Module:hsb-common


local export = {}

local lang = require("Module:languages").getByCode("hsb")
local m_links = require("Module:links")
local m_table = require("Module:table")
local m_string_utilities = require("Module:string utilities")

local u = mw.ustring.char
local rsplit = mw.text.split
local rfind = mw.ustring.find
local rmatch = mw.ustring.match
local rsubn = mw.ustring.gsub
local ulen = mw.ustring.len
local uupper = mw.ustring.upper

-- version of rsubn() that discards all but the first return value
local function rsub(term, foo, bar)
	local retval = rsubn(term, foo, bar)
	return retval
end

-- version of rsubn() that returns a 2nd argument boolean indicating whether
-- a substitution was made.
local function rsubb(term, foo, bar)
	local retval, nsubs = rsubn(term, foo, bar)
	return retval, nsubs > 0
end

export.TEMP_CH = u(0xFFF0) -- used to substitute ch temporarily in the default-reducible code
export.TEMP_SOFT_LABIAL = u(0xFFF1)

local lc_vowel = "aeěioóuy"
local uc_vowel = uupper(lc_vowel)
export.vowel = lc_vowel .. uc_vowel
export.vowel_c = "[" .. export.vowel .. "]"
export.non_vowel_c = "[^" .. export.vowel .. "]"
-- Consonants that can never form a syllabic nucleus.
local lc_non_syllabic_cons = "bcčćdfghjklłmnńpqrřsštvwxzž" .. "bj" .. "dź" .. "ch" .. "mj" .. "nj" .. "pj" .. "rj" .. "tř" .. "wj"
local uc_non_syllabic_cons = uupper(lc_non_syllabic_cons)
export.non_syllabic_cons = lc_non_syllabic_cons .. uc_non_syllabic_cons
export.non_syllabic_cons_c = "[" .. export.non_syllabic_cons .. "]"
local lc_syllabic_cons = "lrř"
local uc_syllabic_cons = uupper(lc_syllabic_cons)
local lc_cons = lc_non_syllabic_cons .. lc_syllabic_cons
local uc_cons = uupper(lc_cons)
export.cons = lc_cons .. uc_cons
export.cons_c = "[" .. export.cons .. "]"
export.lowercase = lc_vowel .. lc_cons
export.lowercase_c = "[" .. export.lowercase .. "]"
export.uppercase = uc_vowel .. uc_cons
export.uppercase_c = "[" .. export.uppercase .. "]"

local lc_velar = "kgh"
local uc_velar = uupper(lc_velar)
export.velar = lc_velar .. uc_velar
export.velar_c = "[" .. export.velar .. "]"

local lc_plain_labial = ""
local lc_labial = lc_plain_labial .. export.TEMP_SOFT_LABIAL
local uc_plain_labial = uupper(lc_plain_labial)
local uc_labial = uupper(lc_labial)
export.plain_labial = lc_plain_labial .. uc_plain_labial
export.labial = lc_labial .. uc_labial
export.labial_c = "[" .. export.labial .. "]"

local lc_paired_palatal = "ndtl"
local uc_paired_palatal = uupper(lc_paired_palatal)
export.paired_palatal = lc_paired_palatal .. uc_paired_palatal
local lc_paired_plain = "ndtłrbpmw"
local uc_paired_plain = uupper(lc_paired_plain)
export.paired_plain = lc_paired_plain .. uc_paired_plain
export.paired_palatal_to_plain = {
	["bj"] = "b",
	["BJ"] = "B",
	["pj"] = "p",
	["PJ"] = "P",
	["mj"] = "m",
	["MJ"] = "M",
	["wj"] = "w",
	["WJ"] = "W",
	["nj"] = "n",
	["NJ"] = "N",
	["rj"] = "r",
	["RJ"] = "R",
	["ć"] = "t",
	["Ć"] = "T",
	["dź"] = "d",
	["Dź"] = "D",
	["l"] = "ł",
	["L"] = "Ł",
}
export.paired_plain_to_palatal = {}
for k, v in pairs(export.paired_palatal_to_plain) do
	export.paired_plain_to_palatal[v] = k
end
export.paired_palatal_to_plain[export.TEMP_SOFT_LABIAL] = ""
for labial in mw.ustring.gmatch(export.plain_labial, ".") do
	export.paired_plain_to_palatal[labial] = labial .. export.TEMP_SOFT_LABIAL
end

local lc_inherently_soft = "čćźńjlšž"
local uc_inherently_soft = uupper(lc_inherently_soft)
export.inherently_soft = lc_inherently_soft .. uc_inherently_soft
export.inherently_soft_c = "[" .. export.inherently_soft .. "]"


