# Module:Age

-- Implement various "age of" and other date-related templates.  

local mtext = {  
-- Message and other text that should be localized.  
-- Also need to localize text in table names in function dateDifference.  
['mt-bad-param1'] = 'Invalid parameter $1',  
['mt-bad-param2'] = 'Parameter $1=$2 is invalid',  
['mt-bad-show'] = 'Parameter show=$1 is not supported here',  
['mt-cannot-add'] = 'Cannot add "$1"',  
['mt-conflicting-show'] = 'Parameter show=$1 conflicts with round=$2',  
['mt-date-wrong-order'] = 'The second date must be later in time than the first date',  
['mt-dd-future'] = 'Death date (first date) must not be in the future',  
['mt-dd-wrong-order'] = 'Death date (first date) must be later in time than the birth date (second date)',  
['mt-invalid-bd-age'] = 'Invalid birth date for calculating age',  
['mt-invalid-dates-age'] = 'Invalid dates for calculating age',  
['mt-invalid-end'] = 'Invalid end date in second parameter',  
['mt-invalid-start'] = 'Invalid start date in first parameter',  
['mt-need-jdn'] = 'Need valid Julian date number',  
['mt-need-valid-bd'] = 'Need valid birth date: year, month, day',  
['mt-need-valid-bd2'] = 'Need valid birth date (second date): year, month, day',  
['mt-need-valid-date'] = 'Need valid date',  
['mt-need-valid-dd'] = 'Need valid death date (first date): year, month, day',  
['mt-need-valid-ymd'] = 'Need valid year, month, day',  
['mt-need-valid-ymd-current'] = 'Need valid year|month|day or "currentdate"',  
['mt-need-valid-ymd2'] = 'Second date should be year, month, day',  
['mt-template-bad-name'] = 'The specified template name is not valid',  
['mt-template-x'] = 'The template invoking this must have "|template=x" where x is the wanted operation',  
['txt-and'] = ' and ',  
['txt-or'] = '&nbsp;or ',  
['txt-category'] = 'Category:Age error',  
['txt-comma-and'] = ', and ',  
['txt-error'] = 'Error: ',  
['txt-format-default'] = 'mf', -- 'df' (day first = dmy) or 'mf' (month first = mdy)  
['txt-module-convertnumeric'] = 'Module:ConvertNumeric',  
['txt-module-date'] = 'Module:Date',  
['txt-sandbox'] = 'sandbox',  
['txt-bda'] = '<span> (<span>$1</span>) </span>$2<span> (age&nbsp;$3)</span>',  
['txt-dda'] = '$2<span>($1)</span> (aged&nbsp;$3)',  
['txt-bda-disp'] = 'disp_raw', -- disp_raw → age is a number only; disp_age → age is a number and unit (normally years but months or days if very young)  
['txt-dda-disp'] = 'disp_raw',  
['txt-dmy'] = '%-d %B %-Y',  
['txt-mdy'] = '%B %-d, %-Y',  
}  

local isWarning = {  
['mt-bad-param1'] = true,  
}  

local translate, from_en, to_en, isZero  
if translate then  
-- Functions to translate from en to local language and reverse go here.  
-- See example at :bn:Module:বয়স.  
else  
from_en = function (text)  
return text  
end  
isZero = function (text)  
return tonumber(text) == 0  
end  
end  

local _Date, _currentDate  
local function getExports  
-- Return objects exported from the date module or its sandbox.  
if not _Date then  
local sandbox = :getTitle:find(mtext['txt-sandbox'], 1, true) and ('/' .. mtext['txt-sandbox']) or ''  
local datemod = require(mtext['txt-module-date'] .. sandbox)  
local realDate = datemod._Date  
_currentDate = datemod._current  
if to_en then  
_Date = function (...)  
local args = {}  
for i, v in ipairs({...}) do  
args[i] = to_en(v)  
end  
return realDate(unpack(args))  
end  
else  
_Date = realDate  
end  
end  
return _Date, _currentDate  
end  

local Collection -- a table to hold items  
Collection = {  
add = function (self, item)  
if item ~= nil then  
self.n = self.n + 1  
self[self.n] = item  
end  
end,  
join = function (self, sep)  
return table.concat(self, sep)  
end,  
remove = function (self, pos)  
if self.n > 0 and (pos == nil or (0 < pos and pos <= self.n)) then  
self.n = self.n - 1  
return table.remove(self, pos)  
end  
end,  
sort = function (self, comp)  
table.sort(self, comp)  
end,  
new = function  
return setmetatable({n = 0}, Collection)  
end  
}  
Collection.__index = Collection  

