Module:Age

Documentation for this module may be created at Module:Age/doc

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

local _Date, _current_date
local function get_exports(frame)
	-- Return objects exported from the date module or its sandbox.
	if not _Date then
		local sandbox = frame:getTitle():find('sandbox', 1, true) and '/sandbox' or ''
		local datemod = require('Module:Date' .. sandbox)
		_Date = datemod._Date
		_current_date = datemod._current
	end
	return _Date, _current_date
end

local function collection()
	-- Return a table to hold items.
	return {
		n = 0,
		add = function (self, item)
			self.n = self.n + 1
			self[self.n] = item
		end,
		join = function (self, sep)
			return table.concat(self, sep)
		end,
	}
end

local function strip_to_nil(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 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, nocat)
	-- Return formatted message text for an error.
	-- Can append "#FormattingError" to URL of a page with a problem to find it.
	local anchor = '<span id="FormattingError" />'
	local category
	if not nocat and mw.title.getCurrentTitle():inNamespaces(0, 10) then
		-- Category only in namespaces: 0=article, 10=template.
		category = '[[Category:Age error]]'
	else
		category = ''
	end
	return anchor ..
		'<strong class="error">Error: ' ..
		mw.text.nowiki(msg) ..
		'</strong>' ..
		category
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()
	local pos = 0
	repeat
		places:add(pos)
		pos = pos + 3
	until pos >= length
	places:add(length)
	local groups = collection()
	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 make_sort(value, sortable)
	-- Return a sort key in a span if specified.
	-- Assume value is a valid number which has not overflowed.
	if 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)
			local prefix
			if value > 0 then
				prefix = 7000 + mag
			else
				prefix = 2999 - mag
				value = value + 10^(mag+1)
			end
			sortkey = string.format('%d', prefix) .. string.format('%015.0f', math.floor(value * 10^(14-mag)))
		end
		local lhs = sortable == 'sortable_debug' and
			'<span style="border:1px solid;display:inline;" class="sortkey">' or
			'<span style="display:none" class="sortkey">'
		return lhs .. sortkey .. '♠</span>'
	end
end

local translate_parameters = {
	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' },
		d = { 'd', id = 'd' },
		dh = { 'd', 'H', id = 'dh' },
		dhm = { 'd', 'H', 'M', id = 'dhm' },
		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',
		debug = 'sortable_debug',
	},
}

local function date_extract(frame)
	-- Return part of a date after performing an optional operation.
	local Date = get_exports(frame)
	local args = frame: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 date = Date(unpack(parms))
	if not date then
		return message('Need valid date')
	end
	local add = strip_to_nil(args.add)
	if add then
		for item in add:gmatch('%S+') do
			date = date + item
			if not date then
				return message('Cannot add "' .. item .. '"')
			end
		end
	end
	local prefix, result
	local sortable = translate_parameters.sortable[args.sortable]
	if sortable then
		local value = (date.partial and date.partial.first or date).jdz
		prefix = make_sort(value, sortable)
	end
	local show = strip_to_nil(args.show) or 'dmy'
	if show ~= 'hide' then
		result = date[show]
		if result == nil then
			result = date:text(show)
		elseif type(result) == 'boolean' then
			result = result and '1' or '0'
		else
			result = tostring(result)
		end
	end
	return (prefix or '') .. (result or '')
end

local function make_text(values, components, names, options)
	-- Return wikitext representing an age or duration.
	local text = collection()
	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 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
				local join = options.range == 'dash' and '–' or '&nbsp;or '
				vstr = fmt(v[1]) .. join .. fmt(v[2])
			else
				vstr = fmt(v)
			end
			local name = names[components[i]]
			if name then
				local plural = names.plural
				if not plural or (islist and v[2] or v) == 1 then
					plural = ''
				end
				text:add(vstr .. sep .. name .. plural)
			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 = ', and '
	else
		first = ', '
		last = ' 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.prefix or '') ..
		sign ..
		text:join() ..
		(options.suffix or '')
end