function export.is_monosyllabic(word)
	-- Convert all vowels to 'e'.
	word = rsub(word, export.vowel_c, "e")
	-- All consonants next to a vowel are non-syllabic; convert to 't'.
	word = rsub(word, export.cons_c .. "e", "te")
	word = rsub(word, "e" .. export.cons_c, "et")
	-- Convert all remaining non-syllabic consonants to 't'.
	word = rsub(word, export.non_syllabic_cons_c, "t")
	-- At this point, what remains is 't', 'e', or a syllabic consonant. Count the latter two types.
	word = word:gsub("t", "")
	return ulen(word) <= 1
end


function export.apply_vowel_alternation(alt, stem)
	local modstem, origvowel
	if alt == "quant" then
		modstem = rsub(stem, "(.)([ó])(" .. export.cons_c .. "*)$",
			function(pre, vowel, post)
				origvowel = vowel
				if vowel == "ó" then
					return pre .. "o" .. post
				end
			end
		)
	else
		return stem, nil
	end
	return modstem, origvowel
end


local function make_try(word)
	return function(from, to)
		local stem = rmatch(word, "^(.*)" .. from .. "$")
		if stem then
			return stem .. to
		end
		return nil
	end
end

-- nosy > noša, wozy > woža, dyrbi > dyrbja
function export.iotate(word)
	local try = make_try(word)
	return
		try("s", "š") or
		try("z", "ž") or
		try("b", "bj") or
		try("p", "pj") or
-- not complete
		word
end

-- pjeku > pječeš, bjeru > bjerješ, sunu > sunješ, du > dźeš, pletu > plećeš
function export.apply_palatalization(word, is_soft)
	local try = make_try(word)
	return
		try("tr", "tř") or
		try("t", "ć") or
		try("d", "dź") or
		try("k", "c") or
		try("ch", "š") or
		try("h", "z") or
		word
end

function export.addj(word)
	local try = make_try(word)
	return
		try("m", "mj") or
		try("b", "bj") or
		try("p", "pj") or
		try("w", "wj") or
		try("ń", "nj") or
		try("r", "rj") or
		word
end

function export.removej(word)
	local try = make_try(word)
	return
		try("mj", "m") or
		try("bj", "b") or
		try("pj", "p") or
		try("wj", "w") or
		try("nj", "n") or
		try("rj", "r") or
		word
end


function export.reduce(word)
	local pre, letter, vowel, post = rmatch(word, "^(.*)([" .. export.cons .. "y%-])([e])(" .. export.cons_c .. "+)$")
	if not pre then
		return nil
	end
	return pre .. letter .. post
end


function export.dereduce(base, stem)
	local pre, letter, post = rmatch(stem, "^(.*)(" .. export.cons_c .. ")(" .. export.cons_c .. ")$")
	if not pre then
		return nil
	end
	local epvowel = "e"
	return pre .. letter .. epvowel .. post
end


function export.convert_paired_plain_to_palatal(stem, ending)
	if ending and not rfind(ending, "^[ěi]") then
		return stem
	end
	local stembegin, lastchar = rmatch(stem, "^(.*)([" .. export.paired_plain .. "])$")
	if lastchar then
		return stembegin .. export.paired_plain_to_palatal[lastchar]
	else
		return stem
	end
end


function export.convert_paired_palatal_to_plain(stem, ending)
	-- For stems that alternate between n/t/d and ň/ť/ď, we always maintain the stem in the latter format and convert
	-- to the corresponding plain as needed, with e -> ě.
	if ending and not rfind(ending, "^[Eěií]") then
		stem = stem:gsub(export.TEMP_SOFT_LABIAL, "")
		return stem, ending
	end
	local stembegin, lastchar = rmatch(stem, "^(.*)([" .. export.paired_palatal .. "])$")
	if lastchar then
		ending = ending and rsub(ending, "^e", "ě") or nil
		stem = stembegin .. export.paired_palatal_to_plain[lastchar]
	end
	-- 'E' has served its purpose of preventing the e -> ě conversion after a paired palatal (i.e. it depalatalizes
	-- paired palatals).
	ending = ending and rsub(ending, "^E", "e") or nil
	return stem, ending
end


function export.combine_stem_ending(base, slot, stem, ending)
	if stem == "?" then
		return "?"
	else
		if base.all_uppercase then
			stem = uupper(stem)
		end
			return stem .. ending
	end
end


return export