local function stripToNil(text)  
-- If text is a string, return its trimmed content, or nil if empty.  
-- Otherwise return text (which may, for example, be nil).  
if type(text) == 'string' then  
text = text:match('(%S.-)%s*$')  
end  
return text  
end  

local function dateFormat(args)  
-- Return string for wanted date format.  
local default = mtext['txt-format-default']  
local other = default == 'df' and 'mf' or 'df'  
local wanted = stripToNil(args[other]) and other or default  
return wanted == 'df' and mtext['txt-dmy'] or mtext['txt-mdy']  
end  

local function substituteParameters(text, ...)  
-- Return text after substituting any given parameters for $1, $2, etc.  
return mw.message.newRawMessage(text, ...):plain  
end  

local function yes(parameter)  
-- Return true if parameter should be interpreted as "yes".  
-- Do not want to accept mixed upper/lowercase unless done by current templates.  
-- Need to accept "on" because "round=on" is wanted.  
return ({ y = true, yes = true, on = true })[parameter]  
end  

local function message(msg, ...)  
-- Return formatted message text for an error or warning.  
local function getText(msg)  
return mtext[msg] or error('Bug: message "' .. tostring(msg) .. '" not defined')  
end  
local categories = {  
error = mtext['txt-category'],  
warning = mtext['txt-category'],  
}  
local a, b, k, category  
local text = substituteParameters(getText(msg), ...)  
if isWarning[msg] then  
a = '<sup>[<i>'  
b = '</i>]</sup>'  
k = 'warning'  
else  
a = '<strong>' .. getText('txt-error')  
b = '</strong>'  
k = 'error'  
end  
if mw.title.getCurrentTitle:inNamespaces(0) then  
-- Category only in namespaces: 0=article.  
category = '[[' .. categories[k] .. ']]'  
end  
return  
a ..  
mw.text.nowiki(text) ..  
b ..  
(category or '')  
end  

local function formatNumber(number)  
-- Return the given number formatted with commas as group separators,  
-- given that the number is an integer.  
local numstr = tostring(number)  
local length = #numstr  
local places = Collection.new  
local pos = 0  
repeat  
places:add(pos)  
pos = pos + 3  
until pos >= length  
places:add(length)  
local groups = Collection.new  
for i = places.n, 2, -1 do  
local p1 = length - places[i] + 1  
local p2 = length - places[i - 1]  
groups:add(numstr:sub(p1, p2))  
end  
return groups:join(',')  
end  

local function spellNumber(number, options, i)  
-- Return result of spelling number, or  
-- return number (as a string) if cannot spell it.  
-- i == 1 for the first number which can optionally start with an uppercase letter.  
number = tostring(number)  
return require(mtext['txt-module-convertnumeric']).spell_number(  
number,  
nil, -- fraction numerator  
nil, -- fraction denominator  
i == 1 and options.upper, -- true: 'One' instead of 'one'  
not options.us, -- true: use 'and' between tens/ones etc  
options.adj, -- true: hyphenated  
options.ordinal -- true: 'first' instead of 'one'  
) or number  
end  

local function makeExtra(args, flagCurrent)  
-- Return extra text that will be inserted before the visible result  
-- but after any sort key.  
local extra = args.prefix or ''  
if mw.ustring.len(extra) > 1 then  
-- Parameter "~" gives "~3" whereas "over" gives "over 3".  
if extra:sub(-6, -1) ~= '&nbsp;' then  
extra = extra .. ' '  
end  
end  
if flagCurrent then  
extra = '<span></span>' .. extra  
end  
return extra  
end  

local function makeSort(value, sortable)  
-- Return a sort key if requested.  
-- Assume value is a valid number which has not overflowed.  
if sortable == 'sortable_table' or sortable == 'sortable_on' or sortable == 'sortable_debug' then  
local sortKey  
if value == 0 then  
sortKey = '5000000000000000000'  
else  
local mag = math.floor(math.log10(math.abs(value)) + 1e-14)  
if value > 0 then  
sortKey = 7000 + mag  
else  
sortKey = 2999 - mag  
value = value + 10^(mag+1)  
end  
sortKey = string.format('%d', sortKey) .. string.format('%015.0f', math.floor(value * 10^(14-mag)))  
end  
local result  
if sortable == 'sortable_table' then  
result = 'data-sort-value="_SORTKEY_"|'  
elseif sortable == 'sortable_debug' then  
result = '<span data-sort-value="_SORTKEY_♠"><span>_SORTKEY_♠</span></span>'  
else  
result = '<span data-sort-value="_SORTKEY_♠"></span>'  
end  
return (result:gsub('_SORTKEY_', sortKey))  
end  
end  

