local export = {}

-- it is either here, or in [[Module:ugly hacks]], and it is not in ugly hacks.
function export.CONTENTMODEL()
	return mw.title.getCurrentTitle().contentModel	
end

local skins = {
	["common"     ] = "";
	["vector"     ] = "Vector";
	["monobook"   ] = "Monobook";
	["cologneblue"] = "Cologne Blue";
	["modern"     ] = "Modern";
}

local Array = require "Module:array"

local function link_lang_cat(lang)
	return ("[[:Category:%s|%s]]")
		:format(lang:getCategoryName(), lang:getCanonicalName())
end

local function compare_pages(page1, page2, text)
	return "[" .. tostring(
		mw.uri.fullUrl("Special:ComparePages", "page1=" .. page1 .. "&page2=" .. page2))
		.. " " .. text .. "]"
end

local function page_exists(title)
	local success, title_obj = pcall(mw.title.new, title)
	return success and title_obj.exists
end

local langs = require "Module:languages/cache"
local function zh_link(word)
	return require("Module:links").full_link{
		lang = langs.zh,
		term = word
	}
end

local function make_zh_data_documentation(title, cats)
	local output = Array()
	
	local zh_data_subpage, lang_code, reconstruction, character =
		mw.ustring.match(title.fullText,
			"^Module:zh/data/((%l%l%l)%-pron%-?([^/]-))/(.+)$")
	if zh_data_subpage == "ltc-pron" or zh_data_subpage == "och-pron-BS"
			or zh_data_subpage == "och-pron-ZS" then
		require('Module:zh-track').track_data_module(title.fullText)
		
		local lang = langs[lang_code]
		
		output:insert(('This module contains data on the pronunciation of %s')
			:format(zh_link(character)))
		
		local see_also_link
		if reconstruction == "BS" then
			see_also_link = 'Wiktionary:About Proto-Sino-Tibetan#Reconstruction by Baxter-Sagart (2014)'
		elseif reconstruction == "ZS" then
			see_also_link = 'Wiktionary:About Proto-Sino-Tibetan#Reconstruction by Zhengzhang (2003)'
		else
			reconstruction = nil
		end
		
		local lang_link = link_lang_cat(lang)
		if reconstruction then
			output:insert(("in the reconstruction of %s by %s.")
				:format(lang_link, reconstruction == "BS" and "Baxter-Sagart" or "Zhengzhang"))
		else
			output:insert(("in %s."):format(lang_link))
		end
		
		if see_also_link then
			output:insert("See " .. require("Module:links").section_link(see_also_link)
				.. " for more information.")
		end
		
		return output:concat(" ")
	end
end

local function make_zh_dial_or_syn_documentation(title, cats)
	local type_of_data, character = title.fullText:match("^Module:zh/data/dial%-(%l+)/(.+)$")
	if character then
		local what, where
		if type_of_data == "pron" then
			what = "the pronunciation"
			where = "dialects"
		elseif type_of_data == "syn" then
			what = "synonyms"
			where = "dialects and varieties"
		end
		
		if what then
			return ("This module contains data on %s of %s in %s of Chinese.")
				:format(what, zh_link(character), where)
		end
	end
end

local function make_zh_glyph_data_documentation(title, cats)
	local character = title.fullText:match("^Module:zh/data/glyph%-data/(.+)")
	if character then
		return ("This module contains data on historical forms of the Chinese character %s.")
			:format(zh_link(character))
	end
end

local function make_accel_documentation(title, cats)
	local doc_content
	local lang_code = title.subpageText
	local lang = langs[lang_code]
	if lang then
		cats:insert(lang:getCanonicalName() .. " modules|accel")
		cats:insert(("Accel submodules|%s"):format(lang:getCanonicalName()))
		return ("This module contains new entry creation rules for %s; see [[WT:ACCEL]].")
			:format(link_lang_cat(lang))
	end
	return doc_content
end


local function make_Unicode_data_documentation(title, cats)
	local subpage, first_three_of_code_point
		= title.fullText:match("^Module:Unicode data/([^/]+)/(%x%x%x)$")
	if subpage == "names" or subpage == "images" then
		local low, high =
			tonumber(first_three_of_code_point .. "000", 16),
			tonumber(first_three_of_code_point .. "FFF", 16)
		return string.format(
			"This data module contains the %s of " .. 
			"[[Appendix:Unicode|Unicode]] code points within the range U+%04X to U+%04X.",
			subpage == "images" and "titles of images" or "names",
			low, high)
	end
end

