/* Copyright (C) 2000-2015 Lavtech.com corp. All rights reserved.

   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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
*/

#include "udm_config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>

#include "udm_common.h"
#include "udm_utils.h"
#include "udm_id3.h"
#include "udm_vars.h"
#include "udm_textlist.h"
#include "udm_http.h"


static udm_rc_t
add_var(UDM_DOCUMENT *Doc,
        const char *name, size_t namelen,
        const char *val, size_t vallen)
{
  const UDM_VAR *Sec; 
  if ((Sec= UdmVarListFind(&Doc->Sections, name)))
  {
    UDM_CONST_TEXTITEM Item;
    UDM_TEXT_PARAM TextParam;
    while (vallen && val[vallen - 1] == ' ')
    {
      vallen--;
    }
    bzero((void*)&Item, sizeof(Item));
    UdmConstStrSet(&Item.text, val, vallen);
    UdmConstStrSet(&Item.section_name, name, namelen);
    UdmTextParamInit(&TextParam, UDM_TEXTLIST_FLAG_NONE, UdmVarSecno(Sec));
    UdmTextListAddConst(&Doc->TextList, &Item, &TextParam);
  }
  return UDM_OK;
}


static udm_rc_t
get_tag(UDM_DOCUMENT *Doc, const UDM_CONST_STR *content)
{
  const char *tag= content->str + content->length - 128;
  UDM_ASSERT(content->length >= 128);
  add_var(Doc, UDM_CSTR_WITH_LEN("MP3.Song"),   tag +  3, 30);
  add_var(Doc, UDM_CSTR_WITH_LEN("MP3.Album"),  tag + 63, 30);
  add_var(Doc, UDM_CSTR_WITH_LEN("MP3.Artist"), tag + 33, 30);
  add_var(Doc, UDM_CSTR_WITH_LEN("MP3.Year"),   tag + 93, 4);
  return UDM_OK;
}

/* 
  id3 header v2.3.0 http://www.id3.org/
  ID3  3
  version  1+1
      flag  1
  size  4
*/

static udm_rc_t
get_id3(UDM_DOCUMENT *Doc, const UDM_CONST_STR *cont)
{
  const char *ch, *end;
  UDM_CONST_STR art, song, alb;

  UDM_ASSERT(cont->length >= 30);

  UdmConstStrSet(&art, "", 0);
  UdmConstStrSet(&song, "", 0);
  UdmConstStrSet(&alb, "", 0);

  ch= cont->str;
  end= cont->str + cont->length;

  if (*(ch + 6) == 'b')
  {
    /*
      extened header:
      size  4
      flag  2
      size of pagging 4
    */
    ch+= 20;
  }
  else
  {
    ch+= 10;
  }

  for ( ; ch + 10 < end; )
  {
    /*
      frame header:
      frame id 4
      size     4
      flags    2 
    */
    size_t frame_size= (unsigned char) ch[7] + 256 * ((unsigned char) ch[6]);
    /*
    printf("frame_size=%d ch=%.*s fr='%.*s'\n", (int) frame_size,
           4, ch, frame_size - 1, ch+11);
    */
    if (frame_size == 0 || ch + frame_size > end)
      break;

    if (!strncmp(ch , "TPE1", 4))
    {
      UdmConstStrSet(&art, ch + 11, frame_size - 1);
    }
    else if(!strncmp(ch , "TALB", 4))
    {
      UdmConstStrSet(&alb, ch + 11, frame_size - 1);
    }
    else if(!strncmp(ch, "TIT2", 4))
    {
      UdmConstStrSet(&song, ch + 11, frame_size - 1);
    }
    /* TODO34: more ID3 tags */
    ch+= frame_size + 10;
  }

  add_var(Doc, UDM_CSTR_WITH_LEN("MP3.Song"), song.str, song.length);
  add_var(Doc, UDM_CSTR_WITH_LEN("MP3.Album"), alb.str, alb.length);
  add_var(Doc, UDM_CSTR_WITH_LEN("MP3.Artist"), art.str, art.length);

  return UDM_OK;
}


udm_mp3type_t
UdmMP3Type(const UDM_DOCUMENT *Doc)
{
  int hd;
  UDM_CONST_STR content;
  if (UdmHTTPBufContentToConstStr(&Doc->Buf, &content) || content.length < 4)
    return UDM_MP3_UNKNOWN;

  hd= ((unsigned char)(content.str[0])+
      256 * (unsigned char)(content.str[1])) & 0xf0ff;

  if (hd == 0xf0ff)
    return UDM_MP3_TAG;

  if (!memcmp(content.str, "RIFF",4))
    return UDM_MP3_RIFF;

  if (!memcmp(content.str, "ID3", 3))
    return UDM_MP3_ID3;

  return UDM_MP3_UNKNOWN;
}


udm_rc_t
UdmMP3Parse(UDM_AGENT *A, UDM_DOCUMENT *Doc)
{
  UDM_CONST_STR content;
  if (UdmHTTPBufContentToConstStr(&Doc->Buf, &content) || content.length < 128)
    return UDM_ERROR;

  if (!memcmp(content.str, "ID3", 3))
    get_id3(Doc, &content);

  if (!memcmp(content.str + content.length - 128, "TAG", 3))
    get_tag(Doc, &content);

  return UDM_OK;
}