local translateParameters = {  
abbr = {  
off = 'abbr_off',  
on = 'abbr_on',  
},  
disp = {  
age = 'disp_age',  
raw = 'disp_raw',  
},  
format = {  
raw = 'format_raw',  
commas = 'format_commas',  
},  
round = {  
on = 'on',  
yes = 'on',  
months = 'ym',  
weeks = 'ymw',  
days = 'ymd',  
hours = 'ymdh',  
},  
sep = {  
comma = 'sep_comma',  
[','] = 'sep_comma',  
serialcomma = 'sep_serialcomma',  
space = 'sep_space',  
},  
show = {  
hide = { id = 'hide' },  
y = { 'y', id = 'y' },  
ym = { 'y', 'm', id = 'ym' },  
ymd = { 'y', 'm', 'd', id = 'ymd' },  
ymw = { 'y', 'm', 'w', id = 'ymw' },  
ymwd = { 'y', 'm', 'w', 'd', id = 'ymwd' },  
yd = { 'y', 'd', id = 'yd', keepZero = true },  
m = { 'm', id = 'm' },  
md = { 'm', 'd', id = 'md' },  
w = { 'w', id = 'w' },  
wd = { 'w', 'd', id = 'wd' },  
h = { 'H', id = 'h' },  
hm = { 'H', 'M', id = 'hm' },  
hms = { 'H', 'M', 'S', id = 'hms' },  
M = { 'M', id = 'M' },  
s = { 'S', id = 's' },  
d = { 'd', id = 'd' },  
dh = { 'd', 'H', id = 'dh' },  
dhm = { 'd', 'H', 'M', id = 'dhm' },  
dhms = { 'd', 'H', 'M', 'S', id = 'dhms' },  
ymdh = { 'y', 'm', 'd', 'H', id = 'ymdh' },  
ymdhm = { 'y', 'm', 'd', 'H', 'M', id = 'ymdhm' },  
ymwdh = { 'y', 'm', 'w', 'd', 'H', id = 'ymwdh' },  
ymwdhm = { 'y', 'm', 'w', 'd', 'H', 'M', id = 'ymwdhm' },  
},  
sortable = {  
off = false,  
on = 'sortable_on',  
table = 'sortable_table',  
debug = 'sortable_debug',  
},  
}  

local spellOptions = {  
cardinal = {},  
Cardinal = { upper = true },  
cardinal_us = { us = true },  
Cardinal_us = { us = true, upper = true },  
ordinal = { ordinal = true },  
Ordinal = { ordinal = true, upper = true },  
ordinal_us = { ordinal = true, us = true },  
Ordinal_us = { ordinal = true, us = true, upper = true },  
}  

local function dateExtract  
-- Return part of a date after performing an optional operation.  
local Date = getExports  
local args = :getParent.args  
local parms = {}  
for i, v in ipairs(args) do  
parms[i] = v  
end  
if yes(args.fix) then  
table.insert(parms, 'fix')  
end  
if yes(args.partial) then  
table.insert(parms, 'partial')  
end  
local show = stripToNil(args.show) or 'dmy'  
local date = Date(unpack(parms))  
if not date then  
if show == 'format' then  
return 'error'  
end  
return message('mt-need-valid-date')  
end  
local add = stripToNil(args.add)  
if add then  
for item in add:gmatch('%S+') do  
date = date + item  
if not date then  
return message('mt-cannot-add', item)  
end  
end  
end  
local sortKey, result  
local sortable = translateParameters.sortable[args.sortable]  
if sortable then  
local value = (date.partial and date.partial.first or date).jdz  
sortKey = makeSort(value, sortable)  
end  
if show ~= 'hide' then  
result = date[show]  
if result == nil then  
result = from_en(date:text(show))  
elseif type(result) == 'boolean' then  
result = result and '1' or '0'  
else  
result = from_en(tostring(result))  
end  
end  
return (sortKey or *) .. makeExtra(args) .. (result or *)  
end  

local function rangeJoin(range)  
-- Return text to be used between a range of ages.  
return range == 'dash' and '–' or mtext['txt-or']  
end  

