/* liblouis Braille Translation and Back-Translation Library

   Copyright (C) 2012 Swiss Library for the Blind, Visually Impaired and Print Disabled

   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 "internal.h"
#include <getopt.h>
#include "progname.h"
#include "unistr.h"
#include "version-etc.h"

static int forward_flag = 0;
static int backward_flag = 0;

static 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 },
};

const char version_etc_copyright[] =
		"Copyright %s %d Swiss Library for the Blind, Visually Impaired and Print "
		"Disabled.";

#define AUTHORS "Bert Frees"

static void
print_help(void) {
	printf("\
Usage: %s [OPTIONS] TABLE[,TABLE,...]\n",
			program_name);
	fputs("\
Examine and debug Braille translation tables. This program allows you\n\
to inspect liblouis translation tables by printing out the list of\n\
applied translation rules for a given input.\n\n",
			stdout);
	fputs("\
  -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);
	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
}

#define BUFSIZE 512
#define RULESSIZE 512

static char *
get_input(void) {
	static char input_buffer[BUFSIZE];
	size_t input_length;
	input_buffer[0] = 0;
	if (!fgets(input_buffer, sizeof(input_buffer), stdin)) exit(EXIT_FAILURE);
	input_length = strlen(input_buffer) - 1;
	if (input_length < 0) exit(0);
	input_buffer[input_length] = 0;
	return input_buffer;
}

static int
get_wide_input(widechar *buffer) {
	return _lou_extParseChars(get_input(), buffer);
}

static char *
print_chars(const widechar *buffer, int length) {
	static uint8_t result_buf[BUFSIZE];
	size_t result_len = BUFSIZE - 1;
#ifdef WIDECHARS_ARE_UCS4
	u32_to_u8(buffer, length, result_buf, &result_len);
#else
	u16_to_u8(buffer, length, result_buf, &result_len);
#endif
	result_buf[result_len] = 0;
	return result_buf;
}

static char *
print_dots(const widechar *buffer, int length) {
	static char dots[BUFSIZE];
	strcpy(dots, _lou_showDots(buffer, length));
	return dots;
}

static char *
print_number(widechar c) {
	static char number[BUFSIZE];
	sprintf(number, "%d", c);
	return number;
}

static char *
print_attributes(unsigned int a) {
	static char attr[BUFSIZE];
	strcpy(attr, _lou_showAttributes(a));
	return attr;
}

static void
append_char(char *destination, int *length, char source) {
	destination[(*length)++] = source;
}

static void
append_string(char *destination, int *length, char *source) {
	strcpy(&destination[(*length)], source);
	(*length) += strlen(source);
}