-- This provides categories and documentation for various data modules, so that
-- [[Category:Uncategorized modules]] isn't unnecessarily cluttered.
local module_regex = {
	["^Module:languages/.+$"] = "Modules dealing with languages and scripts",
	["^Module:scripts/.+$"] = "Modules dealing with languages and scripts",
	["^Module:data tables/data..?.?.?$"] = "Reference module sharded data tables",
	["^Module:Quotations/...?.?.?.?.?.?$"] = "Quotation data modules",
	-- capture submodules of zh/data that do not end with a hanzi in the title
	["^Module:zh/data/.+[a-zA-z0-9]$"] = "Chinese data modules",
	["^Module:zh/data/dial%-pron/.+"] = {
		cat = "Chinese dialectal pronunciation data modules",
		doc = make_zh_dial_or_syn_documentation,
	},
	["^Module:zh/data/dial%-syn/.+"] = {
		cat = "Chinese dialectal synonyms data modules",
		doc = make_zh_dial_or_syn_documentation,
	},
	["^Module:zh/data/glyph%-data/.+"] = {
		cat = "Chinese historical character forms data modules",
		doc = make_zh_glyph_data_documentation,
	},
	["^Module:zh/data/ltc%-pron/.+"] = {
		cat = "Middle Chinese pronunciation data modules",
		doc = make_zh_data_documentation,
	},
	["^Module:zh/data/och%-pron%-BS/.+"] = {
		cat = "Old Chinese (Baxter-Sagart) pronunciation data modules",
		doc = make_zh_data_documentation,
	},
	["^Module:zh/data/och%-pron%-ZS/.+"] = {
		cat = "Old Chinese (Zhengzhang) pronunciation data modules",
		doc = make_zh_data_documentation,
	},
	["^Module:mul/guoxue%-data/cjk%-?(.*)"] = {
		cat = nil,
		doc = function (title, cats)
			local suffix = title.fullText:match("^Module:mul/guoxue%-data/cjk%-?(.*)$")
			local block
			if suffix == "" then
				block = "CJK Unified Ideographs"
			elseif suffix:find("^%l$") then
				block = "CJK Unified Ideographs Extension " .. suffix:upper()
			elseif suffix == "compat" then
				block = "CJK Compatibility Ideographs"
			elseif suffix == "compat-sup" then
				block = "CJK Compatibility Ideographs Supplement"
			else
				mw.log("Unicode block for " .. title.fullText " not found.")
				return
			end
			
			local block_link = ("[[Appendix:Unicode/%s|%s]]"):format(block, block)
			local start, ending = require("Module:Unicode data").get_block_range(block)
			if not start then
				mw.log("Code point range for the Unicode block " .. tostring(block) .. " not found.")
				return
			end
			
			local sortkey = "|guoxue, " .. suffix
			cats:insert("Data modules" .. sortkey)
			cats:insert("Han script" .. sortkey)
			cats:insert("Translingual modules" .. sortkey)
			
			return ("This module contains data on CJK characters in "
				.. "the Unicode block %s (U+%04X&ndash;U+%04X) from [https://guoxuedashi.com guoxuedashi.com].")
				:format(block_link, start, ending)
		end,
	},
	["^Module:Unicode data/(.+)"] = {
		cat = "Unicode data modules|%1",
		doc = make_Unicode_data_documentation,
	},
	["^Module:number list/data/(.+)"] = {
		cat = nil,
		doc = function (title, cats)
			local lang_code = title.fullText:match("^Module:number list/data/(.+)")
			local lang = langs[lang_code]
			
			if lang then
				local canonical_name = lang:getCanonicalName()
				local language_data_modules = canonical_name .. " data modules"
				
				cats:insert((page_exists("Category:" .. language_data_modules)
					and language_data_modules or canonical_name .. " modules")
					.. "|number list")
				cats:insert("Number data modules|" .. canonical_name)
				
