local contrast_ratio = require('Module:Color contrast')._ratio

-- TVRG class
-- The main class.

local TVRG = {}

-- Allow usages of cells
function TVRG.NACell
	local cell = mw.html.create('td')
	local attrMatch = '([%a-]*)="([^"]*)"'
	
	infoParam = frame:expandTemplate{title='N/A',args={text}}
	
	-- Gather styles of and assign to node variable
	while true do
		local a,b = string.match
		if a == nil or b == nil then break end
		cell:attr
		infoParam = string.gsub
	end

	infoParam = string.gsub
	cell:wikitext(infoParam)
	
	return cell
end

-- Create the graph and table
function TVRG.new
	args = args or {}
	
	-- Variables
	local timeline = {}
	local longestseason = -1
	local average = args.average and 1 or 0
	local season_title = args.season_title or '시즌'
	local root = mw.html.create('div')
	
	-- Create the timeline
	
	-- Number of actual viewer numbers
	local numberargs = 0
	for k,v in pairs(args) do 
		if (string.lower(v) == 'n/a') or (not string.match and not string.match) then numberargs = numberargs + 1 end
	end

	-- Determine number of seasons
	local num_seasons = -1
	for k,v in pairs(args) do
		local thisseason = tonumber(string.sub)
		if string.sub == 'color' and thisseason > num_seasons then
			num_seasons = thisseason
		end
	end
	if num_seasons < 1 then
		num_seasons = 1
	end

	-- Determine number of episodes and subtract averages if included (they should be equal to the number of seasons)
	local num_episodes
	if average == 1 then
		num_episodes = numberargs-num_seasons
	else
		num_episodes = numberargs
	end

	-- Bar and graph width
	local barwidth
	if num_episodes >= 80 then barwidth = 9
	elseif num_episodes >= 50 then barwidth = 10
	elseif num_episodes >= 20 then barwidth = 11
	else barwidth = 12
	end

	local graphwidth = num_episodes*barwidth
	
	-- Determine maximum viewer figure
	local maxviewers = -1
	local multiple = '100만'
	for k,v in pairs(args) do
		local num = tonumber(v)
		if tonumber(k) ~= nil and num ~= nil and num > maxviewers then
			maxviewers = num
		end
	end
	if maxviewers <= 1.5 then
		multiple = '1천'
		maxviewers = maxviewers*1000
		for k, v in pairs(args) do
			local num = tonumber(v)
			if tonumber(k) ~= nil and num ~= nil then args[k] = tostring(num*1000) end
		end
	end

	-- Basis parameters
	timeline['type'] = 'stackedrect'
	timeline['width'] = (args.width or graphwidth)
	timeline['height'] = (args.height or 300)
	timeline['legend'] = season_title
	timeline['colors'] = ''
	
	timeline['x'] = ''
	timeline['xType'] = 'string'
	timeline['xAxisAngle'] = '-90'
	timeline['xAxisTitle'] = '에피소드'
	
	timeline['yGrid'] = 'y'
	
	-- Color and legend variables
	for season = 1,num_seasons do 
		args["color" .. season] = args["color" .. season] or '#CCCCFF';
		if num_seasons > 1 then
			timeline['y'..season..'Title'] = (args["legend" .. season] or season) .. " " -- The space after this is not a regular space, it is a copy-pasted non-breaking space so the graph registers season names that are numbers (such as 1984 for American Horror Story) as a string, not a number; if it registers as a number, it will register as the first season. Do not remove/change it.
		elseif timeline['legend'] then
			timeline['legend'] = nil
		end
		timeline['colors'] = timeline['colors'] .. args["color" .. season] .. ','
	end
	
	-- Axis labels
	local countryDisplayUS, countryDisplayUK, countryDisplayOther
	if args.country ~= nil and args.country ~= '' then
		if args.country == "U.S." or args.country == "미국" or args.country == "US" or args.country == "United States" then countryDisplayUS = '미국'
		elseif args.country == "U.K." or args.country == "영국" or args.country == "UK" or args.country == "United Kingdom" then countryDisplayUK = '영국'
		else countryDisplayOther = args.country
		end
	end
	timeline['yAxisTitle'] = ((countryDisplayUS or countryDisplayUK or countryDisplayOther) or "") .. ((countryDisplayUS or countryDisplayUK or countryDisplayOther) and " 시" or "시") .. "청자 수 (" .. multiple .. ")\n"

	-- Add bars to timeline, one per viewer figure
	local bar = 1
	local season = 0
	local thisseason = 0
	local counted_episodes = 0
	
	for k,v in ipairs(args) do
		if string.lower(v) == 'n/a' then v = '' end
		
		if v == '-' then
			-- Hyphen means new season
			season = season + 1
			timeline['y'..season] = ''
			for ep = 1,counted_episodes do 
				timeline['y'..season] = timeline['y'..season] .. ','
			end

