/********************************************************************

 *                                                                  *

 * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *

 *                                                                  *

 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *

 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *

 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *

 *                                                                  *

 * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2003    *

 * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *

 *                                                                  *

 ********************************************************************

 function: maintain the info structure, info <-> header packets

 ********************************************************************/

/* general handling of the header and the vorbis_info structure (and

   substructures) */

#include <stdlib.h>

#include <string.h>

#include <ctype.h>

#include "ogg.h"

#include "ivorbiscodec.h"

#include "codec_internal.h"

#include "codebook.h"

#include "misc.h"

/* helpers */

static void _v_readstring(oggpack_buffer *o,char *buf,int bytes){

  while(bytes--){

    *buf++=oggpack_read(o,8);

  }

}

void vorbis_comment_init(vorbis_comment *vc){

  memset(vc,0,sizeof(*vc));

}

/* This is more or less the same as strncasecmp - but that doesn't exist

 * everywhere, and this is a fairly trivial function, so we include it */

static int tagcompare(const char *s1, const char *s2, int n){

  int c=0;

  while(c < n){

    if(toupper(s1[c]) != toupper(s2[c]))

      return !0;

    c++;

  }

  return 0;

}

char *vorbis_comment_query(vorbis_comment *vc, char *tag, int count){

  long i;

  int found = 0;

  int taglen = strlen(tag)+1; /* +1 for the = we append */

  char *fulltag = (char *)alloca(taglen+ 1);

  strcpy(fulltag, tag);

  strcat(fulltag, "=");

  for(i=0;i<vc->comments;i++){

    if(!tagcompare(vc->user_comments[i], fulltag, taglen)){

      if(count == found)

	/* We return a pointer to the data, not a copy */

      	return vc->user_comments[i] + taglen;

      else

	found++;

    }

  }

  return NULL; /* didn't find anything */

}

int vorbis_comment_query_count(vorbis_comment *vc, char *tag){

  int i,count=0;

  int taglen = strlen(tag)+1; /* +1 for the = we append */

  char *fulltag = (char *)alloca(taglen+1);

  strcpy(fulltag,tag);

  strcat(fulltag, "=");

  for(i=0;i<vc->comments;i++){

    if(!tagcompare(vc->user_comments[i], fulltag, taglen))

      count++;

  }

  return count;

}

void vorbis_comment_clear(vorbis_comment *vc){

  if(vc){

    long i;

    for(i=0;i<vc->comments;i++)

      if(vc->user_comments[i])_ogg_free(vc->user_comments[i]);

    if(vc->user_comments)_ogg_free(vc->user_comments);

	if(vc->comment_lengths)_ogg_free(vc->comment_lengths);

    if(vc->vendor)_ogg_free(vc->vendor);

  }

}

/* blocksize 0 is guaranteed to be short, 1 is guarantted to be long.

   They may be equal, but short will never ge greater than long */

int vorbis_info_blocksize(vorbis_info *vi,int zo){

  codec_setup_info *ci = (codec_setup_info *)vi->codec_setup;

  return ci ? ci->blocksizes[zo] : -1;

}

/* used by synthesis, which has a full, alloced vi */

void vorbis_info_init(vorbis_info *vi){

  memset(vi,0,sizeof(*vi));

  vi->codec_setup=(codec_setup_info *)_ogg_calloc(1,sizeof(codec_setup_info));

}

void vorbis_info_clear(vorbis_info *vi){

  codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;

  int i;

  if(ci){

    }

    _ogg_free(ci);

  }

  memset(vi,0,sizeof(*vi));

}

/* Header packing/unpacking ********************************************/

static int _vorbis_unpack_info(vorbis_info *vi,oggpack_buffer *opb){

  codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;

  if(!ci)return(OV_EFAULT);

  vi->version=oggpack_read(opb,32);

  if(vi->version!=0)return(OV_EVERSION);

  vi->channels=oggpack_read(opb,8);

  vi->rate=oggpack_read(opb,32);

  vi->bitrate_upper=oggpack_read(opb,32);

  vi->bitrate_nominal=oggpack_read(opb,32);

  vi->bitrate_lower=oggpack_read(opb,32);

  ci->blocksizes[0]=1<<oggpack_read(opb,4);

  ci->blocksizes[1]=1<<oggpack_read(opb,4);

  if(vi->rate<1)goto err_out;

  if(vi->channels<1)goto err_out;

  if(ci->blocksizes[0]<64)goto err_out; 

  if(ci->blocksizes[1]<ci->blocksizes[0])goto err_out;

  if(ci->blocksizes[1]>8192)goto err_out;

  if(oggpack_read(opb,1)!=1)goto err_out; /* EOP check */

  return(0);

 err_out:

  vorbis_info_clear(vi);

  return(OV_EBADHEADER);

