/*
   Copyright (C) 2003 Commonwealth Scientific and Industrial Research
   Organisation (CSIRO) Australia

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

   - Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

   - Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

   - Neither the name of CSIRO Australia nor the names of its
   contributors may be used to endorse or promote products derived from
   this software without specific prior written permission.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
   PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE ORGANISATION OR
   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

/*
 * oggz_read.c
 *
 * Conrad Parker <conrad@annodex.net>
 */

#include "config.h"

#if OGGZ_CONFIG_READ

#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <time.h>

#include <ogg/ogg.h>

#include "oggz_compat.h"
#include "oggz_private.h"

/* #define DEBUG */
/* #define DEBUG_VERBOSE */

#define CHUNKSIZE 65536

#define OGGZ_READ_EMPTY (-404)

OGGZ *
oggz_read_init (OGGZ * oggz)
{
  OggzReader * reader = &oggz->x.reader;

  ogg_sync_init (&reader->ogg_sync);
  ogg_stream_init (&reader->ogg_stream, (int)-1);
  reader->current_serialno = -1;

  reader->read_packet = NULL;
  reader->read_user_data = NULL;

  reader->read_page = NULL;
  reader->read_page_user_data = NULL;

  reader->current_unit = 0;

  return oggz;
}

OGGZ *
oggz_read_close (OGGZ * oggz)
{
  OggzReader * reader = &oggz->x.reader;

  ogg_stream_clear (&reader->ogg_stream);
  ogg_sync_clear (&reader->ogg_sync);

  return oggz;
}

int
oggz_set_read_callback (OGGZ * oggz, long serialno,
                        OggzReadPacket read_packet, void * user_data)
{
  OggzReader * reader;
  oggz_stream_t * stream;

  if (oggz == NULL) return OGGZ_ERR_BAD_OGGZ;

  reader =  &oggz->x.reader;

  if (oggz->flags & OGGZ_WRITE) {
    return OGGZ_ERR_INVALID;
  }

  if (serialno == -1) {
    reader->read_packet = read_packet;
    reader->read_user_data = user_data;
  } else {
    stream = oggz_get_stream (oggz, serialno);
#if 0
    if (stream == NULL) return OGGZ_ERR_BAD_SERIALNO;
#else
    if (stream == NULL)
      stream = oggz_add_stream (oggz, serialno);
#endif

    stream->read_packet = read_packet;
    stream->read_user_data = user_data;
  }

  return 0;
}

int
oggz_set_read_page (OGGZ * oggz, long serialno, OggzReadPage read_page,
                    void * user_data)
{
  OggzReader * reader;
  oggz_stream_t * stream;

  if (oggz == NULL) return OGGZ_ERR_BAD_OGGZ;

  reader =  &oggz->x.reader;

  if (oggz->flags & OGGZ_WRITE) {
    return OGGZ_ERR_INVALID;
  }

  if (serialno == -1) {
    reader->read_page = read_page;
    reader->read_page_user_data = user_data;
  } else {
    stream = oggz_get_stream (oggz, serialno);
#if 0
    if (stream == NULL) return OGGZ_ERR_BAD_SERIALNO;
#else
    if (stream == NULL)
      stream = oggz_add_stream (oggz, serialno);
#endif

    stream->read_page = read_page;
    stream->read_page_user_data = user_data;
  }

  return 0;
}

/*
 * oggz_get_next_page_7 (oggz, og, do_read)
 *
 * MODIFIED COPY OF CODE FROM BELOW SEEKING STUFF
 *
 * retrieves the next page.
 * returns >= 0 if found; return value is offset of page start
 * returns -1 on error
 * returns -2 if EOF was encountered
 */
static oggz_off_t
oggz_get_next_page_7 (OGGZ * oggz, ogg_page * og)
{
  OggzReader * reader = &oggz->x.reader;
#if _UNMODIFIED
  char * buffer;
#endif
  long bytes = 0, more;
  oggz_off_t page_offset = 0, ret;
  int found = 0;

  do {
    more = ogg_sync_pageseek (&reader->ogg_sync, og);

    if (more == 0) {
      page_offset = 0;
#if _UMMODIFIED_
      buffer = ogg_sync_buffer (&reader->ogg_sync, CHUNKSIZE);
      if ((bytes = oggz_io_read (oggz, buffer, CHUNKSIZE)) == 0) {
#if 0
  if (ferror (oggz->file)) {
    oggz_set_error (oggz, OGGZ_ERR_SYSTEM);
    return -1;
  }
#endif
      }

