/* plugin_common - Routines common to several plugins

 * Copyright (C) 2002-2009  Josh Coalson

 * Copyright (C) 2011-2016  Xiph.Org Foundation

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 */

#ifdef HAVE_CONFIG_H

#  include <config.h>

#endif

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include "tags.h"

#include "FLAC/assert.h"

#include "FLAC/metadata.h"

#include "share/alloc.h"

#ifndef FLaC__INLINE

#define FLaC__INLINE

#endif

static FLaC__INLINE size_t local__wide_strlen(const FLAC__uint16 *s)

{

	size_t n = 0;

	while(*s++)

		n++;

	return n;

}

/*

 * also disallows non-shortest-form encodings, c.f.

 *   http://www.unicode.org/versions/corrigendum1.html

 * and a more clear explanation at the end of this section:

 *   http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8

 */

static size_t local__utf8len(const FLAC__byte *utf8)

{

	FLAC__ASSERT(0 != utf8);

	if ((utf8[0] & 0x80) == 0) {

		return 1;

	}

	else if ((utf8[0] & 0xE0) == 0xC0 && (utf8[1] & 0xC0) == 0x80) {

		if ((utf8[0] & 0xFE) == 0xC0) /* overlong sequence check */

			return 0;

		return 2;

	}

	else if ((utf8[0] & 0xF0) == 0xE0 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80) {

		if (utf8[0] == 0xE0 && (utf8[1] & 0xE0) == 0x80) /* overlong sequence check */

			return 0;

		/* illegal surrogates check (U+D800...U+DFFF and U+FFFE...U+FFFF) */

		if (utf8[0] == 0xED && (utf8[1] & 0xE0) == 0xA0) /* D800-DFFF */

			return 0;

		if (utf8[0] == 0xEF && utf8[1] == 0xBF && (utf8[2] & 0xFE) == 0xBE) /* FFFE-FFFF */

			return 0;

		return 3;

	}

	else if ((utf8[0] & 0xF8) == 0xF0 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80) {

		if (utf8[0] == 0xF0 && (utf8[1] & 0xF0) == 0x80) /* overlong sequence check */

			return 0;

		return 4;

	}

	else if ((utf8[0] & 0xFC) == 0xF8 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80 && (utf8[4] & 0xC0) == 0x80) {

		if (utf8[0] == 0xF8 && (utf8[1] & 0xF8) == 0x80) /* overlong sequence check */

			return 0;

		return 5;

	}

	else if ((utf8[0] & 0xFE) == 0xFC && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80 && (utf8[4] & 0xC0) == 0x80 && (utf8[5] & 0xC0) == 0x80) {

		if (utf8[0] == 0xFC && (utf8[1] & 0xFC) == 0x80) /* overlong sequence check */

			return 0;

		return 6;

	}

	else {

		return 0;

	}

}

static size_t local__utf8_to_ucs2(const FLAC__byte *utf8, FLAC__uint16 *ucs2)

{

	const size_t len = local__utf8len(utf8);

	FLAC__ASSERT(0 != ucs2);

	if (len == 1)

		*ucs2 = *utf8;

	else if (len == 2)

		*ucs2 = (*utf8 & 0x3F)<<6 | (*(utf8+1) & 0x3F);

	else if (len == 3)

		*ucs2 = (*utf8 & 0x1F)<<12 | (*(utf8+1) & 0x3F)<<6 | (*(utf8+2) & 0x3F);

	else

		*ucs2 = '?';

	return len;

}

static FLAC__uint16 *local__convert_utf8_to_ucs2(const char *src, unsigned length)

{

	FLAC__uint16 *out;

	size_t chars = 0;

	FLAC__ASSERT(0 != src);

	/* calculate length */

	{

		const unsigned char *s, *end;

		for (s=(const unsigned char *)src, end=s+length; s

			const unsigned n = local__utf8len(s);

			if (n == 0)

				return 0;

			s += n;

		}

		FLAC__ASSERT(s == end);

