-- This module implements [[Template:IPAc-en]].

local data = mw.loadData('Module:IPAc-en/data')
local currentFrame = mw.getCurrentFrame()
local p = {}

-- Global container for tracking categories
local categoryHandler = require('Module:Category handler').main
local categories = {}

-- Trims whitespace from a string
local function trim(s)
	return s:match('^%s*(.-)%s*$')
end

-- This implements [[Template:Nowrap]].
local function makeNowrapSpan(s)
	local span = mw.html.create('span')
		:addClass('nowrap')
		:wikitext(s)
	return tostring(span)
end

local function makePronunciationText(id)
	id = id and string.lower(trim(id))
	if id and id ~= '' and data.pronunciation[id] then
		return data.pronunciation[id].text
	end
end

-- This adds a tooltip icon to a label. It implements [[Template:H:title]].
local function makeTooltip(label, tooltip)
	local span = mw.html.create('span')
		:attr('title', tooltip)
		:wikitext(label)
	return tostring(span)
end

local function formatPhonemeGroup(phonemes)
	if #phonemes > 0 then
		local span = mw.html.create('span')
			:css('border-bottom', '1px dotted')
			:wikitext(table.concat(phonemes))
		return tostring(span)
	else
		return ''
	end
end

local function renderCategories()
	local ret = ''
	ret = categoryHandler{
		[1] = 'yes', -- Add categories in these namespaces
		main = 1,
		wikipedia = 1,
		file = 1,
		template = 1,
		help = 1,
		category = 1,
		portal = 1,
		book = 1,
		draft = 1,
		module = 1,
	}
	
	if ret == 'yes' then
		ret = {}
		for cat in pairs(categories) do
			table.insert(ret, string.format('[[Category:%s]]', cat))
		end
		table.sort(ret)
		ret = table.concat(ret)
	else
		ret = ''
	end
	return ret
end

function p._main(args)
	local ret = {}
	local i = 0 -- Keeps track of numbered args

	-- Pronunciation
	do
		local pron = {}
		while true do
			i = i + 1
			local pronItem = makePronunciationText(args[i])
			if pronItem then
				pron[#pron + 1] = pronItem
				pron[#pron + 1] = ' '
			else
				break
			end
		end
		if #pron > 0 then
			ret[#ret + 1] = string.format(
				'<small>%s</small>',
				table.concat(pron)
			)
		end
	end

	-- Phonemes
	do
		-- Loop through the numbered args, separating them into phoneme groups
		-- and separator strings (both called "words" for convenience). We only
		-- underline the phoneme groups, not the separators.
		local words = {}
		words[#words + 1] = '/' -- Opening slash
		i = i - 1 -- Set up i again as it was changed in the pronunciation loop
		local id
		repeat
			local phonemes = {}
			local isWordEnd = false
			while not isWordEnd do
				i = i + 1
				id = args[i]
				id = id and trim(id)
				if not id then
					isWordEnd = true
					words[#words + 1] = formatPhonemeGroup(phonemes)
				elseif id ~= '' then
					local t = data.phonemes[id]
					if not t then
						-- We were passed an invalid id.
						isWordEnd = true
						categories["Ill-formatted IPAc-en transclusions"] = true
						words[#words + 1] = formatPhonemeGroup(phonemes)
						-- Call [[Template:Error]]
						local errorText = currentFrame:expandTemplate{
							title = 'Template:Error',
							args = {
								string.format("[invalid input: '%s']", id)
								}
							}
						words[#words + 1] = makeTooltip(
							errorText,
							'Unrecognized symbol'
						)
					elseif not t.label then
						-- The data module contains bad data, so throw an error.
						error(string.format(
							"no label was found for id '%s'",
							tostring(id)
						))
					elseif t.tooltip then
						-- We are dealing with a regular phoneme.
						phonemes[#phonemes + 1] = makeTooltip(
							t.label,
							t.tooltip
						)
					else
						-- We are dealing with a separator.
						isWordEnd = true
						words[#words + 1] = formatPhonemeGroup(phonemes)
						words[#words + 1] = t.label						
					end
				end
			end
		until not id
		words[#words + 1] = '/' -- Closing slash

		-- Wrap the words in a link to IPA help.
		local span = mw.html.create('span')
			-- Suppress Navigation popups and Page Previews (aka Hovercards)
			:addClass('IPA nopopups noexcerpt')
			:wikitext(string.format(
				'[[Help:IPA/English|%s]]',
				table.concat(words)
			))
		
		ret[#ret + 1] = tostring(span)
	end
	
	-- Audio link
	do
		local file = args.audio and trim(args.audio)
		if file and file ~= '' then
			if args[1] and string.lower(trim(args[1])) == 'uk' then
				categories["Articles including recorded pronunciations (UK English)"] = true
			elseif args[1] and string.lower(trim(args[1])) == 'us' then
				categories["Articles including recorded pronunciations (US English)"] = true
			else
				categories["Articles including recorded pronunciations (English)"] = true
			end
			
			ret[#ret + 1] = currentFrame:expandTemplate{
				title = 'Template:IPA audio link', args = { file } }
		end
	end
	
	-- Nowrap and categories
	ret = makeNowrapSpan(table.concat(ret)) .. renderCategories()

	-- Reset the categories table in case we are run again.
	categories = {}

	return ret
end

function p.main(frame)
	return p._main(frame:getParent().args)
end

return p