ok, empty string else  
end  

----------------------------< C H E C K _ U R L >------------------------------------------------------------  

Determines whether a URL string appears to be valid.  

First we test for space characters. If any are found, return false. Then split the URL into scheme and domain  
portions, or for protocol-relative (//example.com) URLs, just the domain. Use is_url to validate the two  
portions of the URL. If both are valid, or for protocol-relative if domain is valid, return true, else false.  

Because it is different from a standard URL, and because this module used external_link to make external links  
that work for standard and news: links, we validate newsgroup names here. The specification for a newsgroup name  
is at https://tools.ietf.org/html/rfc5536#section-3.1.4  

local function check_url( url_str )  
if nil == url_str:match ("^%S+$") then -- if there are any spaces in |url=value it can't be a proper URL  
return false;  
end  
local scheme, domain;  

scheme, domain = split_url (url_str); -- get scheme or nil and domain or nil from URL;  

if 'news:' == scheme then -- special case for newsgroups  
return domain:match('^[%a%d%+%-_]+%.[%a%d%+%-_%.]*[%a%d%+%-_]$');  
end  

return is_url (scheme, domain); -- return true if value appears to be a valid URL  
end  

--[=[-------------------------< I S _ P A R A M E T E R _ E X T _ W I K I L I N K >----------------------------  

Return true if a parameter value has a string that begins and ends with square brackets [ and ] and the first  
non-space characters following the opening bracket appear to be a URL. The test will also find external wikilinks  
that use protocol-relative URLs. Also finds bare URLs.  

The frontier pattern prevents a match on interwiki-links which are similar to scheme:path URLs. The tests that  
find bracketed URLs are required because the parameters that call this test (currently |title=, |chapter=, |work=,  
and |publisher=) may have wikilinks and there are articles or redirects like '//Hus' so, while uncommon, |title=//Hus  
is possible as might be en://Hus.  

]=]  

local function is_parameter_ext_wikilink (value)  
local scheme, domain;  

if value:match ('%f[%[]%[%a%S*:%S+.*%]') then -- if ext. wikilink with scheme and domain: [xxxx://yyyyy.zzz]  
scheme, domain = split_url (value:match ('%f[%[]%[(%a%S*:%S+).*%]'));  
elseif value:match ('%f[%[]%[//%S+.*%]') then -- if protocol-relative ext. wikilink: [//yyyyy.zzz]  
scheme, domain = split_url (value:match ('%f[%[]%[(//%S+).*%]'));  
elseif value:match ('%a%S*:%S+') then -- if bare URL with scheme; may have leading or trailing plain text  
scheme, domain = split_url (value:match ('(%a%S*:%S+)'));  
elseif value:match ('//%S+') then -- if protocol-relative bare URL: //yyyyy.zzz; may have leading or trailing plain text  
scheme, domain = split_url (value:match ('(//%S+)')); -- what is should be the domain  
else  
return false; -- didn't find anything that is obviously a URL  
end  

return is_url (scheme, domain); -- return true if value appears to be a valid URL  
end  

---------------------------< C H E C K _ F O R _ U R L >-----------------------------------------------------  

loop through a list of parameters and their values. Look at the value and if it has an external link, emit an error message.  

local function check_for_url (parameter_list, error_list)  
for k, v in pairs (parameter_list) do -- for each parameter in the list  
if is_parameter_ext_wikilink (v) then -- look at the value; if there is a URL add an error message  
table.insert (error_list, utilities.wrap_style ('parameter', k));  
end  
end  
end  

----------------------------< S A F E _ F O R _ U R L >------------------------------------------------------  

Escape sequences for content that will be used for URL descriptions  

local function safe_for_url( str )  
if str:match( "%[%[.-%]%]" ) ~= nil then  
utilities.set_message ('err_wikilink_in_url', {});  
end  

return str:gsub( '[%[%]\n]', {  
['['] = '&#91;',  
[']'] = '&#93;',  
['\n'] = ' ' } );  
end  

----------------------------< E X T E R N A L _ L I N K >----------------------------------------------------  

Format an external link with error checking  

local function external_link (URL, label, source, access)  
local err_msg = '';  
local domain;  
local path;  
local base_url;  

if not utilities.is_set (label) then  
label = URL;  
if utilities.is_set (source) then  
utilities.set_message ('err_bare_url_missing_title', {utilities.wrap_style ('parameter', source)});  
else  
error (cfg.messages["bare_url_no_origin"]); -- programmer error; valid parameter name does not have matching meta-parameter  
end  
end  
if not check_url (URL) then  
utilities.set_message ('err_bad_url', {utilities.wrap_style ('parameter', source)});  
end  

domain, path = URL:match ('^([/%.%-%+:%a%d]+)([/%?#].*)$'); -- split the URL into scheme plus domain and path  
if path then -- if there is a path portion  
path = path:gsub ('[%[%]]', {['['] = '%5b', [']'] = '%5d'}); -- replace '[' and ']' with their percent-encoded values  
URL = table.concat ({domain, path}); -- and reassemble  
end  

base_url = table.concat ({ "[", URL, " ", safe_for_url (label), "]" }); -- assemble a wiki-markup URL  

if utilities.is_set (access) then -- access level (subscription, registration, limited)  
base_url = utilities.substitute (cfg.presentation['ext-link-access-signal'], {cfg.presentation[access].class, cfg.presentation[access].title, base_url}); -- add the appropriate icon  
end  

return base_url;  
end  

----------------------------< D E P R E C A T E D _ P A R A M E T E R >--------------------------------------  

Categorize and emit an error message when the citation contains one or more deprecated parameters. The function includes the  
offending parameter name to the error message. Only one error message is emitted regardless of the number of deprecated  
parameters in the citation.  

added_deprecated_cat is a Boolean declared in page scope variables above  

local function deprecated_parameter(name)  
if not added_deprecated_cat then  
added_deprecated_cat = true; -- note that we've added this category  
utilities.set_message ('err_deprecated_params', {name}); -- add error message  
end  
end  

--[=[-------------------------< K E R N _ Q U O T E S >--------------------------------------------------------  

Apply kerning to open the space between the quote mark provided by the module and a leading or trailing quote  
mark contained in a |title= or |chapter= parameter's value.  

This function will positive kern either single or double quotes:  
"'Unkerned title with leading and trailing single quote marks'"  
" 'Kerned title with leading and trailing single quote marks' " (in real life the kerning isn't as wide as this example)  
Double single quotes (italic or bold wiki-markup) are not kerned.  

Replaces Unicode quote marks in plain text or in the label portion of a D style wikilink with typewriter  
quote marks regardless of the need for kerning. Unicode quote marks are not replaced in simple D wikilinks.  

Call this function for chapter titles, for website titles, etc.; not for book titles.  

]=]  

local function kern_quotes (str)  
local cap = '';  
local wl_type, label, link;  

wl_type, label, link = utilities.is_wikilink (str); -- wl_type is: 0, no wl (text in label variable); 1, D; 2, D  

if 1 == wl_type then -- D simple wikilink with or without quote marks  
if mw.ustring.match (str, '%[%[[\"“”\'‘’].+[\"“”\'‘’]%]%]') then -- leading and trailing quote marks  
str = utilities.substitute (cfg.presentation['kern-'], str);  
str = utilities.substitute (cfg.presentation['kern-'], str);  
elseif mw.ustring.match (str, '%[%[[\"“”\'‘’].+%]%]') then -- leading quote marks  
str = utilities.substitute (cfg.presentation['kern-'], str);  
elseif mw.ustring.match (str, '%[%[.+[\"“”\'‘’]%]%]') then -- trailing quote marks  
str = utilities.substitute (cfg.presentation['kern-'], str);  
end  

else -- plain text or D; text in label variable  
label = mw.ustring.gsub (label, '[“”]', '\"'); -- replace “” (U+201C & U+201D) with " (typewriter double quote mark)  
label = mw.ustring.gsub (label, '[‘’]', '\''); -- replace ‘’ (U+2018 & U+2019) with ' (typewriter single quote mark)  

cap = mw.ustring.match (label, "^([\"\'][^\'].+)"); -- match leading double or single quote but not doubled single quotes (italic markup)  
if utilities.is_set (cap) then  
label = utilities.substitute (cfg.presentation['kern-'], cap);  
end  

cap = mw.ustring.match (label, "^(.+[^\'][\"\'])$") -- match trailing double or single quote but not doubled single quotes (italic markup)  
if utilities.is_set (cap) then  
label = utilities.substitute (cfg.presentation['kern-'], cap);  
end  

if 2 == wl_type then  
str = utilities.make_wikilink (link, label); -- reassemble the wikilink  
else  
str = label;  
end  
end  
return str;  
end  

--script-title= holds title parameters that are not written in Latin-based scripts: Chinese, Japanese, Arabic, Hebrew, etc. These scripts should  
not be italicized and may be written -to-. The value supplied by |script-title= is concatenated onto Title after Title has been wrapped  
in italic markup.  

Regardless of language, all values provided by |script-title= are wrapped in <bdi>...</bdi> tags to isolate RTL languages from the English to .  

|script-title= provides a unique feature. The value in |script-title= may be prefixed with a two-character ISO 639-1 language code and a colon:  
|script-title=ja:*** *** (where * represents a Japanese character)  
Spaces between the two-character code and the colon and the colon and the first script character are allowed:  
|script-title=ja : *** ***  
|script-title=ja: *** ***  
|script-title=ja :*** ***  
Spaces preceding the prefix are allowed: |script-title = ja:*** ***  

The prefix is checked for validity. If it is a valid ISO 639-1 language code, the lang attribute (lang="ja") is added to the <bdi> tag so that browsers can  
know the language the tag contains. This may help the browser render the script more correctly. If the prefix is invalid, the lang attribute  
is not added. At this time there is no error message for this condition.  

Supports |script-title=, |script-chapter=, |script-<periodical>=  

local function format_script_value (script_value, script_param)  
local lang=''; -- initialize to empty string  
local name;  
if script_value:match('^%l%l%l?%s*:') then -- if first 3 or 4 non-space characters are script language prefix  
lang = script_value:match('^(%l%l%l?)%s*:%s*%S.*'); -- get the language prefix or nil if there is no script  
if not utilities.is_set (lang) then  
utilities.set_message ('err_script_parameter', {script_param, cfg.err_msg_supl['missing title part']}); -- prefix without 'title'; add error message  
return ''; -- script_value was just the prefix so return empty string  
end  
-- if we get this far we have prefix and script  
name = cfg.lang_tag_remap[lang] or mw.language.fetchLanguageName( lang, cfg.this_wiki_code ); -- get language name so that we can use it to categorize  
if utilities.is_set (name) then -- is prefix a proper ISO 639-1 language code?  
script_value = script_value:gsub ('^%l+%s*:%s*', ''); -- strip prefix from script  
-- is prefix one of these language codes?  
if utilities.in_array (lang, cfg.script_lang_codes) then  
utilities.add_prop_cat ('script', {name, lang})  
else  
utilities.set_message ('err_script_parameter', {script_param, cfg.err_msg_supl['unknown language code']}); -- unknown script-language; add error message  
end  
lang = ' lang="' .. lang .. '" '; -- convert prefix into a lang attribute  
else  
utilities.set_message ('err_script_parameter', {script_param, cfg.err_msg_supl['invalid language code']}); -- invalid language code; add error message  
lang = ''; -- invalid so set lang to empty string  
end  
else  
utilities.set_message ('err_script_parameter', {script_param, cfg.err_msg_supl['missing prefix']}); -- no language code prefix; add error message  
end  
script_value = utilities.substitute (cfg.presentation['bdi'], {lang, script_value}); -- isolate in case script is RTL  

return script_value;  
end  

--title= and |script-title=, this function concatenates those two parameter values after the script  
value has been wrapped in <bdi> tags.  

local function script_concatenate (title, script, script_param)  
if utilities.is_set (script) then  
script = format_script_value (script, script_param); -- <bdi> tags, lang attribute, categorization, etc.; returns empty string on error  
if utilities.is_set (script) then  
title = title .. ' ' .. script; -- concatenate title and script title  
end  
end  
return title;  
end  

----------------------------< W R A P _ M S G >--------------------------------------------------------------  

Applies additional message text to various parameter values. Supplied string is wrapped using a message_list  
configuration taking one argument. Supports lower case text for templates. Additional text taken  
from citation_config.messages - the reason this function is similar to but separate from wrap_style.  

local function wrap_msg (key, str, lower)  
if not utilities.is_set ( str ) then  
return "";  
end  
if true == lower then  
local msg;  
msg = cfg.messages[key]:lower; -- set the message to lower case before  
return utilities.substitute ( msg, str ); -- including template text  
else  
return utilities.substitute ( cfg.messages[key], str );  
end  
end  

--chapter= (or aliases) or |title= or |title-link=  

local function wikisource_url_make (str)  
local wl_type, D, L;  
local ws_url, ws_label;  
local wikisource_prefix = table.concat ({'https://', cfg.this_wiki_code, '.wikisource.org/wiki/'});  

wl_type, D, L = utilities.is_wikilink (str); -- wl_type is 0 (not a wikilink), 1 (simple wikilink), 2 (complex wikilink)  

if 0 == wl_type then -- not a wikilink; might be from |title-link=  
str = D:match ('^[Ww]ikisource:(.+)') or D:match ('^[Ss]:(.+)'); -- article title from interwiki link with long-form or short-form namespace  
if utilities.is_set (str) then  
ws_url = table.concat ({ -- build a Wikisource URL  
wikisource_prefix, -- prefix  
str, -- article title  
});  
ws_label = str; -- label for the URL  
end  
elseif 1 == wl_type then -- simple wikilink: Wikisource:ws article  
str = D:match ('^[Ww]ikisource:(.+)') or D:match ('^[Ss]:(.+)'); -- article title from interwiki link with long-form or short-form namespace  
if utilities.is_set (str) then  
ws_url = table.concat ({ -- build a Wikisource URL  
wikisource_prefix, -- prefix  
str, -- article title  
});  
ws_label = str; -- label for the URL  
end  
elseif 2 == wl_type then -- non-so-simple wikilink: displayed text (D)  
str = L:match ('^[Ww]ikisource:(.+)') or L:match ('^[Ss]:(.+)'); -- article title from interwiki link with long-form or short-form namespace  
if utilities.is_set (str) then  
ws_label = D; -- get ws article name from display portion of interwiki link  
ws_url = table.concat ({ -- build a Wikisource URL  
wikisource_prefix, -- prefix  
str, -- article title without namespace from link portion of wikilink  
});  
end  
end  

if ws_url then  
ws_url = mw.uri.encode (ws_url, 'WIKI'); -- make a usable URL  
ws_url = ws_url:gsub ('%%23', '#'); -- undo percent-encoding of fragment marker  
end  

return ws_url, ws_label, L or D; -- return proper URL or nil and a label or nil  
end  

--script-<periodical>=, |<periodical>=,  
and |trans-<periodical>= into a single Periodical meta-parameter.  

local function format_periodical (script_periodical, script_periodical_source, periodical, trans_periodical)  

if not utilities.is_set (periodical) then  
periodical = ''; -- to be safe for concatenation  
else  
periodical = utilities.wrap_style ('italic-title', periodical); -- style  
end  

periodical = script_concatenate (periodical, script_periodical, script_periodical_source); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped  

if utilities.is_set (trans_periodical) then  
trans_periodical = utilities.wrap_style ('trans-italic-title', trans_periodical);  
if utilities.is_set (periodical) then  
periodical = periodical .. ' ' .. trans_periodical;  
else -- here when trans-periodical without periodical or script-periodical  
periodical = trans_periodical;  
utilities.set_message ('err_trans_missing_title', {'periodical'});  
end  
end  

return periodical;  
end  

--script-chapter=, |chapter=, |trans-chapter=,  
and |chapter-url= into a single chapter meta- parameter (chapter_url_source used  
for error messages).  

local function format_chapter_title (script_chapter, script_chapter_source, chapter, chapter_source, trans_chapter, trans_chapter_source, chapter_url, chapter_url_source, no_quotes, access)  
local ws_url, ws_label, L = wikisource_url_make (chapter); -- make a wikisource URL and label from a wikisource interwiki link  
if ws_url then  
ws_label = ws_label:gsub ('_', ' '); -- replace underscore separators with space characters  
chapter = ws_label;  
end  

if not utilities.is_set (chapter) then  
chapter = ''; -- to be safe for concatenation  
else  
if false == no_quotes then  
chapter = kern_quotes (chapter); -- if necessary, separate chapter title's leading and trailing quote marks from module provided quote marks  
chapter = utilities.wrap_style ('quoted-title', chapter);  
end  
end  

chapter = script_concatenate (chapter, script_chapter, script_chapter_source); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped  

if utilities.is_set (chapter_url) then  
chapter = external_link (chapter_url, chapter, chapter_url_source, access); -- adds bare_url_missing_title error if appropriate  
elseif ws_url then  
chapter = external_link (ws_url, chapter .. '&nbsp;', 'ws link in chapter'); -- adds bare_url_missing_title error if appropriate; space char to move icon away from chap text; TODO: better way to do this?  
chapter = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, chapter});  
end  

if utilities.is_set (trans_chapter) then  
trans_chapter = utilities.wrap_style ('trans-quoted-title', trans_chapter);  
if utilities.is_set (chapter) then  
chapter = chapter .. ' ' .. trans_chapter;  
else -- here when trans_chapter without chapter or script-chapter  
chapter = trans_chapter;  
chapter_source = trans_chapter_source:match ('trans%-?(.+)'); -- when no chapter, get matching name from trans-<param>  
utilities.set_message ('err_trans_missing_title', {chapter_source});  
end  
end  

return chapter;  
end  

------------------< H A S _ I N V I S I B L E _ C H A R S >-------------------  

This function searches a parameter's value for non-printable or invisible characters.  
The search stops at the first match.  

This function will detect the visible replacement character when it is part of the Wikisource.  

Detects but ignores nowiki and math stripmarkers. Also detects other named stripmarkers  
(gallery, math, pre, ref) and identifies them with a slightly different error message.  
See also coins_cleanup.  

Output of this function is an error message that identifies the character or the  
Unicode group, or the stripmarker that was detected along with its position (or,  
for multi-byte characters, the position of its first byte) in the parameter value.  

local function has_invisible_chars (param, v)  
local position = ''; -- position of invisible char or starting position of stripmarker  
local capture; -- used by stripmarker detection to hold name of the stripmarker  
local stripmarker; -- boolean set true when a stripmarker is found  

capture = string.match (v, '[%w%p ]*'); -- test for values that are simple ASCII text and bypass other tests if true  
if capture == v then -- if same there are no Unicode characters  
return;  
end  

for _, invisible_char in ipairs (cfg.invisible_chars) do  
local char_name = invisible_char[1]; -- the character or group name  
local pattern = invisible_char[2]; -- the pattern used to find it  
position, _, capture = mw.ustring.find (v, pattern); -- see if the parameter value contains characters that match the pattern  

if position and (cfg.invisible_defs.zwj == capture) then -- if we found a zero-width joiner character  
if mw.ustring.find (v, cfg.indic_script) then -- it's ok if one of the Indic scripts  
position = nil; -- unset position  
elseif cfg.emoji_t[mw.ustring.codepoint (v, position+1)] then -- is zwj followed by a character listed in emoji{}?  
position = nil; -- unset position  
end  
end  

if position then  
if 'nowiki' == capture or 'math' == capture or -- nowiki and math stripmarkers (not an error condition)  
('templatestyles' == capture and utilities.in_array (param, {'id', 'quote'})) then -- templatestyles stripmarker allowed in these parameters  
stripmarker = true; -- set a flag  
elseif true == stripmarker and cfg.invisible_defs.del == capture then -- because stripmakers begin and end with the delete char, assume that we've found one end of a stripmarker  
position = nil; -- unset  
else  
local err_msg;  
if capture and not (cfg.invisible_defs.del == capture or cfg.invisible_defs.zwj == capture) then  
err_msg = capture .. ' ' .. char_name;  
else  
err_msg = char_name .. ' ' .. 'character';  
end  

utilities.set_message ('err_invisible_char', {err_msg, utilities.wrap_style ('parameter', param), position}); -- add error message  
return; -- and done with this parameter  
end  
end  
end  
end  

---------------------< A R G U M E N T _ W R A P P E R >----------------------  

Argument wrapper. This function provides support for argument mapping defined  
in the configuration file so that multiple names can be transparently aliased to  
single internal variable.  

local function argument_wrapper ( args )  
local origin = {};  

return setmetatable({  
ORIGIN = function ( self, k )  
local dummy = self[k]; -- force the variable to be loaded.  
return origin[k];  
end  
},  
{  
__index = function ( tbl, k )  
if origin[k] ~= nil then  
return nil;  
end  

local args, list, v = args, cfg.aliases[k];  

if type( list ) == 'table' then  
v, origin[k] = utilities.select_one ( args, list, 'err_redundant_parameters' );  
if origin[k] == nil then  
origin[k] = ''; -- Empty string, not nil  
end  
elseif list ~= nil then  
v, origin[k] = args[list], list;  
else  
-- maybe let through instead of raising an error?  
-- v, origin[k] = args[k], k;  
error( cfg.messages['unknown_argument_map'] .. ': ' .. k);  
end  

-- Empty strings, not nil;  
if v == nil then  
v = '';  
origin[k] = '';  
end  

tbl = rawset( tbl, k, v );  
return v;  
end,  
});  
end  

----------------------------< N O W R A P _ D A T E >-------------------------  

When date is YYYY-MM-DD format wrap in nowrap span: <span ...>YYYY-MM-DD</span>.  
When date is DD MMMM YYYY or is MMMM DD, YYYY then wrap in nowrap span:  
<span ...>DD MMMM</span> YYYY or <span ...>MMMM DD,</span> YYYY  

DOES NOT yet support MMMM YYYY or any of the date ranges.  

local function nowrap_date (date)  
local cap = '';  
local cap2 = '';  

if date:match("^%d%d%d%d%-%d%d%-%d%d$") then  
date = utilities.substitute (cfg.presentation['nowrap1'], date);  

elseif date:match("^%a+%s*%d%d?,%s+%d%d%d%d$") or date:match ("^%d%d?%s*%a+%s+%d%d%d%d$") then  
cap, cap2 = string.match (date, "^(.*)%s+(%d%d%d%d)$");  
date = utilities.substitute (cfg.presentation['nowrap2'], {cap, cap2});  
end  

return date;  
end  

--type=<default value>) for those templates that have defaults. Also handles the  
special case where it is desirable to omit the title type from the rendered citation  
(|type=).  

local function set_titletype (cite_class, title_type)  
if utilities.is_set (title_type) then  
if '' == cfg.keywords_xlate[title_type] then  
title_type = ''; -- if |type= then type parameter not displayed  
end  
return title_type; -- if |type= has been set to any other value use that value  
end  

return cfg.title_types [cite_class] or ''; -- set template's default title type; else empty string for concatenation  
end  

----------------------------< S A F E _ J O I N >-----------------------------  

Joins a sequence of strings together while checking for duplicate separation characters.  

local function safe_join( tbl, duplicate_char )  
local f = {}; -- create a function table appropriate to type of 'duplicate character'  
if 1 == #duplicate_char then -- for single byte ASCII characters use the string library functions  
f.gsub = string.gsub  
f.match = string.match  
f.sub = string.sub  
else -- for multi-byte characters use the ustring library functions  
f.gsub = mw.ustring.gsub  
f.match = mw.ustring.match  
f.sub = mw.ustring.sub  
end  

local str = ''; -- the output string  
local comp = ''; -- what does 'comp' mean?  
local end_chr = '';  
local trim;  
for _, value in ipairs( tbl ) do  
if value == nil then value = ''; end  

if str == '' then -- if output string is empty  
str = value; -- assign value to it (first time through the loop)  
elseif value ~= '' then  
if value:sub(1, 1) == '<' then -- special case of values enclosed in spans and other markup.  
comp = value:gsub( "%b<>", "" ); -- remove HTML markup (<span>string</span> -> string)  
else  
comp = value;  
end  
-- typically duplicate_char is sepc  
if f.sub(comp, 1, 1) == duplicate_char then -- is first character same as duplicate_char? why test first character?  
-- Because individual string segments often (always?) begin with terminal punct for the  
-- preceding segment: 'First element' .. 'sepc next element' .. etc.?  
trim = false;  
end_chr = f.sub(str, -1, -1); -- get the last character of the output string  
-- str = str .. "<HERE(enchr=" .. end_chr .. ")" -- debug stuff?  
if end_chr == duplicate_char then -- if same as separator  
str = f.sub(str, 1, -2); -- remove it  
elseif end_chr == "'" then -- if it might be wiki-markup  
if f.sub(str, -3, -1) == duplicate_char .. "*" then -- if last three chars of str are sepc*  
str = f.sub(str, 1, -4) .. "*"; -- remove them and add back *  
elseif f.sub(str, -5, -1) == duplicate_char .. "]]*" then -- if last five chars of str are sepc]]*  
trim = true; -- why? why do this and next differently from previous?  
elseif f.sub(str, -4, -1) == duplicate_char .. "]*" then -- if last four chars of str are sepc]*  
trim = true; -- same question  
end  
elseif end_chr == "]" then -- if it might be wiki-markup  
if f.sub(str, -3, -1) == duplicate_char .. "]]" then -- if last three chars of str are sepc]] wikilink  
trim = true;  
elseif f.sub(str, -3, -1) == duplicate_char .. '"]' then -- if last three chars of str are sepc"] quoted external link  
trim = true;  
elseif f.sub(str, -2, -1) == duplicate_char .. "]" then -- if last two chars of str are sepc] external link  
trim = true;  
elseif f.sub(str, -4, -1) == duplicate_char .. "'']" then -- normal case when |url=something & |title=Title.  
trim = true;  
end  
elseif end_chr == " " then -- if last char of output string is a space  
if f.sub(str, -2, -1) == duplicate_char .. " " then -- if last two chars of str are <sepc><space>  
str = f.sub(str, 1, -3); -- remove them both  
end  
end  

if trim then  
if value ~= comp then -- value does not equal comp when value contains HTML markup  
local dup2 = duplicate_char;  
if f.match(dup2, "%A" ) then dup2 = "%" .. dup2; end -- if duplicate_char not a letter then escape it  

value = f.gsub(value, "(%b<>)" .. dup2, "%1", 1 ) -- remove duplicate_char if it follows HTML markup  
else  
value = f.sub(value, 2, -1 ); -- remove duplicate_char when it is first character  
end  
end  
end  
str = str .. value; -- add it to the output string  
end  
end  
return str;  
end  

----------------------------< I S _ S U F F I X >-----------------------------  

returns true if suffix is properly formed Jr, Sr, or ordinal in the range 1–9.  
Puncutation not allowed.  

local function is_suffix (suffix)  
if utilities.in_array (suffix, {'Jr', 'Sr', 'Jnr', 'Snr', '1st', '2nd', '3rd'}) or suffix:match ('^%dth$') then  
return true;  
end  
return false;  
end  

--[[--------------------< I S _ G O O D _ V A N C _ N A M E >-------------------  

For Vancouver style, author/editor names are supposed to be rendered in Latin  
(read ASCII) characters. When a name uses characters that contain diacritical  
marks, those characters are to be converted to the corresponding Latin  
character. When a name is written using a non-Latin alphabet or logogram, that  
name is to be transliterated into Latin characters. The module doesn't do this  
so editors may/must.  