local function makeText(values, components, names, options, noUpper)  
-- Return wikitext representing an age or duration.  
local text = Collection.new  
local count = #values  
local sep = names.sep or ''  
for i, v in ipairs(values) do  
-- v is a number (say 4 for 4 years), or a table ({4,5} for 4 or 5 years).  
local islist = type(v) == 'table'  
if (islist or v > 0) or (text.n == 0 and i == count) or (text.n > 0 and components.keepZero) then  
local fmt, vstr  
if options.spell then  
fmt = function(number)  
return spellNumber(number, options.spell, noUpper or i)  
end  
elseif i == 1 and options.format == 'format_commas' then  
-- Numbers after the first should be small and not need formatting.  
fmt = formatNumber  
else  
fmt = tostring  
end  
if islist then  
vstr = fmt(v[1]) .. rangeJoin(options.range)  
noUpper = true  
vstr = vstr .. fmt(v[2])  
else  
vstr = fmt(v)  
end  
local name = names[components[i]]  
if name then  
if type(name) == 'table' then  
name = mw.getContentLanguage:plural(islist and v[2] or v, name)  
end  
text:add(vstr .. sep .. name)  
else  
text:add(vstr)  
end  
end  
end  
local first, last  
if options.join == 'sep_space' then  
first = ' '  
last = ' '  
elseif options.join == 'sep_comma' then  
first = ', '  
last = ', '  
elseif options.join == 'sep_serialcomma' and text.n > 2 then  
first = ', '  
last = mtext['txt-comma-and']  
else  
first = ', '  
last = mtext['txt-and']  
end  
for i, v in ipairs(text) do  
if i < text.n then  
text[i] = v .. (i + 1 < text.n and first or last)  
end  
end  
local sign = ''  
if options.isnegative then  
-- Do not display negative zero.  
if text.n > 1 or (text.n == 1 and text[1]:sub(1, 1) ~= '0' ) then  
if options.format == 'format_raw' then  
sign = '-' -- plain hyphen so result can be used in a calculation  
else  
sign = '−' -- Unicode U+2212 MINUS SIGN  
end  
end  
end  
return  
(options.sortKey or '') ..  
(options.extra or '') ..  
sign ..  
text:join ..  
(options.suffix or '')  
end  

local function dateDifference(parms)  
-- Return a formatted date difference using the given parameters  
-- which have been validated.  
local names = {  
-- Each name is:  
-- * a string if no plural form of the name is used; or  
-- * a table of strings, one of which is selected using the rules at  
-- https://translatewiki.net/wiki/Plural/Mediawiki_plural_rules  
abbr_off = {  
plural = '-கள்',  
sep = '&nbsp;',  
y = {'ஆண்டு', 'ஆண்டுகள்'},  
m = {'மாதம்', 'மாதங்கள்'},  
w = {'கிழமை', 'கிழமைகள்'},  
d = {'நாள்', 'நாட்கள்'},  
H = {'மணி', 'மணித்தியாலங்கள்'},  
M = {'நிமிடம்', 'நிமிடங்கள்'},  
S = {'செக்கன்', 'செக்கன்கள்'},  
},  
abbr_on = {  
y = 'y',  
m = 'm',  
w = 'w',  
d = 'd',  
H = 'h',  
M = 'm',  
S = 's',  
},  
abbr_infant = { -- for  
sep = '&nbsp;',  
y = {'yr', 'yrs'},  
m = {'mo', 'mos'},  
w = {'wk', 'wks'},  
d = {'day', 'days'},  
H = {'hr', 'hrs'},  
M = {'min', 'mins'},  
S = {'sec', 'secs'},  
},  
abbr_raw = {},  
}  
local diff = parms.diff -- must be a valid date difference  
local show = parms.show -- may be nil; default is set below  
local abbr = parms.abbr or 'abbr_off'  
local defaultJoin  
if abbr ~= 'abbr_off' then  
defaultJoin = 'sep_space'  
end  
if not show then  
show = 'ymd'  
if parms.disp == 'disp_age' then  
if diff.years < 3 then  
defaultJoin = 'sep_space'  
if diff.years >= 1 then  
show = 'ym'  
else  
show = 'md'  
end  
else  
show = 'y'  
end  
end  
end  
if type(show) ~= 'table' then  
show = translateParameters.show[show]  
end  
if parms.disp == 'disp_raw' then  
defaultJoin = 'sep_space'  
abbr = 'abbr_raw'  
elseif parms.wantSc then  
defaultJoin = 'sep_serialcomma'  
end  
local diffOptions = {  
round = parms.round,  
duration = parms.wantDuration,  
range = parms.range and true or nil,  
}  
local sortKey  
if parms.sortable then  
local value = diff.age_days + (parms.wantDuration and 1 or 0) -- days and fraction of a day  
if diff.isnegative then  
value = -value  
end  
sortKey = makeSort(value, parms.sortable)  
end  
local textOptions = {  
extra = parms.extra,  
format = parms.format,  
join = parms.sep or defaultJoin,  
isnegative = diff.isnegative,  
range = parms.range,  
sortKey = sortKey,  
spell = parms.spell,  
suffix = parms.suffix, -- not currently used  
}  
if show.id == 'hide' then  
return sortKey or ''  
end  
local values = { diff:age(show.id, diffOptions) }  
if values[1] then  
return makeText(values, show, names[abbr], textOptions)  
end  
if diff.partial then  
-- Handle a more complex range such as  
-- → 1 year, 12 days or 2 years, 11 days  
local opt = {  
format = textOptions.format,  
join = textOptions.join,  
isnegative = textOptions.isnegative,  
spell = textOptions.spell,  
}  
return  
(textOptions.sortKey or '') ..  
makeText({ diff.partial.mindiff:age(show.id, diffOptions) }, show, names[abbr], opt) ..  
rangeJoin(textOptions.range) ..  
makeText({ diff.partial.maxdiff:age(show.id, diffOptions) }, show, names[abbr], opt, true) ..  
(textOptions.suffix or '')  
end  
return message('mt-bad-show', show.id)  
end  

