local p = {}
local args = {}
local origArgs = {}
local root
local lists = {
	plainlist_t = {
		patterns = {
			'^plainlist$',
			'%splainlist$',
			'^plainlist%s',
			'%splainlist%s'
		found = false,
		styles = 'Plainlist/styles.css'
	hlist_t = {
		patterns = {
			'^hlist$',
			'%shlist$',
			'^hlist%s',
			'%shlist%s'
		found = false,
		styles = 'Hlist/styles.css'

local function has_list_class(args_to_check)
	for _, list in pairs(lists) do
		if not list.found then
			for _, arg in pairs(args_to_check) do
				for _, pattern in ipairs(list.patterns) do
					if mw.ustring.find then
						list.found = true
						break
					end
				end
				if list.found then break end
			end
		end
	end
end

-- Returns the union of the values of two tables, as a sequence.
local function union

	local vals = {}
	for k, v in pairs(t1) do
		vals[v] = true
	end
	for k, v in pairs(t2) do
		vals[v] = true
	end
	local ret = {}
	for k, v in pairs(vals) do
		table.insert
	end
	return ret
end

-- Returns a table containing the numbers of the arguments that exist
-- for the specified prefix. For example, if the prefix was 'data', and
-- 'data1', 'data2', and 'data5' exist, it would return {1, 2, 5}.
local function getArgNums
	local nums = {}
	for k, v in pairs(args) do
		local num = tostring(k):match('^' .. prefix .. '([0-9]%d*)' .. suffix .. '$')
		if num then table.insert(nums, tonumber(num)) end
	end
	table.sort(nums)
	return nums
end

-- Adds a row to the infobox, with either a header cell
-- or a label/data cell combination.
local function addRow(rowArgs)
	if rowArgs.header then
		has_list_class
		root
					-- @deprecated next; target .infobox- .infobox-header
	elseif rowArgs.label then
		if rowArgs.data then
			has_list_class
			local row = root:tag('tr')
			row:addClass(rowArgs.rowclass)
			row:cssText(rowArgs.rowstyle)
			row
		
			local dataCell = row:tag('td')
			dataCell
				-- @deprecated next; target .infobox- .infobox-data
		elseif rowArgs.dataa or rowArgs.datab or rowArgs.datac then
			has_list_class
			local row = root:tag('tr')
			row:addClass(rowArgs.rowclass)
			row:cssText(rowArgs.rowstyle)
			row

			local dataCella = row:tag('td')
			dataCella
				-- @deprecated next; target .infobox- .infobox-data-a
			if rowArgs.renderb then
				has_list_class({rowArgs.classb})
				local dataCellb = row:tag('td')
				dataCellb
					-- @deprecated next; target .infobox- .infobox-data-b
			end
			if rowArgs.renderc then
				has_list_class({rowArgs.classc})
				local dataCellc = row:tag('td')
				dataCellc
					-- @deprecated next; target .infobox- .infobox-data-c
			end
		end
	elseif rowArgs.data then
		has_list_class
		local row = root:tag('tr')
		row:addClass(rowArgs.rowclass)
		row:cssText(rowArgs.rowstyle)
					
		local dataCell = row:tag('td')
		dataCell
			-- @deprecated next; target .infobox- .infobox-full-data
	end
end

local function renderTitle
	if not args.title then return end
	has_list_class({args.titleclass})

	root
			-- @deprecated next; target .infobox- .infobox-title
end

local function renderAboveRow
	if not args.above then return end
	has_list_class({args.aboveclass})
	
	root
				-- @deprecated next; target .infobox- .infobox-above
end

local function renderBelowRow
	if not args.below then return end
	has_list_class({args.belowclass})
	
	root
				-- @deprecated next; target .infobox- .infobox-below
end

local function addSubheaderRow(subheaderArgs)
	if not subheaderArgs.data then return end
	
	has_list_class
	local row = root:tag('tr')
	row:addClass(subheaderArgs.rowclass)
				
