/*
  * ID3v2 header writer
  *

  * This file is part of FFmpeg.

  *

  * FFmpeg 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.
  *

  * FFmpeg 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 FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <stdint.h>

 #include <string.h>

 #include "libavutil/avstring.h"

 #include "libavutil/dict.h"
 #include "libavutil/intreadwrite.h"
 #include "avformat.h"
 #include "avio.h"
 #include "id3v2.h"
 

 static void id3v2_put_size(AVIOContext *pb, int size)

 {

     avio_w8(pb, size >> 21 & 0x7f);
     avio_w8(pb, size >> 14 & 0x7f);
     avio_w8(pb, size >> 7  & 0x7f);
     avio_w8(pb, size       & 0x7f);

 }
 
 static int string_is_ascii(const uint8_t *str)
 {
     while (*str && *str < 128) str++;
     return !*str;
 }
 

 static void id3v2_encode_string(AVIOContext *pb, const uint8_t *str,
                                enum ID3v2Encoding enc)
 {
     int (*put)(AVIOContext*, const char*);
 
     if (enc == ID3v2_ENCODING_UTF16BOM) {
         avio_wl16(pb, 0xFEFF);      /* BOM */
         put = avio_put_str16le;
     } else
         put = avio_put_str;
 
     put(pb, str);
 }
 

 /**
  * Write a text frame with one (normal frames) or two (TXXX frames) strings
  * according to encoding (only UTF-8 or UTF-16+BOM supported).
  * @return number of bytes written or a negative error code.
  */

 static int id3v2_put_ttag(ID3v2EncContext *id3, AVIOContext *avioc, const char *str1, const char *str2,

                           uint32_t tag, enum ID3v2Encoding enc)
 {
     int len;
     uint8_t *pb;
     AVIOContext *dyn_buf;
     if (avio_open_dyn_buf(&dyn_buf) < 0)
         return AVERROR(ENOMEM);
 
     /* check if the strings are ASCII-only and use UTF16 only if
      * they're not */
     if (enc == ID3v2_ENCODING_UTF16BOM && string_is_ascii(str1) &&
         (!str2 || string_is_ascii(str2)))
         enc = ID3v2_ENCODING_ISO8859;
 
     avio_w8(dyn_buf, enc);

     id3v2_encode_string(dyn_buf, str1, enc);

     if (str2)

         id3v2_encode_string(dyn_buf, str2, enc);

     len = avio_close_dyn_buf(dyn_buf, &pb);
 

     avio_wb32(avioc, tag);
     /* ID3v2.3 frame size is not synchsafe */
     if (id3->version == 3)
         avio_wb32(avioc, len);
     else
         id3v2_put_size(avioc, len);
     avio_wb16(avioc, 0);
     avio_write(avioc, pb, len);

 
     av_freep(&pb);
     return len + ID3v2_HEADER_SIZE;
 }
 

 static int id3v2_check_write_tag(ID3v2EncContext *id3, AVIOContext *pb, AVDictionaryEntry *t,
                                  const char table[][4], enum ID3v2Encoding enc)

 {
     uint32_t tag;
     int i;
 
     if (t->key[0] != 'T' || strlen(t->key) != 4)
         return -1;
     tag = AV_RB32(t->key);
     for (i = 0; *table[i]; i++)
         if (tag == AV_RB32(table[i]))

             return id3v2_put_ttag(id3, pb, t->value, NULL, tag, enc);

     return -1;
 }
 

 static void id3v2_3_metadata_split_date(AVDictionary **pm)
 {
     AVDictionaryEntry *mtag = NULL;
     AVDictionary *dst = NULL;
     const char *key, *value;
     char year[5] = {0}, day_month[5] = {0};
     int i;
 
     while ((mtag = av_dict_get(*pm, "", mtag, AV_DICT_IGNORE_SUFFIX))) {
         key = mtag->key;

         if (!av_strcasecmp(key, "date")) {

             /* split date tag using "YYYY-MM-DD" format into year and month/day segments */
             value = mtag->value;
             i = 0;
             while (value[i] >= '0' && value[i] <= '9') i++;
             if (value[i] == '\0' || value[i] == '-') {
                 av_strlcpy(year, value, sizeof(year));
                 av_dict_set(&dst, "TYER", year, 0);
 
                 if (value[i] == '-' &&
                     value[i+1] >= '0' && value[i+1] <= '1' &&
                     value[i+2] >= '0' && value[i+2] <= '9' &&
                     value[i+3] == '-' &&
                     value[i+4] >= '0' && value[i+4] <= '3' &&
                     value[i+5] >= '0' && value[i+5] <= '9' &&
                     (value[i+6] == '\0' || value[i+6] == ' ')) {
                     snprintf(day_month, sizeof(day_month), "%.2s%.2s", value + i + 4, value + i + 1);
                     av_dict_set(&dst, "TDAT", day_month, 0);
                 }
             } else
                 av_dict_set(&dst, key, value, 0);
         } else
             av_dict_set(&dst, key, mtag->value, 0);
     }
     av_dict_free(pm);
     *pm = dst;
 }
 

 void ff_id3v2_start(ID3v2EncContext *id3, AVIOContext *pb, int id3v2_version,
                     const char *magic)

