#!/bin/sh

#
# By Aleksey Cheusov <vle@gmx.net>
# The following text is encoded with cp1251 character set
#

gawk '

function usage (){
	printf "%s", "\
Convert cyrillic text to latinica and vice versa\n\
using http://www.geocities.com/Athens/Forum/5344/RL/latinica-ref.html\n\
as a specification\n\
\n\
CP-1251 charset is used!!!\n\
\n\
Usage: latinica [OPTIONS] [files...]\n\
OPTIONS:\n\
-h   --help     display this screen\n\
-V   --version  display version\n\
-r   --rus2lat  translates from latinica to Russian\n\
-l   --lat2rus  translates from Russian to latinica (default)\n\
"
}

function show_version (){
	print "Latinica 0.0.2"
	print "Written by Aleksey Cheusov <vle@gmx.net>"
}

BEGIN {
	mode_lat2rus = "1" # 2 for rus2lat

	for (i=1; i <= ARGC; ++i){
		if (ARGV [i] == "-r" || ARGV [i] == "--rus2lat"){
			mode_lat2rus = 2
			ARGV [i] = ""
		}else if (ARGV [i] == "-l" || ARGV [i] == "--lat2rus"){
			mode_lat2rus = 1
			ARGV [i] = ""
		}else if (ARGV [i] == "-h" || ARGV [i] == "--help"){
			usage()
			exit 0
		}else if (ARGV [i] == "-V" || ARGV [i] == "--version"){
			show_version()
			exit 0
		}
	}

	mode = mode_lat2rus
}

function lat2rus (s) {
########################################
	gsub(/E[\'"'"'`]|`E/, "Ý", s)
	gsub(/J[\'"'"'`]/, "É", s)

	gsub(/e[\'"'"'`]|`e/, "ý", s)
	gsub(/j[\'"'"'`]/, "é", s)

########################################
	gsub(/S[Hh][Cc][hH]/, "Ù", s)
	gsub(/s[hH][cC][hH]/, "ù", s)

########################################
	gsub(/[YJ][Oo]/, "¨", s)
	gsub(/[YJ][Uu]/, "Þ", s)
	gsub(/[YJ][Aa]/, "ß", s)

	gsub(/Z[Hh]/, "Æ", s)
	gsub(/C[Hh]/, "×", s)
	gsub(/S[Hh]/, "Ø", s)

	gsub(/[yj][oO]/, "¸", s)
	gsub(/[yj][uU]/, "þ", s)
	gsub(/[yj][aA]/, "ÿ", s)

	gsub(/z[hH]/, "æ", s)
	gsub(/c[hH]/, "÷", s)
	gsub(/s[hH]/, "ø", s)

	gsub(/J[Ee]/, "Å", s)
	gsub(/j[eE]/, "å", s)

########################################
	gsub(/\^[@]/, "Ý", s)
	gsub(/\_[@]/, "ý", s)

	s = gensub(/([[:upper:][:lower:]]\?)[\'"'"']([[:lower:]])/, "\\1ü\\2", "g", s)
	s = gensub(/([[:upper:][:lower:]])[`]([[:lower:]])/, "\\1ü\\2", "g", s)
	s = gensub(/([[:upper:][:lower:]]\?)[~]([[:lower:]])/, "\\1ú\\2", "g", s)
	s = gensub(/([[:upper:][:lower:]]\?)[@]([[:lower:]])/, "\\1ý\\2", "g", s)

	s = gensub(/([[:lower:]])[\'"'"']/, "\\1ü", "g", s)
	s = gensub(/([[:lower:]])[`]/, "\\1ü", "g", s)
	s = gensub(/([[:lower:]])[~]/, "\\1ú", "g", s)
	s = gensub(/([[:lower:]])[@]/, "\\1ý", "g", s)

	s = gensub(/([[:upper:]])[\'"'"']/, "\\1Ü", "g", s)
	s = gensub(/([[:upper:]])[`]/, "\\1Ü", "g", s)
	s = gensub(/([[:upper:]])[~]/, "\\1Ú", "g", s)

	s = gensub(/([^\\])@/, "\\1Ý", "g", s)
	gsub(/^@/, "Ý", s)
	gsub(/\\@/, "@", s)

	gsub(/\^[\'"'"'`]/, "Ü", s)
	gsub(/\_[\'"'"'`]/, "ü", s)

	gsub(/\^[~]/, "Ú", s)
	gsub(/\_[~]/, "ú", s)

	gsub(/\\\x27/, "'"'"'", s)
	gsub(/\\`/, "`", s)
	gsub(/\\~/, "~", s)
	gsub(/\\\\/, "\\", s)

############################## uppercase
	gsub(/A/, "À", s)
	gsub(/B/, "Á", s)
	gsub(/V/, "Â", s)
	gsub(/G/, "Ã", s)
	gsub(/D/, "Ä", s)
	gsub(/E/, "Å", s)
	gsub(/Z/, "Ç", s)
	gsub(/I/, "È", s)
	gsub(/J/, "É", s)
	gsub(/K/, "Ê", s)
	gsub(/L/, "Ë", s)
	gsub(/M/, "Ì", s)
	gsub(/N/, "Í", s)
	gsub(/O/, "Î", s)
	gsub(/P/, "Ï", s)
	gsub(/R/, "Ð", s)
	gsub(/S/, "Ñ", s)
	gsub(/T/, "Ò", s)
	gsub(/U/, "Ó", s)
	gsub(/F/, "Ô", s)
	gsub(/[XH]/, "Õ", s)
	gsub(/C/, "Ö", s)
	gsub(/[WQ]/, "Ù", s)
	gsub(/Y/, "Û", s)

