local p = {}

local getArgs
local yesno = require('Module:Yesno')
local mm = require('Module:Math')
local contrast_ratio = require('Module:Color contrast')._ratio

function p.sublist(frame)
	return main(frame,true)
end

function p.list(frame)
	return main(frame,false)
end

function main(frame, sublist)
	if not getArgs then
		getArgs = require('Module:Arguments').getArgs
	end
	local args

	-- Most parameters should still display when blank, so don't remove blanks
	if sublist then
		args = getArgs(frame, {removeBlanks = false, wrappers = 'Template:Episode list/sublist'})
	else
		args = getArgs(frame, {removeBlanks = false, wrappers = 'Template:Episode list'})
	end
	
	local title = mw.title.getCurrentTitle()
	local page_title = mw.title.getCurrentTitle().text
	local mainlist = args.MainList or args['1'] or ''
	
	-- Is this list on the same page as the page directly calling the template?
	local on_main_page
	
	-- Only sublist had anything about hiding, so only it needs to even check
	if sublist then
		on_main_page = mw.uri.anchorEncode(page_title) == mw.uri.anchorEncode(mainlist)
		-- avoid processing ghost references
		if on_main_page then
			args.ShortSummary = nil
		end
	else
	-- Normal lists can ALWAYS show the summary
		on_main_page = false
	end
	
	-- Declare all the possible <td>/<th> tags here, and the return string
	local EpisodeNumber,EpisodeNumber2,Title,Aux1,DirectedBy,WrittenBy,
			DirectedBy,Aux2,Aux3,OriginalAirDate,AltDate,ProdCode,
			Viewers,Aux4,return_table
	
	-- Need just this parameter removed if blank, no others
	if args.ShortSummary then
		if not args.ShortSummary:find('%S') then
			args.ShortSummary = nil
		end
	end

	-- Default color to light blue
	-- Hash (#) left out because it was left out in the original wikicode, so we can add it later
	local line_color = args.LineColor or 'CCCCFF'
	
	-- List of parameter names to test
	-- Keep this order as is
	local cell_names = {
		'EpisodeNumber2',
		'Title',
		'Aux1',
		'DirectedBy',
		'WrittenBy',
		'Aux2',
		'Aux3',
		'OriginalAirDate',
		'AltDate',
		'ProdCode',
		'Viewers',
		'Aux4'
	}
	
	-- Is there a way to call a variable by its name stored as a string? Doubt it
	-- This list matches strings with the table cell variables
	local td_tags = {
		['EpisodeNumber2'] = EpisodeNumber2,
		['Title'] = Title,
		['Aux1'] = Aux1,
		['DirectedBy'] = DirectedBy,
		['WrittenBy'] = WrittenBy,
		['DirectedBy'] = DirectedBy,
		['Aux2'] = Aux2,
		['Aux3'] = Aux3,
		['OriginalAirDate'] = OriginalAirDate,
		['AltDate'] = AltDate,
		['ProdCode'] = ProdCode,
		['Viewers'] = Viewers,
		['Aux4'] = Aux4,
	}
	
	local table_row = mw.html.create('tr')
				:addClass('vevent')
				:css('text-align','center')
	
	local row_color = yesno(args.RowColor, false)
	if args.RowColor and string.lower(args.RowColor) == 'on' then
		row_color = true
	end

	local top_color
	local epn = mm._cleanNumber(args.EpisodeNumber) or 1
	if args.TopColor then
		top_color = '#'..args.TopColor
	elseif row_color and not on_main_page and mm._mod(epn,2) == 0 then
		top_color = '#E9E9E9'
	elseif not on_main_page and args.ShortSummary then
		top_color = '#F2F2F2'
	else
		top_color = 'inherit'
	end
		
	table_row:css('background',top_color)
	
	-- This will decide the colspan= of the summary cell
	-- Start as 1 because EpisodeNumber is always created
	local nonnil_params = 1
	