}

static int _vorbis_unpack_comment(vorbis_comment *vc,oggpack_buffer *opb){

  int i;

  int vendorlen=oggpack_read(opb,32);

  if(vendorlen<0)goto err_out;

  vc->vendor=(char *)_ogg_calloc(vendorlen+1,1);

  _v_readstring(opb,vc->vendor,vendorlen);

  vc->comments=oggpack_read(opb,32);

  if(vc->comments<0)goto err_out;

  vc->user_comments=(char **)_ogg_calloc(vc->comments+1,sizeof(*vc->user_comments));

  vc->comment_lengths=(int *)_ogg_calloc(vc->comments+1, sizeof(*vc->comment_lengths));

  for(i=0;i<vc->comments;i++){

    int len=oggpack_read(opb,32);

    if(len<0)goto err_out;

	vc->comment_lengths[i]=len;

    vc->user_comments[i]=(char *)_ogg_calloc(len+1,1);

    _v_readstring(opb,vc->user_comments[i],len);

  }	  

  if(oggpack_read(opb,1)!=1)goto err_out; /* EOP check */

  return(0);

 err_out:

  vorbis_comment_clear(vc);

  return(OV_EBADHEADER);

}

/* all of the real encoding details are here.  The modes, books,

   everything */

static int _vorbis_unpack_books(vorbis_info *vi,oggpack_buffer *opb){

  codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;

  int i;

  if(!ci)return(OV_EFAULT);

  /* codebooks */

  ci->books=oggpack_read(opb,8)+1;

  /* floor backend settings */

  ci->floors=oggpack_read(opb,6)+1;

  for(i=0;i<ci->floors;i++){

    ci->floor_type[i]=oggpack_read(opb,16);

    if(ci->floor_type[i]<0 || ci->floor_type[i]>=VI_FLOORB)goto err_out;

    if(!ci->floor_param[i])goto err_out;

  }

  /* residue backend settings */

  ci->residues=oggpack_read(opb,6)+1;

  /* map backend settings */

  ci->maps=oggpack_read(opb,6)+1;

  for(i=0;i<ci->maps;i++){

  }

  /* mode settings */

  ci->modes=oggpack_read(opb,6)+1;

  for(i=0;i<ci->modes;i++){

  }

  if(oggpack_read(opb,1)!=1)goto err_out; /* top level EOP check */

  return(0);

 err_out:

  vorbis_info_clear(vi);

  return(OV_EBADHEADER);

}

/* The Vorbis header is in three packets; the initial small packet in

   the first page that identifies basic parameters, a second packet

   with bitstream comments and a third packet that holds the

   codebook. */

  oggpack_buffer opb;

  if(op){

    oggpack_readinit(&opb,op->packet);

    /* Which of the three types of header is this? */

    /* Also verify header-ness, vorbis */

    {

      char buffer[6];

      int packtype=oggpack_read(&opb,8);

      memset(buffer,0,6);

      _v_readstring(&opb,buffer,6);

      if(memcmp(buffer,"vorbis",6)){

	/* not a vorbis header */

	return(OV_ENOTVORBIS);

      }

      switch(packtype){

      case 0x01: /* least significant *bit* is read first */

	if(!op->b_o_s){

	  /* Not the initial packet */

	  return(OV_EBADHEADER);

	}

	if(vi->rate!=0){

	  /* previously initialized info header */

	  return(OV_EBADHEADER);

	}

	return(_vorbis_unpack_info(vi,&opb));

      case 0x03: /* least significant *bit* is read first */

	if(vi->rate==0){

	  /* um... we didn't get the initial header */

	  return(OV_EBADHEADER);

	}

	return(_vorbis_unpack_comment(vc,&opb));

      case 0x05: /* least significant *bit* is read first */

	if(vi->rate==0 || vc->vendor==NULL){

	  /* um... we didn;t get the initial header or comments yet */

	  return(OV_EBADHEADER);

	}

	return(_vorbis_unpack_books(vi,&opb));

      default:

	/* Not a valid vorbis header type */

	return(OV_EBADHEADER);

	break;

      }

    }

  }

  return(OV_EBADHEADER);

}