/*
 * Copyright (c) 2011-2012 - Mauro Carvalho Chehab
 *
 * 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 version 2
 * of the License.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 * Or, point your browser to http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 */

/*
 * handle character set correctly (e.g. via iconv)
 *   c.f. EN 300 468 annex A
 */

#include <config.h>
#include <iconv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h> /* strcasecmp */

#include <parse_string.h>
#include <libdvbv5/dvb-log.h>
#include <libdvbv5/dvb-fe.h>

#define CS_OPTIONS "//TRANSLIT"

struct charset_conv {
	unsigned len;
	unsigned char  data[3];
};

/* This table is the Latin 00 table. Basically ISO-6937 + Euro sign */
static struct charset_conv en300468_latin_00_to_utf8[256] = {
	[0x00] = { 1, {0x00, } },
	[0x01] = { 1, {0x01, } },
	[0x02] = { 1, {0x02, } },
	[0x03] = { 1, {0x03, } },
	[0x04] = { 1, {0x04, } },
	[0x05] = { 1, {0x05, } },
	[0x06] = { 1, {0x06, } },
	[0x07] = { 1, {0x07, } },
	[0x08] = { 1, {0x08, } },
	[0x09] = { 1, {0x09, } },
	[0x0a] = { 1, {0x0a, } },
	[0x0b] = { 1, {0x0b, } },
	[0x0c] = { 1, {0x0c, } },
	[0x0d] = { 1, {0x0d, } },
	[0x0e] = { 1, {0x0e, } },
	[0x0f] = { 1, {0x0f, } },
	[0x10] = { 1, {0x10, } },
	[0x11] = { 1, {0x11, } },
	[0x12] = { 1, {0x12, } },
	[0x13] = { 1, {0x13, } },
	[0x14] = { 1, {0x14, } },
	[0x15] = { 1, {0x15, } },
	[0x16] = { 1, {0x16, } },
	[0x17] = { 1, {0x17, } },
	[0x18] = { 1, {0x18, } },
	[0x19] = { 1, {0x19, } },
	[0x1a] = { 1, {0x1a, } },
	[0x1b] = { 1, {0x1b, } },
	[0x1c] = { 1, {0x1c, } },
	[0x1d] = { 1, {0x1d, } },
	[0x1e] = { 1, {0x1e, } },
	[0x1f] = { 1, {0x1f, } },
	[0x20] = { 1, {0x20, } },
	[0x21] = { 1, {0x21, } },
	[0x22] = { 1, {0x22, } },
	[0x23] = { 1, {0x23, } },
	[0x24] = { 1, {0x24, } },
	[0x25] = { 1, {0x25, } },
	[0x26] = { 1, {0x26, } },
	[0x27] = { 1, {0x27, } },
	[0x28] = { 1, {0x28, } },
	[0x29] = { 1, {0x29, } },
	[0x2a] = { 1, {0x2a, } },
	[0x2b] = { 1, {0x2b, } },
	[0x2c] = { 1, {0x2c, } },
	[0x2d] = { 1, {0x2d, } },
	[0x2e] = { 1, {0x2e, } },
	[0x2f] = { 1, {0x2f, } },