	-- Created separately because it is the only <th> tag
	
	if args.EpisodeNumber then
		EpisodeNumber = mw.html.create('th')
				:attr('scope','row')
				:attr('id','ep'..args.EpisodeNumber)
				:css('text-align','center')
				:wikitext(args.EpisodeNumber)
		table_row:css('background',top_color)
		table_row:node(EpisodeNumber)
	end
	
	-- The wikitext in the Title cell is a little more involved than the others
	local function add_title()
		local title_string = ''
		
		-- Surround the Title with quotes; no quotes if empty
		if args.Title and args.Title:find('%S') then
			title_string = title_string..'"'..args.Title..'"'
		end
		
		if args.RTitle then
			title_string = title_string..args.RTitle
		end
		
		-- Surround the AltTitle with quotes; no quotes if empty
		if args.AltTitle and args.AltTitle:find('%S') then
			title_string = title_string..'<br>"'..args.AltTitle..'"'
		end
			
		if args.RAltTitle then
			title_string = title_string..args.RAltTitle
		end
		return title_string
	end

	for _,v in ipairs(cell_names) do
		-- Title is in the middle, so it's probably better to just switch back and again instead of doing 2 nodes
		-- and then title, and then the rest in a loop
		if v == 'Title' then
			nonnil_params = nonnil_params + 1
			local title_text = add_title()
			td_tags[v] = mw.html.create('td')
			td_tags[v]:wikitext(title_text)
					:addClass('summary')
					:css('text-align','left')
			table_row:node(td_tags[v])
		elseif args[v] then
			nonnil_params = nonnil_params + 1
			td_tags[v] = mw.html.create('td')
			td_tags[v]:wikitext(args[v])
			table_row:node(td_tags[v])
		end
	end

	-- Production code also has an additional attribute, so add it separately here
	if td_tags.ProdCode and args.ProdCode then
		td_tags.ProdCode:attr('id','pc'..args.ProdCode)
	end
	
	local categories = ''
	
	-- add these categories only in the mainspace and only if they are on the page where the template is used
	if not on_main_page and title.namespace == 0 then
		if args.LineColor and args.LineColor ~= '' then
			local black_cr = contrast_ratio{args.LineColor, 'black', ['error'] = 0}
			local white_cr = contrast_ratio{'white', args.LineColor, ['error'] = 0}
			if black_cr < 7 and white_cr < 7 then
				categories = categories..'[[Category:Episode lists with invalid line colors]]' 
			end
		else
			categories = categories..'[[Category:Episode list using the default LineColor]]'
		end
		
		if args.TopColor and args.TopColor ~= '' then
			categories = categories..'[[Category:Episode lists with row deviations]]'

			-- Track top colors that have a color contrast rating below AAA with
			-- respect to text color, link color, or visited link color. See
			-- [[WP:COLOR]] for more about color contrast requirements.
			local text_cr = contrast_ratio{args.TopColor, 'black', ['error'] = 0}
			local link_cr = contrast_ratio{args.TopColor, '#0B0080', ['error'] = 0}
			local visited_link_cr = contrast_ratio{args.TopColor, '#0645AD', ['error'] = 0}
			if text_cr < 7 or link_cr < 7 or visited_link_cr < 7 then
				categories = categories..'[[Category:Episode lists with invalid top colors]]'
			end
		end
	end
	
	-- Do not show the summary if this is being transcluded on the mainlist page
	-- Do include it on all other lists
	if not on_main_page and args.ShortSummary then
		local bottom_wrapper = mw.html.create('tr')
		-- fix for lists in the Short Summary
		local ss = args.ShortSummary
		if ss:match('^[*:;#]') or ss:match('^{|') then
			ss = '<span></span>\n' .. ss
		end
		if ss:match('\n[*:;#]') then
			ss = ss .. '\n<span></span>'
		end
		local ShortSummary = mw.html.create('td')
					:addClass('description')
					:css('border-bottom','solid 3px #'..line_color)
					:attr('colspan',nonnil_params)
					:newline()
					:wikitext(ss)
		bottom_wrapper:node(ShortSummary)
		return tostring(table_row)..tostring(bottom_wrapper)..categories
	else
		return tostring(table_row)..categories
	end
end

return p