-- This module contains code for Italian headword templates.
-- Templates covered are it-adj and it-noun.
-- See Module:itconj for Italian conjugation templates.
local export = {}

local lang = require("Module:languages").getByCode("it")

function export.itadj(frame)
	local params = {
		[1] = {},
		[2] = {},
		[3] = {},
		[4] = {},
		[5] = {},
		
		["head"] = {},
		["sort"] = {},
	}
	
	local args = require("Module:parameters").process(frame:getParent().args, params)
	
	local data = {lang = lang, pos_category = "adjectives", categories = {}, sort_key = args["sort"], heads = {args["head"]}, genders = {}, inflections = {}}
	
	local stem = args[1]
	local end1 = args[2]
	
	if not stem then -- all specified
		data.heads = args[2]
		data.inflections = {
			{label = "feminine singular", args[3]},
			{label = "masculine plural", args[4]},
			{label = "feminine plural", args[5]}
		}
	elseif not end1 then -- no ending vowel parameters - generate default
		data.inflections = {
			{label = "feminine singular", stem .. "a"},
			{label = "masculine plural", make_plural(stem .. "o","m")},
			{label = "feminine plural", make_plural(stem .. "a","f")}
		}
	else
		local end2 = args[3] or error("Either 0, 2 or 4 vowel endings should be supplied!")
		local end3 = args[4]
		
		if not end3 then -- 2 ending vowel parameters - m and f are identical
			data.inflections = {
				{label = "masculine and feminine plural", stem .. end2}
			}
		else -- 4 ending vowel parameters - specify exactly
			local end4 = args[5] or error("Either 0, 2 or 4 vowel endings should be supplied!")
			data.inflections = {
				{label = "feminine singular", stem .. end2},
				{label = "masculine plural", stem .. end3},
				{label = "feminine plural", stem .. end4}
			}
		end
	end
	
	return require("Module:headword").full_headword(data)
end

function export.itnoun(frame)
	PAGENAME = mw.title.getCurrentTitle().text
	
	local params = {
		[1] = {},
		[2] = {},
		
		["f"] = {},
		["head"] = {},
		["m"] = {},
		["sort"] = {},
	}
	
	local args = require("Module:parameters").process(frame:getParent().args, params)
	
	local data = {lang = lang, pos_category = "nouns", categories = {}, sort_key = args["sort"], heads = {args["head"]}, genders = {}, inflections = {}}
	
	-- Gender
	if args[1] == "mf" then
		data.genders = {"m", "f"}
	else
		data.genders = {args[1]}
	end
	
	if #data.genders == 0 then
		data.genders = {"?"}
	end
	
	-- Plural
	local plural = args[2]
	
	if not plural then
		plural = make_plural(PAGENAME, data.genders[1])
	end
	
	if plural == "~" then
		table.insert(data.inflections, {label = "[[Appendix:Glossary#uncountable|uncountable]]"})
		table.insert(data.categories, "Italian uncountable nouns")
	else
		table.insert(data.categories, "Italian countable nouns")
	end
	
	if plural == "-" then
		table.insert(data.inflections, {label = "invariable"})
	end
	
	if plural == "-" or plural == "~" then
	else
		table.insert(data.inflections, {label = "plural", plural})
	end
	
	-- Other gender
	if args["f"] then
		table.insert(data.inflections, {label = "feminine", args["f"]})
	end
	
	if args["m"] then
		table.insert(data.inflections, {label = "masculine", args["m"]})
	end
	
	-- Category
	if (data.heads[1] or PAGENAME):find('o$') and data.genders[1] == "f" then
		table.insert(data.categories, "Italian nouns with irregular gender")
	end
	
	if (data.heads[1] or PAGENAME):find('a$') and data.genders[1] == "m" then
		table.insert(data.categories, "Italian nouns with irregular gender")
	end
	
	return require("Module:headword").full_headword(data)
end

-- Generate a default plural form, which is correct for most regular nouns
function make_plural(word, gender)
	-- If there are spaces in the term, then we can't reliably form the plural.
	-- Return nothing instead.
	if word:find(" ") then
		return nil
	elseif word:find("io$") then
		word = word:gsub("io$", "i")
	elseif word:find("ologo$") then
		word = word:gsub("o$", "i")
	elseif word:find("[cg]o$") then
		word = word:gsub("o$", "hi")
	elseif word:find("o$") then
		word = word:gsub("o$", "i")
	elseif word:find("[cg]a$") then
		word = word:gsub("a$", (gender == "m" and "hi" or "he"))
	elseif word:find("[cg]ia$") then
		word = word:gsub("ia$", "e")
	elseif word:find("a$") then
		word = word:gsub("a$", (gender == "m" and "i" or "e"))
	elseif word:find("e$") then
		word = word:gsub("e$", "i")
	end
	return word
end

-- Generate a default feminine form
function make_feminine(word, gender)
	if word:find("o$") then
		return word:gsub("o$", "a")
	else
		return word
	end
end

return export