#include "oggstat.h"

using namespace std;

/*
    Most of this code has been blatently copied from ogginfo, a testing
    program that comes with vorbis-tools package on the xiph cvs server.
    It has been stripped down and altered to work correctly (hopefully). 
*/


// checks the beginning headers to make sure it's not corrupt or missing.
// initializes vorbis_info struct as well as others.
int
vorb::test_header (FILE * fp, ogg_sync_state * oy, ogg_stream_state * os,
	     vorbis_info * vi, vorbis_comment * vc, long *serialno)
{
  ogg_page            og;
  ogg_packet          op;
  char               *buffer;
  int                 bytes;
  int                 i, result;
  buffer = ogg_sync_buffer (oy, 4096);
  bytes = fread (buffer, 1, 4096, fp);
  ogg_sync_wrote (oy, bytes);
  vorbis_info_init (vi);
  if (ogg_sync_pageout (oy, &og) != 1)
    return -1;
  *serialno = ogg_page_serialno (&og);
  ogg_stream_init (os, *serialno);
  vorbis_comment_init (vc);
  if (ogg_stream_pagein (os, &og) < 0)
    return 0;
  if (ogg_stream_packetout (os, &op) != 1)
    return 0;
  if (vorbis_synthesis_headerin (vi, vc, &op) < 0)
    return 0;
  i = 0;
  while (i < 2) {
    while (i < 2) {
      result = ogg_sync_pageout (oy, &og);
      if (result == 0)
	break;			/* Need more data */
      if (result == 1) {
	ogg_stream_pagein (os, &og);
	while (i < 2) {
	  result = ogg_stream_packetout (os, &op);
	  if (result == 0)
	    break;
	  if (result < 0)
	    return 0;
	  vorbis_synthesis_headerin (vi, vc, &op);
	  i++;
	}
      }
    }
    buffer = ogg_sync_buffer (oy, 4096);
    bytes = fread (buffer, 1, 4096, fp);
    ogg_sync_wrote (oy, bytes);
    if (bytes == 0 && i < 2)
      return 0;
    
  }
  return 1;
}

// Runs through the packets and grabs info, hopefully handling any errors found.
void
vorb::scan_ogg (FILE * fp, int len, statistic * mp3info2)
{
  int                 header_state = -1;	/* Assume the worst */
  int                 stream_state = -1;
  ogg_sync_state      oy;
  ogg_stream_state    os;
  vorbis_info         vi;
  vorbis_comment      vc;
  ogg_page            og;
  ogg_packet          op;
  ogg_int64_t         bits = 0;
  ogg_int64_t         final_granulepos = 0;
  int                 bytes;
  int                 blocksize = 0;
  char               *buffer;
  int                 eos = 0;
  int                 eof = 0;
  int                 result;
  long                serialno;
  if (!fp)
    exit (0);
  ogg_sync_init (&oy);		/* Now we can read pages */
  while (!eof) {
    bits = 0;
    // calls the test header function which makes sure everything is okydokey
    if ((header_state = test_header (fp, &oy, &os, &vi, &vc, &serialno)) == 1) {
      result = 0;
      while (!eos) {
	while (!eos) {
	  result = ogg_sync_pageout (&oy, &og);
	  if (result == 0)
	    break;		/* need more data */
	  if (result < 0)
	    break;		/* missing or corrupt data at this page position */
	  else {
	    if (ogg_stream_pagein (&os, &og) < 0)
	      exit (-1);
	    while (1) {
	      result = ogg_stream_packetout (&os, &op);
	      if (result == 0)
		break;		/* need more data */
	      if (result < 0)
		break;
	      blocksize = vorbis_packet_blocksize (&vi, &op);
	      mp3info2->addBit((int)((( (double) vi.rate / (double) blocksize) *
		 (double)op.bytes*16) / 1000));
	    }
	    if (ogg_page_eos (&og))
	      eos = 1;
	  }
	}
	if (!eos) {
	  buffer = ogg_sync_buffer (&oy, 4096);
	  bytes = fread (buffer, 1, 4096, fp);
	  bits += 8 * bytes;
	  ogg_sync_wrote (&oy, bytes);
	  if (bytes == 0)
	    eos = 1;
	}
      }
      final_granulepos = ogg_page_granulepos (&og);
      stream_state = ogg_page_eos (&og);
    }
    eof = feof (fp);
  }
  // shutting everything down
  ogg_stream_clear (&os);
  vorbis_comment_clear (&vc);
  vorbis_info_clear (&vi);
  ogg_sync_clear (&oy);
}

// gets the size and sets up the dynamic array for holding all the packet bitrates.
void
vorb::statfile (statistic * mp3info2)
{
  FILE               *fp;
  struct stat         buf;
  int                 len;
  stat (mp3info2->getName().c_str(), &buf);
  len = buf.st_size;
  mp3info2->setSize((double) len / 1024);
  // this is broken i think.
  if ((fp = fopen (mp3info2->getName().c_str(), "rb"))) {
    scan_ogg (fp, len, mp3info2);
    // open file  then after scanning, close it
    fclose (fp);
  }
}

extern "C" input* createi() {
   return new vorb;
}

extern "C" void destroyi(input* tempIn) {
   delete tempIn;
}