	local dataCell = row:tag('td')
	dataCell
end

local function renderSubheaders
	if args.subheader then
		args.subheader1 = args.subheader
	end
	if args.subheaderrowclass then
		args.subheaderrowclass1 = args.subheaderrowclass
	end
	local subheadernums = getArgNums
	for k, num in ipairs(subheadernums) do
		addSubheaderRow({
			data = args['subheader' .. tostring(num)],
			-- @deprecated next; target .infobox- .infobox-subheader
			datastyle = args.subheaderstyle,
			rowcellstyle = args['subheaderstyle' .. tostring(num)],
			class = args.subheaderclass,
			rowclass = args['subheaderrowclass' .. tostring(num)]
	end
end

local function addImageRow(imageArgs)
	if not imageArgs.data then return end
	
	has_list_class
	local row = root:tag('tr')
	row:addClass(imageArgs.rowclass)
				
	local dataCell = row:tag('td')
	dataCell
end

local function renderImages
	if args.image then
		args.image1 = args.image
	end
	if args.caption then
		args.caption1 = args.caption
	end
	local imagenums = getArgNums
	for k, num in ipairs(imagenums) do
		local caption = args['caption' .. tostring(num)]
		local data = mw.html.create:wikitext(args['image' .. tostring(num)])
		if caption then
			data
					-- @deprecated next; target .infobox- .infobox-caption
		end
		addImageRow({
			data = tostring(data),
			-- @deprecated next; target .infobox- .infobox-image
			datastyle = args.imagestyle,
			class = args.imageclass,
			rowclass = args['imagerowclass' .. tostring(num)]
	end
end

-- Gets the union of the header and data argument numbers,
-- and renders them all in order
local function renderRows
	local rownums = union(getArgNums, getArgNums)
	local datab_count = #(getArgNums)
	local datac_count = #(getArgNums)
	table.sort(rownums)
	for k, num in ipairs(rownums) do
		addRow({
			num = tostring(num),
			renderb = datab_count > 0,
			renderc = datac_count > 0,
			header = args['header' .. tostring(num)],
			label = args['label' .. tostring(num)],
			data = args['data' .. tostring(num)],
			datastyle = args.datastyle,
			class = args['class' .. tostring(num)],
			dataa = args['data' .. tostring(num) .. 'a'],
			dataastyle = args.datastylea,
			classa = args['class' .. tostring(num) .. 'a'],
			datab = args['data' .. tostring(num) .. 'b'],
			databstyle = args.datastyleb,
			classb = args['class' .. tostring(num) .. 'b'],
			datac = args['data' .. tostring(num) .. 'c'],
			datacstyle = args.datastylec,
			classc = args['class' .. tostring(num) .. 'c'],
			rowclass = args['rowclass' .. tostring(num)],
			-- @deprecated next; target .infobox- rowclass
			rowstyle = args['rowstyle' .. tostring(num)],
			rowcellstyle = args['rowcellstyle' .. tostring(num)],
	end
end

local function renderNavBar
	if not args.name then return end
	
	root
					args.name,
					mini = 1,
end

local function renderItalicTitle
	local italicTitle = args['italic title'] and mw.ustring.lower(args['italic title'])
	if italicTitle == '' or italicTitle == 'force' or italicTitle == 'yes' then
		root:wikitext(require('Module:Italic title')._main({}))
	end
end

-- Render tracking categories. args.decat == turns off tracking categories.
local function renderTrackingCategories
	local title = mw.title.getCurrentTitle
	if args.decat == 'yes' then return end
	
	if #(getArgNums) == 0 and title.namespace == 0 then
		root:wikitext('')
	end
	
	root:wikitext(check_for_unknown_parameters({
		checkpositional = "y",
		ignoreblank = "y",
		regexp1 = "header[%d]+",
		regexp2 = "label[%d]+",
		regexp3 = "data[%d]+[abc]?",
		regexp4 = "class[%d]+[abc]?",
		regexp5 = "rowclass[%d]+",
		regexp6 = "rowstyle[%d]+",
		regexp7 = "rowcellstyle[%d]+",
		unknown = "",
		"above", "aboveclass", "aboverowclass", "abovestyle", "below", "belowclass",
		"belowrowclass", "belowstyle", "bodyclass", "bodystyle", "caption", "caption1",
		"caption2", "captionstyle", "child", "datastyle", "datastylea", "datastyleb",
		"datastylec", "extracellstyles", "headerstyle", "image", "image1", "image2",
		"imageclass", "imagerowclass1", "imagerowclass2", "imagestyle", "labelstyle",
		"name", "subbox", "subheader", "subheader2", "subheaderclass",
		"subheaderrowclass1", "subheaderrowclass2", "subheaderstyle", "templatestyles",
		"title", "titleclass", "titlestyle",

	if origArgs.header0 or origArgs.label0 or origArgs.data0 or origArgs.data0a
		or origArgs.data0b or origArgs.data0c or origArgs.class0 or origArgs.rowclass0 then
			root:wikitext("")
	end

	if title.namespace == 10 and mw.ustring.sub == "Infobox" then
		root:wikitext("")	
	end
end

--[=[
Loads the templatestyles for the infobox.