				return ("This module contains data on various types of numbers in %s.")
					:format(link_lang_cat(lang))
			end
		end,
	},
	["^Module:es%-conj/data/(.+)"] = "Spanish data modules|%1",
	["^Module:accel/(.+)$"] = {
		cat = nil,
		doc = make_accel_documentation,
	},
	["^Module:inc%-ash.+$"] = {
		cat = "Ashokan Prakrit modules",
		doc = function (title, cats)
			local word = title.fullText:match("^Module:inc%-ash/dial/data/(.+)$")
			if word then
				local lang = langs["inc-ash"]
				return ("This module contains data on the pronunciation of %s in dialects of %s.")
					:format(require("Module:links").full_link({ term = word, lang = lang }, "term"),
						link_lang_cat(lang))
			end
		end,
	},
	["^Module:[%l-]+:Dialects$"] = {
		cat = nil,
		doc = function (title, cats)
			local content = title:getContent()
			local has_aliases = content:find("aliases") and true or false
			return mw.getCurrentFrame():expandTemplate {
				title = "dialectal data module",
				args = { ["labels-aliases"] = has_aliases },
			}
		end,
	},
	["^.+%-translit$"] = {
		cat = nil,
		doc = function (title, cats)
			-- Check that the title begins in a language or script code.
			-- If so, expand {{translit module documentation}} with that code
			-- as the first parameter.
			local code = title.text:match("^([%l-]+)-")
			
			if not (code and require("Module:languages").getByCode(code)) then
				code = title.text:match("^(%u%l%l%l)%-")
				if not require("Module:scripts").getByCode(code) then
					return
				end
			end
			
			return mw.getCurrentFrame():expandTemplate {
				title = "translit module documentation",
				args = { code },
			}
		end,
	},
}

function export.show(frame)
	local params = {
		["hr"] = {},
		["for"] = {},
		["from"] = {},
		["notsubpage"] = { type = "boolean", default = false },
		["nodoc"] = { type = "boolean", default = false },
	}
	
	local args = require("Module:parameters").process(frame.args, params)
	
	local output = Array('\n<div class="documentation" style="display:block; clear:both">\n')
	local cats = Array()
	
	local nodoc = args.nodoc
	
	if (not args.hr) or (args.hr == "above") then
		output:insert("----\n")
	end
	
	local title = ((args['for'] ~= "") and args['for']) and mw.title.new(args['for'])
		or mw.title.getCurrentTitle()
	local doc_title = mw.title.new((args['from'] ~= "") and args['from']
		or (title.fullText .. '/documentation'))
	local contentModel = title.contentModel
	
	local pagetype = mw.getContentLanguage():lcfirst(title.nsText) .. " page"
	local preload, fallback_docs, doc_content, old_doc_title, user_name,
		skin_name, needs_doc
	
	if contentModel == "javascript" then
		pagetype = "script"
		preload  = 'Template:documentation/preloadTemplate' -- XXX
		if title.nsText == 'User' then
			user_name = title.rootText	
		end
	elseif contentModel == "css" then
		pagetype = "style sheet"
		preload  = 'Template:documentation/preloadTemplate' -- XXX
		if title.nsText == 'User' then
			user_name = title.rootText	
		end
	elseif contentModel == "Scribunto" then
		pagetype = "module"
		user_name = title.rootText:match("^[Uu]ser:(.+)")
		if user_name then
			preload  = 'Template:documentation/preloadModuleSandbox'
		else
			preload  = 'Template:documentation/preloadModule'
		end
	elseif title.nsText == "Template" then
		pagetype = "template"
		preload  = 'Template:documentation/preloadTemplate'
	elseif title.nsText == "Wiktionary" then
		pagetype = "project page"
		preload  = 'Template:documentation/preloadTemplate' -- XXX
	end
	
	if doc_title.isRedirect then
		old_doc_title = doc_title
		doc_title = mw.title.new(string.match(doc_title:getContent(),
			"^#[Rr][Ee][Dd][Ii][Rr][Ee][Cc][Tt]%s*:?%s*%[%[([^%[%]]-)%]%]"))
	end

	output:insert("<dl class=\"plainlinks\" style=\"font-size: smaller;\">")
	if doc_title.exists then
		output:insert(
			"<dd><i style=\"font-size: larger;\">The following " ..
			"[[Help:Documenting templates and modules|documentation]] is located at [[" ..
			doc_title.fullText .. "]]. " ..
			"<sup>[[" .. doc_title:fullUrl { action = 'edit' } .. " edit]]</sup> </i></dd>")
	else
		if contentModel == "Scribunto" then
			local automatic_cat
			if user_name then
				fallback_docs = 'documentation/fallback/user module'
				automatic_cat = "User sandbox modules"
			else
				for r, data in pairs(module_regex) do 
					if mw.ustring.find(title.fullText, r) then
						local cat
						if type(data) == "table" then
							doc_content = data.doc(title, cats)
							cat = data.cat
						else
							cat = data
						end
						
						if cat then
							automatic_cat = mw.ustring.gsub(title.fullText, r, cat)
						-- If the documentation function (cat.doc) manages to
						-- generate documentation, it should add a category.
						elseif doc_content then
							automatic_cat = nil
						end
						break
					end
				end
			end
			
				
			if not automatic_cat then
				local success, auto_cats =
					pcall(require("Module:module categorization").categorize, frame, true)
				if success then
					for _, category in ipairs(auto_cats) do
						cats:insert(category)
					end
				end
			end
			
			if title.subpageText == "templates" then
				cats:insert("Template interface modules")
			end
			
			cats:insert(automatic_cat)
			