This test allows |first= and |last= names to contain any of the letters defined  
in the four Unicode Latin character sets  
C0 Controls and Basic Latin 0041–005A, 0061–007A  
C1 Controls and Latin-1 Supplement 00C0–00D6, 00D8–00F6, 00F8–00FF  
Latin Extended-A 0100–017F  
Latin Extended-B 0180–01BF, 01C4–024F  

|lastn= also allowed to contain hyphens, spaces, and apostrophes.  
(http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35029/)  
|firstn= also allowed to contain hyphens, spaces, apostrophes, and periods  

This original test:  
if nil == mw.ustring.find (last, "^[A-Za-zÀ-ÖØ-öø-ƿǄ-ɏ%-%s%']*$")  
or nil == mw.ustring.find (first, "^[A-Za-zÀ-ÖØ-öø-ƿǄ-ɏ%-%s%'%.]+[2-6%a]*$") then  
was written outside of the code editor and pasted here because the code editor  
gets confused between character insertion point and cursor position. The test has  
been rewritten to use decimal character escape sequence for the individual bytes  
of the Unicode characters so that it is not necessary to use an external editor  
to maintain this code.  

\195\128-\195\150 – À-Ö (U+00C0–U+00D6 – C0 controls)  
\195\152-\195\182 – Ø-ö (U+00D8-U+00F6 – C0 controls)  
\195\184-\198\191 – ø-ƿ (U+00F8-U+01BF – C0 controls, Latin extended A & B)  
\199\132-\201\143 – Ǆ-ɏ (U+01C4-U+024F – Latin extended B)  


local function is_good_vanc_name (last, first, suffix, position)  
if not suffix then  
if first:find ('[,%s]') then -- when there is a space or comma, might be first name/initials + generational suffix  
first = first:match ('(.-)[,%s]+'); -- get name/initials  
suffix = first:match ('[,%s]+(.+)$'); -- get generational suffix  
end  
end  
if utilities.is_set (suffix) then  
if not is_suffix (suffix) then  
add_vanc_error (cfg.err_msg_supl.suffix, position);  
return false; -- not a name with an appropriate suffix  
end  
end  
if nil == mw.ustring.find (last, "^[A-Za-z\195\128-\195\150\195\152-\195\182\195\184-\198\191\199\132-\201\143\225\184\128-\225\187\191%-%s%']*$") or  
nil == mw.ustring.find (first, "^[A-Za-z\195\128-\195\150\195\152-\195\182\195\184-\198\191\199\132-\201\143\225\184\128-\225\187\191%-%s%'%.]*$") then  
add_vanc_error (cfg.err_msg_supl['non-Latin char'], position);  
return false; -- not a string of Latin characters; Vancouver requires Romanization  
end;  
return true;  
end  

--name-list-style=vanc.  

Names in |firstn= may be separated by spaces or hyphens, or for initials, a period.  
See http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35062/.  

Vancouver style requires family rank designations (Jr, II, III, etc.) to be rendered  
as Jr, 2nd, 3rd, etc. See http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35085/.  
This code only accepts and understands generational suffix in the Vancouver format  
because Roman numerals look like, and can be mistaken for, initials.  

This function uses ustring functions because firstname initials may be any of the  
Unicode Latin characters accepted by is_good_vanc_name .  

local function reduce_to_initials (first, position)  
if first:find (',', 1, true) then  
return first; -- commas not allowed; abandon  
end  

local name, suffix = mw.ustring.match (first, "^(%u+) ([%dJS][%drndth]+)$");  

if not name then -- if not initials and a suffix  
name = mw.ustring.match (first, "^(%u+)$"); -- is it just initials?  
end  

if name then -- if first is initials with or without suffix  
if 3 > mw.ustring.len (name) then -- if one or two initials  
if suffix then -- if there is a suffix  
if is_suffix (suffix) then -- is it legitimate?  
return first; -- one or two initials and a valid suffix so nothing to do  
else  
add_vanc_error (cfg.err_msg_supl.suffix, position); -- one or two initials with invalid suffix so error message  
return first; -- and return first unmolested  
end  
else  
return first; -- one or two initials without suffix; nothing to do  
end  
end  
end -- if here then name has 3 or more uppercase letters so treat them as a word  

local initials_t, names_t = {}, {}; -- tables to hold name parts and initials  
local i = 1; -- counter for number of initials  

names_t = mw.text.split (first, '[%s%-]+'); -- split into a sequence of names and possible suffix  

while names_t[i] do -- loop through the sequence  
if 1 < i and names_t[i]:match ('[%dJS][%drndth]+%.?$') then -- if not the first name, and looks like a suffix (may have trailing dot)  
names_t[i] = names_t[i]:gsub ('%.', ''); -- remove terminal dot if present  
if is_suffix (names_t[i]) then -- if a legitimate suffix  
table.insert (initials_t, ' ' .. names_t[i]); -- add a separator space, insert at end of initials sequence  
break; -- and done because suffix must fall at the end of a name  
end -- no error message if not a suffix; possibly because of Romanization  
end  
if 3 > i then  
table.insert (initials_t, mw.ustring.sub (names_t[i], 1, 1)); -- insert the initial at end of initials sequence  
end  
i = i + 1; -- bump the counter  
end  

return table.concat (initials_t); -- Vancouver format does not include spaces.  
end  

----------------------------< I N T E R W I K I _ P R E F I X E N _ G E T >----------------------------------  

extract interwiki prefixen from <value>. Returns two one or two values:  
false – no prefixen  
nil – prefix exists but not recognized  
project prefix, language prefix – when value has either of:  
:<project>:<language>:<article>  
:<language>:<project>:<article>  
project prefix, nil – when <value> has only a known single-letter prefix  
nil, language prefix – when <value> has only a known language prefix  

accepts single-letter project prefixen: 'd' (wikidata), 's' (wikisource), and 'w' (wikipedia) prefixes; at this  
writing, the other single-letter prefixen (b (wikibook), c (commons), m (meta), n (wikinews), q (wikiquote), and  
v (wikiversity)) are not supported.  

local function interwiki_prefixen_get (value, is_link)  
if not value:find (':%l+:') then -- if no prefix  
return false; -- abandon; boolean here to distinguish from nil fail returns later  
end  

local prefix_patterns_linked_t = { -- sequence of valid interwiki and inter project prefixen  
'^%[%[:([dsw]):(%l%l+):', -- wikilinked; project and language prefixes  
'^%[%[:(%l%l+):([dsw]):', -- wikilinked; language and project prefixes  
'^%[%[:([dsw]):', -- wikilinked; project prefix  
'^%[%[:(%l%l+):', -- wikilinked; language prefix  
}  

local prefix_patterns_unlinked_t = { -- sequence of valid interwiki and inter project prefixen  
'^:([dsw]):(%l%l+):', -- project and language prefixes  
'^:(%l%l+):([dsw]):', -- language and project prefixes  
'^:([dsw]):', -- project prefix  
'^:(%l%l+):', -- language prefix  
}  

local cap1, cap2;  
for _, pattern in ipairs ((is_link and prefix_patterns_linked_t) or prefix_patterns_unlinked_t) do  
cap1, cap2 = value:match (pattern);  
if cap1 then  
break; -- found a match so stop looking  
end  
end  

if cap1 and cap2 then -- when both then :project:language: or :language:project: (both forms allowed)  
if 1 == #cap1 then -- length == 1 then :project:language:  
if cfg.inter_wiki_map[cap2] then -- is language prefix in the interwiki map?  
return cap1, cap2; -- return interwiki project and interwiki language  
end  
else -- here when :language:project:  
if cfg.inter_wiki_map[cap1] then -- is language prefix in the interwiki map?  
return cap2, cap1; -- return interwiki project and interwiki language  
end  
end  
return nil; -- unknown interwiki language  
elseif not (cap1 or cap2) then -- both are nil?  
return nil; -- we got something that looks like a project prefix but isn't; return fail  
elseif 1 == #cap1 then -- here when one capture  
return cap1, nil; -- length is 1 so return project, nil language  
else -- here when one capture and its length it more than 1  
if cfg.inter_wiki_map[cap1] then -- is language prefix in the interwiki map?  
return nil, cap1; -- return nil project, language  
end  
end  
end  

--<name>-link= has a value  
|<name>-mask- does NOT have a value; masked names are presumed to have been  
rendered previously so should have been linked there  

when |<name>-mask=0, the associated name is not rendered  

local function list_people (control, people, etal)  
local sep;  
local namesep;  
local format = control.format;  
local maximum = control.maximum;  
local name_list = {};  

if 'vanc' == format then -- Vancouver-like name styling?  
sep = cfg.presentation['sep_nl_vanc']; -- name-list separator between names is a comma  
namesep = cfg.presentation['sep_name_vanc']; -- last/first separator is a space  
else  
sep = cfg.presentation['sep_nl']; -- name-list separator between names is a semicolon  
namesep = cfg.presentation['sep_name']; -- last/first separator is <comma><space>  
end  

if sep:sub (-1, -1) ~= " " then sep = sep .. " " end  
if utilities.is_set (maximum) and maximum < 1 then return "", 0; end -- returned 0 is for EditorCount; not used for other names  

for i, person in ipairs (people) do  
if utilities.is_set (person.last) then  
local mask = person.mask;  
local one;  
local sep_one = sep;  

if utilities.is_set (maximum) and i > maximum then  
etal = true;  
break;  
end  

if mask then  
local n = tonumber (mask); -- convert to a number if it can be converted; nil else  
if n then  
one = 0 ~= n and string.rep("&mdash;", n) or nil; -- make a string of (n > 0) mdashes, nil else, to replace name  
person.link = nil; -- don't create link to name if name is replaces with mdash string or has been set nil  
else  
one = mask; -- replace name with mask text (must include name-list separator)  
sep_one = " "; -- modify name-list separator  
end  
else  
one = person.last; -- get surname  
local first = person.first -- get given name  
if utilities.is_set (first) then  
if ("vanc" == format) then -- if Vancouver format  
one = one:gsub ('%.', ''); -- remove periods from surnames (http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35029/)  
if not person.corporate and is_good_vanc_name (one, first, nil, i) then -- and name is all Latin characters; corporate authors not tested  
first = reduce_to_initials (first, i); -- attempt to convert first name(s) to initials  
end  
end  
one = one .. namesep .. first;  
end  
end  
if utilities.is_set (person.link) then  
one = utilities.make_wikilink (person.link, one); -- link author/editor  
end  

if one then -- if <one> has a value (name, mdash replacement, or mask text replacement)  
local proj, tag = interwiki_prefixen_get (one, true); -- get the interwiki prefixen if present  
if 'w' == proj and ('Wikipedia' == mw.site.namespaces.Project['name']) then  
proj = nil; -- for stuff like :w:de:<article>, :w is unnecessary TODO: maint cat?  
end  
if proj then  
local proj_name = ({['d'] = 'Wikidata', ['s'] = 'Wikisource', ['w'] = 'Wikipedia'})[proj]; -- :w (wikipedia) for linking from a non-wikipedia project  
if proj_name then  
one = one .. utilities.wrap_style ('interproj', proj_name); -- add resized leading space, brackets, static text, language name  
utilities.add_prop_cat ('interproj-linked-name', proj); -- categorize it; <proj> is sort key  
tag = nil; -- unset; don't do both project and language  
end  
end  
if tag == cfg.this_wiki_code then  
tag = nil; -- stuff like :en:<article> at en.wiki is pointless TODO: maint cat?  
end  
if tag then  
local lang = cfg.lang_tag_remap[tag] or cfg.mw_languages_by_tag_t[tag];  
if lang then -- error messaging done in extract_names where we know parameter names  
one = one .. utilities.wrap_style ('interwiki', lang); -- add resized leading space, brackets, static text, language name  
utilities.add_prop_cat ('interwiki-linked-name', tag); -- categorize it; <tag> is sort key  
end  
end  

table.insert (name_list, one); -- add it to the list of names  
table.insert (name_list, sep_one); -- add the proper name-list separator  
end  
end  
end  

local count = #name_list / 2; -- (number of names + number of separators) divided by 2  
if 0 < count then  
if 1 < count and not etal then  
if 'amp' == format then  
name_list[#name_list-2] = " & "; -- replace last separator with ampersand text  
elseif 'and' == format then  
if 2 == count then  
name_list[#name_list-2] = cfg.presentation.sep_nl_and; -- replace last separator with 'and' text  
else  
name_list[#name_list-2] = cfg.presentation.sep_nl_end; -- replace last separator with '(sep) and' text  
end  
end  
end  
name_list[#name_list] = nil; -- erase the last separator  
end  

local result = table.concat (name_list); -- construct list  
if etal and utilities.is_set (result) then -- etal may be set by |display-authors=etal but we might not have a last-first list  
result = result .. sep .. cfg.messages['et al']; -- we've got a last-first list and etal so add et al.  
end  

return result, count; -- return name-list string and count of number of names (count used for editor names only)  
end  

----------------------< M A K E _ C I T E R E F _ I D >-----------------------  

Generates a CITEREF anchor ID if we have at least one name or a date. Otherwise  
returns an empty string.  

namelist is one of the contributor-, author-, or editor-name lists chosen in that  
order. year is Year or anchor_year.  

local function make_citeref_id (namelist, year)  
local names={}; -- a table for the one to four names and year  
for i,v in ipairs (namelist) do -- loop through the list and take up to the first four last names  
names[i] = v.last  
if i == 4 then break end -- if four then done  
end  
table.insert (names, year); -- add the year at the end  
local id = table.concat(names); -- concatenate names and year for CITEREF id  
if utilities.is_set (id) then -- if concatenation is not an empty string  
return "CITEREF" .. id; -- add the CITEREF portion  
else  
return ''; -- return an empty string; no reason to include CITEREF id in this citation  
end  
end  

--mode= parameter  

local function cite_class_attribute_make (cite_class, mode)  
local class_t = {};  
table.insert (class_t, 'citation'); -- required for blue highlight  
if 'citation' ~= cite_class then  
table.insert (class_t, cite_class); -- identify this template for user css  
table.insert (class_t, utilities.is_set (mode) and mode or 'cs1'); -- identify the citation style for user css or javascript  
else  
table.insert (class_t, utilities.is_set (mode) and mode or 'cs2'); -- identify the citation style for user css or javascript  
end  
for _, prop_key in ipairs (z.prop_keys_t) do  
table.insert (class_t, prop_key); -- identify various properties for user css or javascript  
end  

return table.concat (class_t, ' '); -- make a big string and done  
end  

--display-<names>=etal parameter  

local function name_has_etal (name, etal, nocat, param)  

if utilities.is_set (name) then -- name can be nil in which case just return  
local patterns = cfg.et_al_patterns; -- get patterns from configuration  

for _, pattern in ipairs (patterns) do -- loop through all of the patterns  
if name:match (pattern) then -- if this 'et al' pattern is found in name  
name = name:gsub (pattern, ''); -- remove the offending text  
etal = true; -- set flag (may have been set previously here or by |display-<names>=etal)  
if not nocat then -- no categorization for |vauthors=  
utilities.set_message ('err_etal', {param}); -- and set an error if not added  
end  
end  
end  
end  

return name, etal;  
end  

-----------------------< N A M E _ I S _ N U M E R I C >----------------------  

Add an error message and category when <name> parameter value does not contain letters.  

Add a maintenance category when <name> parameter value has numeric characters mixed with characters that are  
not numeric characters; could be letters and/or punctuation characters.  

This function will only emit one error and one maint message for the current template. Does not emit both error  
and maint messages/categories for the same parameter value.  

returns nothing  

local function name_is_numeric (name, name_alias, list_name)  
local patterns = {  
'^%D+%d', -- <name> must have digits preceded by other characters  
'^%D*%d+%D+', -- <name> must have digits followed by other characters  
}  

if not added_numeric_name_errs and mw.ustring.match (name, '^[%A]+$') then -- if we have not already set an error message and <name> does not have any alpha characters  
utilities.set_message ('err_numeric_names', name_alias); -- add an error message  
added_numeric_name_errs = true; -- set the flag so we emit only one error message  
return; -- when here no point in further testing; abandon  
end  

if not added_numeric_name_maint then -- if we have already set a maint message  
for _, pattern in ipairs (patterns) do -- spin through list of patterns  
if mw.ustring.match (name, pattern) then -- digits preceded or followed by anything but digits; %D+ includes punctuation  
utilities.set_message ('maint_numeric_names', cfg.special_case_translation [list_name]); -- add a maint cat for this template  
added_numeric_name_maint = true; -- set the flag so we emit only one maint message  
return; -- when here no point in further testing; abandon  
end  
end  
end  
end  

-------------------< N A M E _ H A S _ M U L T _ N A M E S >------------------  

Evaluates the content of last/surname (authors etc.) parameters for multiple names.  
Multiple names are indicated if there is more than one comma or any "unescaped"  
semicolons. Escaped semicolons are ones used as part of selected HTML entities.  
If the condition is met, the function adds the multiple name maintenance category.  

Same test for first except that commas should not appear in given names (MOS:JR says  
that the generational suffix does not take a separator character). Titles, degrees,  
postnominals, affiliations, all normally comma separated don't belong in a citation.  

<name> – name parameter value  
<list_name> – AuthorList, EditorList, etc  
<limit> – number of allowed commas; 1 (default) for surnames; 0 for given names  

returns nothing  

local function name_has_mult_names (name, list_name, limit)  
local _, commas, semicolons, nbsps;  
limit = limit and limit or 1;  
if utilities.is_set (name) then  
_, commas = name:gsub (',', ''); -- count the number of commas  
_, semicolons = name:gsub (';', ''); -- count the number of semicolons  
-- nbsps probably should be its own separate count rather than merged in  
-- some way with semicolons because Lua patterns do not support the  
-- grouping operator that regex does, which means there is no way to add  
-- more entities to escape except by adding more counts with the new  
-- entities  
_, nbsps = name:gsub ('&nbsp;',''); -- count nbsps  

-- There is exactly 1 semicolon per &nbsp; entity, so subtract nbsps  
-- from semicolons to 'escape' them. If additional entities are added,  
-- they also can be subtracted.  
if limit < commas or 0 < (semicolons - nbsps) then  
utilities.set_message ('maint_mult_names', cfg.special_case_translation [list_name]); -- add a maint message  
end  
end  
end  

--[=[-------------------------< I S _ G E N E R I C >----------------------------------------------------------  

Compares values assigned to various parameters according to the string provided as <item> in the function call.  
<item> can have on of two values:  
'generic_names' – for name-holding parameters: |last=, |first=, |editor-last=, etc  
'generic_titles' – for |title=  

There are two types of generic tests. The 'accept' tests look for a pattern that should not be rejected by the  
'reject' test. For example,  
|author=Smith, John  
would be rejected by the 'author' reject test. But piped wikilinks with 'author' disambiguation should not be  
rejected so the 'accept' test prevents that from happening. Accept tests are always performed before reject  
tests.  

Each of the 'accept' and 'reject' sequence tables hold tables for en.wiki (['en']) and local.wiki (['local'])  
that each can hold a test sequence table The sequence table holds, at index [1], a test pattern, and, at index  
[2], a boolean control value. The control value tells string.find or mw.ustring.find to do plain-text search (true)  
or a pattern search (false). The intent of all this complexity is to make these searches as fast as possible so  
that we don't run out of processing time on very large articles.  