	[0x30] = { 1, {0x30, } },
	[0x31] = { 1, {0x31, } },
	[0x32] = { 1, {0x32, } },
	[0x33] = { 1, {0x33, } },
	[0x34] = { 1, {0x34, } },
	[0x35] = { 1, {0x35, } },
	[0x36] = { 1, {0x36, } },
	[0x37] = { 1, {0x37, } },
	[0x38] = { 1, {0x38, } },
	[0x39] = { 1, {0x39, } },
	[0x3a] = { 1, {0x3a, } },
	[0x3b] = { 1, {0x3b, } },
	[0x3c] = { 1, {0x3c, } },
	[0x3d] = { 1, {0x3d, } },
	[0x3e] = { 1, {0x3e, } },
	[0x3f] = { 1, {0x3f, } },
	[0x40] = { 1, {0x40, } },
	[0x41] = { 1, {0x41, } },
	[0x42] = { 1, {0x42, } },
	[0x43] = { 1, {0x43, } },
	[0x44] = { 1, {0x44, } },
	[0x45] = { 1, {0x45, } },
	[0x46] = { 1, {0x46, } },
	[0x47] = { 1, {0x47, } },
	[0x48] = { 1, {0x48, } },
	[0x49] = { 1, {0x49, } },
	[0x4a] = { 1, {0x4a, } },
	[0x4b] = { 1, {0x4b, } },
	[0x4c] = { 1, {0x4c, } },
	[0x4d] = { 1, {0x4d, } },
	[0x4e] = { 1, {0x4e, } },
	[0x4f] = { 1, {0x4f, } },
	[0x50] = { 1, {0x50, } },
	[0x51] = { 1, {0x51, } },
	[0x52] = { 1, {0x52, } },
	[0x53] = { 1, {0x53, } },
	[0x54] = { 1, {0x54, } },
	[0x55] = { 1, {0x55, } },
	[0x56] = { 1, {0x56, } },
	[0x57] = { 1, {0x57, } },
	[0x58] = { 1, {0x58, } },
	[0x59] = { 1, {0x59, } },
	[0x5a] = { 1, {0x5a, } },
	[0x5b] = { 1, {0x5b, } },
	[0x5c] = { 1, {0x5c, } },
	[0x5d] = { 1, {0x5d, } },
	[0x5e] = { 1, {0x5e, } },
	[0x5f] = { 1, {0x5f, } },
	[0x60] = { 1, {0x60, } },
	[0x61] = { 1, {0x61, } },
	[0x62] = { 1, {0x62, } },
	[0x63] = { 1, {0x63, } },
	[0x64] = { 1, {0x64, } },
	[0x65] = { 1, {0x65, } },
	[0x66] = { 1, {0x66, } },
	[0x67] = { 1, {0x67, } },
	[0x68] = { 1, {0x68, } },
	[0x69] = { 1, {0x69, } },
	[0x6a] = { 1, {0x6a, } },
	[0x6b] = { 1, {0x6b, } },
	[0x6c] = { 1, {0x6c, } },
	[0x6d] = { 1, {0x6d, } },
	[0x6e] = { 1, {0x6e, } },
	[0x6f] = { 1, {0x6f, } },
	[0x70] = { 1, {0x70, } },
	[0x71] = { 1, {0x71, } },
	[0x72] = { 1, {0x72, } },
	[0x73] = { 1, {0x73, } },
	[0x74] = { 1, {0x74, } },
	[0x75] = { 1, {0x75, } },
	[0x76] = { 1, {0x76, } },
	[0x77] = { 1, {0x77, } },
	[0x78] = { 1, {0x78, } },
	[0x79] = { 1, {0x79, } },
	[0x7a] = { 1, {0x7a, } },
	[0x7b] = { 1, {0x7b, } },
	[0x7c] = { 1, {0x7c, } },
