-- this module implements [[Template:Overlay]]

local p = {}



local mArguments = require('Module:Arguments')



-- used to cache the calculated font color to avoid repeat calculations

local previous_backgroundcolor = ''

local fontcolor = ''



local function buildicon(n, form, lk, c, t)

	local res

	if form == 'text' then

		return tostring(

				mw.html.create('span')

					:css('font-weight', 'bold')

					:css('color', c)

					:wikitext(n)

				)

	elseif form == 'color' or form == 'colour' then

		return tostring(

				mw.html.create('span')

					:css('background-color', c)

					:wikitext('  ')

				)

	else

		-- check if the color is difference from the previous color

		if c ~= previous_backgroundcolor then

			-- color changed, so look up the best font color

			local greatercontrast = require('Module:Color contrast')._greatercontrast

			fontcolor = greatercontrast{c, 'white', 'black', bias = 1.3}

			-- update the previous value for the next check

			previous_backgroundcolor = c

		end

		-- build the inner span for the icon

		local span = mw.html.create('span')

			:css('color', fontcolor)

			:css('font-size', '88%')

			:css('font-weight', 'bold')

			:attr('title', t)

			:wikitext(n)

		-- build the outer div

		local div = mw.html.create('div')

			:css('display', 'inline-block')

			:css('width', 'auto')

			:css('height', 'auto')

			:css('text-align', 'center')

			:css('padding', ((tonumber(n) or 0) < 10) and '0px 4px' or '0px 2px')

			:css('vertical-align', 'middle')

			:css('border-radius', '3px')

			:css('background-color', c)



		-- link the inner span if requested and insert in the div

		if lk ~= '' then

			div:wikitext('[[:' .. lk .. '|' .. tostring(span) .. ']]')

		else

			div:wikitext(tostring(span))

		end

		-- convert to a string

		return tostring(div)

	end

end



local function buildlegend(data, cols, border, caption)

	-- create the outer table to hold the columns

	local root = mw.html.create('table')

		:css('width', '100%')

		:css('border', (border ~= 'no') and '1px #ccc solid' or '')

	-- create the outer row which will contain the columns

	local outerrow = root:tag('tr')

	local percol = math.ceil((#data) / cols)

	local k = 0

	for j=1,cols do

		-- create the outer cell to hold this column

		local colcell = outerrow:tag('td')

			:css('width', (math.floor(10/cols)/10) .. '%')

			:css('vertical-align', 'top')

		-- create the inner table to hold the entries in the column

		local coltable = colcell:tag('table')

			:css('width', '100%')

			:css('font-size', '85%')

			:css('line-height', '95%')

		-- add the entries to the column

		for l = 1,percol do

			k = k + 1

			if k <= #data then

				local rdata = datak

				local tr = coltable:tag('tr'):css('vertical-align','top')

				tr:tag('td')

					:css('width', '12px')

					:css('text-align', 'right')

					:css('padding-bottom', '2px')

					:wikitext(rdata1 or '')

				tr:tag('td')

					:css('padding-bottom', '2px')

					:wikitext(rdata2 or '')

			end

		end

	end

	return caption .. tostring(root)

end



local function buildlegenditem(im, lk, t)

	local res = {im, ''}

	if t ~= '' then

		if lk ~= '' then

			res2 = '[[:' .. lk .. '|' .. t .. ']]'

		else

			res2 = t

		end

	else

		res2 = '[[:' .. lk .. '|' .. lk .. ']]'

	end

	return res 

end



function p.icon(frame)

	local args = mArguments.getArgs(frame)

	return tostring(

		mw.html.create('div')

			:css('display', 'inline-block')

			:css('line-height', '95%')

			:wikitext(buildicon(args'1' or '', 

								args'form' or 'icon',

								args'link' or '', 

								args'2' or 'red',

								args'tip' or ''))

	)

end



function p.main(frame)

	local args = mArguments.getArgs(frame)

	

	local image = args'image' or ''

	local width = tonumber(args'width' or 500) or 500

	local height = tonumber(args'height' or 500) or 500

	local columns = tonumber(args'columns' or 3) or 3

	local grid = ((args'grid' or ''):lower() == 'yes') and 'yes' or 'no'

	local legendbox = ((args'legendbox' or ''):lower() == 'no') and 'no' or 'yes'

	local overlay = (image == '') and 'no' or ( ((args'overlay' or ''):lower() == 'no') and 'no' or 'yes' )

	local float = args'float' or 'center'

	local border = ((args'border' or ''):lower() == 'no') and 'no' or 'yes'

	local padding = args'padding' or ''



	-- create the root table

	local root = mw.html.create('table')

	if float == 'center' or float == 'centre' then

		root:css('margin-left', 'auto')

			:css('margin-right', 'auto')

	elseif float == 'right' then

		root:css('float', 'right')

			:css('clear', 'right')

			:css('margin-left', '1em')

	elseif float == 'left' then

		root:css('float', 'left')

			:css('clear', 'left')

