Editing Module:Track listing

local yesno = require('Module:Yesno')
local checkType = require('libraryUtil').checkType
local cfg = mw.loadData('Module:Track listing/configuration')

--------------------------------------------------------------------------------
-- Helper functions
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-- Add a mixin to a class.
local function addMixin(class, mixin)
	for k, v in pairs(mixin) do
		if k ~= 'init' then
			class[k] = v
		end
	end
end

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-- Validation mixin
--------------------------------------------------------------------------------

local Validation = {}

function Validation.init(self)
	self.warnings = {}
	self.categories = {}
end

function Validation:addWarning(msg, category)
	table.insert(self.warnings, msg)
	table.insert(self.categories, category)
end

function Validation:addCategory(category)
	table.insert(self.categories, category)
end

function Validation:getWarnings()
	return self.warnings
end

function Validation:getCategories()
	return self.categories
end

-- Validate a track length. If a track length is invalid, a warning is added.
-- A type error is raised if the length is not of type string or nil.
function Validation:validateLength(length)
	checkType('validateLength', 1, length, 'string', true)
	if length == nil then
		-- Do nothing if no length specified
		return nil
	end

	local hours, minutes, seconds

	-- Try to match times like "1:23:45".
	hours, minutes, seconds = length:match('^(%d+):(%d%d):(%d%d)$')
	if hours and hours:sub(1, 1) == '0' then
		-- Disallow times like "0:12:34"
		self:addWarning(
			string.format(cfg.leading_0_in_hours, mw.text.nowiki(length)),
			cfg.input_error_category
		)
		return nil
	end

	if not seconds then
		-- The previous attempt didn't match. Try to match times like "1:23".
		minutes, seconds = length:match('^(%d?%d):(%d%d)$')
		if minutes and minutes:find('^0%d$') then
			-- Special case to disallow lengths like "01:23". This check has to
			-- be here so that lengths like "1:01:23" are still allowed.
			self:addWarning(
				string.format(cfg.leading_0_in_minutes, mw.text.nowiki(length)),
				cfg.input_error_category
			)
			return nil
		end
	end

	-- Add a warning and return if we did not find a match.
	if not seconds then
		self:addWarning(
			string.format(cfg.not_a_time, mw.text.nowiki(length)),
			cfg.input_error_category
		)
		return nil
	end

	-- Check that the minutes are less than 60 if we have an hours field.
	if hours and tonumber(minutes) >= 60 then
		self:addWarning(
			string.format(cfg.more_than_60_minutes, mw.text.nowiki(length)),
			cfg.input_error_category
		)
		return nil
	end
	
	-- Check that the seconds are less than 60
	if tonumber(seconds) >= 60 then
		self:addWarning(
			string.format(cfg.more_than_60_seconds, mw.text.nowiki(length)),
			cfg.input_error_category
		)
	end

	return nil
end

--------------------------------------------------------------------------------
-- Track class
--------------------------------------------------------------------------------

local Track = {}
Track.__index = Track
addMixin(Track, Validation)

Track.fields = cfg.track_field_names

Track.cellMethods = {
	number = 'makeNumberCell',
	title = 'makeTitleCell',
	writer = 'makeWriterCell',
	lyrics = 'makeLyricsCell',
	music = 'makeMusicCell',
	extra = 'makeExtraCell',
	length = 'makeLengthCell',
}

function Track.new(data)
	local self = setmetatable({}, Track)
	Validation.init(self)
	for field in pairs(Track.fields) do
		self[field] = data[field]
	end
	self.number = assert(tonumber(self.number))
	self:validateLength(self.length)
	return self
end

function Track:getLyricsCredit()
	return self.lyrics
end

function Track:getMusicCredit()
	return self.music
end

function Track:getWriterCredit()
	return self.writer
end

function Track:getExtraField()
	return self.extra
end

-- Note: called with single dot syntax
function Track.makeSimpleCell(wikitext)
	return mw.html.create('td')
		:wikitext(wikitext or cfg.blank_cell)
end

function Track:makeNumberCell()
	return mw.html.create('th')
		:attr('id', string.format(cfg.track_id, self.number))
		:attr('scope', 'row')
		:wikitext(string.format(cfg.number_terminated, self.number))
end

function Track:makeTitleCell()
	local titleCell = mw.html.create('td')
	titleCell:wikitext(
		self.title and string.format(cfg.track_title, self.title) or cfg.untitled
	)
	if self.note then
		titleCell:wikitext(string.format(cfg.note, self.note))
	end
	return titleCell
end

function Track:makeWriterCell()
	return Track.makeSimpleCell(self.writer)
end

function Track:makeLyricsCell()
	return Track.makeSimpleCell(self.lyrics)
end

function Track:makeMusicCell()
	return Track.makeSimpleCell(self.music)
end

function Track:makeExtraCell()
	return Track.makeSimpleCell(self.extra)
end

function Track:makeLengthCell()
	return mw.html.create('td')
		:addClass('tracklist-length')
		:wikitext(self.length or cfg.blank_cell)
end

function Track:exportRow(columns)
	local columns = columns or {}
	local row = mw.html.create('tr')
	for i, column in ipairs(columns) do
		local method = Track.cellMethods[column]
		if method then
			row:node(self[method](self))
		end
	end
	return row
end

