local export = {}

local lang = require("Module:languages").getByCode("mt")
local m_utilities = require("Module:utilities")
local m_links = require("Module:links")
local m_headword = require("Module:headword")
local rsplit = mw.text.split

local function link(term, alt, id)
	if word == "" or word == "—" then
		return word
	else
		return m_links.full_link(
			{
				term = term,
				alt = alt,
				lang = lang,
				id = id
			},
			face
		)
	end
end

local function validateRoot(rootTable, joined_root)
	if type(rootTable) ~= "table" then
		error("rootTable is not a table", 2)
	end

	for i, letter in ipairs(rootTable) do
		if mw.ustring.len(letter) > 1 and letter ~= "għ" then
			error("'" ..letter .. "', the " .. ordinal[i] .. " letter in the root '" .. joined_root .. "' should be a single letter.")
		end
	end
end

function export.root(frame)
	local output = {}
	local categories = {}
	local title = mw.title.getCurrentTitle()
	local fulltitle = title.fullText
	local namespace = title.nsText

	local params = {
		[1] = {},
		["nocat"] = {type = "boolean"},
		["plain"] = {type = "boolean"},
		["notext"] = {type = "boolean"},
		["sense"] = {}
	}

	local args = require("Module:parameters").process(frame:getParent().args, params)
	local rootLetters = {}

	if not args[1] and namespace == "Template" then
		rootLetters = {"k", "t", "b"}
	elseif args[1] then
		rootLetters = rsplit(args[1], "-")
	else
		rootLetters = rsplit(fulltitle, "-")
	end

	local joined_root = table.concat(rootLetters, "-")
	validateRoot(rootLetters, joined_root)

	local sense = args["sense"]
	local sense_formatted = ""
	if sense ~= nil then
		sense_formatted = " (" .. sense .. ") "
	end

	if fulltitle == joined_root then
		table.insert(output, m_headword.full_headword({lang = lang, pos_category = "roots", categories = {}, heads = { fulltitle }, nomultiwordcat = true}) )

		if args["nocat"] then
			return table.concat(output)
		else
			return table.concat(output) .. table.concat(categories)
		end
	else
		local link_text

		link_text = link(joined_root, joined_root .. sense_formatted, sense)

		table.insert(output, link_text)

		table.insert(
			categories,
			m_utilities.format_categories({lang:getCanonicalName() .. " terms belonging to the root " .. joined_root .. sense_formatted}, lang)
		)

		if args["nocat"] then
			return table.concat(output)
		elseif args["plain"] then
			return table.concat(output)
		else
			local term_count =
				mw.site.stats.pagesInCategory(
				lang:getCanonicalName() .. " terms belonging to the root " .. joined_root .. sense_formatted,
				"pages"
			)
			return '<table class="wikitable" style="float: right; clear: right; text-align: center;"><tr><th>[[w:Semitic root|Root]]</th></tr><tr><td>' ..
				link_text ..
					"</td></tr><tr><td>[[:Category:" .. lang:getCanonicalName() .. " terms belonging to the root " .. joined_root .. sense_formatted .. "|" .. term_count .. " term" .. (term_count == 1 and "" or "s") .. "]]</td></tr></table>" .. table.concat(categories)
		end
	end
end

return export