-- This module implements {{gallery}}



local p = {}



local templatestyles = 'Module:Gallery/sandbox/styles.css'

local yesno = require('Module:Yesno')



local function trim(s)

	return mw.ustring.gsub(mw.ustring.gsub(s, '%s', ' '), '^%s*(.-)%s*$', '%1')

end



local tracking, preview



local function checkarg(k,v)

	if k and type(k) == 'string' then

		if k == 'align' or k == 'state' or k == 'style' or k == 'title' or

			k == 'width' or k == 'height' or k == 'lines' or k == 'whitebg' or

			k == 'mode' or k == 'footer' or k == 'perrow' or k == 'noborder' or

			k:match('^alt%d+$') or k:match('^%d+$') then

			-- valid

		elseif k == 'captionstyle' then

			if not v:match('^text%-align%s*:%s*center[;%s]*$') then

				table.insert(tracking, '[[Category:Pages using gallery with the captionstyle parameter]]')

			end

		else

			-- invalid

			local vlen = mw.ustring.len(k)

			k = mw.ustring.sub(k, 1, (vlen < 25) and vlen or 25) 

			k = mw.ustring.gsub(k, '[^%w\-_ ]', '?')

			table.insert(tracking, '[[Category:Pages using gallery with unknown parameters|' .. k .. ']]')

			table.insert(preview, '"' .. k .. '"')

		end

	end

end



function p.gallery(frame)

	-- If called via #invoke, use the args passed into the invoking template.

	-- Otherwise, for testing purposes, assume args are being passed directly in.

	local origArgs = (type(frame.getParent) == 'function') and frame:getParent().args or frame

    

    -- ParserFunctions considers the empty string to be false, so to preserve the previous 

    -- behavior of {{gallery}}, change any empty arguments to nil, so Lua will consider

    -- them false too.

    local args = {}

    tracking, preview = {}, {}

    for k, v in pairs(origArgs) do

    	if v ~= '' then

    		argsk = v

    		checkarg(k,v)

    	end

	end

	

	if (args.mode or '') == 'packed' and (args.align or '') == '' then

		args.align = 'center'

	end



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

	tbl:addClass('mod-gallery-sb')

    

	if args.state then

		tbl

			:addClass('mod-gallery-collapsible')

			:addClass('collapsible')

			:addClass(args.state)

	end

	

	if args.style then

		tbl:cssText(args.style)

	else

		tbl:addClass('mod-gallery-default')

	end

	

	if args.align then

		tbl:addClass('mod-gallery-' .. args.align:lower())

	end



	if args.title then

		tbl:tag('div')

			:addClass('title')

				:tag('div')

					:wikitext(args.title)

	end

	

	local gargs = {}

	gargs'class' = 'nochecker' .. (args.noborder and '' or ' bordered-images')

	gargs'widths' = tonumber(args.width) or 180

	gargs'heights' = tonumber(args.height) or 180

	gargs'style' = args.captionstyle

	gargs'perrow' = args.perrow

	gargs'mode' = args.mode

	if yesno(args.whitebg or 'yes') then

		gargs'class' = gargs'class' .. ' whitebg'

	end

	

	local gallery = {}

	

	local imageCount = math.ceil(#args / 2)



    for i = 1, imageCount do

		local img = trim(argsi*2 - 1 or '')

		local caption = trim(argsi*2 or '')

		local alt = trim(args'alt' .. i or '')

		if img ~= '' then

			table.insert(gallery, img .. (alt ~= '' and ('|alt=' .. alt) or '') .. '|' .. caption )

		end

	end

	

	tbl:tag('div')

		:addClass('main')

		:tag('div')

			:wikitext(

				frame:extensionTag{ name = 'gallery', content = '\n' .. table.concat(gallery,'\n'), args = gargs}

				)

    

	if args.footer then

		tbl:tag('div')

			:addClass('footer')

				:tag('div')

					:wikitext(args.footer)

	end



	local trackstr = (#tracking > 0) and table.concat(tracking, '') or ''

	if #preview > 0 then

		trackstr = require('Module:If preview')._warning({

			'Unknown parameters ' .. table.concat(preview, '; ') .. '.'

		}) .. trackstr

	end

	

	return frame:extensionTag{ name = 'templatestyles', args = { src = templatestyles} } .. tostring(tbl) .. trackstr

end



return p