 {

     id3->version = id3v2_version;

     avio_wb32(pb, MKBETAG(magic[0], magic[1], magic[2], id3v2_version));
     avio_w8(pb, 0);
     avio_w8(pb, 0); /* flags */

 
     /* reserve space for size */

     id3->size_pos = avio_tell(pb);
     avio_wb32(pb, 0);
 }
 
 int ff_id3v2_write_metadata(AVFormatContext *s, ID3v2EncContext *id3)
 {
     AVDictionaryEntry *t = NULL;
     int enc = id3->version == 3 ? ID3v2_ENCODING_UTF16BOM :
                                   ID3v2_ENCODING_UTF8;

 
     ff_metadata_conv(&s->metadata, ff_id3v2_34_metadata_conv, NULL);

     if (id3->version == 3)

         id3v2_3_metadata_split_date(&s->metadata);

     else if (id3->version == 4)

         ff_metadata_conv(&s->metadata, ff_id3v2_4_metadata_conv, NULL);
 
     while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX))) {
         int ret;
 

         if ((ret = id3v2_check_write_tag(id3, s->pb, t, ff_id3v2_tags, enc)) > 0) {

             id3->len += ret;

             continue;
         }

         if ((ret = id3v2_check_write_tag(id3, s->pb, t, id3->version == 3 ?

                                                ff_id3v2_3_tags : ff_id3v2_4_tags, enc)) > 0) {

             id3->len += ret;

             continue;
         }
 
         /* unknown tag, write as TXXX frame */

         if ((ret = id3v2_put_ttag(id3, s->pb, t->key, t->value, MKBETAG('T', 'X', 'X', 'X'), enc)) < 0)

             return ret;

         id3->len += ret;

     }
 

     return 0;
 }
 

 int ff_id3v2_write_apic(AVFormatContext *s, ID3v2EncContext *id3, AVPacket *pkt)
 {
     AVStream *st = s->streams[pkt->stream_index];
     AVDictionaryEntry *e;
 
     AVIOContext *dyn_buf;
     uint8_t     *buf;
     const CodecMime *mime = ff_id3v2_mime_tags;
     const char  *mimetype = NULL, *desc = "";
     int enc = id3->version == 3 ? ID3v2_ENCODING_UTF16BOM :
                                   ID3v2_ENCODING_UTF8;
     int i, len, type = 0;
 
     /* get the mimetype*/
     while (mime->id != CODEC_ID_NONE) {
         if (mime->id == st->codec->codec_id) {
             mimetype = mime->str;
             break;
         }
         mime++;
     }
     if (!mimetype) {
         av_log(s, AV_LOG_ERROR, "No mimetype is known for stream %d, cannot "
                "write an attached picture.\n", st->index);
         return AVERROR(EINVAL);
     }
 
     /* get the picture type */
     e = av_dict_get(st->metadata, "comment", NULL, 0);
     for (i = 0; e && i < FF_ARRAY_ELEMS(ff_id3v2_picture_types); i++) {
         if (strstr(ff_id3v2_picture_types[i], e->value) == ff_id3v2_picture_types[i]) {
             type = i;
             break;
         }
     }
 
     /* get the description */
     if ((e = av_dict_get(st->metadata, "title", NULL, 0)))
         desc = e->value;
 
     /* start writing */
     if (avio_open_dyn_buf(&dyn_buf) < 0)
         return AVERROR(ENOMEM);
 
     avio_w8(dyn_buf, enc);
     avio_put_str(dyn_buf, mimetype);
     avio_w8(dyn_buf, type);
     id3v2_encode_string(dyn_buf, desc, enc);
     avio_write(dyn_buf, pkt->data, pkt->size);
     len = avio_close_dyn_buf(dyn_buf, &buf);
 
     avio_wb32(s->pb, MKBETAG('A', 'P', 'I', 'C'));
     if (id3->version == 3)
         avio_wb32(s->pb, len);
     else
         id3v2_put_size(s->pb, len);
     avio_wb16(s->pb, 0);
     avio_write(s->pb, buf, len);
     av_freep(&buf);
 
     id3->len += len + ID3v2_HEADER_SIZE;
 
     return 0;
 }
 

 void ff_id3v2_finish(ID3v2EncContext *id3, AVIOContext *pb)
 {
     int64_t cur_pos = avio_tell(pb);
     avio_seek(pb, id3->size_pos, SEEK_SET);
     id3v2_put_size(pb, id3->len);
     avio_seek(pb, cur_pos, SEEK_SET);
 }
 
 int ff_id3v2_write_simple(struct AVFormatContext *s, int id3v2_version,
                           const char *magic)
 {
     ID3v2EncContext id3 = { 0 };
     int ret;
 
     ff_id3v2_start(&id3, s->pb, id3v2_version, magic);
     if ((ret = ff_id3v2_write_metadata(s, &id3)) < 0)
         return ret;
     ff_id3v2_finish(&id3, s->pb);
 

     return 0;
 }