Mô đun:GetShortDescription

local function isEmpty(value) return value nil or value end

local function notEmpty(value) return not isEmpty(value) end

local function isNone(value) return value:lower() == 'none' end

local function alarmingMessage(message, preview)
message = 'Module:GetShortDescription '..message..'.'
if not preview then
message = message..
end
return message
end

-- Grammatically reasonable concatenation of possible issues into one message per problematic link target.
local function previewWarning(args_name, quantity_of_things)
local message =
if quantity_of_things.params > 3 then
message = message..' with extraneous parameters'
end
if quantity_of_things.descriptions > 1 then
message = message..', declaring '..quantity_of_things.descriptions..' short descriptions'
end
if quantity_of_things.templates > 1 or notEmpty(message) then
message = 'has detected that '..args_name..' has '..
quantity_of_things.templates..' '..message
mw.addWarning(alarmingMessage(message, true))
end
end

local function getWikidataDescription(title, args, fallback)
local wikidata_id = mw.wikibase.getEntityIdForTitle(title)
if isEmpty(wikidata_id) then
return nil
end
local wikidata_description, wikidata_description_lang = mw.wikibase.getDescriptionWithLang(wikidata_id)
if isEmpty(wikidata_description) then
return nil
end
local result = {wikidata = wikidata_description}
if isEmpty(args.lang_no) and notEmpty(wikidata_description_lang) and wikidata_description_lang ~= 'en' then
-- According to the docs this is a possibility...
result.wikidata = require('Module:Lang')._lang{
wikidata_description_lang,
wikidata_description,
italic = args.lang_italic,
nocat = args.lang_nocat,
size = args.lang_size,
cat = args.lang_cat,
rtl = args.lang_rtl
}
end
result.fellback = fallback
return result
end

local function getShortDescriptionTemplates(title_table)
local page_content = title_table:getContent()

-- Assume no content means a nonexistent title because it's cheaper than testing if it exists.
if isEmpty(page_content) then
return {redlink = true}
end

local contents_of_all_short_description_templates = {}

-- Because there could be any number of short description templates, and not all where there should be; get all the templates.
for template in page_content:gmatch('{%b{}}') do
local short_description_content = mw.ustring.match(template, '^')
if notEmpty(short_description_content) then
-- Collect the contents of short description templates.
contents_of_all_short_description_templates[contents_of_all_short_description_templates+1] = short_description_content
end
-- An opportunity for efficiency gain exists - to break if another type of template is found e.g. citation templates,
-- but on an appallingly formatted page, a short description template down by the categories would likely be missed.
end
return contents_of_all_short_description_templates
end

local function getShortDescription(args_name, args_name_title_table, title, title_table, fallback)
local contents_of_all_short_description_templates = {}
local redirected

-- Check for short description templates on redirect pages.
if title ~= args_name then
contents_of_all_short_description_templates = getShortDescriptionTemplates(args_name_title_table)
if contents_of_all_short_description_templates.redlink then
return contents_of_all_short_description_templates
end
redirected = false
end

if contents_of_all_short_description_templates quantity_of_things.params then
quantity_of_things.params = short_description_template_params
end
possible_short_descriptions[template_content_index] = {}
-- Look through the params:
for i, param in ipairs(short_description_template_params) do
if param == 'noreplace' or mw.ustring.match(param, '^2%s=%snoreplace$') then
-- Take note of 'noreplace'-ing for establishment of hierarchy later.
possible_short_descriptions[template_content_index].noreplace = true
else
local has_equals = param:match('=')
if not has_equals or param:match('^1') then
-- Grab the short description.
if has_equals then
param = mw.ustring.gsub(param, '^1%s=%s', )
end
-- If the template has both a numbered and an unnumbered short description;
-- whichever comes last (ltr) will be used by that template, so overwriting works out great.
possible_short_descriptions[template_content_index].description = param
-- And we want to know the total quantity of descriptions being declared.
quantity_of_things.descriptions = quantity_of_things.descriptions + 1
end
end
end
end

local short_descriptions = {}

-- Look through the possible short descriptions for definite short descriptions,
-- and prepare for working out which of possibly multiple short descriptions is actually being applied for the page:
for i, possible_short_description in ipairs(possible_short_descriptions) do
if possible_short_description.description then
-- If a description is 'noreplace'-ing or 'none'; demote it.
if (possible_short_description.noreplace or isNone(possible_short_description.description)) and
possible_short_descriptions > 1 then
-- But don't demote it if it's already at the bottom.
if i > 1 then
table.insert(short_descriptions, short_descriptions, possible_short_description)
else
short_descriptions[short_descriptions+1] = possible_short_description
end
else
short_descriptions[short_descriptions+1] = possible_short_description
end
end
end