local function getDates(, getopt)  
-- Parse template parameters and return one of:  
-- * date (a date table, if single)  
-- * date1, date2 (two date tables, if not single)  
-- * text (a string error message)  
-- A missing date is optionally replaced with the current date.  
-- If wantMixture is true, a missing date component is replaced  
-- from the current date, so can get a bizarre mixture of  
-- specified/current y/m/d as has been done by some "age" templates.  
-- Some results may be placed in table getopt.  
local Date, currentDate = getExports  
getopt = getopt or {}  
local function flagCurrent(text)  
-- This allows the calling template to detect if the current date has been used,  
-- that is, whether both dates have been entered in a template expecting two.  
-- For example, an infobox may want the age when an event occurred, not the current age.  
-- Don't bother detecting if wantMixture is used because not needed and it is a poor option.  
if not text then  
if getopt.noMissing then  
return nil -- this gives a nil date which gives an error  
end  
text = 'currentdate'  
if getopt.flag == 'usesCurrent' then  
getopt.usesCurrent = true  
end  
end  
return text  
end  
local args = :getParent.args  
local fields = {}  
local isNamed = args.year or args.year1 or args.year2 or  
args.month or args.month1 or args.month2 or  
args.day or args.day1 or args.day2  
if isNamed then  
fields[1] = args.year1 or args.year  
fields[2] = args.month1 or args.month  
fields[3] = args.day1 or args.day  
fields[4] = args.year2  
fields[5] = args.month2  
fields[6] = args.day2  
else  
for i = 1, 6 do  
fields[i] = args[i]  
end  
end  
local imax = 0  
for i = 1, 6 do  
fields[i] = stripToNil(fields[i])  
if fields[i] then  
imax = i  
end  
if getopt.omitZero and i % 3 ~= 1 then -- omit zero months and days as unknown values but keep year 0 which is 1 BCE  
if isZero(fields[i]) then  
fields[i] = nil  
getopt.partial = true  
end  
end  
end  
local fix = getopt.fix and 'fix' or ''  
local partialText = getopt.partial and 'partial' or ''  
local dates = {}  
if isNamed or imax >= 3 then  
local nrDates = getopt.single and 1 or 2  
if getopt.wantMixture then  
-- Cannot be partial since empty fields are set from current.  
local components = { 'year', 'month', 'day' }  
for i = 1, nrDates * 3 do  
fields[i] = fields[i] or currentDate[components[i > 3 and i - 3 or i]]  
end  
for i = 1, nrDates do  
local index = i == 1 and 1 or 4  
local y, m, d = fields[index], fields[index+1], fields[index+2]  
if (m == 2 or m == '2') and (d == 29 or d == '29') then  
-- Workaround error with following which attempt to use invalid date 2001-02-29.  
---
---
-- TODO Get rid of wantMixture because even this ugly code does not handle  
-- 'Feb' or 'February' or 'feb' or 'february'.  
if not ((y % 4 == 0 and y % 100 ~= 0) or y % 400 == 0) then  
d = 28  
end  
end  
dates[i] = Date(y, m, d)  
end  
else  
-- If partial dates are allowed, accept  
-- year only, or  
-- year and month only  
-- Do not accept year and day without a month because that makes no sense  
-- (and because, for example, Date('partial', 2001, nil, 12) sets day = nil, not 12).  
for i = 1, nrDates do  
local index = i == 1 and 1 or 4  
local y, m, d = fields[index], fields[index+1], fields[index+2]  
if (getopt.partial and y and (m or not d)) or (y and m and d) then  
dates[i] = Date(fix, partialText, y, m, d)  
elseif not y and not m and not d then  
dates[i] = Date(flagCurrent)  
end  
end  
end  
else  
getopt.textdates = true -- have parsed each date from a single text field  
dates[1] = Date(fix, partialText, flagCurrent(fields[1]))  
if not getopt.single then  
dates[2] = Date(fix, partialText, flagCurrent(fields[2]))  
end  
end  
if not dates[1] then  
return message(getopt.missing1 or 'mt-need-valid-ymd')  
end  
if getopt.single then  
return dates[1]  
end  
if not dates[2] then  
return message(getopt.missing2 or 'mt-need-valid-ymd2')  
end  
return dates[1], dates[2]  
end  