			-- meaning module is not in user's sandbox or one of many datamodule boring series
			needs_doc = not (automatic_cat or fallback_docs)
		elseif title.nsText == "Template" then
			--cats:insert("Uncategorized templates")
			needs_doc = not (fallback_docs or nodoc)
		elseif (contentModel == "css") or (contentModel == "javascript") then
			if user_name then
				skin_name = skins[title.text:sub(#title.rootText + 1):match("^/([a-z]+)%.[jc]ss?$")]
				if skin_name then
					fallback_docs = 'documentation/fallback/user ' .. contentModel
				end
			end
		end
		
		if doc_content then
			output:insert(
				"<dd><i style=\"font-size: larger;\">The following " ..
				"[[Help:Documenting templates and modules|documentation]] is " ..
				"generated by [[Module:documentation]]. <sup>[[" ..
				mw.title.new("Module:documentation"):fullUrl { action = 'edit' } ..
				" edit]]</sup> </i></dd>")
		elseif not nodoc then
			output:insert(
				"<dd><i style=\"font-size: larger;\">This " .. pagetype ..
				" lacks a [[Help:Documenting templates and modules|documentation subpage]]. " ..
				(fallback_docs and "You may " or "Please ") ..
				"[" .. doc_title:fullUrl { action = 'edit', preload = preload }
				.. " create it].</i></dd>\n")
		end
	end
	
	if title.fullText:match("^MediaWiki:Gadget%-") then
		local is_gadget = false
		local gadget_list = mw.title.new("MediaWiki:Gadgets-definition"):getContent()
		
		for line in mw.text.gsplit(gadget_list, "\n") do
			local gadget, opts, items = line:match("^%*%s*([A-Za-z][A-Za-z0-9_%-]*)%[(.-)%]|(.+)$") -- opts is unused
			if not gadget then
				gadget, items = line:match("^%*%s*([A-Za-z][A-Za-z0-9_%-]*)|(.+)$")
			end
			
			if gadget then
				items = Array(mw.text.split(items, "|"))
				for i, item in ipairs(items) do
					if title.fullText == ("MediaWiki:Gadget-" .. item) then
						is_gadget = true

						output:insert("<dd> ''This script is a part of the <code>")
						output:insert(gadget)
						output:insert("</code> gadget ([")
						output:insert(tostring(mw.uri.fullUrl('MediaWiki:Gadgets-definition', 'action=edit')))
						output:insert(" edit definitions])'' <dl>")
						
						output:insert("<dd> ''Description ([")
						output:insert(tostring(mw.uri.fullUrl('MediaWiki:Gadget-' .. gadget, 'action=edit')))
						output:insert(" edit])'': ")
						output:insert(mw.message.new('Gadget-' .. gadget):plain())
						output:insert(" </dd>")

						items:remove(i)
						if #items > 0 then
							for j, item in ipairs(items) do
								items[j] = '[[MediaWiki:Gadget-' .. item .. '|' .. item .. ']]'
							end
							output:insert("<dd> ''Other parts'': ")
							output:insert(mw.text.listToText(items))
							output:insert("</dd>")
						end

						output:insert("</dl></dd>")

						break
					end
				end
			end
		end
		
		if not is_gadget then
			output:insert("<dd> ''This script is not a part of any [")
			output:insert(tostring(mw.uri.fullUrl('Special:Gadgets', 'uselang=en')))
			output:insert(' gadget] ([')
			output:insert(tostring(mw.uri.fullUrl('MediaWiki:Gadgets-definition', 'action=edit')))
			output:insert(' edit definitions]).</dd>')
		--else
		--	cats:insert("Wiktionary gadgets")
		end
	end	
	
	if old_doc_title then
		output:insert("<dd> ''Redirected from'' [")
		output:insert(old_doc_title:fullUrl { redirect = 'no' })
		output:insert(" ")
		output:insert(old_doc_title.fullText)
		output:insert("] ([")
		output:insert(old_doc_title:fullUrl { action = 'edit' })
		output:insert(" edit]).</dd>\n")
	end
	
