--[[

This implements {{progression rainbow}}



]]

require('strict')



local p = {}



-- rounding to first decimal, from http://lua-users.org/wiki/SimpleRound

local function round(num)

	return math.floor(num * 10 + 0.5) / 10

end



local function percent(param, total)

	-- These suck for i18n because the % is forced to the right without spacing,

	-- both in a required context (CSS) and unrequired (to-be-displayed text).

	-- I.e., there should be a separate version of this

	return tostring(round(100 * param / total)) .. '%'

end



local function percent_remaining(sum, total)

	local remaining = total - sum

	if remaining > 0 then

		return percent(remaining, total)

	else

		return nil

	end

end



local function category_count(category, project)

	return mw.site.stats.pagesInCategory(

		string.format('%s %s articles', category, project),

		'pages'

	)

end



-- This is only done once in this module, here for demonstration.

-- Gist: Make it cleaner to initialize 'trivial' variables.

local function arg_or_default(args, from_arg, default)

	if argsfrom_arg and argsfrom_arg ~= '' then

		return argsfrom_arg

	else

		return default

	end

end



function p._main(args)



	local classes = {

		{count = 0, class = 'List', category = 'List-Class'},

		{count = 0, class = 'Stub', category = 'Stub-Class'},

		{count = 0, class = 'Start', category = 'Start-Class'},

		{count = 0, class = 'C', category = 'C-Class'},

		{count = 0, class = 'B', category = 'B-Class'},

		{count = 0, class = 'GA', category = 'GA-Class'},

		{count = 0, class = 'A', category = 'A-Class'},

		{count = 0, class = 'FA', category = 'FA-Class'}

	}

	

	local project_classes = {

		{count = 0, class = 'FL', category = 'FL-Class'},

		{count = 0, class = 'Unassessed', category = 'Unassessed'}

	}



	local project = arg_or_default(args, "project", nil)

	

	local sum_classes = 0

	if project then

		for _, class in ipairs(classes) do

			class.count = category_count(class.category, project)

			if class.class == 'FA' then

				class.count = class.count + category_count(

					project_classes1].category,

					project

				)

			end

			sum_classes = sum_classes + class.count

		end

	else

		for i, class in ipairs(classes) do

			-- 'or class.count' to keep us safe from nil arg

			class.count = tonumber(argsi]) or class.count

			sum_classes = sum_classes + class.count

		end

	end



	local total

	if project then

		-- It makes more sense to do this sum here rather than in the project

		-- loop above because total is initialized here in the non-project case

		total = sum_classes + category_count(

			project_classes2].category,

			project

		)

	else

		total = tonumber(args9]) or 100

	end

	

	local height = arg_or_default(args, 'height', nil)

	

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

	root:addClass('progression-rainbow')

	if height then

		root:css('height', height)

	end



	local current_frame = mw.getCurrentFrame()

	for _, class in ipairs(classes) do

		if class.count ~= 0 then

			local percentage = percent(class.count, total)

				root:newline() -- sprinkled through to make the HTML easier to read

				root:tag('li')

					:css('background', current_frame:expandTemplate{

						title = 'class/colour', args = { class.class }

					})

					:css('width', percentage)

					:attr('title', string.format('%s %s', percentage, class.category))

					:tag('span')

						:addClass('sr-only')

						:wikitext(string.format('%s %s', percentage, class.category))

						:done()

					:done()

		end

	end

	root:newline()

	

	local remaining = percent_remaining(sum_classes, total)

	if remaining then

		root:tag('li')

			:addClass('remaining')

			:css('width', remaining)

			:attr('title', string.format('%s remaining', remaining))

			:tag('span')

				:addClass('sr-only')

				:wikitext(string.format('%s remaining', remaining))

				:done()

			:done()

		:newline()

	end

	root:allDone()

	return current_frame:extensionTag{

		name = 'templatestyles', args = { src = 'Module:Progression rainbow/styles.css'}

	} .. current_frame:extensionTag{

		name = 'templatestyles', args = { src = 'Screen reader-only/styles.css'}

	} .. '\n' .. tostring(root)

end



function p.main(frame)

	return p._main(require('Module:Arguments').getArgs(frame))

end



return p