			:css('margin-right', '1em')

	else

		root:css('float', float)

	end

	if border == 'yes' then

		root:css('border', '1px #ccc solid')

	end



	-- create a list of all the overlay numbers

	local itemnums = {}

	for k, v in pairs( args ) do

		local i = tonumber(tostring(k):match( '^%s*overlay([%d]+)%s*$' ) or '-1')

		if i > -1 then

			table.insert(itemnums, i)

		else

			i = tonumber(tostring(k):match( '^%s*overlay([%d]+)tip%s*$' ) or '-1')

			if i > -1 then

				table.insert(itemnums, i)

			end

		end

	end

	-- sort to process in order

	table.sort( itemnums )

	

	-- remove duplicates

	for k = 2,#itemnums do

		if itemnumsk == itemnumsk-1 then

			table.remove(itemnums, k)

		end

	end



	-- build the overlay markers and text

	itemdata = {}

	local colori = args'color' or args'colour' or 'red'

	local formi = ''	

	for k = 1,#itemnums do

		local i = itemnumsk

		formi = args'overlay' .. i .. 'form' or formi

		colori = args'overlay' .. i .. 'color' or args'overlay' .. i .. 'colour' or colori

		local linki = args'overlay' .. i .. 'link' or ''

		local tipi = args'overlay' .. i .. 'tip' or args'overlay' .. i or ''

		local overlayi = args'overlay' .. i or args'overlay' .. i .. 'tip' or ''

		if (overlayi ~= '' or tipi ~= '') then

			local imagei = buildicon(i, formi, linki, colori, tipi)

			itemdatak = buildlegenditem(imagei, args'overlay' .. i .. 'link' or '', overlayi)

		end

	end



	-- create the overlay image

	if image ~= '' then

		local cell = root:tag('tr'):tag('td')

		cell:attr('align', 'center')

		if( padding ~= '' ) then

			cell:css('padding', padding)

		end

		if( columns > 1 and legendbox == 'yes' ) then

			cell:attr('colspan', columns)

		end

		local imagediv = cell:tag('div')

		imagediv:css('position','relative')

			:css('left', '0px')

			:css('top', '0px')

			:css('width', ((grid == 'yes') and 940 or width) .. 'px')

			:css('height', ((grid == 'yes') and 940 or height) .. 'px')

		if grid == 'yes' then

			imagediv:tag('span')

				:css('position', 'absolute')

				:css('left', '0px')

				:css('top', '0px')

				:css('z-index', '2')

				:wikitext('[[File:Grid 99, 100 int red 50 int yellow (940).svg|940px]]')

		end

		imagediv:tag('span')

			:css('position', 'absolute')

			:css('left', '0px')

			:css('top', '0px')

			:css('z-index', '0')

			:css('width', width .. 'px')

			:css('height', height .. 'px')

			:wikitext('[[File:' .. image .. '|' .. width .. 'x' .. height .. 'px]]')

		if overlay == 'yes' then

			for k = 1,#itemnums do

				local i = itemnumsk

				local imagei = (itemdatak])[1

				for j =0,3 do

					local overlayileftj = args'overlay' .. i .. 'left' .. ((j == 0) and '' or j)] or ''

					local overlayitopj = args'overlay' .. i .. 'top' .. ((j == 0) and '' or j)] or ''

					if overlayileftj ~= '' then

						imagediv:tag('div')

							:css('position', 'absolute')

							:css('left', overlayileftj .. 'px')

							:css('top', overlayitopj .. 'px')

							:css('line-height', '95%')

							:css('z-index', '1')

							:wikitext(imagei)

					end

				end

			end

		end

	end



	-- Split the legend items into sub-legends

	legend = {{}, {}, {}, {}, {}}

	local jmax = itemnums#itemnums

	for i=1,5 do

		if args'legend' .. i .. 'start' then

			-- default is all items

			j1 = 0

			j2 = jmax

			-- set start item number to (legendistart) or (legend(i-1)end + 1)

			if args'legend' .. i .. 'start' then

				j1 = tonumber(args'legend' .. i .. 'start']) or j1

			elseif args'legend' .. (i-1) .. 'end' then

				j1 = (tonumber(args'legend' .. (i-1) .. 'end']) or j1) + 1

			end

			-- set end item number to (legendiend) or (legend(i+1)start - 1)

			if args'legend' .. i .. 'end' then

				j2 = tonumber(args'legend' .. i .. 'end']) or j2

			elseif args'legend' .. (i+1) .. 'start' then

				j2 = (tonumber(args'legend' .. (i+1) .. 'start']) or j2) - 1

			end

			-- get the items within the range, marking them as they are used

			for k=1,#itemnums do

				j = itemnumsk

				if (j >= 0 and j >= j1 and j <= j2) then

					table.insert(legendi], itemdatak])

					itemnumsk = -1

				end

			end

		end

	end



	-- Add any left over items to the first legend

	for k = 1,#itemnums do

		if itemnumsk >= 0 then

			table.insert(legend1], itemdatak])

		end

	end



	-- Build the legend

	if columns > 0 then

		for i = 1,5 do

			local locallegend = legendi

			if (locallegend and #locallegend > 0) then

				local cell = root:tag('tr'):tag('td')

				cell:wikitext(buildlegend(locallegend, columns, border, args'legend' .. i .. 'title' or ''))

			end

		end

	end



	return tostring(root)

end



return p