local function date_difference(parms)
	-- Return a formatted date difference using the given parameters
	-- which have been validated.
	local names = {
		abbr_off = {
			plural = 's',
			sep = '&nbsp;',
			y = 'year',
			m = 'month',
			w = 'week',
			d = 'day',
			H = 'hour',
			M = 'minute',
		},
		abbr_on = {
			y = 'y',
			m = 'm',
			w = 'w',
			d = 'd',
			H = 'h',
			M = 'm',
		},
		abbr_infant = {      -- for {{age for infant}}
			plural = 's',
			sep = '&nbsp;',
			y = 'yr',
			m = 'mo',
			w = 'wk',
			d = 'day',
			H = 'hr',
			M = 'min',
		},
		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 default_join
	if abbr ~= 'abbr_off' then
		default_join = 'sep_space'
	end
	if not show then
		show = 'ymd'
		if parms.disp == 'disp_age' then
			if diff.years < 3 then
				default_join = '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 = translate_parameters.show[show]
	end
	if parms.disp == 'disp_raw' then
		default_join = 'sep_space'
		abbr = 'abbr_raw'
	elseif parms.want_sc then
		default_join = 'sep_serialcomma'
	end
	local diff_options = {
		round = parms.round,
		duration = parms.want_duration,
		range = parms.range and true or nil,
	}
	local prefix
	if parms.sortable then
		local value = diff.age_days + (parms.want_duration and 1 or 0)  -- days and fraction of a day
		if diff.isnegative then
			value = -value
		end
		prefix = make_sort(value, parms.sortable)
	end
	local text_options = {
		prefix = prefix,
		suffix = parms.suffix,  -- not currently used
		format = parms.format,
		join = parms.sep or default_join,
		isnegative = diff.isnegative,
		range = parms.range,
	}
	if show.id == 'hide' then
		return prefix or ''
	end
	local values = { diff:age(show.id, diff_options) }
	return make_text(values, show, names[abbr], text_options)
end

local function get_dates(frame, 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 replaced with the current date.
	-- If want_mixture 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, current_date = get_exports(frame)
	getopt = getopt or {}
	local fix = getopt.fix and 'fix' or ''
	local partial = getopt.range and 'partial' or ''
	local args = frame:getParent().args
	local fields = {}
	local is_named = 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 is_named 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] = strip_to_nil(fields[i])
		if fields[i] then
			imax = i
		end
	end
	local single = getopt.single
	local dates = {}
	if is_named or imax > 2 then
		local nr_dates = single and 1 or 2
		if getopt.want_mixture then
			-- Cannot be partial since empty fields are set from current.
			local components = { 'year', 'month', 'day' }
			for i = 1, nr_dates * 3 do
				fields[i] = fields[i] or current_date[components[i > 3 and i - 3 or i]]
			end
			for i = 1, nr_dates do
				local index = i == 1 and 1 or 4
				dates[i] = Date(fields[index], fields[index+1], fields[index+2])
			end
		else
			for i = 1, nr_dates do
				local index = i == 1 and 1 or 4
				local y, m, d = fields[index], fields[index+1], fields[index+2]
				if (partial and y) or (y and m and d) then
					dates[i] = Date(fix, partial, y, m, d)
				elseif not (y or m or d) then
					dates[i] = Date('currentdate')
				end
			end
		end
	else
		getopt.textdates = true
		dates[1] = Date(fix, partial, fields[1] or 'currentdate')
		if not single then
			dates[2] = Date(fix, partial, fields[2] or 'currentdate')
		end
	end
	if not dates[1] then
		return message('Need valid year, month, day')
	end
	if single then
		return dates[1]
	end
	if not dates[2] then
		return message('Second date should be year, month, day')
	end
	return dates[1], dates[2]
end