			-- Determine highest number of counted_episodes in a season
			if thisseason > longestseason then
				longestseason = thisseason
			end
			thisseason = 0
		elseif average == 0 or (average == 1 and args[k+1] ~= '-' and args[k+1] ~= nil) then
			-- Include bar for viewer figure, do not include if averages are included and the next parameter is a new season marker
			timeline['y'..season] = timeline['y'..season] ..  .. (v ~= '' and v or 0)
			
			-- Increment tracking variables
			counted_episodes = counted_episodes + 1
			thisseason = thisseason + 1
			bar = bar + 1
		end
	end
	-- Determine highest number of episodes in a season after final season's bars
	if thisseason > longestseason then
		longestseason = thisseason
	end
	
	-- X axis variables
	for ep = 1,num_episodes do 
		timeline['x'] = timeline['x'] ..  .. ep
	end
	
	-- If there's a title, add it with the viewers caption, else just display the viewers caption by itself
	if args.title ~= nil and args.title ~= '' then
		root:wikitext("**" .. args.title .. "" .. "&#8202;" .. ": " .. ((countryDisplayUS or countryDisplayUK or countryDisplayOther) or "") .. ((countryDisplayUS or countryDisplayUK or countryDisplayOther) and " 에" or "에") .. "피소드별 시청자 수(" .. multiple .. ")**"):css
	else
		root:wikitext("**에피소드별 시청자 수 (" .. multiple .. ")**"):css
	end
	root:tag('div'):css

	-- Add timeline to div
	if args.no_graph == nil then
		timeline[1] = ''
		-- This reduces the WP:PEIS. Module:Graph:Chart pretends to be
		-- Template:Graph:Chart, and we pass it a modified frame with the
		-- arguments we would have sent to Template:Graph:Chart.
		local oldArgs = frame.args
		frame.args = timeline
		root:wikitext(require('Module:Graph:Chart')[''](frame))
		frame.args = oldArgs
		root:tag('div'):css
	end
	
	-- Create ratings table
	if args.no_table == nil then
		local rtable = mw.html.create('table')
		
			-- Create headers rows
			local row = rtable:tag('tr')
			row:tag('th'):wikitext(season_title)
				
			row:tag('th')
				
			-- Average column
			if average == 1 then
				row:tag('th')
			end

			local row = rtable:tag('tr')
			
			for i = 1,longestseason do
				row:tag('th')
			end
		
		local season = 1
		local thisseason = 0
		
		-- Create table rows and cells
		for k,v in pairs(args) do
			if tonumber(k) ~= nil then
				-- New season marker, or final episode rating
				if v == '-' or (average == 1 and args[k+1] == nil) then
					if season > 1 then
						-- Spanning empty cells with 
						if thisseason < longestseason then
							row:node(TVRG.NACell:attr)
						end
						
						if average == 1 then
							-- If averages included, then set the averages cell with value or TBD
							if v ~= '' then
								row:tag('td'):wikitext(args[k+1] ~= nil and args[k-1] or v)
							else
								row:node(TVRG.NACell)
							end
							thisseason = thisseason + 1
						end
					end
					
					-- New season marker
					if v == '-' then
						-- New row with default or preset caption
						row = rtable:tag('tr')
						row:tag('th')
						
						row:tag('th')
						
						thisseason = 0
						season = season + 1
					end
				elseif average == 0 or (average == 1 and args[k+1] ~= '-' and args[k+1] ~= nil) then
					-- Viewer figures, either as a number or TBD
					if string.lower(v) == 'n/a' then
						row:node(TVRG.NACell)
					elseif v ~= '' then
						row:tag('td'):wikitext(v)
					else
						row:node(TVRG.NACell)
					end
					thisseason = thisseason + 1
				end
			end
		end
		
		-- Finish by checking if final row needs cells
		if average == 0 and thisseason < longestseason then
			row:node(TVRG.NACell:attr)
		end
			
		-- Add table to div root and return
		root:node(rtable)
		root:tag('div'):css
	end
	
	--local current_monthyear = os.date("%B %Y")
	--local span = mw.html.create('span'):wikitext
	local span = ''
	 
	if countryDisplayUS then
		root:wikitext("" .. (args.refs ~= '' and args.refs or tostring(span)))
	elseif countryDisplayUK then
		root:wikitext("" .. (args.refs ~= '' and args.refs or tostring(span)))
	else
		root:wikitext("" .. (args.refs ~= '' and args.refs or tostring(span)))
	end
	
	return tostring(root)
end

-- Exports

local p = {}

function p.main(frame)
	local args = require('Module:Arguments').getArgs(frame, {
		removeBlanks = false,
		wrappers = '틀:텔레비전 시청률 그래프'
	return TVRG.new
end