Modul:ks-Arab-translit

-- TODO: long í support
-- TODO: sort out short e vs palatalisation
-- TODO: add rule for CẹC = CyaC

local u = mw.ustring.char
local gsub = mw.ustring.gsub

local export = {}

local vav = u(0x0648)
local ye = u(0x06CC)
local alif = u(0x0627)
local he = 'ه'

local vw_s_cfu = u(0x0650) -- pesh (i)
local vw_s_ccu = u(0x0655) -- hamza below
local vw_s_cbr = u(0x064F) -- zer (u)
local vw_s_mcu = u(0x0654) -- hamza above
local vw_s_ocu = u(0x064E) -- zabar (a)

local vw_l_cbr = u(0x0657) -- inverted zer
local vw_l_cfu = u(0x0656) -- subscript alif

local hat = u(0x065A)
local inverted_hat = u(0x065B)
local hats = hat .. inverted_hat

local short_vowels_list = vw_s_cfu .. vw_s_ccu .. vw_s_cbr .. vw_s_mcu .. vw_s_ocu 

-- carrier + diacritic combos
local long_u = vav .. vw_l_cbr
local short_o = vav .. inverted_hat
local long_i = ye .. vw_l_cfu
local short_e = ye .. inverted_hat

local vocalised_carrier = long_u .. short_o .. long_i .. short_e .. 'ۆ' .. 'ێ' .. 'ۆ' .. 'اٟ'
local palatalisers = "ۍؠ"

local consonants = "بپتٹجچدڈرڑزژسشفکگلمنهھےثحخذصضطظعغقۍۄیٲآ"
local consonants_latn = "bptṭsjchxdḍzrċsśzʿġfqkglmnhv"

local conv = {
	-- consonants
	['ب'] = 'b', ['پ'] = 'p', ['ت'] = 't', ['ٹ'] = 'ṭ', ['ث'] = 's',
	['ج'] = 'j', ['چ'] = 'c', ['ح'] = 'h', ['خ‬'] = 'x',
	['د'] = 'd', ['ڈ'] = 'ḍ', ['ذ‬'] = 'z',
	['ر'] = 'r', ['ڑ'] = 'ḍ', ['ز'] = 'z', ['ژ'] = 'ċ',
	['س'] = 's', ['ش'] = 'ś', ['ص‬'] = 's', ['ض‬'] = 'z',
	['ط‬'] = 't', ['ظ'] = 'z',
	['ع'] = 'ʿ', ['غ'] = 'ġ',
	['ف'] = 'f', ['ق'] = 'q',
	['ک'] = 'k', ['گ'] = 'g',
	['ل'] = 'l', ['م'] = 'm', ['ن'] = 'n',
	['ه'] = 'h', ['ھ'] = 'h',
	['خ'] = 'x',
	
	-- always word-final
	['ے'] = 'y',
	
	-- incorrect palatalisation marker
	['ۍ'] = '\'',

	-- broken/open vowels
	['ۄ'] = 'ọ', ['ؠ'] = 'ẹ', -- optionally ẹ = ya
	
	-- a carries long vowels
	['ٲ'] = 'ạ̄', ['آ'] = 'ā',

    ['یٖ'] = 'ī', ['اٟ'] = 'ụ̄',

    -- vowels
    ['ۆ'] = 'o', ['ۆ'] = 'o', ['ێ'] = 'e', ['أ'] = 'ạ',
	
	-- numerals
	['۰'] = '0', ['۱'] = '1', ['۲'] = '2', ['۳'] = '3', ['۴'] = '4', ['۵'] = '5', ['۶'] = '6', ['۷'] = '7', ['۸'] = '8', ['۹'] = '9',
}

local short_vowels = {
	-- high vowels
	[u(0x0650)] = 'i', [u(0x0655)] = 'ụ', [u(0x064F)] = 'u', [u(0x065F)] = 'ụ̄',
	
	-- central vowels
	[u(0x0654)] = 'ạ',
	
	-- low vowels
	[u(0x064E)] = 'a',
}

local alif = 'ا'
local waw = 'و'
local ye = 'ی'

function export.tr(text, lang, sc)
    text = gsub(text, '([' .. palatalisers .. ']%f[%s%z])', '\'')

    -- interconsonantal vav is a long ō sound
    text = gsub(text,
        '([' .. consonants ..  ']ھ?)' .. vav .. '([' .. consonants .. '])',
        "%1ō%2")

    -- intervocalic alif is a long a sound
	text = gsub(text, '([' .. consonants .. 'و ' .. '])' .. alif .. '([' .. consonants .. 'و' .. '])', "%1ā%2")

    -- final he + short vowel disregards the he and transliterates the vowel
    text = gsub(text, 'ہ([' ..  short_vowels_list .. '])', short_vowels)

    -- word-initial alif + vowelled carrier drops the alif
    text = gsub(text, '^' .. alif .. '([' .. vocalised_carrier .. '])', "%1")

    -- word-initial alif + short vowel diacritic drops the alif
    text = gsub(text, '^' .. alif .. '([' .. short_vowels_list .. '])', "%1")
	
    -- long /u:/ and /i:/
    text = gsub(text, vav .. vw_s_cbr .. vav .. "([" .. consonants .. "])", vav .. "ū%1")
    text = gsub(text, "([" .. consonants  .. "])" .. vw_s_cfu .. ye .. "([" .. consonants .. "])", "%1ī%2")

    -- vav with hat = short o
    text = gsub(text, vav .. "[" .. hats .. "]", "o")

    -- vav with short vowel
    text = gsub(text,
        vav .. "([" .. short_vowels_list .. "])",
        function(c)
            return "v" .. short_vowels[c]
        end)

    -- nun or re with hat
    -- TODO: add support for re
    text = gsub(text, "ن" .. "[" .. hats.. "]", "n")

    -- ye with hat = short e
    text = gsub(text, ye .. "[" .. hats.. "]", "e")

    -- vav with inverted pish = long u
    text = gsub(text, long_u, "ū")

    -- long i
    text = gsub(text, ye .. vw_l_cfu, 'ī') 

    -- intervocalic ye is a long a sound
    text = gsub(text, '([' .. consonants .. '])' .. ye .. '([' .. consonants .. '])', "%1ē%2")

    -- word-final alif and ye
    text = gsub(text, '([' .. consonants .. '])' .. ye .. '$', "%1ī")
    text = gsub(text, '([' .. consonants .. '])' .. alif .. '$', "%1ā")

    -- regard the consonant + short vowel combinations throughout
	text = gsub(text, '.', short_vowels)

	text = gsub(text, '[أإبپتٹجچدڈرڑزژسشفکگلمنهھےثحخذصضطظعغقۍۄؠٲآۆۆێ]', conv)
	
	-- normal consonants left over
	text = gsub(text, vav, 'v')
	text = gsub(text, 'ہ', 'h')
    text = gsub(text, "ی", "y")

	-- CẹC = CyaC
    text = gsub(text, "([" .. consonants_latn .. "])ẹ([" .. consonants_latn .. "])", "%1ya%2")
	
	return text
end

return export