############################## lowercase
	gsub(/a/, "à", s)
	gsub(/b/, "á", s)
	gsub(/v/, "â", s)
	gsub(/g/, "ã", s)
	gsub(/d/, "ä", s)
	gsub(/e/, "å", s)
	gsub(/z/, "ç", s)
	gsub(/i/, "è", s)
	gsub(/j/, "é", s)
	gsub(/k/, "ê", s)
	gsub(/l/, "ë", s)
	gsub(/m/, "ì", s)
	gsub(/n/, "í", s)
	gsub(/o/, "î", s)
	gsub(/p/, "ï", s)
	gsub(/r/, "ð", s)
	gsub(/s/, "ñ", s)
	gsub(/t/, "ò", s)
	gsub(/u/, "ó", s)
	gsub(/f/, "ô", s)
	gsub(/[xh]/, "õ", s)
	gsub(/c/, "ö", s)
	gsub(/[wq]/, "ù", s)
	gsub(/y/, "û", s)

	return s
}

function rus2lat (s){
	# special characters
	gsub(/[\\]/, "\\\\", s)
	gsub(/[\'"'"']/, "\\'"'"'", s)
	gsub(/~/, "\\~", s)
	gsub(/`/, "\\`", s)
	gsub(/@/, "\\@", s)

	# lowercase
	gsub(/à/, "a", s)
	gsub(/á/, "b", s)
	gsub(/â/, "v", s)
	gsub(/ã/, "g", s)
	gsub(/ä/, "d", s)
	gsub(/å/, "e", s)
	gsub(/¸/, "yo", s)
	gsub(/æ/, "zh", s)
	gsub(/ç/, "z",  s)
	gsub(/è/, "i",  s)
	gsub(/é/, "j'"'"'", s)
	gsub(/ê/, "k", s)
	gsub(/ë/, "l", s)
	gsub(/ì/, "m", s)
	gsub(/í/, "n", s)
	gsub(/î/, "o", s)
	gsub(/ï/, "p", s)
	gsub(/ð/, "r", s)
	gsub(/ñ/, "s", s)
	gsub(/ò/, "t", s)
	gsub(/ó/, "u", s)
	gsub(/ô/, "f", s)
	gsub(/õ/, "x", s)
	gsub(/ö/, "c",    s)
	gsub(/÷/, "ch",   s)
	gsub(/ø/, "sh",   s)
	gsub(/ù/, "shch", s)
	gsub(/ú/, "~",    s)
	gsub(/û/, "y",    s)
	gsub(/ü/, "'"'"'",    s)
	gsub(/ý/, "e'"'"'",   s)
	gsub(/þ/, "yu",   s)
	gsub(/ÿ/, "ya",   s)

	# uppercase
	gsub(/À/, "A", s)
	gsub(/Á/, "B", s)
	gsub(/Â/, "V", s)
	gsub(/Ã/, "G", s)
	gsub(/Ä/, "D", s)
	gsub(/Å/, "E", s)
	gsub(/¨/, "YO", s)
	gsub(/Æ/, "ZH", s)
	gsub(/Ç/, "Z",  s)
	gsub(/È/, "I",  s)
	gsub(/É/, "J'"'"'", s)
	gsub(/Ê/, "K", s)
	gsub(/Ë/, "L", s)
	gsub(/Ì/, "M", s)
	gsub(/Í/, "N", s)
	gsub(/Î/, "O", s)
	gsub(/Ï/, "P", s)
	gsub(/Ð/, "R", s)
	gsub(/Ñ/, "S", s)
	gsub(/Ò/, "T", s)
	gsub(/Ó/, "U", s)
	gsub(/Ô/, "F", s)
	gsub(/Õ/, "X", s)
	gsub(/Ö/, "C",    s)
	gsub(/×/, "CH",   s)
	gsub(/Ø/, "SH",   s)
	gsub(/Ù/, "SHCH", s)
	gsub(/Ú/, "~",    s)
	gsub(/Û/, "Y",    s)
	gsub(/Ü/, "'"'"'",    s)
	gsub(/Ý/, "E'"'"'",   s)
	gsub(/Þ/, "YU",   s)
	gsub(/ß/, "YA",   s)

	# uppercase
	return s
}

function trans (s){
	if (mode == 1){
		return lat2rus(s)
	}else if (mode_lat2rus == 2){
		return rus2lat(s)
	}else{
		return s
	}
}

mode_lat2rus == 1 {
	#### latinica to russian translation

	if (index($0, "\\ ")){
		while (idx = index($0, "\\ ")){
			printf "%s", trans(substr($0, 1, idx-1))
			mode = mode_lat2rus - mode
			$0 = substr($0, idx + 2)
		}

		print trans($0)
	}else{
		print trans($0)
	}

	next
}

mode_lat2rus == 2 {
	#### russian to latinica translation

	if (match($0, /[qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM]+/)){
		while (idx = match($0, /[qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM]+/)){
			printf "%s\\ ", trans(substr($0, 1, idx-1))
			mode = mode_lat2rus - mode
			printf "%s\\ ", trans(substr($0, idx, RLENGTH))

			$0 = substr($0, idx + RLENGTH)
		}

		print trans($0)
	}else{
		print trans($0)
	}

	next
}
{
	print "It'"'"'s impossible" > "/dev/stderr"
	exit 1
}' "$@"