-- Let previewWarning() work out if these numbers are bad.
previewWarning(args_name, quantity_of_things)

if short_descriptions >= 1 then
-- Pop!
local short_description = short_descriptions[short_descriptions].description
if notEmpty(short_description) then
return {explicit = short_description, fellback = fallback, redirected = redirected}
end
end
return nil
end

local function isSisterProjectLink(title)
local sister_project_prefixes = {
'wiktionary', 'wikt',
'wikinews', 'n',
'wikibooks', 'b',
'wikiquote', 'q',
'wikisource', 's',
'wikispecies', 'species',
'wikiversity', 'v',
'wikivoyage', 'voy',
'commons', 'c',
'wikidata', 'd',
'mediawikiwiki', 'mw',
'wikimedia', 'foundation', 'wmf',
'meta', 'm',
'incubator',
'phabricator', 'phab'
}
local pre_colon = title:match('^(%a+):')
if pre_colon then
for i, sister in ipairs(sister_project_prefixes) do
if pre_colon == sister then
return true
end
end
end
return false
end

-- Literally testing if title_table.isRedirect can be expensive;
-- processing this way resolves (multiple) redirects without the possibly expensive check.
local function getTitleAndTable(orig_name)
local title_table = mw.title.new(orig_name)
title_table = title_table.redirectTarget or title_table
local title = title_table.prefixedText
if title == orig_name then
return title, title_table
end
return getTitleAndTable(title)
end

local function getDescription(args)
local args_name = args.name
if isEmpty(args_name) then
return {alarm = 'requires a page name (including namespace)'}
end

-- Keep the orginal name, cleaned up, and its title_table for later.
local args_name_title_table = mw.title.new(args_name)
args_name = args_name_title_table.prefixedText

if isSisterProjectLink(args_name) then
return nil
end

local title, title_table = getTitleAndTable(args_name)

if title ~= args_name then
if isSisterProjectLink(title) then
return nil
end
end

local only = args.only
local prefer = args.prefer or 'explicit'

-- Pass args_name to getShortDescription() so previewWarning()s won't be confusing for redirects.

if notEmpty(only) then
if only 'explicit' then
return getShortDescription(args_name, args_name_title_table, title, title_table)
end
if only 'wikidata' then
return getWikidataDescription(title, args)
end
return {alarm = 'accepts either "explicit" or "wikidata" as the value of |only='}
end

if notEmpty(prefer) then
if prefer == 'explicit' then
local short_description = getShortDescription(args_name, args_name_title_table, title, title_table)
if notEmpty(short_description) then
-- Assume a Wikidata search would be a bad idea for an assumed nonexistent title.
if short_description.redlink or (not isNone(short_description.explicit) or args.none_is_valid) then
return short_description
end
end
return getWikidataDescription(title, args, true)
end
if prefer == 'wikidata' then
return getWikidataDescription(title, args) or getShortDescription(args_name, args_name_title_table, title, title_table, true)
end
return {alarm = 'accepts either "explicit" or "wikidata" as the value of |prefer='}
end
end

local function main(args)
local result = getDescription(args)
if notEmpty(result) then
if result.alarm then
result.alarm = alarmingMessage(result.alarm)
end
if args.stringify then
if result.alarm then
result = result.alarm
else
result = result.explicit or result.wikidata
if args.none_is_nil and isNone(result) then
result = nil
end
end
elseif not result.alarm and args.none_is_nil then
local description = result.explicit or result.wikidata
if description and args.none_is_nil and isNone(description) then
result = nil
end
end
end
return result
end

local p = {}

function p.main(frame)
local args = require('Module:Arguments').getArgs(frame)
if isEmpty(args) then
return alarmingMessage('could not getArgs') -- This really would be alarming.
end
return main(args)
end

return p