-------------------------------------------------------------------------------

--                         Module:Wikipedia ads

--

-- This module displays a random banner-style advert for a Wikipedia project,

-- page or process. It implements [[Template:Wikipedia ads]].

-------------------------------------------------------------------------------



-- Set constants

local LIST_MODULE = 'Module:Wikipedia ads/list'

local DATA_MODULE = 'Module:Wikipedia ads/data'



local p = {}

local warnings = {}



local function addWarning(msg)

	table.insert(warnings, msg)

end



local function makeWikilink(page, display)

	return string.format('[[%s|%s]]', page, display)

end



local function makeUrlLink(url, display)

	url = tostring(url)

	return string.format('[%s %s]', url, display)

end



local function colorText(s, color)

	return string.format('<span style="color:%s">%s</span>', color, s)

end



local function getImageData(args)

	-- This function gets an image data from the data module. It also tracks

	-- whether the image data choice was random.

	local data = mw.loadData(DATA_MODULE)



	local function getSomeImageData(id, param)

		id = tonumber(id) or id

		local someImageData = data.idsid

		if someImageData then

			return someImageData

		else

			addWarning(string.format("ID '%s' does not exist", tostring(id)))

			return nil

		end

	end



	-- Get the image data of the ad to display.

	local imageData, isRandom

	if args.ad then

		imageData = getSomeImageData(args.ad, 'ad')

		if not imageData then

			return nil

		end

		isRandom = false

	else

		local imageDataArray, length

		if args1 then

			imageDataArray = {}

			for i, id in ipairs(args) do

				imageDataArray#imageDataArray + 1 = getSomeImageData(id, i)

			end

			length = #imageDataArray

			if length < 1 then

				return nil

			end

		else

			imageDataArray = data.list

			length = data.noAds

		end

		assert(length >= 1, string.format(

			'no ads were found in [[%s]]',

			DATA_MODULE

		))

		isRandom = length > 1

		if isRandom then

			math.randomseed(os.clock() * 1000000000)

			imageData = imageDataArraymath.random(length)]

		else

			imageData = imageDataArray1

		end

	end



	-- Check that the image data has the required fields. We have already

	-- checked the ID in the data module.

	for i, field in ipairs{'image', 'link'} do

		assert(imageDatafield], string.format(

			"Invalid image data in [[%s]]; table with ID '%s' has no '%s' field",

			LIST_MODULE, tostring(imageData.id), field

		))

	end



	return imageData, isRandom

end



local function renderAd(imageData, args, title, isRandom)

	local width = tonumber(args.width) or 468

	local maxWidth = width + 9

	local linkColor = args.linkcolor or '#002bb8'



	-- Table root

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

	root

		:addClass('plainlinks qxz-ads')

		:css('color', args.color or '#555555')

		:css('border', 'none')

		:css('background', args.background)

		:css('line-height', '1em')

		:css('font-size', '90%')

		:css('display', 'block')

		:css('overflow', 'auto')

		:css('max-width', maxWidth .. 'px')

	if args.float then

		root:css('float', args.float)

		root:css('margin', args.margin)

	else

		root:css('margin', args.margin or '0 auto')

	end

	

	-- Image row

	root

		:tag('tr')

			:tag('td')

				:attr('colspan', 2)

				:css('border', 'none')

				:wikitext(string.format(

					'[[File:%s|%dpx|alt=Wikipedia ad for %s|link=%s]]',

					imageData.image,

					width,

					imageData.link,

					imageData.link

				))

	

	-- Links row

	if not args.nolinks then

		local linksRow = root:tag('tr')



		-- Wikipedia ads link

		linksRow

			:tag('td')

				:css('border', 'none')

				:wikitext(makeWikilink(

					'Template:Wikipedia ads',

					colorText('Wikipedia ads', linkColor)

				))



		-- File info, purge and ID

		local links = {}

		links#links + 1 = makeWikilink(

			':File:' .. imageData.image,

			colorText('file info', linkColor)

		)

		if args.showpurge or isRandom then

			links#links + 1 = makeUrlLink(

				title:fullUrl{action = 'purge'},

				colorText('show another', linkColor)

			)

		end

		links#links + 1 = '#' .. tostring(imageData.id)

		linksRow

			:tag('td')

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

				:css('border', 'none')

				:wikitext(table.concat(links, ' – '))

	end



	return tostring(root)

end



local function renderWarnings(args, title)

	if #warnings < 1 then

		return nil

	end



	-- Error list

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

		:css('width', '468px')

	if args.float then

		root

			:css('float', args.float)

			:css('clear', 'both')

	else

		root:css('margin', '0 auto')

	end

	local list = root:tag('ul')

		:addClass('error')

		:css('font-size', '90%')

	for _, msg in ipairs(warnings) do

		list

			:tag('li')

				:wikitext(string.format(

					'Wikipedia ads error: %s ([[Template:Wikipedia ads#Errors|help]]).',

					msg

				))

	end



	-- Category. We use [[Module:Category handler]] for its blacklist.

	local mCatHandler = require('Module:Category handler')

	local category = mCatHandler._main{

		all = '[[Category:Wikipedia ads templates with errors]]',

		nocat = args.nocat,

		page = title and title.prefixedText

	}



	local ret = tostring(root)

	if category then

		ret = ret .. category

	end

	return ret

end



function p._main(args, title)

	title = title or mw.title.getCurrentTitle()

	local ret = {}

	local imageData, isRandom = getImageData(args)

	if imageData then

		ret#ret + 1 = renderAd(imageData, args, title, isRandom)

	end

	ret#ret + 1 = renderWarnings(args, title)

	if #ret > 0 then

		return table.concat(ret)

	else

		return nil

	end

end



function p.main(frame)

	local args = require('Module:Arguments').getArgs(frame, {

		wrappers = 'Template:Wikipedia ads'

	})

	return p._main(args)

end



return p