--------------------------------------------------------------------------------
-- TrackListing class
--------------------------------------------------------------------------------

local TrackListing = {}
TrackListing.__index = TrackListing
addMixin(TrackListing, Validation)
TrackListing.fields = cfg.track_listing_field_names
TrackListing.deprecatedFields = cfg.deprecated_track_listing_field_names

function TrackListing.new(data)
	local self = setmetatable({}, TrackListing)
	Validation.init(self)

	-- Check for deprecated arguments
	for deprecatedField in pairs(TrackListing.deprecatedFields) do
		if data[deprecatedField] then
			self:addCategory(cfg.deprecated_parameter_category)
			break
		end
	end

	-- Validate total length
	if data.total_length then
		self:validateLength(data.total_length)
	end
	
	-- Add properties
	for field in pairs(TrackListing.fields) do
		self[field] = data[field]
	end
	
	-- Evaluate boolean properties
	self.showCategories = yesno(self.category) ~= false
	self.category = nil

	-- Make track objects
	self.tracks = {}
	for i, trackData in ipairs(data.tracks or {}) do
		table.insert(self.tracks, Track.new(trackData))
	end

	-- Find which of the optional columns we have.
	-- We could just check every column for every track object, but that would
	-- be no fun^H^H^H^H^H^H inefficient, so we use four different strategies
	-- to try and check only as many columns and track objects as necessary.
	do
		local optionalColumns = {}
		local columnMethods = {
			lyrics = 'getLyricsCredit',
			music = 'getMusicCredit',
			writer = 'getWriterCredit',
			extra = 'getExtraField',
		}
		local doneWriterCheck = false
		for i, trackObj in ipairs(self.tracks) do
			for column, method in pairs(columnMethods) do
				if trackObj[method](trackObj) then
					optionalColumns[column] = true
					columnMethods[column] = nil
				end
			end
			if not doneWriterCheck and optionalColumns.writer then
				doneWriterCheck = true
				optionalColumns.lyrics = nil
				optionalColumns.music = nil
				columnMethods.lyrics = nil
				columnMethods.music = nil
			end
			if not next(columnMethods) then
				break
			end
		end
		self.optionalColumns = optionalColumns
	end

	return self
end

function TrackListing:makeIntro()
	if self.all_writing then
		return string.format(cfg.tracks_written, self.all_writing)
	elseif self.all_lyrics and self.all_music then
		return mw.message.newRawMessage(
			cfg.lyrics_written_music_composed,
			self.all_lyrics,
			self.all_music
		):plain()
	elseif self.all_lyrics then
		return string.format(cfg.lyrics_written, self.all_lyrics)
	elseif self.all_music then
		return string.format(cfg.music_composed, self.all_music)
	else
		return nil
	end
end

function TrackListing:renderTrackingCategories()
	if not self.showCategories or mw.title.getCurrentTitle().namespace ~= 0 then
		return ''
	end

	local ret = ''

	local function addCategory(cat)
		ret = ret .. string.format('[[Category:%s]]', cat)
	end

	for i, category in ipairs(self:getCategories()) do
		addCategory(category)
	end

	for i, track in ipairs(self.tracks) do
		for j, category in ipairs(track:getCategories()) do
			addCategory(category)
		end
	end

	return ret
end

function TrackListing:renderWarnings()
	if not cfg.show_warnings then
		return ''
	end

	local ret = {}

	local function addWarning(msg)
		table.insert(ret, string.format(cfg.track_listing_error, msg))
	end

	for i, warning in ipairs(self:getWarnings()) do
		addWarning(warning)
	end

	for i, track in ipairs(self.tracks) do
		for j, warning in ipairs(track:getWarnings()) do
			addWarning(warning)
		end
	end

	return table.concat(ret, '<br>')
end

function TrackListing:__tostring()
	-- Root of the output
	local root = mw.html.create('div')
		:addClass('track-listing')
	
	local intro = self:makeIntro()
	if intro then
		root:tag('p')
			:wikitext(intro)
			:done()
	end
	