Returns  
true when a reject test finds the pattern or string  
false when an accept test finds the pattern or string  
nil else  

]=]  

local function is_generic (item, value, wiki)  
local test_val;  
local str_lower = { -- use string.lower for en.wiki (['en']) and use mw.ustring.lower or local.wiki (['local'])  
['en'] = string.lower,  
['local'] = mw.ustring.lower,  
}  
local str_find = { -- use string.find for en.wiki (['en']) and use mw.ustring.find or local.wiki (['local'])  
['en'] = string.find,  
['local'] = mw.ustring.find,  
}  

local function test (val, test_t, wiki) -- local function to do the testing; <wiki> selects lower and find functions  
val = test_t[2] and str_lower[wiki](value) or val; -- when <test_t[2]> set to 'true', plaintext search using lowercase value  
return str_find[wiki] (val, test_t[1], 1, test_t[2]); -- return nil when not found or matched  
end  

local test_types_t = {'accept', 'reject'}; -- test accept patterns first, then reject patterns  
local wikis_t = {'en', 'local'}; -- do tests for each of these keys; en.wiki first, local.wiki second  

for _, test_type in ipairs (test_types_t) do -- for each test type  
for _, generic_value in pairs (cfg.special_case_translation[item][test_type]) do -- spin through the list of generic value fragments to accept or reject  
for _, wiki in ipairs (wikis_t) do  
if generic_value[wiki] then  
if test (value, generic_value[wiki], wiki) then -- go do the test  
return ('reject' == test_type); -- param value rejected, return true; false else  
end  
end  
end  
end  
end  
end  

----------------------------< N A M E _ I S _ G E N E R I C >------------------------------------------------  

calls is_generic to determine if <name> is a 'generic name' listed in cfg.generic_names; <name_alias> is the  
parameter name used in error messaging  

local function name_is_generic (name, name_alias)  
if not added_generic_name_errs and is_generic ('generic_names', name) then  
utilities.set_message ('err_generic_name', name_alias); -- set an error message  
added_generic_name_errs = true;  
end  
end  

----------------------------< N A M E _ C H E C K S >--------------------------------------------------------  

This function calls various name checking functions used to validate the content of the various name-holding parameters.  

local function name_checks (last, first, list_name, last_alias, first_alias)  
local accept_name;  

if utilities.is_set (last) then  
last, accept_name = utilities.has_accept_as_written (last); -- remove accept-this-as-written markup when it wraps all of <last>  

if not accept_name then -- <last> not wrapped in accept-as-written markup  
name_has_mult_names (last, list_name); -- check for multiple names in the parameter  
name_is_numeric (last, last_alias, list_name); -- check for names that have no letters or are a mix of digits and other characters  
name_is_generic (last, last_alias); -- check for names found in the generic names list  
end  
end  

if utilities.is_set (first) then  
first, accept_name = utilities.has_accept_as_written (first); -- remove accept-this-as-written markup when it wraps all of <first>  

if not accept_name then -- <first> not wrapped in accept-as-written markup  
name_has_mult_names (first, list_name, 0); -- check for multiple names in the parameter; 0 is number of allowed commas in a given name  
name_is_numeric (first, first_alias, list_name); -- check for names that have no letters or are a mix of digits and other characters  
name_is_generic (first, first_alias); -- check for names found in the generic names list  
end  
local wl_type, D = utilities.is_wikilink (first);  
if 0 ~= wl_type then  
first = D;  
utilities.set_message ('err_bad_paramlink', first_alias);  
end  
end  

return last, first; -- done  
end  

--lastn= and |firstn= parameters  
(or their aliases), and their matching link and mask parameters. Stops searching  
when both |lastn= and |firstn= are not found in args after two sequential attempts:  
found |last1=, |last2=, and |last3= but doesn't find |last4= and |last5= then the  
search is done.  

This function emits an error message when there is a |firstn= without a matching  
|lastn=. When there are 'holes' in the list of last names, |last1= and |last3=  
are present but |last2= is missing, an error message is emitted. |lastn= is not  
required to have a matching |firstn=.  

When an author or editor parameter contains some form of 'et al.', the 'et al.'  
is stripped from the parameter and a flag (etal) returned that will cause list_people  
to add the static 'et al.' text from Module:Citation/CS1/Configuration. This keeps  
'et al.' out of the template's metadata. When this occurs, an error is emitted.  

local function extract_names(args, list_name)  
local names = {}; -- table of names  
local last; -- individual name components  
local first;  
local link;  
local mask;  
local i = 1; -- loop counter/indexer  
local n = 1; -- output table indexer  
local count = 0; -- used to count the number of times we haven't found a |last= (or alias for authors, |editor-last or alias for editors)  
local etal = false; -- return value set to true when we find some form of et al. in an author parameter  

local last_alias, first_alias, link_alias; -- selected parameter aliases used in error messaging  
while true do  
last, last_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], 'err_redundant_parameters', i ); -- search through args for name components beginning at 1  
first, first_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-First'], 'err_redundant_parameters', i );  
link, link_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-Link'], 'err_redundant_parameters', i );  
mask = utilities.select_one ( args, cfg.aliases[list_name .. '-Mask'], 'err_redundant_parameters', i );  

if last then -- error check |lastn= alias for unknown interwiki link prefix; done here because this is where we have the parameter name  
local project, language = interwiki_prefixen_get (last, true); -- true because we expect interwiki links in |lastn= to be wikilinked  
if nil == project and nil == language then -- when both are nil  
utilities.set_message ('err_bad_paramlink', last_alias); -- not known, emit an error message -- TODO: err_bad_interwiki?  
last = utilities.remove_wiki_link (last); -- remove wikilink markup; show display value only  
end  
end  

if link then -- error check |linkn= alias for unknown interwiki link prefix  
local project, language = interwiki_prefixen_get (link, false); -- false because wiki links in |author-linkn= is an error  
if nil == project and nil == language then -- when both are nil  
utilities.set_message ('err_bad_paramlink', link_alias); -- not known, emit an error message -- TODO: err_bad_interwiki?  
link = nil; -- unset so we don't link  
link_alias = nil;  
end  
end  

last, etal = name_has_etal (last, etal, false, last_alias); -- find and remove variations on et al.  
first, etal = name_has_etal (first, etal, false, first_alias); -- find and remove variations on et al.  
last, first = name_checks (last, first, list_name, last_alias, first_alias); -- multiple names, extraneous annotation, etc. checks  

if first and not last then -- if there is a firstn without a matching lastn  
local alias = first_alias:find ('given', 1, true) and 'given' or 'first'; -- get first or given form of the alias  
utilities.set_message ('err_first_missing_last', {  
first_alias, -- param name of alias missing its mate  
first_alias:gsub (alias, {['first'] = 'last', ['given'] = 'surname'}), -- make param name appropriate to the alias form  
}); -- add this error message  
elseif not first and not last then -- if both firstn and lastn aren't found, are we done?  
count = count + 1; -- number of times we haven't found last and first  
if 2 <= count then -- two missing names and we give up  
break; -- normal exit or there is a two-name hole in the list; can't tell which  
end  
else -- we have last with or without a first  
local result;  
link = link_title_ok (link, link_alias, last, last_alias); -- check for improper wiki-markup  

if first then  
link = link_title_ok (link, link_alias, first, first_alias); -- check for improper wiki-markup  
end  

names[n] = {last = last, first = first, link = link, mask = mask, corporate = false}; -- add this name to our names list (corporate for |vauthors= only)  
n = n + 1; -- point to next location in the names table  
if 1 == count then -- if the previous name was missing  
utilities.set_message ('err_missing_name', {list_name:match ("(%w+)List"):lower, i - 1}); -- add this error message  
end  
count = 0; -- reset the counter, we're looking for two consecutive missing names  
end  
i = i + 1; -- point to next args location  
end  

return names, etal; -- all done, return our list of names and the etal flag  
end  

--language=<lang_param> and return language name and matching tag; nil else.  

This function looks for:  
<lang_param> as a tag in cfg.lang_tag_remap{}  
<lang_param> as a name in cfg.lang_name_remap{}  

<lang_param> as a name in cfg.mw_languages_by_name_t  
<lang_param> as a tag in cfg.mw_languages_by_tag_t  
when those fail, presume that <lang_param> is an IETF-like tag that MediaWiki does not recognize. Strip all  
script, region, variant, whatever subtags from <lang_param> to leave just a two or three character language tag  
and look for the new <lang_param> in cfg.mw_languages_by_tag_t{}  

on success, returns name (in properly capitalized form) and matching tag (in lowercase); on failure returns nil  

local function name_tag_get (lang_param)  
local lang_param_lc = mw.ustring.lower (lang_param); -- use lowercase as an index into the various tables  
local name;  
local tag;  

name = cfg.lang_tag_remap[lang_param_lc]; -- assume <lang_param_lc> is a tag; attempt to get remapped language name  
if name then -- when <name>, <lang_param> is a tag for a remapped language name  
if cfg.lang_name_remap[name:lower][2] ~= lang_param_lc then  
utilities.set_message ('maint_unknown_lang'); -- add maint category if not already added  
return name, cfg.lang_name_remap[name:lower][2]; -- so return name and tag from lang_name_remap[name]; special case to xlate sr-ec and sr-el to sr-cyrl and sr-latn  
end  
return name, lang_param_lc; -- so return <name> from remap and <lang_param_lc>  
end  

tag = lang_param_lc:match ('^(%a%a%a?)%-.*'); -- still assuming that <lang_param_lc> is a tag; strip script, region, variant subtags  
name = cfg.lang_tag_remap[tag]; -- attempt to get remapped language name with language subtag only  
if name then -- when <name>, <tag> is a tag for a remapped language name  
return name, tag; -- so return <name> from remap and <tag>  
end  

if cfg.lang_name_remap[lang_param_lc] then -- not a remapped tag, assume <lang_param_lc> is a name; attempt to get remapped language tag  
return cfg.lang_name_remap[lang_param_lc][1], cfg.lang_name_remap[lang_param_lc][2]; -- for this <lang_param_lc>, return a (possibly) new name and appropriate tag  
end  

name = cfg.mw_languages_by_tag_t[lang_param_lc]; -- assume that <lang_param_lc> is a tag; attempt to get its matching language name  

if name then  
return name, lang_param_lc; -- <lang_param_lc> is a tag so return it and <name>  
end  

tag = cfg.mw_languages_by_name_t[lang_param_lc]; -- assume that <lang_param_lc> is a language name; attempt to get its matching tag  

if tag then  
return cfg.mw_languages_by_tag_t[tag], tag; -- <lang_param_lc> is a name so return the name from the table and <tag>  
end  

tag = lang_param_lc:match ('^(%a%a%a?)%-.*'); -- is <lang_param_lc> an IETF-like tag that MediaWiki doesn't recognize? <tag> gets the language subtag; nil else  

if tag then  
name = cfg.mw_languages_by_tag_t[tag]; -- attempt to get a language name using the shortened <tag>  
if name then  
return name, tag; -- <lang_param_lc> is an unrecognized IETF-like tag so return <name> and language subtag  
end  
end  
end  

--language= contains a recognized language (either code or name), the page is  
assigned to the category for that code: Category:Norwegian-language sources (no).  
For valid three-character code languages, the page is assigned to the single category  
for '639-2' codes: Category:CS1 ISO 639-2 language sources.  

Languages that are the same as the local wiki are not categorized. MediaWiki does  
not recognize three-character equivalents of two-character codes: code 'ar' is  
recognized but code 'ara' is not.  

This function supports multiple languages in the form |language=nb, French, th  
where the language names or codes are separated from each other by commas with  
optional space characters.  

local function language_parameter (lang)  
local tag; -- some form of IETF-like language tag; language subtag with optional region, sript, vatiant, etc subtags  
local lang_subtag; -- ve populates |language= with mostly unecessary region subtags the MediaWiki does not recognize; this is the base language subtag  
local name; -- the language name  
local language_list = {}; -- table of language names to be rendered  
local names_t = {}; -- table made from the value assigned to |language=  

local this_wiki_name = mw.language.fetchLanguageName (cfg.this_wiki_code, cfg.this_wiki_code); -- get this wiki's language name  

names_t = mw.text.split (lang, '%s*,%s*'); -- names should be a comma separated list  

for _, lang in ipairs (names_t) do -- reuse lang here because we don't yet know if lang is a language name or a language tag  
name, tag = name_tag_get (lang); -- attempt to get name/tag pair for <lang>; <name> has proper capitalization; <tag> is lowercase  

if utilities.is_set (tag) then  
lang_subtag = tag:gsub ('^(%a%a%a?)%-.*', '%1'); -- for categorization, strip any IETF-like tags from language tag  

if cfg.this_wiki_code ~= lang_subtag then -- when the language is not the same as this wiki's language  
if 2 == lang_subtag:len then -- and is a two-character tag  
utilities.add_prop_cat ('foreign-lang-source', {name, tag}, lang_subtag); -- categorize it; tag appended to allow for multiple language categorization  
else -- or is a recognized language (but has a three-character tag)  
utilities.add_prop_cat ('foreign-lang-source-2', {lang_subtag}, lang_subtag); -- categorize it differently TODO: support multiple three-character tag categories per cs1|2 template?  
end  
elseif cfg.local_lang_cat_enable then -- when the language and this wiki's language are the same and categorization is enabled  
utilities.add_prop_cat ('local-lang-source', {name, lang_subtag}); -- categorize it  
end  
else  
name = lang; -- return whatever <lang> has so that we show something  
utilities.set_message ('maint_unknown_lang'); -- add maint category if not already added  
end  

table.insert (language_list, name);  
name = ''; -- so we can reuse it  
end  

name = utilities.make_sep_list (#language_list, language_list);  
if (1 == #language_list) and (lang_subtag == cfg.this_wiki_code) then -- when only one language, find lang name in this wiki lang name; for |language=en-us, 'English' in 'American English'  
return ''; -- if one language and that language is this wiki's return an empty string (no annotation)  
end  
return (" " .. wrap_msg ('language', name)); -- otherwise wrap with '(in ...)'  
-- TODO: should only return blank or name rather than full list  
so we can clean up the bunched parenthetical elements Language, Type, Format  

end  

-------------------------< S E T _ C S _ S T Y L E >--------------------------  

Gets the default CS style configuration for the given mode.  
Returns default separator and either postscript as passed in or the default.  
In CS1, the default postscript and separator are '.'.  
In CS2, the default postscript is the empty string and the default separator is ','.  

local function set_cs_style (postscript, mode)  
if utilities.is_set(postscript) then  
-- emit a maintenance message if user postscript is the default cs1 postscript  
-- we catch the opposite case for cs2 in set_style  
if mode == 'cs1' and postscript == cfg.presentation['ps_' .. mode] then  
utilities.set_message ('maint_postscript');  
end  
else  
postscript = cfg.presentation['ps_' .. mode];  
end  
return cfg.presentation['sep_' .. mode], postscript;  
end  

--mode= first and the  
1. invoke CitationClass second. Removes the postscript if postscript == .

local function set_style (mode, postscript, cite_class)  
local sep;  
if 'cs2' == mode then  
sep, postscript = set_cs_style (postscript, 'cs2');  
elseif 'cs1' == mode then  
sep, postscript = set_cs_style (postscript, 'cs1');  
elseif 'citation' == cite_class then  
sep, postscript = set_cs_style (postscript, 'cs2');  
else  
sep, postscript = set_cs_style (postscript, 'cs1');  
end  

if cfg.keywords_xlate[postscript:lower] == '' then  
-- emit a maintenance message if user postscript is the default cs2 postscript  
-- we catch the opposite case for cs1 in set_cs_style  
if 'cs2' == mode or ('cs1' ~= mode and 'citation' == cite_class) then -- should not emit maint message  
utilities.set_message ('maint_postscript');  
end  
postscript = '';  
end  

return sep, postscript  
end  

--[=[-------------------------< I S _ P D F >-----------------------------------  

Determines if a URL has the file extension that is one of the PDF file extensions  
used by MediaWiki:Common.css when applying the PDF icon to external links.  

returns true if file extension is one of the recognized extensions, else false  

]=]  

local function is_pdf (url)  
return url:match ('%.pdf$') or url:match ('%.PDF$') or  
url:match ('%.pdf[%?#]') or url:match ('%.PDF[%?#]') or  
url:match ('%.PDF&#035') or url:match ('%.pdf&#035');  
end  

--format=, |chapter-format=, etc. Also emits an error message  
if the format parameter does not have a matching URL parameter. If the format parameter  
is not set and the URL contains a file extension that is recognized as a PDF document  
by MediaWiki's commons.css, this code will set the format parameter to (PDF) with  
the appropriate styling.  

local function style_format (format, url, fmt_param, url_param)  
if utilities.is_set (format) then  
format = utilities.wrap_style ('format', format); -- add leading space, parentheses, resize  
if not utilities.is_set (url) then  
utilities.set_message ('err_format_missing_url', {fmt_param, url_param}); -- add an error message  
end  
elseif is_pdf (url) then -- format is not set so if URL is a PDF file then  
format = utilities.wrap_style ('format', 'PDF'); -- set format to PDF  
else  
format = ''; -- empty string for concatenation  
end  
return format;  
end  

--[[---------------------< G E T _ D I S P L A Y _ N A M E S >------------------  

Returns a number that defines the number of names displayed for author and editor  
name lists and a Boolean flag to indicate when et al. should be appended to the name list.  

When the value assigned to |display-xxxxors= is a number greater than or equal to zero,  
return the number and the previous state of the 'etal' flag (false by default  
but may have been set to true if the name list contains some variant of the text 'et al.').  

When the value assigned to |display-xxxxors= is the keyword 'etal', return a number  
that is one greater than the number of authors in the list and set the 'etal' flag true.  
This will cause the list_people to display all of the names in the name list followed by 'et al.'  

In all other cases, returns nil and the previous state of the 'etal' flag.  

inputs:  
max: A['DisplayAuthors'] or A['DisplayEditors'], etc; a number or some flavor of etal  
count: #a or #e  
list_name: 'authors' or 'editors'  
etal: author_etal or editor_etal  

This function sets an error message when |display-xxxxors= value greater than or equal to number of names but  
not when <max> comes from global settings. When using global settings, <param> is set to the  
keyword 'cs1 config' which is used to supress the normal error. Error is suppressed because it is to be expected  
that some citations in an article will have the same or fewer names that the limit specified in .  


local function get_display_names (max, count, list_name, etal, param)  
if utilities.is_set (max) then  
if 'etal' == max:lower:gsub("[ '%.]", '') then -- the :gsub portion makes 'etal' from a variety of 'et al.' spellings and stylings  
max = count + 1; -- number of authors + 1 so display all author name plus et al.  
etal = true; -- overrides value set by extract_names  
elseif max:match ('^%d+$') then -- if is a string of numbers  
max = tonumber (max); -- make it a number  
if (max >= count) and ('cs1 config' ~= param) then -- error when local |display-xxxxors= value greater than or equal to number of names; not an error when using global setting  
utilities.set_message ('err_disp_name', {param, max}); -- add error message  
max = nil;  
end  
else -- not a valid keyword or number  
utilities.set_message ('err_disp_name', {param, max}); -- add error message  
max = nil; -- unset; as if |display-xxxxors= had not been set  
end  
end  

return max, etal;  
end  

--[[----------< E X T R A _ T E X T _ I N _ P A G E _ C H E C K >---------------  

Adds error if |page=, |pages=, |quote-page=, |quote-pages= has what appears to be  
some form of p. or pp. abbreviation in the first characters of the parameter content.  

check page for extraneous p, p., pp, pp., pg, pg. at start of parameter value:  
good pattern: '^P[^%.P%l]' matches when page begins PX or P# but not Px  
where x and X are letters and # is a digit  
bad pattern: '^[Pp][PpGg]' matches when page begins pp, pP, Pp, PP, pg, pG, Pg, PG  


local function extra_text_in_page_check (val, name)  
if not val:match (cfg.vol_iss_pg_patterns.good_ppattern) then  
for _, pattern in ipairs (cfg.vol_iss_pg_patterns.bad_ppatterns) do -- spin through the selected sequence table of patterns  
if val:match (pattern) then -- when a match, error so  
utilities.set_message ('err_extra_text_pages', name); -- add error message  
return; -- and done  
end  
end  
end  
end  

--volume= or |issue= has what appears to be some form of redundant 'type' indicator. Applies to  
both; this function looks for issue text in both |issue= and |volume= and looks for volume-like text in |voluem=  
and |issue=.  

For |volume=:  
'V.', or 'Vol.' (with or without the dot) abbreviations or 'Volume' in the first characters of the parameter  
content (all case insensitive). 'V' and 'v' (without the dot) are presumed to be roman numerals so  
are allowed.  

For |issue=:  
'No.', 'I.', 'Iss.' (with or without the dot) abbreviations, or 'Issue' in the first characters of the  
parameter content (all case insensitive); numero styling: 'n°' with degree sign U+00B0, and № precomposed  
numero sign U+2116.  

Single character values ('v', 'i', 'n') allowed when not followed by separator character ('.', ':', '=', or  
whitespace character) – param values are trimmed of whitespace by MediaWiki before delivered to the module.  

<val> is |volume= or |issue= parameter value  
<name> is |volume= or |issue= parameter name for error message  
<selector> is 'v' for |volume=, 'i' for |issue=  

sets error message on failure; returns nothing  

local function extra_text_in_vol_iss_check (val, name, selector)  
if not utilities.is_set (val) then  
return;  
end  

local handler = 'v' == selector and 'err_extra_text_volume' or 'err_extra_text_issue';  
val = val:lower; -- force parameter value to lower case  

for _, pattern in ipairs (cfg.vol_iss_pg_patterns.vi_patterns_t) do -- spin through the sequence table of patterns  
if val:match (pattern) then -- when a match, error so  
utilities.set_message (handler, name); -- add error message  
return; -- and done  
end  
end  
end  

--[=[-------------------------< G E T _ V _ N A M E _ T A B L E >----------------------------------------------  

split apart a |vauthors= or |veditors= parameter. This function allows for corporate names, wrapped in doubled  
parentheses to also have commas; in the old version of the code, the doubled parentheses were included in the  
rendered citation and in the metadata. Individual author names may be wikilinked  

|vauthors=Jones AB, White EB, ((Black, Brown, and Co.))  

]=]  

local function get_v_name_table (vparam, output_table, output_link_table)  
local name_table = mw.text.split(vparam, "%s*,%s*"); -- names are separated by commas  
local wl_type, label, link; -- wl_type not used here; just a placeholder  

local i = 1;  

while name_table[i] do  
if name_table[i]:match ('^%(%(.*[^%)][^%)]$') then -- first segment of corporate with one or more commas; this segment has the opening doubled parentheses  
local name = name_table[i];  
i = i + 1; -- bump indexer to next segment  
while name_table[i] do  
name = name .. ', ' .. name_table[i]; -- concatenate with previous segments  
if name_table[i]:match ('^.*%)%)$') then -- if this table member has the closing doubled parentheses  
break; -- and done reassembling so  
end  
i = i + 1; -- bump indexer  
end  
table.insert (output_table, name); -- and add corporate name to the output table  
table.insert (output_link_table, ''); -- no wikilink  
else  
wl_type, label, link = utilities.is_wikilink (name_table[i]); -- wl_type is: 0, no wl (text in label variable); 1, D; 2, D  
table.insert (output_table, label); -- add this name  
if 1 == wl_type then  
table.insert (output_link_table, label); -- simple wikilink D  
else  
table.insert (output_link_table, link); -- no wikilink or D; add this link if there is one, else empty string  
end  
end  
i = i + 1;  
end  
return output_table;  
end  

--vauthors= or |veditors= and finds matching |xxxxor-maskn= and  
|xxxxor-linkn= in args. It then returns a table of assembled names just as extract_names does.  

Author / editor names in |vauthors= or |veditors= must be in Vancouver system style. Corporate or institutional names  
may sometimes be required and because such names will often fail the is_good_vanc_name and other format compliance  
tests, are wrapped in doubled parentheses ((corporate name)) to suppress the format tests.  

Supports generational suffixes Jr, 2nd, 3rd, 4th–6th.  