	[0x7d] = { 1, {0x7d, } },
	[0x7e] = { 1, {0x7e, } },
	[0x7f] = { 1, {0x7f, } },
	[0x80] = { 2, {0xc2, 0x80, } },
	[0x81] = { 2, {0xc2, 0x81, } },
	[0x82] = { 2, {0xc2, 0x82, } },
	[0x83] = { 2, {0xc2, 0x83, } },
	[0x84] = { 2, {0xc2, 0x84, } },
	[0x85] = { 2, {0xc2, 0x85, } },
	[0x86] = { 2, {0xc2, 0x86, } },
	[0x87] = { 2, {0xc2, 0x87, } },
	[0x88] = { 2, {0xc2, 0x88, } },
	[0x89] = { 2, {0xc2, 0x89, } },
	[0x8a] = { 2, {0xc2, 0x8a, } },
	[0x8b] = { 2, {0xc2, 0x8b, } },
	[0x8c] = { 2, {0xc2, 0x8c, } },
	[0x8d] = { 2, {0xc2, 0x8d, } },
	[0x8e] = { 2, {0xc2, 0x8e, } },
	[0x8f] = { 2, {0xc2, 0x8f, } },
	[0x90] = { 2, {0xc2, 0x90, } },
	[0x91] = { 2, {0xc2, 0x91, } },
	[0x92] = { 2, {0xc2, 0x92, } },
	[0x93] = { 2, {0xc2, 0x93, } },
	[0x94] = { 2, {0xc2, 0x94, } },
	[0x95] = { 2, {0xc2, 0x95, } },
	[0x96] = { 2, {0xc2, 0x96, } },
	[0x97] = { 2, {0xc2, 0x97, } },
	[0x98] = { 2, {0xc2, 0x98, } },
	[0x99] = { 2, {0xc2, 0x99, } },
	[0x9a] = { 2, {0xc2, 0x9a, } },
	[0x9b] = { 2, {0xc2, 0x9b, } },
	[0x9c] = { 2, {0xc2, 0x9c, } },
	[0x9d] = { 2, {0xc2, 0x9d, } },
	[0x9e] = { 2, {0xc2, 0x9e, } },
	[0x9f] = { 2, {0xc2, 0x9f, } },
	[0xa0] = { 2, {0xc2, 0xa0, } },
	[0xa1] = { 2, {0xc2, 0xa1, } },
	[0xa2] = { 2, {0xc2, 0xa2, } },
	[0xa3] = { 2, {0xc2, 0xa3, } },
	[0xa4] = { 3, { 0xe2, 0x82, 0xac,} },		/* Euro sign. Addition over the ISO-6937 standard */
	[0xa5] = { 2, {0xc2, 0xa5, } },
	[0xa6] = { 0, {} },
	[0xa7] = { 2, {0xc2, 0xa7, } },
	[0xa8] = { 2, {0xc2, 0xa4, } },
	[0xa9] = { 3, {0xe2, 0x80, 0x98, } },
	[0xaa] = { 3, {0xe2, 0x80, 0x9c, } },
	[0xab] = { 2, {0xc2, 0xab, } },
	[0xac] = { 3, {0xe2, 0x86, 0x90, } },
	[0xad] = { 3, {0xe2, 0x86, 0x91, } },
	[0xae] = { 3, {0xe2, 0x86, 0x92, } },
	[0xaf] = { 3, {0xe2, 0x86, 0x93, } },
	[0xb0] = { 2, {0xc2, 0xb0, } },
	[0xb1] = { 2, {0xc2, 0xb1, } },
	[0xb2] = { 2, {0xc2, 0xb2, } },
	[0xb3] = { 2, {0xc2, 0xb3, } },
	[0xb4] = { 2, {0xc3, 0x97, } },
	[0xb5] = { 2, {0xc2, 0xb5, } },
	[0xb6] = { 2, {0xc2, 0xb6, } },
	[0xb7] = { 2, {0xc2, 0xb7, } },
	[0xb8] = { 2, {0xc3, 0xb7, } },
	[0xb9] = { 3, {0xe2, 0x80, 0x99, } },
	[0xba] = { 3, {0xe2, 0x80, 0x9d, } },