local function ageGeneric  
-- Return the result required by the specified template.  
-- Can use sortable=x where x = on/table/off/debug in any supported template.  
-- Some templates default to sortable=on but can be overridden.  
local name = .args.template  
if not name then  
return message('mt-template-x')  
end  
local args = :getParent.args  
local specs = {  
age_days = { --  
show = 'd',  
disp = 'disp_raw',  
},  
age_days_nts = { --  
show = 'd',  
disp = 'disp_raw',  
format = 'format_commas',  
sortable = 'on',  
},  
duration_days = { --  
show = 'd',  
disp = 'disp_raw',  
duration = true,  
},  
duration_days_nts = { --  
show = 'd',  
disp = 'disp_raw',  
format = 'format_commas',  
sortable = 'on',  
duration = true,  
},  
age_full_years = { --  
show = 'y',  
abbr = 'abbr_raw',  
flag = 'usesCurrent',  
omitZero = true,  
range = 'dash',  
},  
age_full_years_nts = { --  
show = 'y',  
abbr = 'abbr_raw',  
format = 'format_commas',  
sortable = 'on',  
},  
age_in_years = { --  
show = 'y',  
abbr = 'abbr_raw',  
negative = 'error',  
range = 'dash',  
},  
age_in_years_nts = { --  
show = 'y',  
abbr = 'abbr_raw',  
negative = 'error',  
range = 'dash',  
format = 'format_commas',  
sortable = 'on',  
},  
age_infant = { --  
-- Do not set show because special processing is done later.  
abbr = yes(args.abbr) and 'abbr_infant' or 'abbr_off',  
disp = 'disp_age',  
sep = 'sep_space',  
sortable = 'on',  
},  
age_m = { --  
show = 'm',  
disp = 'disp_raw',  
},  
age_w = { --  
show = 'w',  
disp = 'disp_raw',  
},  
age_wd = { --  
show = 'wd',  
},  
age_yd = { --  
show = 'yd',  
format = 'format_commas',  
sep = args.sep ~= 'and' and 'sep_comma' or nil,  
},  
age_yd_nts = { --  
show = 'yd',  
format = 'format_commas',  
sep = args.sep ~= 'and' and 'sep_comma' or nil,  
sortable = 'on',  
},  
age_ym = { --  
show = 'ym',  
sep = 'sep_comma',  
},  
age_ymd = { --  
show = 'ymd',  
range = true,  
},  
age_ymwd = { --  
show = 'ymwd',  
wantMixture = true,  
},  
}  
local spec = specs[name]  
if not spec then  
return message('mt-template-bad-name')  
end  
if name == 'age_days' then  
local su = stripToNil(args['show unit'])  
if su then  
if su == 'abbr' or su == 'full' then  
spec.disp = nil  
spec.abbr = su == 'abbr' and 'abbr_on' or nil  
end  
end  
end  
local partial, autofill  
local range = stripToNil(args.range) or spec.range  
if range then  
-- Suppose partial dates are used and age could be 11 or 12 years.  
-- "|range=" (empty value) has no effect (spec is used).  
-- "|range=yes" or spec.range == true sets range = true (gives "11 or 12")  
-- "|range=dash" or spec.range == 'dash' sets range = 'dash' (gives "11–12").  
-- "|range=no" or spec.range == 'no' sets range = nil and fills each date in the diff (gives "12").  
-- ("on" is equivalent to "yes", and "off" is equivalent to "no").  
-- "|range=OTHER" sets range = nil and rejects partial dates.  
range = ({ dash = 'dash', off = 'no', no = 'no', [true] = true })[range] or yes(range)  
if range then  
partial = true -- accept partial dates with a possible age range for the result  
if range == 'no' then  
autofill = true -- missing month/day in first or second date are filled from other date or 1  
range = nil  
end  
end  
end  
local getopt = {  
fix = yes(args.fix),  
flag = stripToNil(args.flag) or spec.flag,  
omitZero = spec.omitZero,  
partial = partial,  
wantMixture = spec.wantMixture,  
}  
local date1, date2 = getDates(, getopt)  
if type(date1) == 'string' then  
return date1  
end  
local format = stripToNil(args.format)  
local spell = spellOptions[format]  
if format then  
format = 'format_' .. format  
elseif name == 'age_days' and getopt.textdates then  
format = 'format_commas'  
end  
local parms = {  
diff = date2:subtract(date1, { fill = autofill }),  
wantDuration = spec.duration or yes(args.duration),  
range = range,  
wantSc = yes(args.sc),  
show = args.show == 'hide' and 'hide' or spec.show,  
abbr = spec.abbr,  
disp = spec.disp,  
extra = makeExtra(args, getopt.usesCurrent and format ~= 'format_raw'),  
format = format or spec.format,  
round = yes(args.round),  
sep = spec.sep,  
sortable = translateParameters.sortable[args.sortable or spec.sortable],  
spell = spell,  
}  
if (spec.negative or .args.negative) == 'error' and parms.diff.isnegative then  
return message('mt-date-wrong-order')  
end  
return from_en(dateDifference(parms))  
end  

