local checkType = libUtil.checkType
local mTableTools = require('Module:TableTools')

local p = {}

local listTypes = {
	['bulleted'] = true,
	['unbulleted'] = true,
	['horizontal'] = true,
	['ordered'] = true,
	['horizontal_ordered'] = true

function p.makeListData
	-- Constructs a data table to be passed to p.renderList.
	local data = {}

	-- Classes and TemplateStyles
	data.classes = {}
	data.templatestyles = ''
	if listType == 'horizontal' or listType == 'horizontal_ordered' then
		table.insert
		data.templatestyles = mw.getCurrentFrame:extensionTag{
			name = 'templatestyles', args = { src = 'Hlist/styles.css' }
	elseif listType == 'unbulleted' then
		table.insert
		data.templatestyles = mw.getCurrentFrame:extensionTag{
			name = 'templatestyles', args = { src = 'Plainlist/styles.css' }
	end
	table.insert

	-- Main div style
	data.style = args.style

	-- Indent for horizontal lists
	if listType == 'horizontal' or listType == 'horizontal_ordered' then
		local indent = tonumber(args.indent)
		indent = indent and indent * 1.6 or 0
		if indent > 0 then
			data.marginLeft = indent .. 'em'
		end
	end
	
	-- List style types for ordered lists
	-- This could be "1, 2, 3", "a, b, c", or a number of others. The list style
	-- type is either set by the "type" attribute or the "list-style-type" CSS
	-- property.
	if listType == 'ordered' or listType == 'horizontal_ordered' then 
		data.listStyleType = args.list_style_type or args['list-style-type']
		data.type = args['type']

		-- Detect invalid type attributes and attempt to convert them to
		-- list-style-type CSS properties.
		if data.type 
			and not data.listStyleType
			and not tostring(data.type):find('^%s*[1AaIi]%s*$')
		then
			data.listStyleType = data.type
			data.type = nil
		end
	end
	
	-- List tag type
	if listType == 'ordered' or listType == 'horizontal_ordered' then
		data.listTag = 'ol'
	else
		data.listTag = 'ul'
	end

	-- Start number for ordered lists
	data.start = args.start
	if listType == 'horizontal_ordered' then
		-- Apply fix to get start numbers working with horizontal ordered lists.
		local startNum = tonumber(data.start)
		if startNum then
			data.counterReset = 'listitem ' .. tostring(startNum - 1)
		end
	end

	-- List style
	 -- ul_style and ol_style are included for backwards compatibility. No
	 -- distinction is made for ordered or unordered lists.
	data.listStyle = args.list_style

	-- List items
	-- li_style is included for backwards compatibility. item_style was included
	-- to be easier to understand for non-coders.
	data.itemStyle = args.item_style or args.li_style
	data.items = {}
	for _, num in ipairs(mTableTools.numKeys(args)) do
		local item = {}
		item.content = args[num]
		item.style = args['item' .. tostring(num) .. '_style']
			or args['item_style' .. tostring(num)]
		item.value = args['item' .. tostring(num) .. '_value']
			or args['item_value' .. tostring(num)]
		table.insert
	end
	
	return data
end

function p.renderList(data)
	-- Renders the list HTML.
	
	-- Return the blank string if there are no list items.
	if type(data.items) ~= 'table' or #data.items < 1 then
		return ''
	end
	
	-- Render the main div tag.
	local root = mw.html.create('div')
	for _, class in ipairs(data.classes or {}) do
		root:addClass(class)
	end
	root:css{['margin-left'] = data.marginLeft}
	if data.style then
		root:cssText(data.style)
	end

	-- Render the list tag.
	local list = root:tag(data.listTag or 'ul')
	list
			['counter-reset'] = data.counterReset,
			['list-style-type'] = data.listStyleType
	if data.listStyle then
		list:cssText(data.listStyle)
	end

	-- Render the list items
	for _, t in ipairs(data.items or {}) do
		local item = list:tag('li')
		if data.itemStyle then
			item:cssText(data.itemStyle)
		end
		if t.style then
			item:cssText(t.style)
		end
		item
	end

	return data.templatestyles .. tostring(root)
end

function p.renderTrackingCategories(args)
	local isDeprecated = false -- Tracks deprecated parameters.
	for k, v in pairs(args) do
		k = tostring(k)
		if k:find('^item_style%d+$') or k:find('^item_value%d+$') then
			isDeprecated = true
			break
		end
	end
	local ret = ''
	if isDeprecated then
		ret = ret .. 'Category:List templates with deprecated parameters'
	end
	return ret
end

function p.makeList
	if not listType or not listTypes[listType] then
		error(string.format(
			"bad argument #1 to 'makeList' ('%s' is not a valid list type)",
			tostring(listType)
		), 2)
	end
	checkType
	local data = p.makeListData
	local list = p.renderList(data)
	local trackingCategories = p.renderTrackingCategories(args)
	return list .. trackingCategories
end

for listType in pairs(listTypes) do
	p[listType] = function (frame)
		local mArguments = require('Module:Arguments')
		local origArgs = mArguments.getArgs(frame, {
			valueFunc = function 
			if not value or not mw.ustring.find then return nil end
			if mw.ustring.find then
				return value
			else
				return value:match('^%s*(.-)%s*$')
			end
			return nil
		end
		-- Copy all the arguments to a new table, for faster indexing.
		local args = {}
		for k, v in pairs(origArgs) do
			args[k] = v
		end
		return p.makeList
	end
end