	[0xbb] = { 2, {0xc2, 0xbb, } },
	[0xbc] = { 2, {0xc2, 0xbc, } },
	[0xbd] = { 2, {0xc2, 0xbd, } },
	[0xbe] = { 2, {0xc2, 0xbe, } },
	[0xbf] = { 2, {0xc2, 0xbf, } },
	[0xc0] = { 0, {} },
	[0xc1] = { 0, {} },
	[0xc2] = { 0, {} },
	[0xc3] = { 0, {} },
	[0xc4] = { 0, {} },
	[0xc5] = { 0, {} },
	[0xc6] = { 0, {} },
	[0xc7] = { 0, {} },
	[0xc8] = { 0, {} },
	[0xc9] = { 0, {} },
	[0xca] = { 0, {} },
	[0xcb] = { 0, {} },
	[0xcc] = { 0, {} },
	[0xcd] = { 0, {} },
	[0xce] = { 0, {} },
	[0xcf] = { 0, {} },
	[0xd0] = { 3, {0xe2, 0x80, 0x94, } },
	[0xd1] = { 2, {0xc2, 0xb9, } },
	[0xd2] = { 2, {0xc2, 0xae, } },
	[0xd3] = { 2, {0xc2, 0xa9, } },
	[0xd4] = { 3, {0xe2, 0x84, 0xa2, } },
	[0xd5] = { 3, {0xe2, 0x99, 0xaa, } },
	[0xd6] = { 2, {0xc2, 0xac, } },
	[0xd7] = { 2, {0xc2, 0xa6, } },
	[0xd8] = { 0, {} },
	[0xd9] = { 0, {} },
	[0xda] = { 0, {} },
	[0xdb] = { 0, {} },
	[0xdc] = { 3, {0xe2, 0x85, 0x9b, } },
	[0xdd] = { 3, {0xe2, 0x85, 0x9c, } },
	[0xde] = { 3, {0xe2, 0x85, 0x9d, } },
	[0xdf] = { 3, {0xe2, 0x85, 0x9e, } },
	[0xe0] = { 3, {0xe2, 0x84, 0xa6, } },
	[0xe1] = { 2, {0xc3, 0x86, } },
	[0xe2] = { 2, {0xc3, 0x90, } },
	[0xe3] = { 2, {0xc2, 0xaa, } },
	[0xe4] = { 2, {0xc4, 0xa6, } },
	[0xe5] = { 0, {} },
	[0xe6] = { 2, {0xc4, 0xb2, } },
	[0xe7] = { 2, {0xc4, 0xbf, } },
	[0xe8] = { 2, {0xc5, 0x81, } },
	[0xe9] = { 2, {0xc3, 0x98, } },
	[0xea] = { 2, {0xc5, 0x92, } },
	[0xeb] = { 2, {0xc2, 0xba, } },
	[0xec] = { 2, {0xc3, 0x9e, } },
	[0xed] = { 2, {0xc5, 0xa6, } },
	[0xee] = { 2, {0xc5, 0x8a, } },
	[0xef] = { 2, {0xc5, 0x89, } },
	[0xf0] = { 2, {0xc4, 0xb8, } },
	[0xf1] = { 2, {0xc3, 0xa6, } },
	[0xf2] = { 2, {0xc4, 0x91, } },
	[0xf3] = { 2, {0xc3, 0xb0, } },
	[0xf4] = { 2, {0xc4, 0xa7, } },
	[0xf5] = { 2, {0xc4, 0xb1, } },
	[0xf6] = { 2, {0xc4, 0xb3, } },
	[0xf7] = { 2, {0xc5, 0x80, } },
	[0xf8] = { 2, {0xc5, 0x82, } },
	[0xf9] = { 2, {0xc3, 0xb8, } },
	[0xfa] = { 2, {0xc5, 0x93, } },
	[0xfb] = { 2, {0xc3, 0x9f, } },
	[0xfc] = { 2, {0xc3, 0xbe, } },
	[0xfd] = { 2, {0xc5, 0xa7, } },
	[0xfe] = { 2, {0xc5, 0x8b, } },
	[0xff] = { 2, {0xc2, 0xad, } },
};