TODO: FINISH loading base templatestyles here rather than in
MediaWiki:Common.css. There are 4-5000 pages with 'raw' infobox tables.
See Mediawiki_talk:Common.css/to_do#Infobox and/or come help :).
When we do this we should clean up the inline CSS below too.
Will have to do some bizarre conversion category like with sidebar.

]=]
local function loadTemplateStyles
	local frame = mw.getCurrentFrame
	
	local hlist_templatestyles = ''
	if lists.hlist_t.found then
		hlist_templatestyles = frame:extensionTag{
			name = 'templatestyles', args = { src = lists.hlist_t.styles }
	end
	
	local plainlist_templatestyles = ''
	if lists.plainlist_t.found then
		plainlist_templatestyles = frame:extensionTag{
			name = 'templatestyles', args = { src = lists.plainlist_t.styles }
	end
	
	-- See function description
	local base_templatestyles = frame:extensionTag{
		name = 'templatestyles', args = { src = 'Module:Infobox/styles.css' }

	local templatestyles = ''
	if args['templatestyles'] then
		templatestyles = frame:extensionTag{
			name = 'templatestyles', args = { src = args['templatestyles'] }
	end
	
	local child_templatestyles = ''
	if args['child templatestyles'] then
		child_templatestyles = frame:extensionTag{
			name = 'templatestyles', args = { src = args['child templatestyles'] }
	end
	
	local grandchild_templatestyles = ''
	if args['grandchild templatestyles'] then
		grandchild_templatestyles = frame:extensionTag{
			name = 'templatestyles', args = { src = args['grandchild templatestyles'] }
	end

	return table.concat({
		-- hlist -> plainlist -> base is best-effort to preserve old Common.css ordering.
		-- this ordering is not a guarantee because the rows of interest invoking
		-- each class may not be on a specific page
		hlist_templatestyles,
		plainlist_templatestyles,
		base_templatestyles,
		templatestyles,
		child_templatestyles,
		grandchild_templatestyles
	
end

-- common functions between the child and non child cases
local function structure_infobox_common
	renderSubheaders
	renderImages
--	preprocessRows
	renderRows
	renderBelowRow
	renderNavBar
	renderItalicTitle
--	renderEmptyRowCategories
	renderTrackingCategories
--	cleanInfobox
end

-- Specify the overall layout of the infobox, with special settings if the
-- infobox is used as a 'child' inside another infobox.
local function _infobox

	root = mw.html.create('table')
	has_list_class({args.bodyclass})
		
	root
		-- @deprecated next; target .infobox-
	
	renderTitle
	renderAboveRow
	structure_infobox_common
	
	return loadTemplateStyles .. tostring(root)
end

-- If the argument exists and isn't blank, add it to the argument table.
-- Blank arguments are treated as nil to match the behaviour of ParserFunctions.
local function preprocessSingleArg(argName)
	if origArgs[argName] and origArgs[argName] ~= '' then
		args[argName] = origArgs[argName]
	end
end

-- Assign the parameters with the given prefixes to the args table, in order, in
-- batches of the step size specified. This is to prevent references etc. from
-- appearing in the wrong order. The prefixTable should be an array containing
-- tables, each of which has two possible fields, a "prefix" string and a
-- "depend" table. The function always parses parameters containing the "prefix"
-- string, but only parses parameters in the "depend" table if the prefix
-- parameter is present and non-blank.
local function preprocessArgs
	if type(prefixTable) ~= 'table' then
		error
	end
	if type(step) ~= 'number' then
		error
	end