	}

	/* allocate */

	out = safe_malloc_mul_2op_(chars, /*times*/sizeof(FLAC__uint16));

	if (0 == out) {

		FLAC__ASSERT(0);

		return 0;

	}

	/* convert */

	{

		const unsigned char *s = (const unsigned char *)src;

		FLAC__uint16 *u = out;

		for ( ; chars; chars--)

			s += local__utf8_to_ucs2(s, u++);

	}

	return out;

}

static FLaC__INLINE size_t local__ucs2len(FLAC__uint16 ucs2)

{

	if (ucs2 < 0x0080)

		return 1;

	else if (ucs2 < 0x0800)

		return 2;

	else

		return 3;

}

static size_t local__ucs2_to_utf8(FLAC__uint16 ucs2, FLAC__byte *utf8)

{

	if (ucs2 < 0x080) {

		utf8[0] = (FLAC__byte)ucs2;

		return 1;

	}

	else if (ucs2 < 0x800) {

		utf8[0] = 0xc0 | (ucs2 >> 6);

		utf8[1] = 0x80 | (ucs2 & 0x3f);

		return 2;

	}

	else {

		utf8[0] = 0xe0 | (ucs2 >> 12);

		utf8[1] = 0x80 | ((ucs2 >> 6) & 0x3f);

		utf8[2] = 0x80 | (ucs2 & 0x3f);

		return 3;

	}

}

static char *local__convert_ucs2_to_utf8(const FLAC__uint16 *src, unsigned length)

{

	char *out;

	size_t len = 0, n;

	FLAC__ASSERT(0 != src);

	/* calculate length */

	{

		unsigned i;

		for (i = 0; i < length; i++) {

			n = local__ucs2len(src[i]);

			if(len + n < len) /* overflow check */

				return 0;

			len += n;

		}

	}

	/* allocate */

	out = safe_malloc_mul_2op_(len, /*times*/sizeof(char));

	if (0 == out)

		return 0;

	/* convert */

	{

		unsigned char *u = (unsigned char *)out;

		for ( ; *src; src++)

			u += local__ucs2_to_utf8(*src, u);

		local__ucs2_to_utf8(*src, u);

	}

	return out;

}

FLAC__bool FLAC_plugin__tags_get(const char *filename, FLAC__StreamMetadata **tags)

{

	if(!FLAC__metadata_get_tags(filename, tags))

		if(0 == (*tags = FLAC__metadata_object_new(FLAC__METADATA_TYPE_VORBIS_COMMENT)))

			return false;

	return true;

}

FLAC__bool FLAC_plugin__tags_set(const char *filename, const FLAC__StreamMetadata *tags)

{

	FLAC__Metadata_Chain *chain;

	FLAC__Metadata_Iterator *iterator;

	FLAC__StreamMetadata *block;

	FLAC__bool got_vorbis_comments = false;

	FLAC__bool ok;

	if(0 == (chain = FLAC__metadata_chain_new()))

		return false;

	if(!FLAC__metadata_chain_read(chain, filename)) {

		FLAC__metadata_chain_delete(chain);

		return false;

	}

	if(0 == (iterator = FLAC__metadata_iterator_new())) {

		FLAC__metadata_chain_delete(chain);

		return false;

	}

	FLAC__metadata_iterator_init(iterator, chain);

	do {

		if(FLAC__metadata_iterator_get_block_type(iterator) == FLAC__METADATA_TYPE_VORBIS_COMMENT)

			got_vorbis_comments = true;

	} while(!got_vorbis_comments && FLAC__metadata_iterator_next(iterator));

	if(0 == (block = FLAC__metadata_object_clone(tags))) {

		FLAC__metadata_chain_delete(chain);

		FLAC__metadata_iterator_delete(iterator);

		return false;

	}

	if(got_vorbis_comments)

		ok = FLAC__metadata_iterator_set_block(iterator, block);

	else

		ok = FLAC__metadata_iterator_insert_block_after(iterator, block);

	FLAC__metadata_iterator_delete(iterator);

	if(ok) {

		FLAC__metadata_chain_sort_padding(chain);

		ok = FLAC__metadata_chain_write(chain, /*use_padding=*/true, /*preserve_file_stats=*/true);