This function sets the Vancouver error when a required comma is missing and when there is a space between an author's initials.  

local function parse_vauthors_veditors (args, vparam, list_name)  
local names = {}; -- table of names assembled from |vauthors=, |author-maskn=, |author-linkn=  
local v_name_table = {};  
local v_link_table = {}; -- when name is wikilinked, targets go in this table  
local etal = false; -- return value set to true when we find some form of et al. vauthors parameter  
local last, first, link, mask, suffix;  
local corporate = false;  

vparam, etal = name_has_etal (vparam, etal, true); -- find and remove variations on et al. do not categorize (do it here because et al. might have a period)  
v_name_table = get_v_name_table (vparam, v_name_table, v_link_table); -- names are separated by commas  

for i, v_name in ipairs(v_name_table) do  
first = ''; -- set to empty string for concatenation and because it may have been set for previous author/editor  
local accept_name;  
v_name, accept_name = utilities.has_accept_as_written (v_name); -- remove accept-this-as-written markup when it wraps all of <v_name>  

if accept_name then  
last = v_name;  
corporate = true; -- flag used in list_people  
elseif string.find(v_name, "%s") then  
if v_name:find('[;%.]') then -- look for commonly occurring punctuation characters;  
add_vanc_error (cfg.err_msg_supl.punctuation, i);  
end  
local lastfirstTable = {}  
lastfirstTable = mw.text.split(v_name, "%s+")  
first = table.remove(lastfirstTable); -- removes and returns value of last element in table which should be initials or generational suffix  

if not mw.ustring.match (first, '^%u+$') then -- mw.ustring here so that later we will catch non-Latin characters  
suffix = first; -- not initials so assume that whatever we got is a generational suffix  
first = table.remove(lastfirstTable); -- get what should be the initials from the table  
end  
last = table.concat(lastfirstTable, ' ') -- returns a string that is the concatenation of all other names that are not initials and generational suffix  
if not utilities.is_set (last) then  
first = ''; -- unset  
last = v_name; -- last empty because something wrong with first  
add_vanc_error (cfg.err_msg_supl.name, i);  
end  
if mw.ustring.match (last, '%a+%s+%u+%s+%a+') then  
add_vanc_error (cfg.err_msg_supl['missing comma'], i); -- matches last II last; the case when a comma is missing  
end  
if mw.ustring.match (v_name, ' %u %u$') then -- this test is in the wrong place TODO: move or replace with a more appropriate test  
add_vanc_error (cfg.err_msg_supl.initials, i); -- matches a space between two initials  
end  
else  
last = v_name; -- last name or single corporate name? Doesn't support multiword corporate names? do we need this?  
end  

if utilities.is_set (first) then  
if not mw.ustring.match (first, "^%u?%u$") then -- first shall contain one or two upper-case letters, nothing else  
add_vanc_error (cfg.err_msg_supl.initials, i); -- too many initials; mixed case initials (which may be ok Romanization); hyphenated initials  
end  
is_good_vanc_name (last, first, suffix, i); -- check first and last before restoring the suffix which may have a non-Latin digit  
if utilities.is_set (suffix) then  
first = first .. ' ' .. suffix; -- if there was a suffix concatenate with the initials  
suffix = ''; -- unset so we don't add this suffix to all subsequent names  
end  
else  
if not corporate then  
is_good_vanc_name (last, '', nil, i);  
end  
end  

link = utilities.select_one ( args, cfg.aliases[list_name .. '-Link'], 'err_redundant_parameters', i ) or v_link_table[i];  
mask = utilities.select_one ( args, cfg.aliases[list_name .. '-Mask'], 'err_redundant_parameters', i );  
names[i] = {last = last, first = first, link = link, mask = mask, corporate = corporate}; -- add this assembled name to our names list  
end  
return names, etal; -- all done, return our list of names  
end  

--authors=, |authorn= / |lastn / firstn=, or |vauthors= as the source of the author name list or  
select one of |editorn= / editor-lastn= / |editor-firstn= or |veditors= as the source of the editor name list.  

Only one of these appropriate three will be used. The hierarchy is: |authorn= (and aliases) highest and |authors= lowest;  
|editorn= (and aliases) highest and |veditors= lowest (support for |editors= withdrawn)  

When looking for |authorn= / |editorn= parameters, test |xxxxor1= and |xxxxor2= (and all of their aliases); stops after the second  
test which mimicks the test used in extract_names when looking for a hole in the author name list. There may be a better  
way to do this, I just haven't discovered what that way is.  

Emits an error message when more than one xxxxor name source is provided.  

In this function, vxxxxors = vauthors or veditors; xxxxors = authors as appropriate.  

local function select_author_editor_source (vxxxxors, xxxxors, args, list_name)  
local lastfirst = false;  
if utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], '', 1 ) or -- do this twice in case we have a |first1= without a |last1=; this ...  
utilities.select_one ( args, cfg.aliases[list_name .. '-First'], '', 1 ) or -- ... also catches the case where |first= is used with |vauthors=  
utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], '', 2 ) or  
utilities.select_one ( args, cfg.aliases[list_name .. '-First'], '', 2 ) then  
lastfirst = true;  
end  

if (utilities.is_set (vxxxxors) and true == lastfirst) or -- these are the three error conditions  
(utilities.is_set (vxxxxors) and utilities.is_set (xxxxors)) or  
(true == lastfirst and utilities.is_set (xxxxors)) then  
local err_name;  
if 'AuthorList' == list_name then -- figure out which name should be used in error message  
err_name = 'author';  
else  
err_name = 'editor';  
end  
utilities.set_message ('err_redundant_parameters', err_name .. '-name-list parameters'); -- add error message  
end  

if true == lastfirst then return 1 end; -- return a number indicating which author name source to use  
if utilities.is_set (vxxxxors) then return 2 end;  
if utilities.is_set (xxxxors) then return 3 end;  
return 1; -- no authors so return 1; this allows missing author name test to run in case there is a first without last  
end  

----------------------------< I S _ V A L I D _ P A R A M E T E R _ V A L U E >------------------------------  

This function is used to validate a parameter's assigned value for those parameters that have only a limited number  
of allowable values (yes, y, true, live, dead, etc.). When the parameter value has not been assigned a value (missing  
or empty in the source template) the function returns the value specified by ret_val. If the parameter value is one  
of the list of allowed values returns the translated value; else, emits an error message and returns the value  
specified by ret_val.  

TODO: explain <invert>  

local function is_valid_parameter_value (value, name, possible, ret_val, invert)  
if not utilities.is_set (value) then  
return ret_val; -- an empty parameter is ok  
end  

if (not invert and utilities.in_array (value, possible)) then -- normal; <value> is in <possible> table  
return cfg.keywords_xlate[value]; -- return translation of parameter keyword  
elseif invert and not utilities.in_array (value, possible) then -- invert; <value> is not in <possible> table  
return value; -- return <value> as it is  
else  
utilities.set_message ('err_invalid_param_val', {name, value}); -- not an allowed value so add error message  
return ret_val;  
end  
end  

----------------------------< T E R M I N A T E _ N A M E _ L I S T >----------------------------------------  

This function terminates a name list (author, contributor, editor) with a separator character (sepc) and a space  
when the last character is not a sepc character or when the last three characters are not sepc followed by two  
closing square brackets (close of a wikilink). When either of these is true, the name_list is terminated with a  
single space character.  

local function terminate_name_list (name_list, sepc)  
if (string.sub (name_list, -3, -1) == sepc .. '. ') then -- if already properly terminated  
return name_list; -- just return the name list  
elseif (string.sub (name_list, -1, -1) == sepc) or (string.sub (name_list, -3, -1) == sepc .. ']]') then -- if last name in list ends with sepc char  
return name_list .. " "; -- don't add another  
else  
return name_list .. sepc .. ' '; -- otherwise terminate the name list  
end  
end  

---------------------------< F O R M A T _ V O L U M E _ I S S U E >-----------------------------------------  

returns the concatenation of the formatted volume and issue (or journal article number) parameters as a single  
string; or formatted volume or formatted issue, or an empty string if neither are set.  

local function format_volume_issue (volume, issue, article, cite_class, origin, sepc, lower)  
if not utilities.is_set (volume) and not utilities.is_set (issue) and not utilities.is_set (article) then  
return '';  
end  

-- same condition as in format_pages_sheets  
local is_journal = 'journal' == cite_class or (utilities.in_array (cite_class, {'citation', 'map', 'interview'}) and 'journal' == origin);  

local is_numeric_vol = volume and (volume:match ('^[MDCLXVI]+$') or volume:match ('^%d+$')); -- is only uppercase roman numerals or only digits?  
local is_long_vol = volume and (4 < mw.ustring.len(volume)); -- is |volume= value longer than 4 characters?  

if volume and (not is_numeric_vol and is_long_vol) then -- when not all digits or Roman numerals, is |volume= longer than 4 characters?  
utilities.add_prop_cat ('long-vol'); -- yes, add properties cat  
end  

if is_journal then -- journal-style formatting  
local vol = '';  

if utilities.is_set (volume) then  
if is_numeric_vol then -- |volume= value all digits or all uppercase Roman numerals?  
vol = utilities.substitute (cfg.presentation['vol-bold'], {sepc, volume}); -- render in bold face  
elseif is_long_vol then -- not all digits or Roman numerals; longer than 4 characters?  
vol = utilities.substitute (cfg.messages['j-vol'], {sepc, utilities.hyphen_to_dash (volume)}); -- not bold  
else -- four or fewer characters  
vol = utilities.substitute (cfg.presentation['vol-bold'], {sepc, utilities.hyphen_to_dash (volume)}); -- bold  
end  
end  
vol = vol .. (utilities.is_set (issue) and utilities.substitute (cfg.messages['j-issue'], issue) or '')  
vol = vol .. (utilities.is_set (article) and utilities.substitute (cfg.messages['j-article-num'], article) or '')  
return vol;  
end  

if 'podcast' == cite_class and utilities.is_set (issue) then  
return wrap_msg ('issue', {sepc, issue}, lower);  
end  

if 'conference' == cite_class and utilities.is_set (article) then -- |article-number= supported only in journal and conference cites  
if utilities.is_set (volume) and utilities.is_set (article) then -- both volume and article number  
return wrap_msg ('vol-art', {sepc, utilities.hyphen_to_dash (volume), article}, lower);  
elseif utilities.is_set (article) then -- article number alone; when volume alone, handled below  
return wrap_msg ('art', {sepc, article}, lower);  
end  
end  

-- all other types of citation  
if utilities.is_set (volume) and utilities.is_set (issue) then  
return wrap_msg ('vol-no', {sepc, utilities.hyphen_to_dash (volume), issue}, lower);  
elseif utilities.is_set (volume) then  
return wrap_msg ('vol', {sepc, utilities.hyphen_to_dash (volume)}, lower);  
else  
return wrap_msg ('issue', {sepc, issue}, lower);  
end  
end  

--page(s)= or |sheet(s)= values and returns it with all of the others set to empty strings.  
The return order is:  
page, pages, sheet, sheets  

Singular has priority over plural when both are provided.  

local function format_pages_sheets (page, pages, sheet, sheets, cite_class, origin, sepc, nopp, lower)  
if 'map' == cite_class then -- only cite map supports sheet(s) as in-source locators  
if utilities.is_set (sheet) then  
if 'journal' == origin then  
return *, *, wrap_msg ('j-sheet', sheet, lower), '';  
else  
return *, *, wrap_msg ('sheet', {sepc, sheet}, lower), '';  
end  
elseif utilities.is_set (sheets) then  
if 'journal' == origin then  
return *, *, '', wrap_msg ('j-sheets', sheets, lower);  
else  
return *, *, '', wrap_msg ('sheets', {sepc, sheets}, lower);  
end  
end  
end  

local is_journal = 'journal' == cite_class or (utilities.in_array (cite_class, {'citation', 'map', 'interview'}) and 'journal' == origin);  

if utilities.is_set (page) then  
if is_journal then  
return utilities.substitute (cfg.messages['j-page(s)'], page), *, *, '';  
elseif not nopp then  
return utilities.substitute (cfg.messages['p-prefix'], {sepc, page}), *, *, '';  
else  
return utilities.substitute (cfg.messages['nopp'], {sepc, page}), *, *, '';  
end  
elseif utilities.is_set (pages) then  
if is_journal then  
return utilities.substitute (cfg.messages['j-page(s)'], pages), *, *, '';  
elseif tonumber(pages) ~= nil and not nopp then -- if pages is only digits, assume a single page number  
return *, utilities.substitute (cfg.messages['p-prefix'], {sepc, pages}), *, '';  
elseif not nopp then  
return *, utilities.substitute (cfg.messages['pp-prefix'], {sepc, pages}), *, '';  
else  
return *, utilities.substitute (cfg.messages['nopp'], {sepc, pages}), *, '';  
end  
end  

return *, *, *, *; -- return empty strings  
end  

----------------------------< I N S O U R C E _ L O C _ G E T >----------------------------------------------  

returns one of the in-source locators: page, pages, or at.  

If any of these are interwiki links to Wikisource, returns the label portion of the interwiki-link as plain text  
for use in COinS. This COinS thing is done because here we convert an interwiki-link to an external link and  
add an icon span around that; get_coins_pages doesn't know about the span. TODO: should it?  

TODO: add support for sheet and sheets?; streamline;  

TODO: make it so that this function returns only one of the three as the single in-source (the return value assigned  
to a new name)?  

local function insource_loc_get (page, page_orig, pages, pages_orig, at)  
local ws_url, ws_label, coins_pages, L; -- for Wikisource interwiki-links; TODO: this corrupts page metadata (span remains in place after cleanup; fix there?)  

if utilities.is_set (page) then  
if utilities.is_set (pages) or utilities.is_set (at) then  
pages = ''; -- unset the others  
at = '';  
end  
extra_text_in_page_check (page, page_orig); -- emit error message when |page= value begins with what looks like p., pp., etc.  

ws_url, ws_label, L = wikisource_url_make (page); -- make ws URL from |page= interwiki link; link portion L becomes tooltip label  
if ws_url then  
page = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in page'); -- space char after label to move icon away from in-source text; TODO: a better way to do this?  
page = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, page});  
coins_pages = ws_label;  
end  
elseif utilities.is_set (pages) then  
if utilities.is_set (at) then  
at = ''; -- unset  
end  
extra_text_in_page_check (pages, pages_orig); -- emit error message when |page= value begins with what looks like p., pp., etc.  

ws_url, ws_label, L = wikisource_url_make (pages); -- make ws URL from |pages= interwiki link; link portion L becomes tooltip label  
if ws_url then  
pages = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in pages'); -- space char after label to move icon away from in-source text; TODO: a better way to do this?  
pages = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, pages});  
coins_pages = ws_label;  
end  
elseif utilities.is_set (at) then  
ws_url, ws_label, L = wikisource_url_make (at); -- make ws URL from |at= interwiki link; link portion L becomes tooltip label  
if ws_url then  
at = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in at'); -- space char after label to move icon away from in-source text; TODO: a better way to do this?  
at = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, at});  
coins_pages = ws_label;  
end  
end  

return page, pages, at, coins_pages;  
end  

--archive-url= value is same as |url= or chapter-url= (or alias...) value  

local function is_unique_archive_url (archive, url, c_url, source, date)  
if utilities.is_set (archive) then  
if archive == url or archive == c_url then  
utilities.set_message ('err_bad_url', {utilities.wrap_style ('parameter', source)}); -- add error message  
return *, *; -- unset |archive-url= and |archive-date= because same as |url= or |chapter-url=  
end  
end  

return archive, date;  
end  

--[=[-------------------------< A R C H I V E _ U R L _ C H E C K >--------------------------------------------  

Check archive.org URLs to make sure they at least look like they are pointing at valid archives and not to the  
save snapshot URL or to calendar pages. When the archive URL is 'https://web.archive.org/save/' (or http://...)  
archive.org saves a snapshot of the target page in the URL. That is something that Wikipedia should not allow  
unwitting readers to do.  

When the archive.org URL does not have a complete timestamp, archive.org chooses a snapshot according to its own  
algorithm or provides a calendar 'search' result. WP:ELNO discourages links to search results.  

This function looks at the value assigned to |archive-url= and returns empty strings for |archive-url= and  
|archive-date= and an error message when:  
|archive-url= holds an archive.org save command URL  
|archive-url= is an archive.org URL that does not have a complete timestamp (YYYYMMDDhhmmss 14 digits) in the  
correct place  
otherwise returns |archive-url= and |archive-date=  

There are two mostly compatible archive.org URLs:  
//web.archive.org/<timestamp>... -- the old form  
//web.archive.org/web/<timestamp>... -- the new form  

The old form does not support or map to the new form when it contains a display flag. There are four identified flags  
('id_', 'js_', 'cs_', 'im_') but since archive.org ignores others following the same form (two letters and an underscore)  
we don't check for these specific flags but we do check the form.  

This function supports a preview mode. When the article is rendered in preview mode, this function may return a modified  
archive URL:  
for save command errors, return undated wildcard (/*/)  
for timestamp errors when the timestamp has a wildcard, return the URL unmodified  
for timestamp errors when the timestamp does not have a wildcard, return with timestamp limited to six digits plus wildcard (/yyyymm*/)  

A secondary function is to return an archive-url timestamp from those urls that have them (archive.org and  
archive.today). The timestamp is used by validation.archive_date_check to see if the value in |archive-date=  
matches the timestamp in the archive url.  

]=]  

local function archive_url_check (url, date)  
local err_msg = ''; -- start with the error message empty  
local path, timestamp, flag; -- portions of the archive.org URL  

timestamp = url:match ('//archive.today/(%d%d%d%d%d%d%d%d%d%d%d%d%d%d)/') or -- get timestamp from archive.today urls  
url:match ('//archive.today/(%d%d%d%d%.%d%d%.%d%d%-%d%d%d%d%d%d)/'); -- this timestamp needs cleanup  
if timestamp then -- if this was an archive.today url ...  
return url, date, timestamp:gsub ('[%.%-]', ''); -- return ArchiveURL, ArchiveDate, and timestamp (dots and dashes removed) from |archive-url=, and done  
end  
-- here for archive.org urls  
if (not url:match('//web%.archive%.org/')) and (not url:match('//liveweb%.archive%.org/')) then -- also deprecated liveweb Wayback machine URL  
return url, date; -- not an archive.org archive, return ArchiveURL and ArchiveDate  
end  

if url:match('//web%.archive%.org/save/') then -- if a save command URL, we don't want to allow saving of the target page  
err_msg = cfg.err_msg_supl.save;  
url = url:gsub ('(//web%.archive%.org)/save/', '%1/*/', 1); -- for preview mode: modify ArchiveURL  
elseif url:match('//liveweb%.archive%.org/') then  
err_msg = cfg.err_msg_supl.liveweb;  
else  
path, timestamp, flag = url:match('//web%.archive%.org/([^%d]*)(%d+)([^/]*)/'); -- split out some of the URL parts for evaluation  
if not path then -- malformed in some way; pattern did not match  
err_msg = cfg.err_msg_supl.timestamp;  
elseif 14 ~= timestamp:len then -- path and flag optional, must have 14-digit timestamp here  
err_msg = cfg.err_msg_supl.timestamp;  
if '*' ~= flag then  
local replacement = timestamp:match ('^%d%d%d%d%d%d') or timestamp:match ('^%d%d%d%d'); -- get the first 6 (YYYYMM) or first 4 digits (YYYY)  
if replacement then -- nil if there aren't at least 4 digits (year)  
replacement = replacement .. string.rep ('0', 14 - replacement:len); -- year or yearmo (4 or 6 digits) zero-fill to make 14-digit timestamp  
url=url:gsub ('(//web%.archive%.org/[^%d]*)%d[^/]*', '%1' .. replacement .. '*', 1) -- for preview, modify ts to 14 digits plus splat for calendar display  
end  
end  
elseif utilities.is_set (path) and 'web/' ~= path then -- older archive URLs do not have the extra 'web/' path element  
err_msg = cfg.err_msg_supl.path;  
elseif utilities.is_set (flag) and not utilities.is_set (path) then -- flag not allowed with the old form URL (without the 'web/' path element)  
err_msg = cfg.err_msg_supl.flag;  
elseif utilities.is_set (flag) and not flag:match ('%a%a_') then -- flag if present must be two alpha characters and underscore (requires 'web/' path element)  
err_msg = cfg.err_msg_supl.flag;  
else  
return url, date, timestamp; -- return ArchiveURL, ArchiveDate, and timestamp from |archive-url=  
end  
end  
-- if here, something not so  
utilities.set_message ('err_archive_url', {err_msg}); -- add error message and  

if is_preview_mode then  
return url, date, timestamp; -- preview mode so return ArchiveURL, ArchiveDate, and timestamp from |archive-url=  
else  
return *, *; -- return empty strings for ArchiveURL and ArchiveDate  
end  
end  

--place=, |publication-place=, |location= to see if these params include digits. This function added because  
many editors misuse location to specify the in-source location (|page(s)= and |at= are supposed to do that)  

returns the original parameter value without modification; added maint cat when parameter value contains digits  

local function place_check (param_val)  
if not utilities.is_set (param_val) then -- parameter empty or omitted  
return param_val; -- return that empty state  
end  

if mw.ustring.find (param_val, '%d') then -- not empty, are there digits in the parameter value  
utilities.set_message ('maint_location'); -- yep, add maint cat  
end  

return param_val; -- and done  
end  

--title= to 'Archived copy' (placeholder added by bots that can't find proper title); if matches, return true; nil else  

local function is_archived_copy (title)  
title = mw.ustring.lower(title); -- switch title to lower case  
if title:find (cfg.special_case_translation.archived_copy.en) then -- if title is 'Archived copy'  
return true;  
elseif cfg.special_case_translation.archived_copy['local'] then  
if mw.ustring.find (title, cfg.special_case_translation.archived_copy['local']) then -- mw.ustring because might not be Latin script  
return true;  
end  
end  
end  

--display-authors=, |display-editors=, etc parameters, select either the local or global setting.  
When both are present, look at <local_display_names> value. When the value is some sort of 'et al.'string,  
special handling is required.  