	-- Get arguments without a number suffix, and check for bad input.
	for i,v in ipairs(prefixTable) do
		if type(v) ~= 'table' or type(v.prefix) ~= "string" or
			(v.depend and type(v.depend) ~= 'table') then
			error
		end
		preprocessSingleArg(v.prefix)
		-- Only parse the depend parameter if the prefix parameter is present
		-- and not blank.
		if args[v.prefix] and v.depend then
			for j, dependValue in ipairs(v.depend) do
				if type(dependValue) ~= 'string' then
					error('Invalid "depend" parameter value detected in preprocessArgs')
				end
				preprocessSingleArg(dependValue)
			end
		end
	end

	-- Get arguments with number suffixes.
	local a = 0 -- Counter variable.
	local moreArgumentsExist = true
	while moreArgumentsExist == true do
		moreArgumentsExist = false
		for i = a, a + step - 1 do
			for j,v in ipairs(prefixTable) do
				local prefixArgName = v.prefix .. tostring(i) .. (v.suffix or '')
				if origArgs[prefixArgName] then
					-- Do another loop if any arguments are found, even blank ones.
					moreArgumentsExist = true
					preprocessSingleArg(prefixArgName)
				end
				-- Process the depend table if the prefix argument is present
				-- and not blank, or we are processing "prefix1" and "prefix" is
				-- present and not blank, and if the depend table is present.
				if v.depend and (args[prefixArgName] or (i == 1 and args[v.prefix])) then
					for j,dependValue in ipairs(v.depend) do
						local dependArgName = dependValue .. tostring(i) .. (v.dependsuffix or '')
						preprocessSingleArg(dependArgName)
					end
				end
			end
		end
		a = a + step
	end
end

-- Parse the data parameters in the same order that the old did, so
-- that references etc. will display in the expected places. Parameters that
-- depend on another parameter are only processed if that parameter is present,
-- to avoid phantom references appearing in article reference lists.
local function parseDataParameters
	preprocessSingleArg('child')
	preprocessSingleArg('bodyclass')
	preprocessSingleArg('subbox')
	preprocessSingleArg('bodystyle')
	preprocessSingleArg('title')
	preprocessSingleArg('titleclass')
	preprocessSingleArg('titlestyle')
	preprocessSingleArg('above')
	preprocessSingleArg('aboveclass')
	preprocessSingleArg('abovestyle')
	preprocessArgs({
	preprocessSingleArg('subheaderstyle')
	preprocessSingleArg('subheaderclass')
	preprocessSingleArg('image')
	preprocessSingleArg('caption')
	preprocessArgs({
	preprocessSingleArg('captionstyle')
	preprocessSingleArg('imagestyle')
	preprocessSingleArg('imageclass')
	preprocessArgs({
	preprocessSingleArg('headerclass')
	preprocessSingleArg('headerstyle')
	preprocessSingleArg('labelstyle')
	preprocessSingleArg('datastyle')
	preprocessSingleArg('datastylea')
	preprocessSingleArg('datastyleb')
	preprocessSingleArg('datastylec')
	preprocessSingleArg('below')
	preprocessSingleArg('belowclass')
	preprocessSingleArg('belowstyle')
	preprocessSingleArg('name')
	-- different behaviour for italics if blank or absent
	args['italic title'] = origArgs['italic title']
	preprocessSingleArg('decat')
	preprocessSingleArg('templatestyles')
	preprocessSingleArg('child templatestyles')
	preprocessSingleArg('grandchild templatestyles')

	args['extracellstyles'] = {}
	for line in mw.text.gsplit do
		local equals = line:find('=')
		if equals then
			for i in mw.text.gsplit(line:sub, '%s*,%s*') do
				args.extracellstyles[i] = line:sub(equals + 1)
			end
		end
	end
end

-- If called via #invoke, use the args passed into the invoking template.
-- Otherwise, for testing purposes, assume args are being passed directly in.
function p.infobox(frame)
	if frame == mw.getCurrentFrame then
		origArgs = frame:getParent.args
	else
		origArgs = frame
	end
	
	parseDataParameters
	
	return _infobox
end

-- For calling via #invoke within a template
function p.infoboxTemplate
	origArgs = extra_args or {}
	for k,v in pairs(frame.args) do origArgs[k] = mw.text.trim(v) end
	
	parseDataParameters
	
	return _infobox
end

-- Shortcut for making child infoboxes via #invoke.
function p.child(frame)
	return p.infoboxTemplate
end