	local links = Array()
	
	if title.isSubpage and not args.notsubpage then
		links:insert("[[:" .. title.nsText .. ":" .. title.rootText .. "|root page]]")
		links:insert("[[Special:PrefixIndex/" .. title.nsText .. ":" .. title.rootText .. "/|root page's subpages]]")
	else
		links:insert("[[Special:PrefixIndex/" .. title.fullText .. "/|subpage list]]")
	end
	
	if (contentModel == "javascript") or (contentModel == "css") then
		links:insert("[[Special:WhatLinksHere/" .. title.fullText .. "|what links here]]")

		if user_name then
			links:insert("[[Special:MyPage" .. title.text:sub(#title.rootText + 1) .. "|your own]]")
		end
	else
		links:insert(
			'[' .. tostring(mw.uri.fullUrl('Special:WhatLinksHere/' .. title.fullText,
				'hidelinks=1&hideredirs=1')) .. ' transclusions]')

		if contentModel ~= "Scribunto" then
			links:insert(
				'[' .. tostring(mw.uri.fullUrl('Special:WhatLinksHere/' .. title.fullText,
				'hidelinks=1&hidetrans=1')) .. ' redirects]')
		end
	end
	
	if contentModel == "Scribunto" then
		local is_testcases = title.isSubpage and title.subpageText == "testcases"
		local without_subpage = title.nsText .. ":" .. title.baseText
		if is_testcases then
			links:insert("[[:" .. without_subpage .. "|tested module]]")
		else
			links:insert("[[" .. title.fullText .. "/testcases|testcases]]")
		end
		
		if user_name then
			links:insert("[[User:" .. user_name .. "|user page]]")
			links:insert("[[User talk:" .. user_name .. "|user talk page]]")
			links:insert("[[Special:PrefixIndex/User:" .. user_name .. "/|userspace]]")
		else
			-- If sandbox module, add a link to the module that this is a sandbox of.
			-- Exclude user sandbox modules like [[User:Dine2016/sandbox]].
			if title.text:find("/sandbox%d*%f[/%z]") then
				cats:insert("Sandbox modules")
				
				-- Sandbox modules don't really need documentation.
				needs_doc = false
				
				-- Will behave badly if "/sandbox" occurs twice in title!
				local sandbox_of = title.fullText:gsub("/sandbox%d*%f[/%z]", "")
				
				local diff
				if page_exists(sandbox_of) then
					diff = " (" .. compare_pages(title.fullText, sandbox_of, "diff") .. ")"
				else
					require("Module:debug").track("documentation/no sandbox of")
				end
				
				links:insert("[[:" .. sandbox_of .. "|sandbox of]]" .. (diff or ""))
			
			-- If not a sandbox module, add link to sandbox module.
			-- Sometimes there are multiple sandboxes for a single module:
			-- [[Module:sa-pronunc/sandbox]],  [[Module:sa-pronunc/sandbox2]].
			-- Occasionally sandbox modules have their own subpages that are also
			-- sandboxes: [[Module:grc-decl/sandbox/decl]].
			else
				local sandbox_title
				if title.fullText:find("^Module:grc%-decl/") then
					sandbox_title = title.fullText:gsub("^Module:grc%-decl/", "Module:grc-decl/sandbox/")
				elseif is_testcases then
					sandbox_title = title.fullText:gsub("/testcases", "/sandbox/testcases")
				else
					sandbox_title = title.fullText .. "/sandbox"
				end
				local sandbox_link = "[[:" .. sandbox_title .. "|sandbox]]"
				
				local diff
				if page_exists(sandbox_title) then
					diff = " (" .. compare_pages(title.fullText, sandbox_title, "diff") .. ")"
				end
				
				links:insert(sandbox_link .. (diff or ""))
			end	
		end
	end
	
	if title.nsText == "Template" then
		if title.isSubpage and title.text:find("/sandbox%d*%f[/%z]") then -- This is a sandbox template.
			-- At the moment there are no user sandbox templates with subpage
			-- "/sandbox".
			cats:insert("Sandbox templates")
			