	}

	FLAC__metadata_chain_delete(chain);

	return ok;

}

void FLAC_plugin__tags_destroy(FLAC__StreamMetadata **tags)

{

	FLAC__metadata_object_delete(*tags);

	*tags = 0;

}

const char *FLAC_plugin__tags_get_tag_utf8(const FLAC__StreamMetadata *tags, const char *name)

{

	const int i = FLAC__metadata_object_vorbiscomment_find_entry_from(tags, /*offset=*/0, name);

	return (i < 0? 0 : strchr((const char *)tags->data.vorbis_comment.comments[i].entry, '=')+1);

}

FLAC__uint16 *FLAC_plugin__tags_get_tag_ucs2(const FLAC__StreamMetadata *tags, const char *name)

{

	const char *utf8 = FLAC_plugin__tags_get_tag_utf8(tags, name);

	if(0 == utf8)

		return 0;

	return local__convert_utf8_to_ucs2(utf8, strlen(utf8)+1); /* +1 for terminating null */

}

int FLAC_plugin__tags_delete_tag(FLAC__StreamMetadata *tags, const char *name)

{

	return FLAC__metadata_object_vorbiscomment_remove_entries_matching(tags, name);

}

int FLAC_plugin__tags_delete_all(FLAC__StreamMetadata *tags)

{

	int n = (int)tags->data.vorbis_comment.num_comments;

	if(n > 0) {

		if(!FLAC__metadata_object_vorbiscomment_resize_comments(tags, 0))

			n = -1;

	}

	return n;

}

FLAC__bool FLAC_plugin__tags_add_tag_utf8(FLAC__StreamMetadata *tags, const char *name, const char *value, const char *separator)

{

	int i;

	FLAC__ASSERT(0 != tags);

	FLAC__ASSERT(0 != name);

	FLAC__ASSERT(0 != value);

	if(separator && (i = FLAC__metadata_object_vorbiscomment_find_entry_from(tags, /*offset=*/0, name)) >= 0) {

		FLAC__StreamMetadata_VorbisComment_Entry *entry = tags->data.vorbis_comment.comments+i;

		const size_t value_len = strlen(value);

		const size_t separator_len = strlen(separator);

		FLAC__byte *new_entry;

		if(0 == (new_entry = safe_realloc_add_4op_(entry->entry, entry->length, /*+*/value_len, /*+*/separator_len, /*+*/1)))

			return false;

		memcpy(new_entry+entry->length, separator, separator_len);

		entry->length += separator_len;

		memcpy(new_entry+entry->length, value, value_len);

		entry->length += value_len;

		new_entry[entry->length] = '\0';

		entry->entry = new_entry;

	}

	else {

		FLAC__StreamMetadata_VorbisComment_Entry entry;

		if(!FLAC__metadata_object_vorbiscomment_entry_from_name_value_pair(&entry, name, value))

			return false;

		FLAC__metadata_object_vorbiscomment_append_comment(tags, entry, /*copy=*/false);

	}

	return true;

}

FLAC__bool FLAC_plugin__tags_set_tag_ucs2(FLAC__StreamMetadata *tags, const char *name, const FLAC__uint16 *value, FLAC__bool replace_all)

{

	FLAC__StreamMetadata_VorbisComment_Entry entry;

	FLAC__ASSERT(0 != tags);

	FLAC__ASSERT(0 != name);

	FLAC__ASSERT(0 != value);

	{

		char *utf8 = local__convert_ucs2_to_utf8(value, local__wide_strlen(value)+1); /* +1 for the terminating null */

		if(0 == utf8)

			return false;

		if(!FLAC__metadata_object_vorbiscomment_entry_from_name_value_pair(&entry, name, utf8)) {

			free(utf8);

			return false;

		}

		free(utf8);

	}

	if(!FLAC__metadata_object_vorbiscomment_replace_comment(tags, entry, replace_all, /*copy=*/false))

		return false;

	return true;

}