local function isFake(args)  
-- Some templates have TemplateData with an auto value like "".  
-- Return true if that appears to be the case so the caller can output nothing rather than an error.  
return args[1] == 'YYYY'  
end  

local function bda  
-- Implement Template:Birth date and age.  
local args = :getParent.args  
if isFake(args) then  
return ''  
end  
local options = {  
missing1 = 'mt-need-valid-bd',  
noMissing = true,  
single = true,  
}  
local date = getDates(, options)  
if type(date) == 'string' then  
return date -- error text  
end  
local Date = getExports  
local diff = Date('currentdate') - date  
if diff.isnegative or diff.years > 150 then  
return message('mt-invalid-bd-age')  
end  
local disp = mtext['txt-bda-disp']  
local show = 'y'  
if diff.years < 2 then  
disp = 'disp_age'  
if diff.years == 0 and diff.months == 0 then  
show = 'd'  
else  
show = 'm'  
end  
end  
local result = substituteParameters(  
mtext['txt-bda'],  
date:text('%-Y-%m-%d'),  
from_en(date:text(dateFormat(args))),  
from_en(dateDifference({  
diff = diff,  
show = show,  
abbr = 'abbr_off',  
disp = disp,  
sep = 'sep_space',  
}))  
local warnings = tonumber(.args.warnings)  
if warnings and warnings > 0 then  
local good = {  
df = true,  
mf = true,  
day = true,  
day1 = true,  
month = true,  
month1 = true,  
year = true,  
year1 = true,  
}  
local invalid  
local imax = options.textdates and 1 or 3  
for k, _ in pairs(args) do  
if type(k) == 'number' then  
if k > imax then  
invalid = tostring(k)  
break  
end  
else  
if not good[k] then  
invalid = k  
break  
end  
end  
end  
if invalid then  
result = result .. message('mt-bad-param1', invalid)  
end  
end  
return result  
end  

local function dda  
-- Implement Template:Death date and age.  
local args = :getParent.args  
if isFake(args) then  
return ''  
end  
local options = {  
missing1 = 'mt-need-valid-dd',  
missing2 = 'mt-need-valid-bd2',  
noMissing = true,  
partial = true,  
}  
local date1, date2 = getDates(, options)  
if type(date1) == 'string' then  
return date1  
end  
local diff = date1 - date2  
if diff.isnegative then  
return message('mt-dd-wrong-order')  
end  
local Date = getExports  
local today = Date('currentdate') + 1 -- one day in future allows for timezones  
if date1 > today then  
return message('mt-dd-future')  
end  
local years  
if diff.partial then  
years = diff.partial.years  
years = type(years) == 'table' and years[2] or years  
else  
years = diff.years  
end  
if years > 150 then  
return message('mt-invalid-dates-age')  
end  
local fmt_date, fmt_ymd  
if date1.day then -- y, m, d known  
fmt_date = dateFormat(args)  
fmt_ymd = '%-Y-%m-%d'  
elseif date1.month then -- y, m known; d unknown  
fmt_date = '%B %-Y'  
fmt_ymd = '%-Y-%m-00'  
else -- y known; m, d unknown  
fmt_date = '%-Y'  
fmt_ymd = '%-Y-00-00'  
end  
local sortKey  
local sortable = translateParameters.sortable[args.sortable]  
if sortable then  
local value = (date1.partial and date1.partial.first or date1).jdz  
sortKey = makeSort(value, sortable)  
end  
local result = (sortKey or '') .. substituteParameters(  
mtext['txt-dda'],  
date1:text(fmt_ymd),  
from_en(date1:text(fmt_date)),  
from_en(dateDifference({  
diff = diff,  
show = 'y',  
abbr = 'abbr_off',  
disp = mtext['txt-dda-disp'],  
range = 'dash',  
sep = 'sep_space',  
}))  
local warnings = tonumber(.args.warnings)  
if warnings and warnings > 0 then  
local good = {  
df = true,  
mf = true,  
}  
local invalid  
local imax = options.textdates and 2 or 6  
for k, _ in pairs(args) do  
if type(k) == 'number' then  
if k > imax then  
invalid = tostring(k)  
break  
end  
else  
if not good[k] then  
invalid = k  
break  
end  
end  
end  
if invalid then  
result = result .. message('mt-bad-param1', invalid)  
end  
end  
return result  
end  