When has |display-<namelist>= AND this template has |display-<namelist>=etal AND:  
the number of names specified by <number_of_names> is:  
greater than the number specified in the global |display-<namelist>= parameter (<global_display_names>)  
use global |display-<namelist>= parameter value  
set overridden maint category  
less than or equal to the number specified in the global |display-<namelist>= parameter  
use local |display-<namelist>= parameter value  

The purpose of this function is to prevent categorizing a template that has fewer names than the global setting  
to keep the etal annotation specified by <local_display_names>.  

local function display_names_select (global_display_names, local_display_names, param_name, number_of_names, test)  
if global_display_names and utilities.is_set (local_display_names) then -- when both  
if 'etal' == local_display_names:lower:gsub("[ '%.]", '') then -- the :gsub portion makes 'etal' from a variety of 'et al.' spellings and stylings  
number_of_names = tonumber (number_of_names); -- convert these to numbers for comparison  
local global_display_names_num = tonumber (global_display_names); -- <global_display_names> not set when parameter value is not digits  

if number_of_names > global_display_names_num then -- template has more names than global config allows to be displayed?  
utilities.set_message ('maint_overridden_setting'); -- set a maint message because global is overriding local |display-<namelist>=etal  
return global_display_names, 'cs1 config'; -- return global with spoof parameter name (for get_display_names)  
else  
return local_display_names, param_name; -- return local because fewer names so let <local_display_names> control  
end  
end  
-- here when <global_display_names> and <local_display_names> both numbers; <global_display_names> controls  
utilities.set_message ('maint_overridden_setting'); -- set a maint message  
return global_display_names, 'cs1 config'; -- return global with spoof parameter name (for get_display_names)  
end  
-- here when only one of <global_display_names> or <local_display_names> set  
if global_display_names then  
return global_display_names, 'cs1 config'; -- return global with spoof parameter name (for get_display_names)  
else  
return local_display_names, param_name; -- return local  
end  
end  

----------------------------< C I T A T I O N 0 >------------------------------------------------------------  

This is the main function doing the majority of the citation formatting.  

local function citation0( config, args )  
---
Load Input Parameters  
The argument_wrapper facilitates the mapping of multiple aliases to single internal variable.  

local A = argument_wrapper ( args );  
local i  

-- Pick out the relevant fields from the arguments. Different citation templates  
-- define different field names for the same underlying things.  

local author_etal;  
local a = {}; -- authors list from |lastn= / |firstn= pairs or |vauthors=  
local Authors;  
local NameListStyle;  
if cfg.global_cs1_config_t['NameListStyle'] then -- global setting in overrides local |name-list-style= parameter value; nil when empty or assigned value invalid  
NameListStyle = is_valid_parameter_value (cfg.global_cs1_config_t['NameListStyle'], 'cs1 config: name-list-style', cfg.keywords_lists['name-list-style'], ''); -- error messaging 'param' here is a hoax  
else  
NameListStyle = is_valid_parameter_value (A['NameListStyle'], A:ORIGIN('NameListStyle'), cfg.keywords_lists['name-list-style'], '');  
end  

if cfg.global_cs1_config_t['NameListStyle'] and utilities.is_set (A['NameListStyle']) then -- when template has |name-list-style=<something> which global setting has overridden  
utilities.set_message ('maint_overridden_setting'); -- set a maint message  
end  

local Collaboration = A['Collaboration'];  

do -- to limit scope of selected  
local selected = select_author_editor_source (A['Vauthors'], A['Authors'], args, 'AuthorList');  
if 1 == selected then  
a, author_etal = extract_names (args, 'AuthorList'); -- fetch author list from |authorn= / |lastn= / |firstn=, |author-linkn=, and |author-maskn=  
elseif 2 == selected then  
NameList; -- override whatever |name-list-style= might be  
a, author_etal = parse_vauthors_veditors (args, A['Vauthors'], 'AuthorList'); -- fetch author list from |vauthors=, |author-linkn=, and |author-maskn=  
elseif 3 == selected then  
Authors = A['Authors']; -- use content of |people= or |credits=; |authors= is deprecated; TODO: constrain |people= and |credits= to cite av media, episode, serial?  
end  
if utilities.is_set (Collaboration) then  
author_etal = true; -- so that |display-authors=etal not required  
end  
end  

local editor_etal;  
local e = {}; -- editors list from |editor-lastn= / |editor-firstn= pairs or |veditors=  

do -- to limit scope of selected  
local selected = select_author_editor_source (A['Veditors'], nil, args, 'EditorList'); -- support for |editors= withdrawn  
if 1 == selected then  
e, editor_etal = extract_names (args, 'EditorList'); -- fetch editor list from |editorn= / |editor-lastn= / |editor-firstn=, |editor-linkn=, and |editor-maskn=  
elseif 2 == selected then  
NameList; -- override whatever |name-list-style= might be  
e, editor_etal = parse_vauthors_veditors (args, args.veditors, 'EditorList'); -- fetch editor list from |veditors=, |editor-linkn=, and |editor-maskn=  
end  
end  

local Chapter = A['Chapter']; -- done here so that we have access to |contribution= from |chapter= aliases  
local Chapter_origin = A:ORIGIN ('Chapter');  
local Contribution; -- because contribution is required for contributor(s)  
if 'contribution' == Chapter_origin then  
Contribution = Chapter; -- get the name of the contribution  
end  
local c = {}; -- contributors list from |contributor-lastn= / contributor-firstn= pairs  

if utilities.in_array (config.CitationClass, {"book", "citation"}) and not utilities.is_set (A['Periodical']) then -- |contributor= and |contribution= only supported in book cites  
c = extract_names (args, 'ContributorList'); -- fetch contributor list from |contributorn= / |contributor-lastn=, -firstn=, -linkn=, -maskn=  

if 0 < #c then  
if not utilities.is_set (Contribution) then -- |contributor= requires |contribution=  
utilities.set_message ('err_contributor_missing_required_param', 'contribution'); -- add missing contribution error message  
c = {}; -- blank the contributors' table; it is used as a flag later  
end  
if 0 == #a then -- |contributor= requires |author=  
utilities.set_message ('err_contributor_missing_required_param', 'author'); -- add missing author error message  
c = {}; -- blank the contributors' table; it is used as a flag later  
end  
end  
else -- if not a book cite  
if utilities.select_one (args, cfg.aliases['ContributorList-Last'], 'err_redundant_parameters', 1 ) then -- are there contributor name list parameters?  
utilities.set_message ('err_contributor_ignored'); -- add contributor ignored error message  
end  
Contribution = nil; -- unset  
end  

local Title = A['Title'];  
local TitleLink = A['TitleLink'];  

local auto_select = ''; -- default is auto  
local accept_link;  
TitleLink, accept_link = utilities.has_accept_as_written (TitleLink, true); -- test for accept-this-as-written markup  
if (not accept_link) and utilities.in_array (TitleLink, {'', 'pmc', 'doi'}) then -- check for special keywords  
auto_select = TitleLink; -- remember selection for later  
TitleLink = ''; -- treat as if |title-link= would have been empty  
end  

TitleLink = link_title_ok (TitleLink, A:ORIGIN ('TitleLink'), Title, 'title'); -- check for wiki-markup in |title-link= or wiki-markup in |title= when |title-link= is set  

local Section = ''; -- only; preset to empty string for concatenation if not used  
if 'map' == config.CitationClass and 'section' == Chapter_origin then  
Section = A['Chapter']; -- get |section= from |chapter= alias list; |chapter= and the other aliases not supported in  
Chapter = ''; -- unset for now; will be reset later from |map= if present  
end  

local Periodical = A['Periodical'];  
local Periodical_origin = A:ORIGIN('Periodical');  
local ScriptPeriodical = A['ScriptPeriodical'];  
local ScriptPeriodical_origin = A:ORIGIN('ScriptPeriodical');  
local TransPeriodical = A['TransPeriodical'];  
local TransPeriodical_origin = A:ORIGIN ('TransPeriodical');  

if (utilities.in_array (config.CitationClass, {'book', 'encyclopaedia'}) and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical) or utilities.is_set (TransPeriodical))) then  
local param;  
if utilities.is_set (Periodical) then -- get a parameter name from one of these periodical related meta-parameters  
Periodical = ''; -- unset because not valid or parameters  
param = Periodical_origin -- get parameter name for error messaging  
elseif utilities.is_set (TransPeriodical) then  
TransPeriodical = ''; -- unset because not valid or parameters  
param = TransPeriodical_origin; -- get parameter name for error messaging  
elseif utilities.is_set (ScriptPeriodical) then  
ScriptPeriodical = ''; -- unset because not valid or parameters  
param = ScriptPeriodical_origin; -- get parameter name for error messaging  
end  

if utilities.is_set (param) then -- if we found one  
utilities.set_message ('err_periodical_ignored', {param}); -- emit an error message  
end  
end  

if utilities.is_set (Periodical) then  
local i;  
Periodical, i = utilities.strip_apostrophe_markup (Periodical); -- strip apostrophe markup so that metadata isn't contaminated  
if i then -- non-zero when markup was stripped so emit an error message  
utilities.set_message ('err_apostrophe_markup', {Periodical_origin});  
end  
end  

if 'mailinglist' == config.CitationClass then -- special case for  
if utilities.is_set (Periodical) and utilities.is_set (A ['MailingList']) then -- both set emit an error TODO: make a function for this and similar?  
utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', Periodical_origin) .. cfg.presentation['sep_list_pair'] .. utilities.wrap_style ('parameter', 'mailinglist')});  
end  

Periodical = A ['MailingList']; -- error or no, set Periodical to |mailinglist= value because this template is  
Periodical_origin = A:ORIGIN('MailingList');  
end  

-- web and news not tested for now because of  
-- Wikipedia:Administrators%27_noticeboard#Is_there_a_semi-automated_tool_that_could_fix_these_annoying_"Cite_Web"_errors?  
if not (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) then -- 'periodical' templates require periodical parameter  
-- local p = {['journal'] = 'journal', ['magazine'] = 'magazine', ['news'] = 'newspaper', ['web'] = 'website'}; -- for error message  
local p = {['journal'] = 'journal', ['magazine'] = 'magazine'}; -- for error message  
if p[config.CitationClass] then  
utilities.set_message ('err_missing_periodical', {config.CitationClass, p[config.CitationClass]});  
end  
end  

local Volume;  
if 'citation' == config.CitationClass then  
if utilities.is_set (Periodical) then  
if not utilities.in_array (Periodical_origin, cfg.citation_no_volume_t) then -- does not render |volume= when these parameters are used  
Volume = A['Volume']; -- but does for all other 'periodicals'  
end  
elseif utilities.is_set (ScriptPeriodical) then  
if 'script-website' ~= ScriptPeriodical_origin then -- does not render volume for |script-website=  
Volume = A['Volume']; -- but does for all other 'periodicals'  
end  
else  
Volume = A['Volume']; -- and does for non-'periodical' cites  
end  
elseif utilities.in_array (config.CitationClass, cfg.templates_using_volume) then -- render |volume= for cs1 according to the configuration settings  
Volume = A['Volume'];  
end  
extra_text_in_vol_iss_check (Volume, A:ORIGIN ('Volume'), 'v');  

local Issue;  
if 'citation' == config.CitationClass then  
if utilities.is_set (Periodical) and utilities.in_array (Periodical_origin, cfg.citation_issue_t) then -- may render |issue= when these parameters are used  
Issue = utilities.hyphen_to_dash (A['Issue']);  
end  
elseif utilities.in_array (config.CitationClass, cfg.templates_using_issue) then -- conference & map books do not support issue; listed here because included in settings table  
if not (utilities.in_array (config.CitationClass, {'conference', 'map', 'citation'}) and not (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical))) then  
Issue = utilities.hyphen_to_dash (A['Issue']);  
end  
end  

local ArticleNumber;  

if utilities.in_array (config.CitationClass, {'journal', 'conference'}) or ('citation' == config.CitationClass and utilities.is_set (Periodical) and 'journal' == Periodical_origin) then  
ArticleNumber = A['ArticleNumber'];  
end  

extra_text_in_vol_iss_check (Issue, A:ORIGIN ('Issue'), 'i');  

local Page;  
local Pages;  
local At;  
local QuotePage;  
local QuotePages;  
if not utilities.in_array (config.CitationClass, cfg.templates_not_using_page) then -- TODO: rewrite to emit ignored parameter error message?  
Page = A['Page'];  
Pages = utilities.hyphen_to_dash (A['Pages']);  
At = A['At'];  
QuotePage = A['QuotePage'];  
QuotePages = utilities.hyphen_to_dash (A['QuotePages']);  
end  

local Edition = A['Edition'];  
local PublicationPlace = place_check (A['PublicationPlace'], A:ORIGIN('PublicationPlace'));  
local Place = place_check (A['Place'], A:ORIGIN('Place'));  

local PublisherName = A['PublisherName'];  
local PublisherName_origin = A:ORIGIN('PublisherName');  
if utilities.is_set (PublisherName) and (cfg.keywords_xlate[''] ~= PublisherName) then  
local i = 0;  
PublisherName, i = utilities.strip_apostrophe_markup (PublisherName); -- strip apostrophe markup so that metadata isn't contaminated; publisher is never italicized  
if i and (0 < i) then -- non-zero when markup was stripped so emit an error message  
utilities.set_message ('err_apostrophe_markup', {PublisherName_origin});  
end  
end  

if ('document' == config.CitationClass) and not utilities.is_set (PublisherName) then  
utilities.set_message ('err_missing_publisher', {config.CitationClass, 'publisher'});  
end  

local Newsgroup = A['Newsgroup']; -- TODO: strip apostrophe markup?  
local Newsgroup_origin = A:ORIGIN('Newsgroup');  

if 'newsgroup' == config.CitationClass then  
if utilities.is_set (PublisherName) and (cfg.keywords_xlate[''] ~= PublisherName) then -- general use parameter |publisher= not allowed in cite newsgroup  
utilities.set_message ('err_parameter_ignored', {PublisherName_origin});  
end  

PublisherName = nil; -- ensure that this parameter is unset for the time being; will be used again after COinS  
end  

local URL = A['URL']; -- TODO: better way to do this for URL, ChapterURL, and MapURL?  
local UrlAccess = is_valid_parameter_value (A['UrlAccess'], A:ORIGIN('UrlAccess'), cfg.keywords_lists['url-access'], nil);  

if not utilities.is_set (URL) and utilities.is_set (UrlAccess) then  
UrlAccess = nil;  
utilities.set_message ('err_param_access_requires_param', 'url');  
end  

local ChapterURL = A['ChapterURL'];  
local ChapterUrlAccess = is_valid_parameter_value (A['ChapterUrlAccess'], A:ORIGIN('ChapterUrlAccess'), cfg.keywords_lists['url-access'], nil);  
if not utilities.is_set (ChapterURL) and utilities.is_set (ChapterUrlAccess) then  
ChapterUrlAccess = nil;  
utilities.set_message ('err_param_access_requires_param', {A:ORIGIN('ChapterUrlAccess'):gsub ('%-access', '')});  
end  

local MapUrlAccess = is_valid_parameter_value (A['MapUrlAccess'], A:ORIGIN('MapUrlAccess'), cfg.keywords_lists['url-access'], nil);  
if not utilities.is_set (A['MapURL']) and utilities.is_set (MapUrlAccess) then  
MapUrlAccess = nil;  
utilities.set_message ('err_param_access_requires_param', {'map-url'});  
end  

local this_page = mw.title.getCurrentTitle; -- also used for COinS and for language  
local no_tracking_cats = is_valid_parameter_value (A['NoTracking'], A:ORIGIN('NoTracking'), cfg.keywords_lists['yes_true_y'], nil);  

-- check this page to see if it is in one of the namespaces that cs1 is not supposed to add to the error categories  
if not utilities.is_set (no_tracking_cats) then -- ignore if we are already not going to categorize this page  
if cfg.uncategorized_namespaces[this_page.namespace] then -- is this page's namespace id one of the uncategorized namespace ids?  
no_tracking_cats = "true"; -- set no_tracking_cats  
end  
for _, v in ipairs (cfg.uncategorized_subpages) do -- cycle through page name patterns  
if this_page.text:match (v) then -- test page name against each pattern  
no_tracking_cats = "true"; -- set no_tracking_cats  
break; -- bail out if one is found  
end  
end  
end  
-- check for extra |page=, |pages= or |at= parameters. (also sheet and sheets while we're at it)  
utilities.select_one (args, {'page', 'p', 'pp', 'pages', 'at', 'sheet', 'sheets'}, 'err_redundant_parameters'); -- this is a dummy call simply to get the error message and category  

local coins_pages;  

Page, Pages, At, coins_pages = insource_loc_get (Page, A:ORIGIN('Page'), Pages, A:ORIGIN('Pages'), At);  

local NoPP = is_valid_parameter_value (A['NoPP'], A:ORIGIN('NoPP'), cfg.keywords_lists['yes_true_y'], nil);  

if utilities.is_set (PublicationPlace) and utilities.is_set (Place) then -- both |publication-place= and |place= (|location=) allowed if different  
utilities.add_prop_cat ('location-test'); -- add property cat to evaluate how often PublicationPlace and Place are used together  
if PublicationPlace == Place then  
Place = ''; -- unset; don't need both if they are the same  
end  
elseif not utilities.is_set (PublicationPlace) and utilities.is_set (Place) then -- when only |place= (|location=) is set ...  
PublicationPlace = Place; -- promote |place= (|location=) to |publication-place  
end  

if PublicationPlace == Place then Place = ''; end -- don't need both if they are the same  

local URL_origin = A:ORIGIN('URL'); -- get name of parameter that holds URL  
local ChapterURL_origin = A:ORIGIN('ChapterURL'); -- get name of parameter that holds ChapterURL  
local ScriptChapter = A['ScriptChapter'];  
local ScriptChapter_origin = A:ORIGIN ('ScriptChapter');  
local Format = A['Format'];  
local ChapterFormat = A['ChapterFormat'];  
local TransChapter = A['TransChapter'];  
local TransChapter_origin = A:ORIGIN ('TransChapter');  
local TransTitle = A['TransTitle'];  
local ScriptTitle = A['ScriptTitle'];  

--encyclopedia= and |title= then map |title= to |article= and |encyclopedia= to |title= for rendering  
|encyclopedia= and |article= then map |encyclopedia= to |title= for rendering  

|trans-title= maps to |trans-chapter= when |title= is re-mapped  
|url= maps to |chapter-url= when |title= is remapped  

All other combinations of |encyclopedia=, |title=, and |article= are not modified  

local Encyclopedia = A['Encyclopedia']; -- used as a flag by this module and by ~/COinS  
local ScriptEncyclopedia = A['ScriptEncyclopedia'];  
local TransEncyclopedia = A['TransEncyclopedia'];  

if utilities.is_set (Encyclopedia) or utilities.is_set (ScriptEncyclopedia) then -- emit error message when Encyclopedia set but template is other than or  
if 'encyclopaedia' ~= config.CitationClass and 'citation' ~= config.CitationClass then  
if utilities.is_set (Encyclopedia) then  
utilities.set_message ('err_parameter_ignored', {A:ORIGIN ('Encyclopedia')});  
else  
utilities.set_message ('err_parameter_ignored', {A:ORIGIN ('ScriptEncyclopedia')});  
end  
Encyclopedia = nil; -- unset these because not supported by this template  
ScriptEncyclopedia = nil;  
TransEncyclopedia = nil;  
end  
elseif utilities.is_set (TransEncyclopedia) then  
utilities.set_message ('err_trans_missing_title', {'encyclopedia'});  
end  

if ('encyclopaedia' == config.CitationClass) or ('citation' == config.CitationClass and utilities.is_set (Encyclopedia)) then  
if utilities.is_set (Periodical) and utilities.is_set (Encyclopedia) then -- when both parameters set emit an error message; only; Periodical not allowed in  
utilities.set_message ('err_periodical_ignored', {Periodical_origin});  
end  

if utilities.is_set (Encyclopedia) or utilities.is_set (ScriptEncyclopedia) then  
Periodical = Encyclopedia; -- error or no, set Periodical to Encyclopedia for rendering; could (not legitimately) have both; use Encyclopedia  
Periodical_origin = A:ORIGIN ('Encyclopedia');  
ScriptPeriodical = ScriptEncyclopedia;  
ScriptPeriodical_origin = A:ORIGIN ('ScriptEncyclopedia');  

if utilities.is_set (Title) or utilities.is_set (ScriptTitle) then  
if not utilities.is_set (Chapter) then  
Chapter = Title; -- |encyclopedia= and |title= are set so map |title= params to |article= params for rendering  
ScriptChapter = ScriptTitle;  
ScriptChapter_origin = A:ORIGIN('ScriptTitle')  
TransChapter = TransTitle;  
ChapterURL = URL;  
ChapterURL_origin = URL_origin;  
ChapterUrlAccess = UrlAccess;  
ChapterFormat = Format;  

if not utilities.is_set (ChapterURL) and utilities.is_set (TitleLink) then  
Chapter = utilities.make_wikilink (TitleLink, Chapter);  
end  
Title = Periodical; -- now map |encyclopedia= params to |title= params for rendering  
ScriptTitle = ScriptPeriodical or '';  
TransTitle = TransEncyclopedia or '';  
Periodical = ''; -- redundant so unset  
ScriptPeriodical = '';  
URL = '';  
Format = '';  
TitleLink = '';  
end  
elseif utilities.is_set (Chapter) or utilities.is_set (ScriptChapter) then -- |title= not set  
Title = Periodical; -- |encyclopedia= set and |article= set so map |encyclopedia= to |title= for rendering  
ScriptTitle = ScriptPeriodical or '';  
TransTitle = TransEncyclopedia or '';  
Periodical = ''; -- redundant so unset  
ScriptPeriodical = '';  
end  
end  
end  

-- special case for cite techreport.  
local ID = A['ID'];  
if (config.CitationClass == "techreport") then -- special case for cite techreport  
if utilities.is_set (A['Number']) then -- cite techreport uses 'number', which other citations alias to 'issue'  
if not utilities.is_set (ID) then -- can we use ID for the "number"?  
ID = A['Number']; -- yes, use it  
else -- ID has a value so emit error message  
utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'id') .. cfg.presentation['sep_list_pair'] .. utilities.wrap_style ('parameter', 'number')});  
end  
end  
end  

-- Account for the oddity that is , before generation of COinS data.  
local ChapterLink -- = A['ChapterLink']; -- deprecated as a parameter but still used internally by cite episode  
local Conference = A['Conference'];  
local BookTitle = A['BookTitle'];  
local TransTitle_origin = A:ORIGIN ('TransTitle');  
if 'conference' == config.CitationClass then  
if utilities.is_set (BookTitle) then  
Chapter = Title;  
Chapter_origin = 'title';  
-- ChapterLink = TitleLink; -- |chapter-link= is deprecated  
ChapterURL = URL;  
ChapterUrlAccess = UrlAccess;  
ChapterURL_origin = URL_origin;  
URL_origin = '';  
ChapterFormat = Format;  
TransChapter = TransTitle;  
TransChapter_origin = TransTitle_origin;  
Title = BookTitle;  
Format = '';  
-- TitleLink = '';  
TransTitle = '';  
URL = '';  
end  
elseif 'speech' ~= config.CitationClass then  
Conference = ''; -- not cite conference or cite speech so make sure this is empty string  
end  

-- CS1/2 mode  
local Mode;  
if cfg.global_cs1_config_t['Mode'] then -- global setting in overrides local |mode= parameter value; nil when empty or assigned value invalid  
Mode = is_valid_parameter_value (cfg.global_cs1_config_t['Mode'], 'cs1 config: mode', cfg.keywords_lists['mode'], ''); -- error messaging 'param' here is a hoax  
else  
Mode = is_valid_parameter_value (A['Mode'], A:ORIGIN('Mode'), cfg.keywords_lists['mode'], '');  
end  

if cfg.global_cs1_config_t['Mode'] and utilities.is_set (A['Mode']) then -- when template has |mode=<something> which global setting has overridden  
utilities.set_message ('maint_overridden_setting'); -- set a maint message  
end  

-- separator character and postscript  
local sepc, PostScript = set_style (Mode:lower, A['PostScript'], config.CitationClass);  
-- controls capitalization of certain static text  
local use_lowercase = ( sepc == ',' );  

-- cite map oddities  
local Cartography = "";  
local Scale = "";  
local Sheet = A['Sheet'] or '';  
local Sheets = A['Sheets'] or '';  
if config.CitationClass == "map" then  
if utilities.is_set (Chapter) then --TODO: make a function for this and similar?  
utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'map') .. cfg.presentation['sep_list_pair'] .. utilities.wrap_style ('parameter', Chapter_origin)}); -- add error message  
end  
Chapter = A['Map'];  
Chapter_origin = A:ORIGIN('Map');  
ChapterURL = A['MapURL'];  
ChapterURL_origin = A:ORIGIN('MapURL');  
TransChapter = A['TransMap'];  
ScriptChapter = A['ScriptMap']  
ScriptChapter_origin = A:ORIGIN('ScriptMap')  

ChapterUrlAccess = MapUrlAccess;  
ChapterFormat = A['MapFormat'];  

Cartography = A['Cartography'];  
if utilities.is_set ( Cartography ) then  
Cartography = sepc .. " " .. wrap_msg ('cartography', Cartography, use_lowercase);  
end  
Scale = A['Scale'];  
if utilities.is_set ( Scale ) then  
Scale = sepc .. " " .. Scale;  
end  
end  

-- Account for the oddities that are and , before generation of COinS data.  
local Series = A['Series'];  
if 'episode' == config.CitationClass or 'serial' == config.CitationClass then  
local SeriesLink = A['SeriesLink'];  

SeriesLink = link_title_ok (SeriesLink, A:ORIGIN ('SeriesLink'), Series, 'series'); -- check for wiki-markup in |series-link= or wiki-markup in |series= when |series-link= is set  

local Network = A['Network'];  
local Station = A['Station'];  
local s, n = {}, {};  
-- do common parameters first  
if utilities.is_set (Network) then table.insert(n, Network); end  
if utilities.is_set (Station) then table.insert(n, Station); end  
ID = table.concat(n, sepc .. ' ');  

if 'episode' == config.CitationClass then -- handle the oddities that are strictly  
local Season = A['Season'];  
local SeriesNumber = A['SeriesNumber'];  

if utilities.is_set (Season) and utilities.is_set (SeriesNumber) then -- these are mutually exclusive so if both are set TODO: make a function for this and similar?  
utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'season') .. cfg.presentation['sep_list_pair'] .. utilities.wrap_style ('parameter', 'seriesno')}); -- add error message  
SeriesNumber = ''; -- unset; prefer |season= over |seriesno=  
end  
-- assemble a table of parts concatenated later into Series  
if utilities.is_set (Season) then table.insert(s, wrap_msg ('season', Season, use_lowercase)); end  
if utilities.is_set (SeriesNumber) then table.insert(s, wrap_msg ('seriesnum', SeriesNumber, use_lowercase)); end  
if utilities.is_set (Issue) then table.insert(s, wrap_msg ('episode', Issue, use_lowercase)); end  
Issue = ''; -- unset because this is not a unique parameter  