void dvb_iconv_to_charset(struct dvb_v5_fe_parms *parms,
			  char *dest,
			  size_t destlen,
			  const unsigned char *src,
			  size_t len,
			  char *input_charset, char *output_charset)
{
	char out_cs[strlen(output_charset) + 1 + sizeof(CS_OPTIONS)];
	char *p = dest;

	strcpy(out_cs, output_charset);
	strcat(out_cs, CS_OPTIONS);

	iconv_t cd = iconv_open(out_cs, input_charset);
	if (cd == (iconv_t)(-1)) {
		memcpy(p, src, len);
		p[len] = '\0';
		dvb_logerr("Conversion from %s to %s not supported\n",
				input_charset, output_charset);
		if (!strcasecmp(input_charset, "ARIB-STD-B24"))
			dvb_log("Try setting GCONV_PATH to the bundled gconv dir.\n");
	} else {
		iconv(cd, (ICONV_CONST char **)&src, &len, &p, &destlen);
		iconv_close(cd);
		*p = '\0';
	}
}

static void charset_conversion(struct dvb_v5_fe_parms *parms, char **dest, const unsigned char *s,
			       size_t len, char *input_charset)
{
	size_t destlen = len * 3;
	int need_conversion = 1;

	/* Special handler for ISO-6937 */
	if (!strcasecmp(input_charset, "ISO-6937")) {
		char *p = *dest;
		unsigned char *tmp;
		unsigned char *p1, *p2;

		/* Convert charset to UTF-8 using Code table 00 - Latin */
		for (p1 = (unsigned char *)s; p1 < s + len; p1++)
			for (p2 = en300468_latin_00_to_utf8[*p1].data;
			     p2 < en300468_latin_00_to_utf8[*p1].data + en300468_latin_00_to_utf8[*p1].len;
			     p2++)
				*p++ = *p2;
		*p = '\0';

		/* If desired charset is not UTF-8, prepare for conversion */
		if (strcasecmp(parms->output_charset, "UTF-8")) {
			tmp = (unsigned char *)*dest;
			len = p - *dest;

			*dest = malloc(destlen + 1);
			input_charset = "UTF-8";
			s = tmp;
		} else
			need_conversion = 0;

	}

	/* Convert from original charset to the desired one */
	if (need_conversion)
		dvb_iconv_to_charset(parms, *dest, destlen, s, len,
				     input_charset,
				     parms->output_charset);
}

void dvb_parse_string(struct dvb_v5_fe_parms *parms, char **dest, char **emph,
		      const unsigned char *src, size_t len)
{
	size_t destlen, i, len2 = 0;
	char *p, *p2, *type = parms->default_charset;
	unsigned char *tmp1 = NULL, *tmp2 = NULL;
	const unsigned char *s;
	int emphasis = 0;

	if (*dest) {
		free(*dest);
		*dest = NULL;
	}
	if (*emph) {
		free(*emph);
		*emph = NULL;
	}
	if (!len)
		return;

	/*
	 * Strings in ISDB-S/T(JP) do not start with a charset identifier,
	 * and can start with a control character (< 0x20).
	 */
	if (strcasecmp(type, "ARIB-STD-B24") && *src < 0x20) {
		switch (*src) {
		case 0x00:	type = "ISO-6937";		break;
		case 0x01:	type = "ISO-8859-5";		break;
		case 0x02:	type = "ISO-8859-6";		break;
		case 0x03:	type = "ISO-8859-7";		break;
		case 0x04:	type = "ISO-8859-8";		break;
		case 0x05:	type = "ISO-8859-9";		break;
		case 0x06:	type = "ISO-8859-10";		break;
		case 0x07:	type = "ISO-8859-11";		break;
		case 0x09:	type = "ISO-8859-13";		break;
		case 0x0a:	type = "ISO-8859-14";		break;
		case 0x0b:	type = "ISO-8859-15";		break;
		case 0x11:	type = "ISO-10646/UCS2";	break;
		case 0x12:	type = "ISO-2022-KR";		break;
		case 0x13:	type = "GB2312";		break;
		case 0x14:	type = "UTF-16BE";		break;
		case 0x15:	type = "ISO-10646/UTF-8";	break;
		case 0x10: /* ISO8859 */
			if (len < 2)
				break;
			if ((*(src + 1) != 0) || *(src + 2) > 0x0f)
				break;
			src+=2;
			len-=2;
			switch(*src) {
			case 0x01:	type = "ISO-8859-1";		break;
			case 0x02:	type = "ISO-8859-2";		break;
			case 0x03:	type = "ISO-8859-3";		break;
			case 0x04:	type = "ISO-8859-4";		break;
			case 0x05:	type = "ISO-8859-5";		break;
			case 0x06:	type = "ISO-8859-6";		break;
			case 0x07:	type = "ISO-8859-7";		break;
			case 0x08:	type = "ISO-8859-8";		break;
			case 0x09:	type = "ISO-8859-9";		break;
			case 0x0a:	type = "ISO-8859-10";		break;
			case 0x0b:	type = "ISO-8859-11";		break;
			case 0x0d:	type = "ISO-8859-13";		break;
			case 0x0e:	type = "ISO-8859-14";		break;
			case 0x0f:	type = "ISO-8859-15";		break;
			}
		}
		src++;
		len--;
	}