static char *
print_script(const widechar *buffer, int length) {
	static char script[BUFSIZE];
	int i = 0;
	int j = 0;
	while (i < length) {
		switch (buffer[i]) {
		case pass_first:
		case pass_last:
		case pass_not:
		case pass_startReplace:
		case pass_endReplace:
		case pass_search:
		case pass_copy:
		case pass_omit:
			append_char(script, &j, buffer[i++]);
			break;
		case pass_lookback:
			append_char(script, &j, buffer[i++]);
			if (buffer[i] > 1) append_string(script, &j, print_number(buffer[i++]));
			break;
		case pass_string:
			append_char(script, &j, buffer[i]);
			append_string(script, &j, print_chars(&buffer[i + 2], buffer[i + 1]));
			append_char(script, &j, buffer[i]);
			i += (2 + buffer[i + 1]);
			break;
		case pass_dots:
			append_char(script, &j, buffer[i++]);
			append_string(script, &j, print_dots(&buffer[i + 1], buffer[i]));
			i += (1 + buffer[i]);
			break;
		case pass_eq:
		case pass_lt:
		case pass_gt:
		case pass_lteq:
		case pass_gteq:
			append_char(script, &j, '#');
			append_string(script, &j, print_number(buffer[i + 1]));
			append_char(script, &j, buffer[i]);
			append_string(script, &j, print_number(buffer[i + 2]));
			i += 3;
			break;
		case pass_hyphen:
		case pass_plus:
			append_char(script, &j, '#');
			append_string(script, &j, print_number(buffer[i + 1]));
			append_char(script, &j, buffer[i]);
			i += 2;
			break;
		case pass_attributes:
			append_char(script, &j, buffer[i]);
			append_string(
					script, &j, print_attributes(buffer[i + 1] << 16 | buffer[i + 2]));
			i += 3;
			if (buffer[i] == 1 && buffer[i + 1] == 1) {
			} else if (buffer[i] == 1 && buffer[i + 1] == 0xffff)
				append_char(script, &j, pass_until);
			else if (buffer[i] == buffer[i + 1])
				append_string(script, &j, print_number(buffer[i]));
			else {
				append_string(script, &j, print_number(buffer[i]));
				append_char(script, &j, '-');
				append_string(script, &j, print_number(buffer[i + 1]));
			}
			i += 2;
			break;
		case pass_endTest:
			append_char(script, &j, '\t');
			i++;
			break;
		case pass_swap:
		case pass_groupstart:
		case pass_groupend:
		case pass_groupreplace:
		/* TBD */
		default:
			i++;
			break;
		}
	}
	script[j] = 0;
	return script;
}

static void
print_rule(const TranslationTableRule *rule) {
	const char *opcode = _lou_findOpcodeName(rule->opcode);
	char *chars;
	char *dots;
	char *script;
	switch (rule->opcode) {
	case CTO_Context:
	case CTO_Correct:
	case CTO_SwapCd:
	case CTO_SwapDd:
	case CTO_Pass2:
	case CTO_Pass3:
	case CTO_Pass4:
		script = print_script(&rule->charsdots[rule->charslen], rule->dotslen);
		printf("%s\t%s\n", opcode, script);
		break;
	default:
		chars = print_chars(rule->charsdots, rule->charslen);
		dots = print_dots(&rule->charsdots[rule->charslen], rule->dotslen);
		printf("%s\t%s\t%s\n", opcode, chars, dots);
		break;
	}
}

static void
main_loop(int backward_translation, char *table) {
	widechar inbuf[BUFSIZE];
	widechar outbuf[BUFSIZE];
	int inlen;
	int outlen;
	const TranslationTableRule **rules = malloc(512 * sizeof(TranslationTableRule));
	int ruleslen;
	int i, j;
	while (1) {
		inlen = get_wide_input(inbuf);
		outlen = BUFSIZE;
		ruleslen = RULESSIZE;
		if (backward_translation) {
			if (!_lou_backTranslateWithTracing(table, inbuf, &inlen, outbuf, &outlen,
						NULL, NULL, NULL, NULL, NULL, 0, rules, &ruleslen))
				break;
		} else if (!_lou_translateWithTracing(table, inbuf, &inlen, outbuf, &outlen, NULL,
						   NULL, NULL, NULL, NULL, 0, rules, &ruleslen))
			break;
		printf("%s\n", print_chars(outbuf, outlen));
		j = 0;
		for (i = 0; i < ruleslen; i++) {
			if (rules[i]->opcode < 0 || rules[i]->opcode >= CTO_None) continue;
			printf("%d.\t", ++j);
			print_rule(rules[i]);
		}
	}
}

int
main(int argc, char **argv) {
	int optc;
	char *table;
	set_program_name(argv[0]);
	while ((optc = getopt_long(argc, argv, "hvfb", longopts, NULL)) != -1) {
		switch (optc) {
		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) {
		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);
	}
	table = argv[optind];
	if (!lou_getTable(table)) {
		lou_free();
		exit(EXIT_FAILURE);
	}
	main_loop(backward_flag, table);
	lou_free();
	exit(EXIT_SUCCESS);
}