local function dateToGsd  
-- Implement Template:Gregorian serial date.  
-- Return Gregorian serial date of the given date, or the current date.  
-- The returned value is negative for dates before 1 January 1 AD  
-- despite the fact that GSD is not defined for such dates.  
local date = getDates(, { wantMixture=true, single=true })  
if type(date) == 'string' then  
return date  
end  
return tostring(date.gsd)  
end  

local function jdToDate  
-- Return formatted date from a Julian date.  
-- The result includes a time if the input includes a fraction.  
-- The word 'Julian' is accepted for the Julian calendar.  
local Date = getExports  
local args = :getParent.args  
local date = Date('juliandate', args[1], args[2])  
if date then  
return from_en(date:text)  
end  
return message('mt-need-jdn')  
end  

local function dateToJd  
-- Return Julian date (a number) from a date which may include a time,  
-- or the current date ('currentdate') or current date and time ('currentdatetime').  
-- The word 'Julian' is accepted for the Julian calendar.  
local Date = getExports  
local args = :getParent.args  
local date = Date(args[1], args[2], args[3], args[4], args[5], args[6], args[7])  
if date then  
return tostring(date.jd)  
end  
return message('mt-need-valid-ymd-current')  
end  

local function timeInterval  
-- Implement Template:Time interval.  
-- There are two positional arguments: date1, date2.  
-- The default for each is the current date and time.  
-- Result is date2 - date1 formatted.  
local Date = getExports  
local args = :getParent.args  
local parms = {  
extra = makeExtra(args),  
wantDuration = yes(args.duration),  
range = yes(args.range) or (args.range == 'dash' and 'dash' or nil),  
wantSc = yes(args.sc),  
}  
local fix = yes(args.fix) and 'fix' or ''  
local date1 = Date(fix, 'partial', stripToNil(args[1]) or 'currentdatetime')  
if not date1 then  
return message('mt-invalid-start')  
end  
local date2 = Date(fix, 'partial', stripToNil(args[2]) or 'currentdatetime')  
if not date2 then  
return message('mt-invalid-end')  
end  
parms.diff = date2 - date1  
for argname, translate in pairs(translateParameters) do  
local parm = stripToNil(args[argname])  
if parm then  
parm = translate[parm]  
if parm == nil then -- test for nil because false is a valid setting  
return message('mt-bad-param2', argname, args[argname])  
end  
parms[argname] = parm  
end  
end  
if parms.round then  
local round = parms.round  
local show = parms.show  
if round ~= 'on' then  
if show then  
if show.id ~= round then  
return message('mt-conflicting-show', args.show, args.round)  
end  
else  
parms.show = translateParameters.show[round]  
end  
end  
parms.round = true  
end  
return from_en(dateDifference(parms))  
end  

local function templateGeneric  
local name = .args.template  
if not name then  
return message('mt-template-x')  
end  
return ageGeneric(:newChild{title = mw.title.new(name, 10), args = .args})  
end  

return {  
age_generic = ageGeneric, -- can emulate several age templates  
birth_date_and_age = bda, -- Template:Birth_date_and_age  
death_date_and_age = dda, -- Template:Death_date_and_age  
gsd = dateToGsd, -- Template:Gregorian_serial_date  
extract = dateExtract, -- Template:Extract  
jd_to_date = jdToDate, -- Template:?  
JULIANDAY = dateToJd, -- Template:JULIANDAY  
time_interval = timeInterval, -- Template:Time_interval  
[''] = templateGeneric -- same as age_generic, but can be invoked directly  
}