	/*
	 * Destination length should be bigger. As the worse case seems to
	 * use 3 chars for one code, use it for destlen
	 */
	destlen = len * 3;
	*dest = malloc(destlen + 1);
	*emph = malloc(destlen + 1);

	/* Remove special chars */
	if (!strncasecmp(type, "ISO-8859", 8) || !strcasecmp(type, "ISO-6937") || !strcasecmp(type, "ISO-10646/UTF-8")) {
		/*
		 * Handles the ISO/IEC 10646 1-byte control codes
		 * (EN 300 468 v1.11.1 Table A.1)
		 */
		tmp1 = malloc(len + 2);
		tmp2 = malloc(len + 2);
		p = (char *)tmp1;
		p2 = (char *)tmp2;
		s = src;
		for (i = 0; i < len; i++, s++) {
			if (*s == 0x86)
				emphasis = 1;
			else if (*s == 0x87 && emphasis)
				emphasis = 0;
			else  if (*s >= 0x20 && (*s < 0x80 || *s > 0x9f)) {
				*p++ = *s;
				if (emphasis)
					*p2++ = *s;
			}
		}
		*p = '\0';
		*p2 = '\0';
		len = p - (char *)tmp1;
		len2 = p2 - (char *)tmp2;
	} else if (!strcasecmp(type, "ISO-10646/UCS2")) {
		/*
		 * Handles the ISO/IEC 10646 2-bytes control codes
		 * (EN 300 468 v1.11.1 Table A.2)
		 */
		uint16_t *in_code = (void *)src;
		uint16_t *out_code;
		uint16_t *out_emph;

		tmp1 = malloc(len + 2);
		tmp2 = malloc(len + 2);
		out_code = (void *)tmp1;
		out_emph = (void *)tmp2;

		for (i = 0; i < len / 2; i ++, in_code++) {
			uint16_t code = *in_code;

			/*
			 * FIXME: should it do bswap16(code) here?
			 */
			if (code == 0xe086)
				emphasis = 1;
			else if (code == 0xe087 && emphasis)
				emphasis = 0;
			else if (code >= 0xe080 && code <= 0xe09f)
				continue;

			*out_code++ = code;
			if (emphasis)
				*out_emph++ = code;
		}
		*out_code = 0;
		*out_emph = 0;
		len = (char *)out_code - (char *)tmp1;
		len2 = (char *)out_emph - (char *)tmp2;
	}

	if (tmp1)
		s = tmp1;
	else
		s = src;

	charset_conversion(parms, dest, s, len, type);
	/* The code had over-sized the space. Fix it. */
	if (*dest)
		*dest = realloc(*dest, strlen(*dest) + 1);

	if (!len2) {
		if (tmp2) {
			free (tmp2);
			tmp2 = NULL;
		}
		free (*emph);
		*emph = NULL;
	} else {
		charset_conversion(parms, emph, tmp2, len2, type);
		*emph = realloc(*emph, strlen(*emph) + 1);
	}

	if (tmp1)
		free(tmp1);
	if (tmp2)
		free(tmp2);
}