Chapter = Title; -- promote title parameters to chapter  
ScriptChapter = ScriptTitle;  
ScriptChapter_origin = A:ORIGIN('ScriptTitle');  
ChapterLink = TitleLink; -- alias |episode-link=  
TransChapter = TransTitle;  
ChapterURL = URL;  
ChapterUrlAccess = UrlAccess;  
ChapterURL_origin = URL_origin;  
ChapterFormat = Format;  

Title = Series; -- promote series to title  
TitleLink = SeriesLink;  
Series = table.concat(s, sepc .. ' '); -- this is concatenation of season, seriesno, episode number  

if utilities.is_set (ChapterLink) and not utilities.is_set (ChapterURL) then -- link but not URL  
Chapter = utilities.make_wikilink (ChapterLink, Chapter);  
elseif utilities.is_set (ChapterLink) and utilities.is_set (ChapterURL) then -- if both are set, URL links episode;  
Series = utilities.make_wikilink (ChapterLink, Series);  
end  
URL = ''; -- unset  
TransTitle = '';  
ScriptTitle = '';  
Format = '';  

else -- now oddities that are cite serial  
Issue = ''; -- unset because this parameter no longer supported by the citation/core version of cite serial  
Chapter = A['Episode']; -- TODO: make |episode= available to cite episode someday?  
if utilities.is_set (Series) and utilities.is_set (SeriesLink) then  
Series = utilities.make_wikilink (SeriesLink, Series);  
end  
Series = utilities.wrap_style ('italic-title', Series); -- series is italicized  
end  
end  
-- end of stuff  

-- handle type parameter for those CS1 citations that have default values  
local TitleType = A['TitleType'];  
local Degree = A['Degree'];  
if utilities.in_array (config.CitationClass, {'AV-media-notes', 'document', 'interview', 'mailinglist', 'map', 'podcast', 'pressrelease', 'report', 'speech', 'techreport', 'thesis'}) then  
TitleType = set_titletype (config.CitationClass, TitleType);  
if utilities.is_set (Degree) and "Thesis" == TitleType then -- special case for cite thesis  
TitleType = Degree .. ' ' .. cfg.title_types ['thesis']:lower;  
end  
end  

if utilities.is_set (TitleType) then -- if type parameter is specified  
TitleType = utilities.substitute ( cfg.messages['type'], TitleType); -- display it in parentheses  
-- TODO: Hack on TitleType to fix bunched parentheses problem  
end  

-- legacy: promote PublicationDate to Date if neither Date nor Year are set.  
local Date = A['Date'];  
local Date_origin; -- to hold the name of parameter promoted to Date; required for date error messaging  
local PublicationDate = A['PublicationDate'];  
local Year = A['Year'];  

if utilities.is_set (Year) then  
validation.year_check (Year); -- returns nothing; emits maint message when |year= doesn't hold a 'year' value  
end  

if not utilities.is_set (Date) then  
Date = Year; -- promote Year to Date  
Year = nil; -- make nil so Year as empty string isn't used for CITEREF  
if not utilities.is_set (Date) and utilities.is_set (PublicationDate) then -- use PublicationDate when |date= and |year= are not set  
Date = PublicationDate; -- promote PublicationDate to Date  
PublicationDate = ''; -- unset, no longer needed  
Date_origin = A:ORIGIN('PublicationDate'); -- save the name of the promoted parameter  
else  
Date_origin = A:ORIGIN('Year'); -- save the name of the promoted parameter  
end  
else  
Date_origin = A:ORIGIN('Date'); -- not a promotion; name required for error messaging  
end  

if PublicationDate == Date then PublicationDate = ''; end -- if PublicationDate is same as Date, don't display in rendered citation  

---
Go test all of the date-holding parameters for valid MOS:DATE format and make sure that dates are real dates. This must be done before we do COinS because here is where  
we get the date used in the metadata.  

Date validation supporting code is in Module:Citation/CS1/Date_validation  

local DF = is_valid_parameter_value (A['DF'], A:ORIGIN('DF'), cfg.keywords_lists['df'], '');  
if not utilities.is_set (DF) then  
DF = cfg.global_df; -- local |df= if present overrides global df set by template  
end  

local ArchiveURL;  
local ArchiveDate;  
local ArchiveFormat = A['ArchiveFormat'];  
local archive_url_timestamp; -- timestamp from wayback machine url  

ArchiveURL, ArchiveDate, archive_url_timestamp = archive_url_check (A['ArchiveURL'], A['ArchiveDate'])  
ArchiveFormat = style_format (ArchiveFormat, ArchiveURL, 'archive-format', 'archive-url');  

ArchiveURL, ArchiveDate = is_unique_archive_url (ArchiveURL, URL, ChapterURL, A:ORIGIN('ArchiveURL'), ArchiveDate); -- add error message when URL or ChapterURL == ArchiveURL  

local AccessDate = A['AccessDate'];  
local COinS_date = {}; -- holds date info extracted from |date= for the COinS metadata by Module:Date verification  
local DoiBroken = A['DoiBroken'];  
local Embargo = A['Embargo'];  
local anchor_year; -- used in the CITEREF identifier  
do -- create defined block to contain local variables error_message, date_parameters_list, mismatch  
local error_message = '';  
-- AirDate has been promoted to Date so not necessary to check it  
local date_parameters_list = {  
['access-date'] = {val = AccessDate, name = A:ORIGIN ('AccessDate')},  
['archive-date'] = {val = ArchiveDate, name = A:ORIGIN ('ArchiveDate')},  
['date'] = {val = Date, name = Date_origin},  
['doi-broken-date'] = {val = DoiBroken, name = A:ORIGIN ('DoiBroken')},  
['pmc-embargo-date'] = {val = Embargo, name = A:ORIGIN ('Embargo')},  
['publication-date'] = {val = PublicationDate, name = A:ORIGIN ('PublicationDate')},  
['year'] = {val = Year, name = A:ORIGIN ('Year')},  
};  

local error_list = {};  
anchor_year, Embargo = validation.dates(date_parameters_list, COinS_date, error_list);  

if utilities.is_set (Year) and utilities.is_set (Date) then -- both |date= and |year= not normally needed;  
validation.year_date_check (Year, A:ORIGIN ('Year'), Date, A:ORIGIN ('Date'), error_list);  
end  

if 0 == #error_list then -- error free dates only; 0 when error_list is empty  
local modified = false; -- flag  

if utilities.is_set (DF) then -- if we need to reformat dates  
modified = validation.reformat_dates (date_parameters_list, DF); -- reformat to DF format, use long month names if appropriate  
end  

if true == validation.date_hyphen_to_dash (date_parameters_list) then -- convert hyphens to dashes where appropriate  
modified = true;  
utilities.set_message ('maint_date_format'); -- hyphens were converted so add maint category  
end  

-- for those wikis that can and want to have English date names translated to the local language; not supported at en.wiki  
if cfg.date_name_auto_xlate_enable and validation.date_name_xlate (date_parameters_list, cfg.date_digit_auto_xlate_enable ) then  
utilities.set_message ('maint_date_auto_xlated'); -- add maint cat  
modified = true;  
end  

if modified then -- if the date_parameters_list values were modified  
AccessDate = date_parameters_list['access-date'].val; -- overwrite date holding parameters with modified values  
ArchiveDate = date_parameters_list['archive-date'].val;  
Date = date_parameters_list['date'].val;  
DoiBroken = date_parameters_list['doi-broken-date'].val;  
PublicationDate = date_parameters_list['publication-date'].val;  
end  

if archive_url_timestamp and utilities.is_set (ArchiveDate) then  
validation.archive_date_check (ArchiveDate, archive_url_timestamp, DF); -- does YYYYMMDD in archive_url_timestamp match date in ArchiveDate  
end  
else  
utilities.set_message ('err_bad_date', {utilities.make_sep_list (#error_list, error_list)}); -- add this error message  
end  
end -- end of do  

if utilities.in_array (config.CitationClass, {'book', 'encyclopaedia'}) or -- , ; TODO: and others?  
('citation' == config.CitationClass and utilities.is_set (Encyclopedia)) or -- as an encylopedia citation  
('citation' == config.CitationClass and not utilities.is_set (Periodical)) then -- as a book citation  
if utilities.is_set (PublicationPlace) then  
if not utilities.is_set (PublisherName) then  
local date = COinS_date.rftdate and tonumber (COinS_date.rftdate:match ('%d%d%d%d')); -- get year portion of COinS date (because in Arabic numerals); convert string to number  
if date and (1850 <= date) then -- location has no publisher; if date is 1850 or later  
utilities.set_message ('maint_location_no_publisher'); -- add maint cat  
end  
else -- PublisherName has a value  
if cfg.keywords_xlate[*] == PublisherName then -- if that value is * (only for book and encyclopedia citations)  
PublisherName = ''; -- unset  
end  
end  
end  
end  

local ID_list = {}; -- sequence table of rendered identifiers  
local ID_list_coins = {}; -- table of identifiers and their values from args; key is same as cfg.id_handlers's key  
local Class = A['Class']; -- arxiv class identifier  

local ID_support = {  
{A['ASINTLD'], 'ASIN', 'err_asintld_missing_asin', A:ORIGIN ('ASINTLD')},  
{DoiBroken, 'DOI', 'err_doibroken_missing_doi', A:ORIGIN ('DoiBroken')},  
{Embargo, 'PMC', 'err_embargo_missing_pmc', A:ORIGIN ('Embargo')},  
}  

ID_list, ID_list_coins = identifiers.identifier_lists_get (args, {DoiBroken = DoiBroken, ASINTLD = A['ASINTLD'], Embargo = Embargo, Class = Class}, ID_support);  

-- Account for the oddities that are , , , , , before generation of COinS data.  
if utilities.in_array (config.CitationClass, whitelist.preprint_template_list_t) then -- |arxiv= or |eprint= required for cite arxiv; |biorxiv=, |citeseerx=, |medrxiv=, |ssrn= required for their templates  
if not (args[cfg.id_handlers[config.CitationClass:upper].parameters[1]] or -- can't use ID_list_coins k/v table here because invalid parameters omitted  
args[cfg.id_handlers[config.CitationClass:upper].parameters[2]]) then -- which causes unexpected parameter missing error message  
utilities.set_message ('err_' .. config.CitationClass .. '_missing'); -- add error message  
end  

Periodical = ({['arxiv'] = 'arXiv', ['biorxiv'] = 'bioRxiv', ['citeseerx'] = 'CiteSeerX', ['medrxiv'] = 'medRxiv', ['ssrn'] = 'Social Science Research Network'})[config.CitationClass];  
end  

-- Link the title of the work if no |url= was provided, but we have a |pmc= or a |doi= with |doi-access=free  

if config.CitationClass == "journal" and not utilities.is_set (URL) and not utilities.is_set (TitleLink) and not utilities.in_array (cfg.keywords_xlate[Title], {'off', *}) then -- TODO: remove * once existing citations have been switched to 'off', so '' can be used as token for "no title" instead  
if '' ~= cfg.keywords_xlate[auto_select] then -- if auto-linking not disabled  
if identifiers.auto_link_urls[auto_select] then -- manual selection  
URL = identifiers.auto_link_urls[auto_select]; -- set URL to be the same as identifier's external link  
URL_origin = cfg.id_handlers[auto_select:upper].parameters[1]; -- set URL_origin to parameter name for use in error message if citation is missing a |title=  
elseif identifiers.auto_link_urls['pmc'] then -- auto-select PMC  
URL = identifiers.auto_link_urls['pmc']; -- set URL to be the same as the PMC external link if not embargoed  
URL_origin = cfg.id_handlers['PMC'].parameters[1]; -- set URL_origin to parameter name for use in error message if citation is missing a |title=  
elseif identifiers.auto_link_urls['doi'] then -- auto-select DOI  
URL = identifiers.auto_link_urls['doi'];  
URL_origin = cfg.id_handlers['DOI'].parameters[1];  
end  
end  

if utilities.is_set (URL) then -- set when using an identifier-created URL  
if utilities.is_set (AccessDate) then -- |access-date= requires |url=; identifier-created URL is not |url=  
utilities.set_message ('err_accessdate_missing_url'); -- add an error message  
AccessDate = ''; -- unset  
end  

if utilities.is_set (ArchiveURL) then -- |archive-url= requires |url=; identifier-created URL is not |url=  
utilities.set_message ('err_archive_missing_url'); -- add an error message  
ArchiveURL = ''; -- unset  
end  
end  
end  

-- At this point fields may be nil if they weren't specified in the template use. We can use that fact.  
-- Test if citation has no title  
if not utilities.is_set (Title) and not utilities.is_set (TransTitle) and not utilities.is_set (ScriptTitle) then -- has special case for cite episode  
utilities.set_message ('err_citation_missing_title', {'episode' == config.CitationClass and 'series' or 'title'});  
end  

if utilities.in_array (cfg.keywords_xlate[Title], {'off', ''}) and  
utilities.in_array (config.CitationClass, {'journal', 'citation'}) and  
(utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and  
('journal' == Periodical_origin or 'script-journal' == ScriptPeriodical_origin) then -- special case for journal cites  
Title = ''; -- set title to empty string  
utilities.set_message ('maint_untitled'); -- add maint cat  
end  

-- COinS metadata (see <http://ocoins.info/>) for automated parsing of citation information.  
-- handle the oddity that is cite encyclopedia and . Here we presume that  
-- when Periodical, Title, and Chapter are all set, then Periodical is the book (encyclopedia) title, Title  
-- is the article title, and Chapter is a section within the article. So, we remap  

local coins_chapter = Chapter; -- default assuming that remapping not required  
local coins_title = Title; -- et tu  
if 'encyclopaedia' == config.CitationClass or ('citation' == config.CitationClass and utilities.is_set (Encyclopedia)) then  
if utilities.is_set (Chapter) and utilities.is_set (Title) and utilities.is_set (Periodical) then -- if all are used then  
coins_chapter = Title; -- remap  
coins_title = Periodical;  
end  
end  
local coins_author = a; -- default for coins rft.au  
if 0 < #c then -- but if contributor list  
coins_author = c; -- use that instead  
end  

-- this is the function call to COinS  
local OCinSoutput = metadata.COinS({  
['Periodical'] = utilities.strip_apostrophe_markup (Periodical), -- no markup in the metadata  
['Encyclopedia'] = Encyclopedia, -- just a flag; content ignored by ~/COinS  
['Chapter'] = metadata.make_coins_title (coins_chapter, ScriptChapter), -- Chapter and ScriptChapter stripped of bold / italic / accept-as-written markup  
['Degree'] = Degree; -- cite thesis only  
['Title'] = metadata.make_coins_title (coins_title, ScriptTitle), -- Title and ScriptTitle stripped of bold / italic / accept-as-written markup  
['PublicationPlace'] = PublicationPlace,  
['Date'] = COinS_date.rftdate, -- COinS_date.* has correctly formatted date values if Date is valid;  
['Season'] = COinS_date.rftssn,  
['Quarter'] = COinS_date.rftquarter,  
['Chron'] = COinS_date.rftchron,  
['Series'] = Series,  
['Volume'] = Volume,  
['Issue'] = Issue,  
['ArticleNumber'] = ArticleNumber,  
['Pages'] = coins_pages or metadata.get_coins_pages (first_set ({Sheet, Sheets, Page, Pages, At, QuotePage, QuotePages}, 7)), -- pages stripped of external links  
['Edition'] = Edition,  
['PublisherName'] = PublisherName or Newsgroup, -- any apostrophe markup already removed from PublisherName  
['URL'] = first_set ({ChapterURL, URL}, 2),  
['Authors'] = coins_author,  
['ID_list'] = ID_list_coins,  
['RawPage'] = this_page.prefixedText,  
}, config.CitationClass);  

-- Account for the oddities that are , , , , and AFTER generation of COinS data.  
if utilities.in_array (config.CitationClass, whitelist.preprint_template_list_t) then -- we have set rft.jtitle in COinS to arXiv, bioRxiv, CiteSeerX, medRxiv, or ssrn now unset so it isn't displayed  
Periodical = ''; -- periodical not allowed in these templates; if article has been published, use cite journal  
end  

-- special case for cite newsgroup. Do this after COinS because we are modifying Publishername to include some static text  
if 'newsgroup' == config.CitationClass and utilities.is_set (Newsgroup) then  
PublisherName = utilities.substitute (cfg.messages['newsgroup'], external_link( 'news:' .. Newsgroup, Newsgroup, Newsgroup_origin, nil ));  
end  

local Editors;  
local EditorCount; -- used only for choosing {ed.) or (eds.) annotation at end of editor name-list  
local Contributors; -- assembled contributors name list  
local contributor_etal;  
local Translators; -- assembled translators name list  
local translator_etal;  
local t = {}; -- translators list from |translator-lastn= / translator-firstn= pairs  
t = extract_names (args, 'TranslatorList'); -- fetch translator list from |translatorn= / |translator-lastn=, -firstn=, -linkn=, -maskn=  
local Interviewers;  
local interviewers_list = {};  
interviewers_list = extract_names (args, 'InterviewerList'); -- process preferred interviewers parameters  
local interviewer_etal;  

-- Now perform various field substitutions.  
-- We also add leading spaces and surrounding markup and punctuation to the  
-- various parts of the citation, but only when they are non-nil.  
do  
local last_first_list;  
local control = {  
format = NameListStyle, -- empty string, '&', 'amp', 'and', or 'vanc'  
maximum = nil, -- as if display-authors or display-editors not set  
mode = Mode  
};  

do -- do editor name list first because the now unsupported coauthors used to modify control table  
local display_names, param = display_names_select (cfg.global_cs1_config_t['DisplayEditors'], A['DisplayEditors'], A:ORIGIN ('DisplayEditors'), #e);  
control.maximum, editor_etal = get_display_names (display_names, #e, 'editors', editor_etal, param);  

Editors, EditorCount = list_people (control, e, editor_etal);  

if 1 == EditorCount and (true == editor_etal or 1 < #e) then -- only one editor displayed but includes etal then  
EditorCount = 2; -- spoof to display (eds.) annotation  
end  
end  
do -- now do interviewers  
local display_names, param = display_names_select (cfg.global_cs1_config_t['DisplayInterviewers'], A['DisplayInterviewers'], A:ORIGIN ('DisplayInterviewers'), #interviewers_list);  
control.maximum, interviewer_etal = get_display_names (display_names, #interviewers_list, 'interviewers', interviewer_etal, param);  

Interviewers = list_people (control, interviewers_list, interviewer_etal);  
end  
do -- now do translators  
local display_names, param = display_names_select (cfg.global_cs1_config_t['DisplayTranslators'], A['DisplayTranslators'], A:ORIGIN ('DisplayTranslators'), #t);  
control.maximum, translator_etal = get_display_names (display_names, #t, 'translators', translator_etal, param);  

Translators = list_people (control, t, translator_etal);  
end  
do -- now do contributors  
local display_names, param = display_names_select (cfg.global_cs1_config_t['DisplayContributors'], A['DisplayContributors'], A:ORIGIN ('DisplayContributors'), #c);  
control.maximum, contributor_etal = get_display_names (display_names, #c, 'contributors', contributor_etal, param);  

Contributors = list_people (control, c, contributor_etal);  
end  
do -- now do authors  
local display_names, param = display_names_select (cfg.global_cs1_config_t['DisplayAuthors'], A['DisplayAuthors'], A:ORIGIN ('DisplayAuthors'), #a, author_etal);  
control.maximum, author_etal = get_display_names (display_names, #a, 'authors', author_etal, param);  

last_first_list = list_people (control, a, author_etal);  

if utilities.is_set (Authors) then  
Authors, author_etal = name_has_etal (Authors, author_etal, false, 'authors'); -- find and remove variations on et al.  
if author_etal then  
Authors = Authors .. ' ' .. cfg.messages['et al']; -- add et al. to authors parameter  
end  
else  
Authors = last_first_list; -- either an author name list or an empty string  
end  
end -- end of do  

if utilities.is_set (Authors) and utilities.is_set (Collaboration) then  
Authors = Authors .. ' (' .. Collaboration .. ')'; -- add collaboration after et al.  
end  

end  

local ConferenceFormat = A['ConferenceFormat'];  
local ConferenceURL = A['ConferenceURL'];  
ConferenceFormat = style_format (ConferenceFormat, ConferenceURL, 'conference-format', 'conference-url');  
Format = style_format (Format, URL, 'format', 'url');  

-- special case for chapter format so no error message or cat when chapter not supported  
if not (utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'pressrelease', 'podcast', 'newsgroup', 'arxiv', 'biorxiv', 'citeseerx', 'medrxiv', 'ssrn'}) or  
('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia))) then  
ChapterFormat = style_format (ChapterFormat, ChapterURL, 'chapter-format', 'chapter-url');  
end  

if not utilities.is_set (URL) then  
if utilities.in_array (config.CitationClass, {"web", "podcast", "mailinglist"}) or -- |url= required for cite web, cite podcast, and cite mailinglist  
('citation' == config.CitationClass and ('website' == Periodical_origin or 'script-website' == ScriptPeriodical_origin)) then -- and required for with |website= or |script-website=  
utilities.set_message ('err_cite_web_url');  
end  

-- do we have |accessdate= without either |url= or |chapter-url=?  
if utilities.is_set (AccessDate) and not utilities.is_set (ChapterURL) then -- ChapterURL may be set when URL is not set;  
utilities.set_message ('err_accessdate_missing_url');  
AccessDate = '';  
end  
end  

local UrlStatus = is_valid_parameter_value (A['UrlStatus'], A:ORIGIN('UrlStatus'), cfg.keywords_lists['url-status'], '');  
local OriginalURL  
local OriginalURL_origin  
local OriginalFormat  
local OriginalAccess;  
UrlStatus = UrlStatus:lower; -- used later when assembling archived text  
if utilities.is_set ( ArchiveURL ) then  
if utilities.is_set (ChapterURL) then -- if chapter-url= is set apply archive url to it  
OriginalURL = ChapterURL; -- save copy of source chapter's url for archive text  
OriginalURL_origin = ChapterURL_origin; -- name of |chapter-url= parameter for error messages  
OriginalFormat = ChapterFormat; -- and original |chapter-format=  

if 'live' ~= UrlStatus then  
ChapterURL = ArchiveURL -- swap-in the archive's URL  
ChapterURL_origin = A:ORIGIN('ArchiveURL') -- name of |archive-url= parameter for error messages  
ChapterFormat = ArchiveFormat or ''; -- swap in archive's format  
ChapterUrlAccess = nil; -- restricted access levels do not make sense for archived URLs  
end  
elseif utilities.is_set (URL) then  
OriginalURL = URL; -- save copy of original source URL  
OriginalURL_origin = URL_origin; -- name of URL parameter for error messages  
OriginalFormat = Format; -- and original |format=  
OriginalAccess = UrlAccess;  

if 'live' ~= UrlStatus then -- if URL set then |archive-url= applies to it  
URL = ArchiveURL -- swap-in the archive's URL  
URL_origin = A:ORIGIN('ArchiveURL') -- name of archive URL parameter for error messages  
Format = ArchiveFormat or ''; -- swap in archive's format  
UrlAccess = nil; -- restricted access levels do not make sense for archived URLs  
end  
end  
elseif utilities.is_set (UrlStatus) then -- if |url-status= is set when |archive-url= is not set  
utilities.set_message ('maint_url_status'); -- add maint cat  
end  

if utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'pressrelease', 'podcast', 'newsgroup', 'arxiv', 'biorxiv', 'citeseerx', 'medrxiv', 'ssrn'}) or -- if any of the 'periodical' cites except encyclopedia  
('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia)) then  
local chap_param;  
if utilities.is_set (Chapter) then -- get a parameter name from one of these chapter related meta-parameters  
chap_param = A:ORIGIN ('Chapter')  
elseif utilities.is_set (TransChapter) then  
chap_param = A:ORIGIN ('TransChapter')  
elseif utilities.is_set (ChapterURL) then  
chap_param = A:ORIGIN ('ChapterURL')  
elseif utilities.is_set (ScriptChapter) then  
chap_param = ScriptChapter_origin;  
else utilities.is_set (ChapterFormat)  
chap_param = A:ORIGIN ('ChapterFormat')  
end  

if utilities.is_set (chap_param) then -- if we found one  
utilities.set_message ('err_chapter_ignored', {chap_param}); -- add error message  
Chapter = ''; -- and set them to empty string to be safe with concatenation  
TransChapter = '';  
ChapterURL = '';  
ScriptChapter = '';  
ChapterFormat = '';  
end  
else -- otherwise, format chapter / article title  
local no_quotes = false; -- default assume that we will be quoting the chapter parameter value  
if utilities.is_set (Contribution) and 0 < #c then -- if this is a contribution with contributor(s)  
if utilities.in_array (Contribution:lower, cfg.keywords_lists.contribution) then -- and a generic contribution title  
no_quotes = true; -- then render it unquoted  
end  
end  

