/* liblouis Braille Translation and Back-Translation Library

   Based on the Linux screenreader BRLTTY, copyright (C) 1999-2006 by
   The BRLTTY Team

   Copyright (C) 2004, 2005, 2006, 2009
   ViewPlus Technologies, Inc. www.viewplus.com and
   JJB Software, Inc. www.jjb-software.com

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <config.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <getopt.h>
#include "liblouis.h"
#include "internal.h"
#include "progname.h"
#include "unistr.h"
#include "version-etc.h"

const char version_etc_copyright[] =
		"Copyright %s %d ViewPlus Technologies, Inc. and JJB Software, Inc.";

#define AUTHORS "John J. Boyer"

static void
translate_input(int forward_translation, char *table_name, FILE *input) {
	char charbuf[MAXSTRING];
	uint8_t *outputbuf;
	size_t outlen;
	widechar inbuf[MAXSTRING];
	widechar transbuf[MAXSTRING];
	int inlen;
	int translen;
	int k;
	int ch = 0;
	int result;
	while (1) {
		translen = MAXSTRING;
		k = 0;
		while ((ch = fgetc(input)) != '\n' && ch != EOF && k < MAXSTRING - 1)
			charbuf[k++] = ch;
		if (ch == EOF && k == 0) break;
		charbuf[k] = 0;
		inlen = _lou_extParseChars(charbuf, inbuf);
		if (forward_translation)
			result = lou_translateString(
					table_name, inbuf, &inlen, transbuf, &translen, NULL, NULL, 0);
		else
			result = lou_backTranslateString(
					table_name, inbuf, &inlen, transbuf, &translen, NULL, NULL, 0);
		if (!result) break;
#ifdef WIDECHARS_ARE_UCS4
		outputbuf = u32_to_u8(transbuf, translen, NULL, &outlen);
#else
		outputbuf = u16_to_u8(transbuf, translen, NULL, &outlen);
#endif
		printf(ch == EOF ? "%.*s" : "%.*s\n", (int)outlen, outputbuf);
		free(outputbuf);
	}
	lou_free();
}

static void
print_help(void) {
	printf("\
Usage: %s [OPTIONS] TABLE[,TABLE,...]\n",
			program_name);

	fputs("\
Translate whatever is on standard input and print it on standard\n\
output. It is intended for large-scale testing of the accuracy of\n\
Braille translation and back-translation.\n\n",
			stdout);

	fputs("\
Options:\n\
  -h, --help          display this help and exit\n\
  -v, --version       display version information and exit\n\
  -f, --forward       forward translation using the given table\n\
  -b, --backward      backward translation using the given table\n\
                      If neither -f nor -b are specified forward translation\n\
                      is assumed\n",
			stdout);
	fputs("\
Examples:\n\
  lou_translate --forward en-us-g2.ctb < input.txt\n\
  \n\
  Do a forward translation with table en-us-g2.ctb. The resulting braille is\n\
  ASCII encoded.\n\
  \n\
  lou_translate unicode.dis,en-us-g2.ctb < input.txt\n\
  \n\
  Do a forward translation with table en-us-g2.ctb. The resulting braille is\n\
  encoded as Unicode dot patterns.\n\
  \n\
  echo \",! qk br{n fox\" | lou_translate --backward en-us-g2.ctb\n\
  \n\
  Do a backward translation with table en-us-g2.ctb.\n",
			stdout);
	printf("\n");
	printf("Report bugs to %s.\n", PACKAGE_BUGREPORT);

#ifdef PACKAGE_PACKAGER_BUG_REPORTS
	printf("Report %s bugs to: %s\n", PACKAGE_PACKAGER, PACKAGE_PACKAGER_BUG_REPORTS);
#endif
#ifdef PACKAGE_URL
	printf("%s home page: <%s>\n", PACKAGE_NAME, PACKAGE_URL);
#endif
}

int
main(int argc, char **argv) {
	int optc;

	int forward_flag = 0;
	int backward_flag = 0;

	const struct option longopts[] = {
		{ "help", no_argument, NULL, 'h' },
		{ "version", no_argument, NULL, 'v' },
		{ "forward", no_argument, NULL, 'f' },
		{ "backward", no_argument, NULL, 'b' },
		{ NULL, 0, NULL, 0 },
	};

	set_program_name(argv[0]);
	while ((optc = getopt_long(argc, argv, "hvfb", longopts, NULL)) != -1) {
		switch (optc) {
		/* --help and --version exit immediately, per GNU coding standards. */
		case 'v':
			version_etc(
					stdout, program_name, PACKAGE_NAME, VERSION, AUTHORS, (char *)NULL);
			exit(EXIT_SUCCESS);
			break;
		case 'h':
			print_help();
			exit(EXIT_SUCCESS);
			break;
		case 'f':
			forward_flag = 1;
			break;
		case 'b':
			backward_flag = 1;
			break;
		default:
			fprintf(stderr, "Try `%s --help' for more information.\n", program_name);
			exit(EXIT_FAILURE);
			break;
		}
	}

	if (forward_flag && backward_flag) {
		fprintf(stderr, "%s: specify either -f or -b but not both\n", program_name);
		fprintf(stderr, "Try `%s --help' for more information.\n", program_name);
		exit(EXIT_FAILURE);
	}

	if (optind != argc - 1) {
		// Print error message and exit.
		if (optind < argc - 1)
			fprintf(stderr, "%s: extra operand: %s\n", program_name, argv[optind + 1]);
		else
			fprintf(stderr, "%s: no table specified\n", program_name);
		fprintf(stderr, "Try `%s --help' for more information.\n", program_name);
		exit(EXIT_FAILURE);
	}
	/* assume forward translation by default */
	translate_input(!backward_flag, argv[optind], stdin);
	exit(EXIT_SUCCESS);
}