local function age_generic(frame)
	-- Return the result required by the specified template.
	-- Can use sortable=x where x = on/off/debug in any supported template.
	-- Some templates default to sortable=on but can be overridden with sortable=off.
	local name = frame.args.template
	if not name then
		return message('The template invoking this must have "|template=x" where x is the wanted operation')
	end
	local args = frame:getParent().args
	local specs = {
		age_days = {                -- {{age in days}}
			show = 'd',
			disp = 'disp_raw',
		},
		age_days_nts = {            -- {{age in days nts}}
			show = 'd',
			disp = 'disp_raw',
			format = 'format_commas',
			sortable = 'on',
		},
		duration_days = {           -- {{duration in days}}
			show = 'd',
			disp = 'disp_raw',
			duration = true,
		},
		duration_days_nts = {       -- {{duration in days nts}}
			show = 'd',
			disp = 'disp_raw',
			format = 'format_commas',
			sortable = 'on',
			duration = true,
		},
		age_full_years = {          -- {{age}}
			show = 'y',
			abbr = 'abbr_raw',
		},
		age_full_years_nts = {      -- {{age nts}}
			show = 'y',
			abbr = 'abbr_raw',
			format = 'format_commas',
			sortable = 'on',
		},
		age_in_years = {            -- {{age in years}}
			show = 'y',
			abbr = 'abbr_raw',
			negative = 'error',
			range = 'dash',
		},
		age_in_years_nts = {        -- {{age in years nts}}
			show = 'y',
			abbr = 'abbr_raw',
			negative = 'error',
			range = 'dash',
			format = 'format_commas',
			sortable = 'on',
		},
		age_infant = {              -- {{age for 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 = {                   -- {{age in months}}
			show = 'm',
			disp = 'disp_raw',
		},
		age_w = {                   -- {{age in weeks}}
			show = 'w',
			disp = 'disp_raw',
		},
		age_wd = {                  -- {{age in weeks and days}}
			show = 'wd',
		},
		age_yd = {                  -- {{age in years and days}}
			show = 'yd',
			sep = args.sep ~= 'and' and 'sep_comma' or nil,
			sortable = 'on',
		},
		age_ym = {                  -- {{age in years and months}}
			show = 'ym',
			sep = 'sep_comma',
		},
		age_ymd = {                 -- {{age in years, months and days}}
			show = 'ymd',
			range = true,
		},
		age_ymwd = {                -- {{age in years, months, weeks and days}}
			show = 'ymwd',
			want_mixture = true,
		},
	}
	local spec = specs[name]
	if not spec then
		return message('The specified template name is not valid')
	end
	if name == 'age_days' then
		local su = strip_to_nil(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 range = spec.range or yes(args.range) or (args.range == 'dash' and 'dash' or nil)
	local getopt = {
		fix = yes(args.fix),
		range = range,
		want_mixture = spec.want_mixture,
	}
	local date1, date2 = get_dates(frame, getopt)
	if type(date1) == 'string' then
		return date1
	end
	local format = strip_to_nil(args.format)
	if format then
		format = 'format_' .. format
	elseif name == 'age_days' and getopt.textdates then
		format = 'format_commas'
	end
	local parms = {
		diff = date2 - date1,
		want_duration = spec.duration or yes(args.duration),
		range = range,
		want_sc = yes(args.sc),
		show = args.show == 'hide' and 'hide' or spec.show,
		abbr = spec.abbr,
		disp = spec.disp,
		format = format or spec.format,
		round = yes(args.round),
		sep = spec.sep,
		sortable = translate_parameters.sortable[args.sortable or spec.sortable],
	}
	if (spec.negative or frame.args.negative) == 'error' and parms.diff.isnegative then
		return message('The second date should not be before the first date')
	end
	return date_difference(parms)
end

local function date_to_gsd(frame)
	-- This implements {{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 = get_dates(frame, { want_mixture=true, single=true })
	if type(date) == 'string' then
		return date
	end
	return tostring(date.gsd)
end

local function jd_to_date(frame)
	-- 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 = get_exports(frame)
	local args = frame:getParent().args
	local date = Date('juliandate', args[1], args[2])
	if date then
		return date:text()
	end
	return message('Need valid Julian date number')
end

local function date_to_jd(frame)
	-- 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 = get_exports(frame)
	local args = frame: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('Need valid year/month/day or "currentdate"')
end

local function time_interval(frame)
	-- This implements {{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 = get_exports(frame)
	local args = frame:getParent().args
	local parms = {
		want_duration = yes(args.duration),
		range = yes(args.range) or (args.range == 'dash' and 'dash' or nil),
		want_sc = yes(args.sc),
	}
	local fix = yes(args.fix) and 'fix' or ''
	local date1 = Date(fix, 'partial', strip_to_nil(args[1]) or 'currentdatetime')
	if not date1 then
		return message('Invalid start date in first parameter')
	end
	local date2 = Date(fix, 'partial', strip_to_nil(args[2]) or 'currentdatetime')
	if not date2 then
		return message('Invalid end date in second parameter')
	end
	parms.diff = date2 - date1
	for argname, translate in pairs(translate_parameters) do
		local parm = strip_to_nil(args[argname])
		if parm then
			parm = translate[parm]
			if parm == nil then  -- test for nil because false is a valid setting
				return message('Parameter ' .. argname .. '=' .. args[argname] .. ' is invalid')
			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('Parameter show=' .. args.show .. ' conflicts with round=' .. args.round)
				end
			else
				parms.show = translate_parameters.show[round]
			end
		end
		parms.round = true
	end
	return date_difference(parms)
end

return {
	age_generic = age_generic,         -- can emulate several age templates
	gsd = date_to_gsd,                 -- Template:Gregorian_serial_date
	extract = date_extract,            -- Template:Extract
	jd_to_date = jd_to_date,           -- Template:?
	JULIANDAY = date_to_jd,            -- Template:JULIANDAY
	time_interval = time_interval,     -- Template:Time_interval
}