	-- Start of track listing table
	local tableRoot = mw.html.create('table')
	tableRoot
		:addClass('tracklist')
	
	-- Overall table width
	if self.width then
		tableRoot
			:css('width', self.width)
	end
	
	-- Header row
	if self.headline then
		tableRoot:tag('caption')
			:wikitext(self.headline or cfg.track_listing)
	end

	-- Headers
	local headerRow = tableRoot:tag('tr')

	---- Track number
	headerRow
		:tag('th')
			:addClass('tracklist-number-header')
			:attr('scope', 'col')
			:tag('abbr')
				:attr('title', cfg.number)
				:wikitext(cfg.number_abbr)

	-- Find columns to output
	local columns = {'number', 'title'}
	if self.optionalColumns.writer then
		columns[#columns + 1] = 'writer'
	else
		if self.optionalColumns.lyrics then
			columns[#columns + 1] = 'lyrics'
		end
		if self.optionalColumns.music then
			columns[#columns + 1] = 'music'
		end
	end
	if self.optionalColumns.extra then
		columns[#columns + 1] = 'extra'
	end
	columns[#columns + 1] = 'length'
	
	-- Find column width
	local nColumns = #columns
	local nOptionalColumns = nColumns - 3
	
	local titleColumnWidth = 100
	if nColumns >= 5 then
		titleColumnWidth = 40
	elseif nColumns >= 4 then
		titleColumnWidth = 60
	end
	
	local optionalColumnWidth = ((100 - titleColumnWidth) / nOptionalColumns) .. '%'
	titleColumnWidth = titleColumnWidth .. '%'
	
	---- Title column
	headerRow:tag('th')
		:attr('scope', 'col')
		:css('width', self.title_width or titleColumnWidth)
		:wikitext(cfg.title)

	---- Optional headers: writer, lyrics, music, and extra
	local function addOptionalHeader(field, headerText, width)
		if self.optionalColumns[field] then
			headerRow:tag('th')
				:attr('scope', 'col')
				:css('width', width or optionalColumnWidth)
				:wikitext(headerText)
		end
	end
	addOptionalHeader('writer', cfg.writer, self.writing_width)
	addOptionalHeader('lyrics', cfg.lyrics, self.lyrics_width)
	addOptionalHeader('music', cfg.music, self.music_width)
	addOptionalHeader(
		'extra',
		self.extra_column or cfg.extra,
		self.extra_width
	)

	---- Track length
	headerRow:tag('th')
		:addClass('tracklist-length-header')
		:attr('scope', 'col')
		:wikitext(cfg.length)

	-- Tracks
	for i, track in ipairs(self.tracks) do
		tableRoot:node(track:exportRow(columns))
	end

	-- Total length
	if self.total_length then
		tableRoot
			:tag('tr')
				:addClass('tracklist-total-length')
				:tag('th')
					:attr('colspan', nColumns - 1)
					:attr('scope', 'row')
					:tag('span')
						:wikitext(cfg.total_length)
						:done()
					:done()
				:tag('td')
					:wikitext(self.total_length)
	end
	
	root:node(tableRoot)
	-- Warnings and tracking categories
	root:wikitext(self:renderWarnings())
	root:wikitext(self:renderTrackingCategories())
	
	return mw.getCurrentFrame():extensionTag{
		name = 'templatestyles', args = { src = 'Module:Track listing/styles.css' }
	} .. tostring(root)
end

--------------------------------------------------------------------------------
-- Exports
--------------------------------------------------------------------------------

local p = {}

function p._main(args)
	-- Process numerical args so that we can iterate through them.
	local data, tracks = {}, {}
	for k, v in pairs(args) do
		if type(k) == 'string' then
			local prefix, num = k:match('^(%D.-)(%d+)$')
			if prefix and Track.fields[prefix] and (num == '0' or num:sub(1, 1) ~= '0') then
				-- Allow numbers like 0, 1, 2 ..., but not 00, 01, 02...,
				-- 000, 001, 002... etc.
				num = tonumber(num)
				tracks[num] = tracks[num] or {}
				tracks[num][prefix] = v
			else
				data[k] = v
			end
		end
	end
	data.tracks = (function (t)
		-- Compress sparse array
		local ret = {}
		for num, trackData in pairs(t) do
			trackData.number = num
			table.insert(ret, trackData) 
		end
		table.sort(ret, function (t1, t2)
			return t1.number < t2.number
		end)
		return ret
	end)(tracks)

	return tostring(TrackListing.new(data))
end

function p.main(frame)
	local args = require('Module:Arguments').getArgs(frame, {
		wrappers = 'Template:Track listing'
	})
	return p._main(args)
end

return p