Chapter = format_chapter_title (ScriptChapter, ScriptChapter_origin, Chapter, Chapter_origin, TransChapter, TransChapter_origin, ChapterURL, ChapterURL_origin, no_quotes, ChapterUrlAccess); -- Contribution is also in Chapter  
if utilities.is_set (Chapter) then  
Chapter = Chapter .. ChapterFormat ;  
if 'map' == config.CitationClass and utilities.is_set (TitleType) then  
Chapter = Chapter .. ' ' .. TitleType; -- map annotation here; not after title  
end  
Chapter = Chapter .. sepc .. ' ';  
elseif utilities.is_set (ChapterFormat) then -- |chapter= not set but |chapter-format= is so ...  
Chapter = ChapterFormat .. sepc .. ' '; -- ... ChapterFormat has error message, we want to see it  
end  
end  

-- Format main title  
local plain_title = false;  
local accept_title;  
Title, accept_title = utilities.has_accept_as_written (Title, true); -- remove accept-this-as-written markup when it wraps all of <Title>  
if accept_title and ('' == Title) then -- only support forced empty for now "()"  
Title = cfg.messages['notitle']; -- replace by predefined "No title" message  
-- TODO: utilities.set_message ( 'err_redundant_parameters', ...); -- issue proper error message instead of muting  
ScriptTitle = ''; -- just mute for now  
TransTitle = ''; -- just mute for now  
plain_title = true; -- suppress text decoration for descriptive title  
utilities.set_message ('maint_untitled'); -- add maint cat  
end  

if not accept_title then -- <Title> not wrapped in accept-as-written markup  
if '...' == Title:sub (-3) then -- if ellipsis is the last three characters of |title=  
Title = Title:gsub ('(%.%.%.)%.+$', '%1'); -- limit the number of dots to three  
elseif not mw.ustring.find (Title, '%.%s*%a%.$') and -- end of title is not a 'dot-(optional space-)letter-dot' initialism ...  
not mw.ustring.find (Title, '%s+%a%.$') then -- ...and not a 'space-letter-dot' initial (*Allium canadense* L.)  
Title = mw.ustring.gsub(Title, '%' .. sepc .. '$', ''); -- remove any trailing separator character; sepc and ms.ustring here for languages that use multibyte separator characters  
end  

if utilities.is_set (ArchiveURL) and is_archived_copy (Title) then  
utilities.set_message ('maint_archived_copy'); -- add maintenance category before we modify the content of Title  
end  

if is_generic ('generic_titles', Title) then  
utilities.set_message ('err_generic_title'); -- set an error message  
end  
end  

if (not plain_title) and (utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'document', 'pressrelease', 'podcast', 'newsgroup', 'mailinglist', 'interview', 'arxiv', 'biorxiv', 'citeseerx', 'medrxiv', 'ssrn'}) or  
('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia)) or  
('map' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)))) then -- special case for cite map when the map is in a periodical treat as an article  
Title = kern_quotes (Title); -- if necessary, separate title's leading and trailing quote marks from module provided quote marks  
Title = utilities.wrap_style ('quoted-title', Title);  
Title = script_concatenate (Title, ScriptTitle, 'script-title'); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped  
TransTitle = utilities.wrap_style ('trans-quoted-title', TransTitle );  
elseif plain_title or ('report' == config.CitationClass) then -- no styling for cite report and descriptive titles (otherwise same as above)  
Title = script_concatenate (Title, ScriptTitle, 'script-title'); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped  
TransTitle = utilities.wrap_style ('trans-quoted-title', TransTitle ); -- for cite report, use this form for trans-title  
else  
Title = utilities.wrap_style ('italic-title', Title);  
Title = script_concatenate (Title, ScriptTitle, 'script-title'); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped  
TransTitle = utilities.wrap_style ('trans-italic-title', TransTitle);  
end  

if utilities.is_set (TransTitle) then  
if utilities.is_set (Title) then  
TransTitle = " " .. TransTitle;  
else  
utilities.set_message ('err_trans_missing_title', {'title'});  
end  
end  

if utilities.is_set (Title) then -- TODO: is this the place to be making Wikisource URLs?  
if utilities.is_set (TitleLink) and utilities.is_set (URL) then  
utilities.set_message ('err_wikilink_in_url'); -- set an error message because we can't have both  
TitleLink = ''; -- unset  
end  

if not utilities.is_set (TitleLink) and utilities.is_set (URL) then  
Title = external_link (URL, Title, URL_origin, UrlAccess) .. TransTitle .. Format;  
URL = ''; -- unset these because no longer needed  
Format = "";  
elseif utilities.is_set (TitleLink) and not utilities.is_set (URL) then  
local ws_url;  
ws_url = wikisource_url_make (TitleLink); -- ignore ws_label return; not used here  
if ws_url then  
Title = external_link (ws_url, Title .. '&nbsp;', 'ws link in title-link'); -- space char after Title to move icon away from italic text; TODO: a better way to do this?  
Title = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], TitleLink, Title});  
Title = Title .. TransTitle;  
else  
Title = utilities.make_wikilink (TitleLink, Title) .. TransTitle;  
end  
else  
local ws_url, ws_label, L; -- Title has italic or quote markup by the time we get here which causes is_wikilink to return 0 (not a wikilink)  
ws_url, ws_label, L = wikisource_url_make (Title:gsub('^[\'"]*(.-)[\'"]*$', '%1')); -- make ws URL from |title= interwiki link (strip italic or quote markup); link portion L becomes tooltip label  
if ws_url then  
Title = Title:gsub ('%b[]', ws_label); -- replace interwiki link with ws_label to retain markup  
Title = external_link (ws_url, Title .. '&nbsp;', 'ws link in title'); -- space char after Title to move icon away from italic text; TODO: a better way to do this?  
Title = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, Title});  
Title = Title .. TransTitle;  
else  
Title = Title .. TransTitle;  
end  
end  
else  
Title = TransTitle;  
end  

if utilities.is_set (Place) then  
Place = " " .. wrap_msg ('written', Place, use_lowercase) .. sepc .. " ";  
end  

local ConferenceURL_origin = A:ORIGIN('ConferenceURL'); -- get name of parameter that holds ConferenceURL  
if utilities.is_set (Conference) then  
if utilities.is_set (ConferenceURL) then  
Conference = external_link( ConferenceURL, Conference, ConferenceURL_origin, nil );  
end  
Conference = sepc .. " " .. Conference .. ConferenceFormat;  
elseif utilities.is_set (ConferenceURL) then  
Conference = sepc .. " " .. external_link( ConferenceURL, nil, ConferenceURL_origin, nil );  
end  

local Position = '';  
if not utilities.is_set (Position) then  
local Minutes = A['Minutes'];  
local Time = A['Time'];  

if utilities.is_set (Minutes) then  
if utilities.is_set (Time) then --TODO: make a function for this and similar?  
utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'minutes') .. cfg.presentation['sep_list_pair'] .. utilities.wrap_style ('parameter', 'time')});  
end  
Position = " " .. Minutes .. " " .. cfg.messages['minutes'];  
else  
if utilities.is_set (Time) then  
local TimeCaption = A['TimeCaption']  
if not utilities.is_set (TimeCaption) then  
TimeCaption = cfg.messages['event'];  
if sepc ~= '.' then  
TimeCaption = TimeCaption:lower;  
end  
end  
Position = " " .. TimeCaption .. " " .. Time;  
end  
end  
else  
Position = " " .. Position;  
At = '';  
end  

Page, Pages, Sheet, Sheets = format_pages_sheets (Page, Pages, Sheet, Sheets, config.CitationClass, Periodical_origin, sepc, NoPP, use_lowercase);  

At = utilities.is_set (At) and (sepc .. " " .. At) or "";  
Position = utilities.is_set (Position) and (sepc .. " " .. Position) or "";  
if config.CitationClass == 'map' then  
local Sections = A['Sections']; -- Section (singular) is an alias of Chapter so set earlier  
local Inset = A['Inset'];  

if utilities.is_set ( Inset ) then  
Inset = sepc .. " " .. wrap_msg ('inset', Inset, use_lowercase);  
end  

if utilities.is_set ( Sections ) then  
Section = sepc .. " " .. wrap_msg ('sections', Sections, use_lowercase);  
elseif utilities.is_set ( Section ) then  
Section = sepc .. " " .. wrap_msg ('section', Section, use_lowercase);  
end  
At = At .. Inset .. Section;  
end  

local Others = A['Others'];  
if utilities.is_set (Others) and 0 == #a and 0 == #e then -- add maint cat when |others= has value and used without |author=, |editor=  
if config.CitationClass == "AV-media-notes"  
or config.CitationClass == "audio-visual" then -- special maint for AV/M which has a lot of 'false' positives now  
utilities.set_message ('maint_others_avm')  
else  
utilities.set_message ('maint_others');  
end  
end  
Others = utilities.is_set (Others) and (sepc .. " " .. Others) or "";  

if utilities.is_set (Translators) then  
Others = safe_join ({sepc .. ' ', wrap_msg ('translated', Translators, use_lowercase), Others}, sepc);  
end  
if utilities.is_set (Interviewers) then  
Others = safe_join ({sepc .. ' ', wrap_msg ('interview', Interviewers, use_lowercase), Others}, sepc);  
end  

local TitleNote = A['TitleNote'];  
TitleNote = utilities.is_set (TitleNote) and (sepc .. " " .. TitleNote) or "";  
if utilities.is_set (Edition) then  
if Edition:match ('%f[%a][Ee]d%n?%.?$') or Edition:match ('%f[%a][Ee]dition$') then -- Ed, ed, Ed., ed., Edn, edn, Edn., edn.  
utilities.set_message ('err_extra_text_edition'); -- add error message  
end  
Edition = " " .. wrap_msg ('edition', Edition);  
else  
Edition = '';  
end  

Series = utilities.is_set (Series) and wrap_msg ('series', {sepc, Series}) or ""; -- not the same as SeriesNum  
local Agency = A['Agency'] or ''; -- |agency= is supported by , , , , and certain templates  
if utilities.is_set (Agency) then -- this testing done here because supports 'news' citations  
if utilities.in_array (config.CitationClass, {'magazine', 'news', 'pressrelease', 'web'}) or ('citation' == config.CitationClass and utilities.in_array (Periodical_origin, {"magazine", "newspaper", "work"})) then  
Agency = wrap_msg ('agency', {sepc, Agency}); -- format for rendering  
else  
Agency = ''; -- unset; not supported  
utilities.set_message ('err_parameter_ignored', {'agency'}); -- add error message  
end  
end  

Volume = format_volume_issue (Volume, Issue, ArticleNumber, config.CitationClass, Periodical_origin, sepc, use_lowercase);  

if utilities.is_set (AccessDate) then  
local retrv_text = " " .. cfg.messages['retrieved']  

AccessDate = nowrap_date (AccessDate); -- wrap in nowrap span if date in appropriate format  
if (sepc ~= ".") then retrv_text = retrv_text:lower end -- if mode is cs2, lower case  
AccessDate = utilities.substitute (retrv_text, AccessDate); -- add retrieved text  

AccessDate = utilities.substitute (cfg.presentation['accessdate'], {sepc, AccessDate}); -- allow editors to hide accessdates  
end  

if utilities.is_set (ID) then ID = sepc .. " " .. ID; end  

local Docket = A['Docket'];  
if "thesis" == config.CitationClass and utilities.is_set (Docket) then  
ID = sepc .. " Docket " .. Docket .. ID;  
end  
if "report" == config.CitationClass and utilities.is_set (Docket) then -- for cite report when |docket= is set  
ID = sepc .. ' ' .. Docket; -- overwrite ID even if |id= is set  
end  

if utilities.is_set (URL) then  
URL = " " .. external_link( URL, nil, URL_origin, UrlAccess );  
end  

local Quote = A['Quote'];  
local TransQuote = A['TransQuote'];  
local ScriptQuote = A['ScriptQuote'];  
if utilities.is_set (Quote) or utilities.is_set (TransQuote) or utilities.is_set (ScriptQuote) then  

if utilities.is_set (Quote) then  
if Quote:sub(1, 1) == '"' and Quote:sub(-1, -1) == '"' then -- if first and last characters of quote are quote marks  
Quote = Quote:sub(2, -2); -- strip them off  
end  
end  

Quote = kern_quotes (Quote); -- kern if needed  
Quote = utilities.wrap_style ('quoted-text', Quote ); -- wrap in <q>...</q> tags  

if utilities.is_set (ScriptQuote) then  
Quote = script_concatenate (Quote, ScriptQuote, 'script-quote'); -- <bdi> tags, lang attribute, categorization, etc.; must be done after quote is wrapped  
end  

if utilities.is_set (TransQuote) then  
if TransQuote:sub(1, 1) == '"' and TransQuote:sub(-1, -1) == '"' then -- if first and last characters of |trans-quote are quote marks  
TransQuote = TransQuote:sub(2, -2); -- strip them off  
end  
Quote = Quote .. " " .. utilities.wrap_style ('trans-quoted-title', TransQuote );  
end  

if utilities.is_set (QuotePage) or utilities.is_set (QuotePages) then -- add page prefix  
local quote_prefix = '';  
if utilities.is_set (QuotePage) then  
extra_text_in_page_check (QuotePage, 'quote-page'); -- add to maint cat if |quote-page= value begins with what looks like p., pp., etc.  
if not NoPP then  
quote_prefix = utilities.substitute (cfg.messages['p-prefix'], {sepc, QuotePage}), *, *, '';  
else  
quote_prefix = utilities.substitute (cfg.messages['nopp'], {sepc, QuotePage}), *, *, '';  
end  
elseif utilities.is_set (QuotePages) then  
extra_text_in_page_check (QuotePages, 'quote-pages'); -- add to maint cat if |quote-pages= value begins with what looks like p., pp., etc.  
if tonumber(QuotePages) ~= nil and not NoPP then -- if only digits, assume single page  
quote_prefix = utilities.substitute (cfg.messages['p-prefix'], {sepc, QuotePages}), *, *;  
elseif not NoPP then  
quote_prefix = utilities.substitute (cfg.messages['pp-prefix'], {sepc, QuotePages}), *, *;  
else  
quote_prefix = utilities.substitute (cfg.messages['nopp'], {sepc, QuotePages}), *, *;  
end  
end  

Quote = quote_prefix .. ": " .. Quote;  
else  
Quote = sepc .. " " .. Quote;  
end  

PostScript = ""; -- cs1|2 does not supply terminal punctuation when |quote= is set  
end  

-- We check length of PostScript here because it will have been nuked by  
-- the quote parameters. We'd otherwise emit a message even if there wasn't  
-- a displayed postscript.  
-- TODO: Should the max size (1) be configurable?  
-- TODO: Should we check a specific pattern?  
if utilities.is_set(PostScript) and mw.ustring.len(PostScript) > 1 then  
utilities.set_message ('maint_postscript')  
end  

local Archived;  
if utilities.is_set (ArchiveURL) then  
if not utilities.is_set (ArchiveDate) then -- ArchiveURL set but ArchiveDate not set  
utilities.set_message ('err_archive_missing_date'); -- emit an error message  
ArchiveURL = ''; -- empty string for concatenation  
ArchiveDate = ''; -- empty string for concatenation  
end  
else  
if utilities.is_set (ArchiveDate) then -- ArchiveURL not set but ArchiveDate is set  
utilities.set_message ('err_archive_date_missing_url'); -- emit an error message  
ArchiveURL = ''; -- empty string for concatenation  
ArchiveDate = ''; -- empty string for concatenation  
end  
end  

if utilities.is_set (ArchiveURL) then  
local arch_text;  
if "live" == UrlStatus then  
arch_text = cfg.messages['archived'];  
if sepc ~= "." then arch_text = arch_text:lower end  
if utilities.is_set (ArchiveDate) then  
Archived = sepc .. ' ' .. utilities.substitute ( cfg.messages['archived-live'],  
{external_link( ArchiveURL, arch_text, A:ORIGIN('ArchiveURL'), nil) .. ArchiveFormat, ArchiveDate } );  
else  
Archived = '';  
end  
if not utilities.is_set (OriginalURL) then  
utilities.set_message ('err_archive_missing_url');  
Archived = ''; -- empty string for concatenation  
end  
elseif utilities.is_set (OriginalURL) then -- UrlStatus is empty, 'dead', 'unfit', 'usurped', 'bot: unknown'  
if utilities.in_array (UrlStatus, {'unfit', 'usurped', 'bot: unknown'}) then  
arch_text = cfg.messages['archived-unfit'];  
if sepc ~= "." then arch_text = arch_text:lower end  
Archived = sepc .. ' ' .. arch_text .. ArchiveDate; -- format already styled  
if 'bot: unknown' == UrlStatus then  
utilities.set_message ('maint_bot_unknown'); -- and add a category if not already added  
else  
-- utilities.set_message ('maint_unfit'); -- and add a category if not already added  
utilities.add_prop_cat ('unfit'); -- and add a category if not already added  
end  
else -- UrlStatus is empty, 'dead'  
arch_text = cfg.messages['archived-dead'];  
if sepc ~= "." then arch_text = arch_text:lower end  
if utilities.is_set (ArchiveDate) then  
Archived = sepc .. " " .. utilities.substitute ( arch_text,  
{ external_link( OriginalURL, cfg.messages['original'], OriginalURL_origin, OriginalAccess ) .. OriginalFormat, ArchiveDate } ); -- format already styled  
else  
Archived = ''; -- unset for concatenation  
end  
end  
else -- OriginalUrl not set  
utilities.set_message ('err_archive_missing_url');  
Archived = ''; -- empty string for concatenation  
end  
elseif utilities.is_set (ArchiveFormat) then  
Archived = ArchiveFormat; -- if set and ArchiveURL not set ArchiveFormat has error message  
else  
Archived = '';  
end  

local TranscriptURL = A['TranscriptURL']  
local TranscriptFormat = A['TranscriptFormat'];  
TranscriptFormat = style_format (TranscriptFormat, TranscriptURL, 'transcript-format', 'transcripturl');  
local Transcript = A['Transcript'];  
local TranscriptURL_origin = A:ORIGIN('TranscriptURL'); -- get name of parameter that holds TranscriptURL  
if utilities.is_set (Transcript) then  
if utilities.is_set (TranscriptURL) then  
Transcript = external_link( TranscriptURL, Transcript, TranscriptURL_origin, nil );  
end  
Transcript = sepc .. ' ' .. Transcript .. TranscriptFormat;  
elseif utilities.is_set (TranscriptURL) then  
Transcript = external_link( TranscriptURL, nil, TranscriptURL_origin, nil );  
end  

local Publisher;  
if utilities.is_set (PublicationDate) then  
PublicationDate = wrap_msg ('published', PublicationDate);  
end  
if utilities.is_set (PublisherName) then  
if utilities.is_set (PublicationPlace) then  
Publisher = sepc .. " " .. PublicationPlace .. ": " .. PublisherName .. PublicationDate;  
else  
Publisher = sepc .. " " .. PublisherName .. PublicationDate;  
end  
elseif utilities.is_set (PublicationPlace) then  
Publisher= sepc .. " " .. PublicationPlace .. PublicationDate;  
else  
Publisher = PublicationDate;  
end  

-- Several of the above rely upon detecting this as nil, so do it last.  
if (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical) or utilities.is_set (TransPeriodical)) then  
if utilities.is_set (Title) or utilities.is_set (TitleNote) then  
Periodical = sepc .. " " .. format_periodical (ScriptPeriodical, ScriptPeriodical_origin, Periodical, TransPeriodical, TransPeriodical_origin);  
else  
Periodical = format_periodical (ScriptPeriodical, ScriptPeriodical_origin, Periodical, TransPeriodical, TransPeriodical_origin);  
end  
end  

local Language = A['Language'];  
if utilities.is_set (Language) then  
Language = language_parameter (Language); -- format, categories, name from ISO639-1, etc.  
else  
Language=''; -- language not specified so make sure this is an empty string;  
-- TODO: need to extract the wrap_msg from language_parameter  
so that we can solve parentheses bunching problem with Format/Language/TitleType  

end  

--department=) and forces it to be " (Speech)" so that  
the annotation directly follows the |title= parameter value in the citation rather than the |event= parameter value (if provided).  

if "speech" == config.CitationClass then -- cite speech only  
TitleNote = TitleType; -- move TitleType to TitleNote so that it renders ahead of |event=  
TitleType = ''; -- and unset  

if utilities.is_set (Periodical) then -- if Periodical, perhaps because of an included |website= or |journal= parameter  
if utilities.is_set (Conference) then -- and if |event= is set  
Conference = Conference .. sepc .. " "; -- then add appropriate punctuation to the end of the Conference variable before rendering  
end  
end  
end  

-- Piece all bits together at last. Here, all should be non-nil.  
-- We build things this way because it is more efficient in LUA  
-- not to keep reassigning to the same string variable over and over.  