			-- Sandbox templates don't really need documentation.
			needs_doc = false
			
			-- Will behave badly if "/sandbox" occurs twice in title!
			local sandbox_of = title.fullText:gsub("/sandbox%d*%f[/%z]", "")
			
			local diff
			if page_exists(sandbox_of) then
				diff = " (" .. compare_pages(title.fullText, sandbox_of, "diff") .. ")"
			else
				require("Module:debug").track("documentation/no sandbox of")
			end
			
			links:insert("[[:" .. sandbox_of .. "|sandbox of]]" .. (diff or ""))
		else -- This is a template that can have a sandbox.
			local sandbox_title = title.fullText .. "/sandbox"
			
			local diff
			if page_exists(sandbox_title) then
				diff = " (" .. compare_pages(title.fullText, sandbox_title, "diff") .. ")"
			end
			
			links:insert("[[:" .. sandbox_title .. "|sandbox]]" .. (diff or ""))
		end
	end
	
	if #links > 0 then
		output:insert("<dd> ''Useful links'': " .. links:concat(" • ") .. "</dd>")
	end
	
	output:insert("</dl>\n")
	
	if doc_title.exists then
		-- Override automatic documentation, if present.
		doc_content = frame:expandTemplate { title = doc_title.fullText }
	elseif not doc_content and fallback_docs then
		doc_content = frame:expandTemplate {
			title = fallback_docs;
			args = {
				['user'] = user_name;
				['page'] = title.fullText;
				['skin name'] = skin_name;
			}
		}
	end

	if doc_content then
		output:insert(doc_content)
	end

	output:insert(('\n<%s style="clear: both;" />'):format(args.hr == "below" and "hr" or "br"))
	
	if not cats[1] and not doc_content then
		if contentModel == "Scribunto" then
			cats:insert("Uncategorized modules")
		-- elseif title.nsText == "Template" then
			-- cats:insert("Uncategorized templates")
		end
	end
	
	if needs_doc then
		cats:insert("Templates and modules needing documentation")
	end
	
	for _, cat in ipairs(cats) do
		output:insert("[[Category:" .. cat .. "]]")
	end
	
	output:insert("</div>\n")

	return output:concat()
end

-- Used by {{translit module documentation}}.
function export.translitModuleLangList(frame)
	local pagename, subpage
	
	if frame.args[1] then
		pagename = frame.args[1]
	else
		local title = mw.title.getCurrentTitle()
		subpage = title.subpageText
		pagename = title.text
		
		if subpage ~= pagename then
			pagename = title.rootText
		end
	end
	
	local translitModule = pagename
	
	local languageObjects = require("Module:languages/byTranslitModule")(translitModule)
	local codeInPagename = pagename:match("^([%l-]+)%-.*translit$")
	
	local categories = require("Module:array")()
	if codeInPagename then
		local langs = {}
		local codeInPagenameInList = false
		if languageObjects[1] and subpage ~= "documentation" then
			local agreement = languageObjects[2] and "s" or ""
			categories:insert("[[Category:Transliteration modules used by " ..
				#languageObjects .. " language" .. agreement .. "]]")
		end
		
		for i, lang in ipairs(languageObjects) do
			if lang:getCode() == codeInPagename then
				table.remove(languageObjects, i)
				codeInPagenameInList = true
				break
			end
		end
	end
	
	for script_code in pagename:gmatch("%f[^-%z]%u%l%l%l%f[-]") do
		local script = require "Module:scripts".getByCode(script_code)
		if script then
			categories:insert("[[Category:" .. script:getCategoryName() .. "]]")
		end
	end
	
	if subpage ~= "documentation" and not page_exists("Module:" .. pagename .. "/testcases") then
		categories:insert("[[Category:Transliteration modules without a testcases subpage]]")
	end
	
	-- TODO: Use serialCommaJoin in [[Module:table]].
	if not languageObjects[1] then
		return categories:concat()
	end
	
	table.sort(languageObjects,
		function(lang1, lang2)
			return lang1:getCode() < lang2:getCode()
		end)
	if languageObjects[3] then
		for i, lang in ipairs(languageObjects) do
			table.insert(langs, link_lang_cat(lang))
			if languageObjects[i + 2] then
				table.insert(langs, ", ")
			elseif languageObjects[i + 1] then
				table.insert(langs, '<span class="serial-comma">,</span> and ')
			end
		end
	else
		for i, lang in ipairs(languageObjects) do
			table.insert(langs, link_lang_cat(lang))
			
			if languageObjects[i + 1] then
				table.insert(langs, " and ")
			end
		end
	end
	
	langs = table.concat(langs)
	
	return "It is " .. ( codeInPagenameInList and "also" or "" ) ..
		" used to transliterate " .. langs .. "." .. categories:concat()
end

return export