local tcommon;  
local tcommon2; -- used for book cite when |contributor= is set  

if utilities.in_array (config.CitationClass, {"book", "citation"}) and not utilities.is_set (Periodical) then -- special cases for book cites  
if utilities.is_set (Contributors) then -- when we are citing foreword, preface, introduction, etc.  
tcommon = safe_join ({Title, TitleNote}, sepc); -- author and other stuff will come after this and before tcommon2  
tcommon2 = safe_join ({TitleType, Series, Language, Volume, Others, Edition, Publisher}, sepc);  
else  
tcommon = safe_join ({Title, TitleNote, TitleType, Series, Language, Volume, Others, Edition, Publisher}, sepc);  
end  

elseif 'map' == config.CitationClass then -- special cases for cite map  
if utilities.is_set (Chapter) then -- map in a book; TitleType is part of Chapter  
tcommon = safe_join ({Title, Edition, Scale, Series, Language, Cartography, Others, Publisher, Volume}, sepc);  
elseif utilities.is_set (Periodical) then -- map in a periodical  
tcommon = safe_join ({Title, TitleType, Periodical, Scale, Series, Language, Cartography, Others, Publisher, Volume}, sepc);  
else -- a sheet or stand-alone map  
tcommon = safe_join ({Title, TitleType, Edition, Scale, Series, Language, Cartography, Others, Publisher}, sepc);  
end  

elseif 'episode' == config.CitationClass then -- special case for cite episode  
tcommon = safe_join ({Title, TitleNote, TitleType, Series, Language, Edition, Publisher}, sepc);  

else -- all other CS1 templates  
tcommon = safe_join ({Title, TitleNote, Conference, Periodical, TitleType, Series, Language, Volume, Others, Edition, Publisher, Agency}, sepc);  
end  

if #ID_list > 0 then  
ID_list = safe_join( { sepc .. " ", table.concat( ID_list, sepc .. " " ), ID }, sepc );  
else  
ID_list = ID;  
end  

local Via = A['Via'];  
Via = utilities.is_set (Via) and wrap_msg ('via', Via) or '';  
local idcommon;  
if 'audio-visual' == config.CitationClass or 'episode' == config.CitationClass then -- special case for cite AV media & cite episode position transcript  
idcommon = safe_join( { ID_list, URL, Archived, Transcript, AccessDate, Via, Quote }, sepc );  
else  
idcommon = safe_join( { ID_list, URL, Archived, AccessDate, Via, Quote }, sepc );  
end  

local text;  
local pgtext = Position .. Sheet .. Sheets .. Page .. Pages .. At;  

local OrigDate = A['OrigDate'];  
OrigDate = utilities.is_set (OrigDate) and wrap_msg ('origdate', OrigDate) or '';  
if utilities.is_set (Date) then  
if utilities.is_set (Authors) or utilities.is_set (Editors) then -- date follows authors or editors when authors not set  
Date = " (" .. Date .. ")" .. OrigDate .. sepc .. " "; -- in parentheses  
else -- neither of authors and editors set  
if (string.sub(tcommon, -1, -1) == sepc) then -- if the last character of tcommon is sepc  
Date = " " .. Date .. OrigDate; -- Date does not begin with sepc  
else  
Date = sepc .. " " .. Date .. OrigDate; -- Date begins with sepc  
end  
end  
end  
if utilities.is_set (Authors) then  
if (not utilities.is_set (Date)) then -- when date is set it's in parentheses; no Authors termination  
Authors = terminate_name_list (Authors, sepc); -- when no date, terminate with 0 or 1 sepc and a space  
end  
if utilities.is_set (Editors) then  
local in_text = '';  
local post_text = '';  
if utilities.is_set (Chapter) and 0 == #c then  
in_text = cfg.messages['in'] .. ' ';  
if (sepc ~= '.') then  
in_text = in_text:lower; -- lowercase for cs2  
end  
end  
if EditorCount <= 1 then  
post_text = ' (' .. cfg.messages['editor'] .. ')'; -- be consistent with no-author, no-date case  
else  
post_text = ' (' .. cfg.messages['editors'] .. ')';  
end  
Editors = terminate_name_list (in_text .. Editors .. post_text, sepc); -- terminate with 0 or 1 sepc and a space  
end  
if utilities.is_set (Contributors) then -- book cite and we're citing the intro, preface, etc.  
local by_text = sepc .. ' ' .. cfg.messages['by'] .. ' ';  
if (sepc ~= '.') then by_text = by_text:lower end -- lowercase for cs2  
Authors = by_text .. Authors; -- author follows title so tweak it here  
if utilities.is_set (Editors) and utilities.is_set (Date) then -- when Editors make sure that Authors gets terminated  
Authors = terminate_name_list (Authors, sepc); -- terminate with 0 or 1 sepc and a space  
end  
if (not utilities.is_set (Date)) then -- when date is set it's in parentheses; no Contributors termination  
Contributors = terminate_name_list (Contributors, sepc); -- terminate with 0 or 1 sepc and a space  
end  
text = safe_join( {Contributors, Date, Chapter, tcommon, Authors, Place, Editors, tcommon2, pgtext, idcommon }, sepc );  
else  
text = safe_join( {Authors, Date, Chapter, Place, Editors, tcommon, pgtext, idcommon }, sepc );  
end  
elseif utilities.is_set (Editors) then  
if utilities.is_set (Date) then  
if EditorCount <= 1 then  
Editors = Editors .. cfg.presentation['sep_name'] .. cfg.messages['editor'];  
else  
Editors = Editors .. cfg.presentation['sep_name'] .. cfg.messages['editors'];  
end  
else  
if EditorCount <= 1 then  
Editors = Editors .. " (" .. cfg.messages['editor'] .. ")" .. sepc .. " "  
else  
Editors = Editors .. " (" .. cfg.messages['editors'] .. ")" .. sepc .. " "  
end  
end  
text = safe_join( {Editors, Date, Chapter, Place, tcommon, pgtext, idcommon}, sepc );  
else  
if utilities.in_array (config.CitationClass, {"journal", "citation"}) and utilities.is_set (Periodical) then  
text = safe_join( {Chapter, Place, tcommon, pgtext, Date, idcommon}, sepc );  
else  
text = safe_join( {Chapter, Place, tcommon, Date, pgtext, idcommon}, sepc );  
end  
end  

if utilities.is_set (PostScript) and PostScript ~= sepc then  
text = safe_join( {text, sepc}, sepc ); -- Deals with italics, spaces, etc.  
if '.' == sepc then -- remove final seperator if present  
text = text:gsub ('%' .. sepc .. '$', ''); -- dot must be escaped here  
else  
text = mw.ustring.gsub (text, sepc .. '$', ''); -- using ustring for non-dot sepc (likely a non-Latin character)  
end  
end  

text = safe_join( {text, PostScript}, sepc );  

-- Now enclose the whole thing in a <cite> element  
local options_t = {};  
options_t.class = cite_class_attribute_make (config.CitationClass, Mode);  

local Ref = is_valid_parameter_value (A['Ref'], A:ORIGIN('Ref'), cfg.keywords_lists['ref'], nil, true); -- nil when |ref=harv; A['Ref'] else  

if * ~= cfg.keywords_xlate[(Ref and Ref:lower) or *] then  
local namelist_t = {}; -- holds selected contributor, author, editor name list  
local year = first_set ({Year, anchor_year}, 2); -- Year first for legacy citations and for YMD dates that require disambiguation  

if #c > 0 then -- if there is a contributor list  
namelist_t = c; -- select it  
elseif #a > 0 then -- or an author list  
namelist_t = a;  
elseif #e > 0 then -- or an editor list  
namelist_t = e;  
end  
local citeref_id;  
if #namelist_t > 0 then -- if there are names in namelist_t  
citeref_id = make_citeref_id (namelist_t, year); -- go make the CITEREF anchor  
if mw.uri.anchorEncode (citeref_id) == ((Ref and mw.uri.anchorEncode (Ref)) or '') then -- Ref may already be encoded (by ) so citeref_id must be encoded before comparison  
utilities.set_message ('maint_ref_duplicates_default');  
end  
else  
citeref_id = ''; -- unset  
end  
options_t.id = Ref or citeref_id;  
end  

if string.len (text:gsub('%b<>', '')) <= 2 then -- remove html and html-like tags; then get length of what remains;  
z.error_cats_t = {}; -- blank the categories list  
z.error_msgs_t = {}; -- blank the error messages list  
OCinSoutput = nil; -- blank the metadata string  
text = ''; -- blank the the citation  
utilities.set_message ('err_empty_citation'); -- set empty citation message and category  
end  

local render_t = {}; -- here we collect the final bits for concatenation into the rendered citation  

if utilities.is_set (options_t.id) then -- here we wrap the rendered citation in <cite ...>...</cite> tags  
table.insert (render_t, utilities.substitute (cfg.presentation['cite-id'], {mw.uri.anchorEncode(options_t.id), mw.text.nowiki(options_t.class), text})); -- when |ref= is set or when there is a namelist  
else  
table.insert (render_t, utilities.substitute (cfg.presentation['cite'], {mw.text.nowiki(options_t.class), text})); -- when |ref= or when namelist_t empty and |ref= is missing or is empty  
end  

if OCinSoutput then -- blanked when citation is 'empty' so don't bother to add boilerplate metadata span  
table.insert (render_t, utilities.substitute (cfg.presentation['ocins'], OCinSoutput)); -- format and append metadata to the citation  
end  

local template_name = ('citation' == config.CitationClass) and 'citation' or 'cite ' .. (cfg.citation_class_map_t[config.CitationClass] or config.CitationClass);  
local template_link = * .. template_name .. *;  
local msg_prefix = '<code></code>: ';  

if 0 ~= #z.error_msgs_t then  
mw.addWarning (utilities.substitute (cfg.messages.warning_msg_e, template_link));  

table.insert (render_t, ' '); -- insert a space between citation and its error messages  
table.sort (z.error_msgs_t); -- sort the error messages list; sorting includes wrapping <span> and <code> tags; hidden-error sorts ahead of visible-error  

local hidden = true; -- presume that the only error messages emited by this template are hidden  
for _, v in ipairs (z.error_msgs_t) do -- spin through the list of error messages  
if v:find ('cs1-visible-error', 1, true) then -- look for the visible error class name  
hidden = false; -- found one; so don't hide the error message prefix  
break; -- and done because no need to look further  
end  
end  

z.error_msgs_t[1] = table.concat ({utilities.error_comment (msg_prefix, hidden), z.error_msgs_t[1]}); -- add error message prefix to first error message to prevent extraneous punctuation  
table.insert (render_t, table.concat (z.error_msgs_t, '; ')); -- make a big string of error messages and add it to the rendering  
end  

if 0 ~= #z.maint_cats_t then  
mw.addWarning (utilities.substitute (cfg.messages.warning_msg_m, template_link));  

table.sort (z.maint_cats_t); -- sort the maintenance messages list  

local maint_msgs_t = {}; -- here we collect all of the maint messages  

if 0 == #z.error_msgs_t then -- if no error messages  
table.insert (maint_msgs_t, msg_prefix); -- insert message prefix in maint message livery  
end  

for _, v in ipairs( z.maint_cats_t ) do -- append maintenance categories  
table.insert (maint_msgs_t, -- assemble new maint message and add it to the maint_msgs_t table  
table.concat ({v, ' (', utilities.substitute (cfg.messages[':cat wikilink'], v), ')'})  
);  
end  
table.insert (render_t, utilities.substitute (cfg.presentation['hidden-maint'], table.concat (maint_msgs_t, ' '))); -- wrap the group of maint messages with proper presentation and save  
end  

if not no_tracking_cats then  
local sort_key;  
local cat_wikilink = 'cat wikilink';  
if cfg.enable_sort_keys then -- when namespace sort keys enabled  
local namespace_number = mw.title.getCurrentTitle.namespace; -- get namespace number for this wikitext  
sort_key = (0 ~= namespace_number and (cfg.name_space_sort_keys[namespace_number] or cfg.name_space_sort_keys.other)) or nil; -- get sort key character; nil for mainspace  
cat_wikilink = (not sort_key and 'cat wikilink') or 'cat wikilink sk'; -- make <cfg.messages> key  
end  

for _, v in ipairs (z.error_cats_t) do -- append error categories  
table.insert (render_t, utilities.substitute (cfg.messages[cat_wikilink], {v, sort_key}));  
end  
if cfg.id_limits_data_load_fail then -- boolean true when load failed  
utilities.set_message ('maint_id_limit_load_fail'); -- done here because this maint cat emits no message  
end  
for _, v in ipairs (z.maint_cats_t) do -- append maintenance categories  
table.insert (render_t, utilities.substitute (cfg.messages[cat_wikilink], {v, sort_key}));  
end  
for _, v in ipairs (z.prop_cats_t) do -- append properties categories  
table.insert (render_t, utilities.substitute (cfg.messages['cat wikilink'], v)); -- no sort keys  
end  
end  

return table.concat (render_t); -- make a big string and done  
end  

----------------------------< V A L I D A T E >--------------------------------------------------------------  

Looks for a parameter's name in one of several whitelists.  

Parameters in the whitelist can have three values:  
true - active, supported parameters  
false - deprecated, supported parameters  
nil - unsupported parameters  

local function validate (name, cite_class, empty)  
local name = tostring (name);  
local enum_name; -- parameter name with enumerator (if any) replaced with '#'  
local state;  
local function state_test (state, name) -- local function to do testing of state values  
if true == state then return true; end -- valid actively supported parameter  
if false == state then  
if empty then return nil; end -- empty deprecated parameters are treated as unknowns  
deprecated_parameter (name); -- parameter is deprecated but still supported  
return true;  
end  
if 'tracked' == state then  
local base_name = name:gsub ('%d', ''); -- strip enumerators from parameter names that have them to get the base name  
utilities.add_prop_cat ('tracked-param', {base_name}, base_name); -- add a properties category; <base_name> modifies <key>  
return true;  
end  
return nil;  
end  

if name:find ('#') then -- # is a cs1|2 reserved character so parameters with # not permitted  
return nil;  
end  
-- replace enumerator digit(s) with # (|last25= becomes |last#=) (mw.ustring because non-Western 'local' digits)  
enum_name = mw.ustring.gsub (name, '%d+$', '#'); -- where enumerator is last charaters in parameter name (these to protect |s2cid=)  
enum_name = mw.ustring.gsub (enum_name, '%d+([%-l])', '#%1'); -- where enumerator is in the middle of the parameter name; |author#link= is the oddity  

if 'document' == cite_class then -- special case for  
state = whitelist.document_parameters_t[enum_name]; -- this list holds enumerated and nonenumerated parameters  
if true == state_test (state, name) then return true; end  

return false;  
end  

if utilities.in_array (cite_class, whitelist.preprint_template_list_t) then -- limited parameter sets allowed for these templates  
state = whitelist.limited_parameters_t[enum_name]; -- this list holds enumerated and nonenumerated parameters  
if true == state_test (state, name) then return true; end  

state = whitelist.preprint_arguments_t[cite_class][name]; -- look in the parameter-list for the template identified by cite_class  
if true == state_test (state, name) then return true; end  

return false; -- not supported because not found or name is set to nil  
end -- end limited parameter-set templates  

if utilities.in_array (cite_class, whitelist.unique_param_template_list_t) then -- template-specific parameters for templates that accept parameters from the basic argument list  
state = whitelist.unique_arguments_t[cite_class][name]; -- look in the template-specific parameter-lists for the template identified by cite_class  
if true == state_test (state, name) then return true; end  
end -- if here, fall into general validation  

state = whitelist.common_parameters_t[enum_name]; -- all other templates; all normal parameters allowed; this list holds enumerated and nonenumerated parameters  
if true == state_test (state, name) then return true; end  

return false; -- not supported because not found or name is set to nil  
end  

--[=[-------------------------< I N T E R _ W I K I _ C H E C K >----------------------------------------------  

check <value> for inter-language interwiki-link markup. <prefix> must be a MediaWiki-recognized language  
code. when these values have the form (without leading colon):  
label return label as plain-text  
<prefix>:link return <prefix>:link as plain-text  

return value as is else  

]=]  

local function inter_wiki_check (parameter, value)  
local prefix = value:match ('%[%[(%a+):'); -- get an interwiki prefix if one exists  
local _;  

if prefix and cfg.inter_wiki_map[prefix:lower] then -- if prefix is in the map, needs preceding colon so  
utilities.set_message ('err_bad_paramlink', parameter); -- emit an error message  
_, value, _ = utilities.is_wikilink (value); -- extract label portion from wikilink  
end  
return value;  
end  

--2 parameters. If found, then the string is possibly a  
parameter that is missing its pipe. There are two tests made:  
-- the first parameter has a value and whitespace separates that value from the missing pipe parameter name  
-- the first parameter has no value (whitespace after the first = is trimmed by MediaWiki)  
cs1|2 shares some parameter names with XML/HTML attributes: class=, title=, etc. To prevent false positives XML/HTML  
tags are removed before the search.  

If a missing pipe is detected, this function adds the missing pipe maintenance category.  

local function missing_pipe_check (parameter, value)  
local capture;  
value = value:gsub ('%b<>', ''); -- remove XML/HTML tags because attributes: class=, title=, etc.  

capture = value:match ('%s+(%a[%w%-]+)%s*=') or value:match ('^(%a[%w%-]+)%s*='); -- find and categorize parameters with possible missing pipes  
if capture and validate (capture) then -- if the capture is a valid parameter name  
utilities.set_message ('err_missing_pipe', parameter);  
end  
end  

----------------------------< H A S _ E X T R A N E O U S _ P U N C T >--------------------------------------  

look for extraneous terminal punctuation in most parameter values; parameters listed in skip table are not checked  

local function has_extraneous_punc (param, value)  
if 'number' == type (param) then  
return;  
end  

param = param:gsub ('%d+', '#'); -- enumerated name-list mask params allow terminal punct; normalize  
if cfg.punct_skip[param] then  
return; -- parameter name found in the skip table so done  
end  

if value:match ('[,;:]$') then  
utilities.set_message ('maint_extra_punct'); -- has extraneous punctuation; add maint cat  
end  
if value:match ('^=') then -- sometimes an extraneous '=' character appears ...  
utilities.set_message ('maint_extra_punct'); -- has extraneous punctuation; add maint cat  
end  
end  

----------------------------< H A S _ E X T R A N E O U S _ U R L >------------------------------------------  

look for extraneous url parameter values; parameters listed in skip table are not checked  

local function has_extraneous_url (url_param_t)  
local url_error_t = {};  

check_for_url (url_param_t, url_error_t); -- extraneous url check  
if 0 ~= #url_error_t then -- non-zero when there are errors  
table.sort (url_error_t);  
utilities.set_message ('err_param_has_ext_link', {utilities.make_sep_list (#url_error_t, url_error_t)}); -- add this error message  
end  
end  

----------------------------< C I T A T I O N >--------------------------------------------------------------  

This is used by templates such as to create the actual citation text.  

local function citation  
Frame = ; -- save a copy in case we need to display an error message in preview mode  

local config = {}; -- table to store parameters from the module  
for k, v in pairs( .args ) do -- get parameters from the  
config[k] = v;  
-- args[k] = v; -- crude debug support that allows us to render a citation from module ; skips parameter validation; TODO: keep?  
end  
-- i18n: set the name that your wiki uses to identify sandbox subpages from sandbox template invoke (or can be set here)  
local sandbox = ((config.SandboxPath and '' ~= config.SandboxPath) and config.SandboxPath) or '/sandbox'; -- sandbox path from  
is_sandbox = nil ~= string.find (:getTitle, sandbox, 1, true); -- is this invoke the sandbox module?  
sandbox = is_sandbox and sandbox or ''; -- use i18n sandbox to load sandbox modules when this module is the sandox; live modules else  

local pframe = :getParent  
local styles;  

cfg = mw.loadData ('Module:Citation/CS1/Configuration' .. sandbox); -- load sandbox versions of support modules when ; live modules else  
whitelist = mw.loadData ('Module:Citation/CS1/Whitelist' .. sandbox);  
utilities = require ('Module:Citation/CS1/Utilities' .. sandbox);  
validation = require ('Module:Citation/CS1/Date_validation' .. sandbox);  
identifiers = require ('Module:Citation/CS1/Identifiers' .. sandbox);  
metadata = require ('Module:Citation/CS1/COinS' .. sandbox);  
styles = 'Module:Citation/CS1' .. sandbox .. '/styles.css';  

utilities.set_selected_modules (cfg); -- so that functions in Utilities can see the selected cfg tables  
identifiers.set_selected_modules (cfg, utilities); -- so that functions in Identifiers can see the selected cfg tables and selected Utilities module  
validation.set_selected_modules (cfg, utilities); -- so that functions in Date validataion can see selected cfg tables and the selected Utilities module  
metadata.set_selected_modules (cfg, utilities); -- so that functions in COinS can see the selected cfg tables and selected Utilities module  

z = utilities.z; -- table of error and category tables in Module:Citation/CS1/Utilities  

is_preview_mode = not utilities.is_set (:preprocess (''));  

local args = {}; -- table where we store all of the template's arguments  
local suggestions = {}; -- table where we store suggestions if we need to loadData them  
local error_text; -- used as a flag  

local capture; -- the single supported capture when matching unknown parameters using patterns  
local empty_unknowns = {}; -- sequence table to hold empty unknown params for error message listing  
for k, v in pairs( pframe.args ) do -- get parameters from the parent (template)  
v = mw.ustring.gsub (v, '^%s*(.-)%s*$', '%1'); -- trim leading/trailing whitespace; when v is only whitespace, becomes empty string  
if v ~= '' then  
if ('string' == type (k)) then  
k = mw.ustring.gsub (k, '%d', cfg.date_names.local_digits); -- for enumerated parameters, translate 'local' digits to Western 0-9  
end  
if not validate( k, config.CitationClass ) then  
if type (k) ~= 'string' then -- exclude empty numbered parameters  
if v:match("%S+") ~= nil then  
error_text = utilities.set_message ('err_text_ignored', {v});  
end  
elseif validate (k:lower, config.CitationClass) then  
error_text = utilities.set_message ('err_parameter_ignored_suggest', {k, k:lower}); -- suggest the lowercase version of the parameter  
else  
if nil == suggestions.suggestions then -- if this table is nil then we need to load it  
suggestions = mw.loadData ('Module:Citation/CS1/Suggestions' .. sandbox); --load sandbox version of suggestion module when ; live module else  
end  
for pattern, param in pairs (suggestions.patterns) do -- loop through the patterns to see if we can suggest a proper parameter  
capture = k:match (pattern); -- the whole match if no capture in pattern else the capture if a match  
if capture then -- if the pattern matches  
param = utilities.substitute (param, capture); -- add the capture to the suggested parameter (typically the enumerator)  
if validate (param, config.CitationClass) then -- validate the suggestion to make sure that the suggestion is supported by this template (necessary for limited parameter lists)  
error_text = utilities.set_message ('err_parameter_ignored_suggest', {k, param}); -- set the suggestion error message  
else  
error_text = utilities.set_message ('err_parameter_ignored', {k}); -- suggested param not supported by this template  
v = ''; -- unset  
end  
end  
end  
if not utilities.is_set (error_text) then -- couldn't match with a pattern, is there an explicit suggestion?  
if (suggestions.suggestions[ k:lower ] ~= nil) and validate (suggestions.suggestions[ k:lower ], config.CitationClass) then  
utilities.set_message ('err_parameter_ignored_suggest', {k, suggestions.suggestions[ k:lower ]});  
else  
utilities.set_message ('err_parameter_ignored', {k});  
v = ''; -- unset value assigned to unrecognized parameters (this for the limited parameter lists)  
end  
end  
end  
end  

args[k] = v; -- save this parameter and its value  

elseif not utilities.is_set (v) then -- for empty parameters  
if not validate (k, config.CitationClass, true) then -- is this empty parameter a valid parameter  
k = ('' == k) and '(empty string)' or k; -- when k is empty string (or was space(s) trimmed to empty string), replace with descriptive text  
table.insert (empty_unknowns, utilities.wrap_style ('parameter', k)); -- format for error message and add to the list  
end  
-- crude debug support that allows us to render a citation from module TODO: keep?  
-- elseif args[k] ~= nil or (k == 'postscript') then -- when args[k] has a value from (we don't normally do that)  
-- args[k] = v; -- overwrite args[k] with empty string from pframe.args[k] (template ); v is empty string here  
end -- not sure about the postscript bit; that gets handled in parameter validation; historical artifact?  
end  

if 0 ~= #empty_unknowns then -- create empty unknown error message  
utilities.set_message ('err_param_unknown_empty', {  
1 == #empty_unknowns and '' or 's',  
utilities.make_sep_list (#empty_unknowns, empty_unknowns)  
});  
end  

local url_param_t = {};  

for k, v in pairs( args ) do  
if 'string' == type (k) then -- don't evaluate positional parameters  
has_invisible_chars (k, v); -- look for invisible characters  
end  
has_extraneous_punc (k, v); -- look for extraneous terminal punctuation in parameter values  
missing_pipe_check (k, v); -- do we think that there is a parameter that is missing a pipe?  
args[k] = inter_wiki_check (k, v); -- when language interwiki-linked parameter missing leading colon replace with wiki-link label  

if 'string' == type (k) and not cfg.url_skip[k] then -- when parameter k is not positional and not in url skip table  
url_param_t[k] = v; -- make a parameter/value list for extraneous url check  
end  
end  

has_extraneous_url (url_param_t); -- look for url in parameter values where a url does not belong  

return table.concat ({  
:extensionTag ('templatestyles', '', {src=styles}),  
citation0( config, args)  
});  
end  

----------------------------< E X P O R T E D F U N C T I O N S >------------------------------------------  

return {citation = citation};