      if (bytes == 0) {
        return -2;
      }

      ogg_sync_wrote(&reader->ogg_sync, bytes);
#else
      return -2;
#endif
    } else if (more < 0) {
#ifdef DEBUG_VERBOSE
      printf ("get_next_page: skipped %ld bytes\n", -more);
#endif
      page_offset -= more;
    } else {
#ifdef DEBUG_VERBOSE
      printf ("get_next_page: page has %ld bytes\n", more);
#endif
      found = 1;
    }

  } while (!found);

  /* Calculate the byte offset of the page which was found */
  if (bytes > 0) {
    oggz->offset = oggz_io_tell (oggz) - bytes + page_offset;
    ret = oggz->offset;
  } else {
    /* didn't need to do any reading -- accumulate the page_offset */
    ret = oggz->offset + page_offset;
    oggz->offset += page_offset + more;
  }

  return ret;
}

static int
oggz_read_sync (OGGZ * oggz)
{
  OggzReader * reader = &oggz->x.reader;

  oggz_stream_t * stream;
  ogg_stream_state * os;
  ogg_packet * op;
  long serialno;

  ogg_packet packet;
  ogg_page og;

  int cb_ret = 0;

  /*os = &reader->ogg_stream;*/
  op = &packet;

  /* handle one packet.  Try to fetch it from current stream state */
  /* extract packets from page */
  while(cb_ret == 0) {

    if (reader->current_serialno != -1) {
    /* process a packet if we can.  If the machine isn't loaded,
       neither is a page */
      while(cb_ret == 0) {
        ogg_int64_t granulepos;
        int result;

        serialno = reader->current_serialno;

        stream = oggz_get_stream (oggz, serialno);

        if (stream == NULL) {
          /* new stream ... check bos etc. */
          if ((stream = oggz_add_stream (oggz, serialno)) == NULL) {
            /* error -- could not add stream */
            return -7;
          }
        }
        os = &stream->ogg_stream;

        result = ogg_stream_packetout(os, op);

        if(result == -1) {
#ifdef DEBUG
          printf ("oggz_read_sync: hole in the data\n");
#endif
          result = ogg_stream_packetout(os, op);
          if (result == -1) {
#ifdef DEBUG
            /*
             * libogg flags "holes in the data" (which are really 
             * inconsistencies in the page sequence number) by returning
             * -1.  This occurs in some files and pretty much doesn't matter,
             *  so we silently swallow the notification and reget the packet.
             *  If the result is *still* -1 then something strange is happening.
             */
            printf ("shouldn't get here");
#endif
            return -7;
          }
        }

        if(result > 0){
          int content;
          
          /* got a packet.  process it */
          granulepos = op->granulepos;

          content = oggz_stream_get_content(oggz, serialno);
  
          /*
           * if we have no metrics for this stream yet, then generate them
           */      
          if 
          (
            (!stream->metric || (content == OGGZ_CONTENT_SKELETON)) 
            && 
            (oggz->flags & OGGZ_AUTO)
          ) 
          {
            oggz_auto_get_granulerate (oggz, op, serialno, NULL);
          }

          /* attempt to determine granulepos for this packet */
          if (oggz->flags & OGGZ_AUTO) {
            reader->current_granulepos = 
              oggz_auto_calculate_granulepos (content, granulepos, stream, op); 
          } else {
            reader->current_granulepos = granulepos;
          }
          stream->last_granulepos = reader->current_granulepos;
        
          /* set unit on last packet of page */
          if 
          (
            (oggz->metric || stream->metric) && reader->current_granulepos != -1
          ) 
          {
            reader->current_unit =
              oggz_get_unit (oggz, serialno, reader->current_granulepos);
          }

          if (stream->read_packet) {
            cb_ret =
              stream->read_packet (oggz, op, serialno, stream->read_user_data);
          } else if (reader->read_packet) {
            cb_ret =
              reader->read_packet (oggz, op, serialno, reader->read_user_data);
          }
        }
        else
          break;
      }
    }

    /* If we've got a stop already, don't read more data in */
    if (cb_ret == OGGZ_STOP_OK || cb_ret == OGGZ_STOP_ERR) return cb_ret;

    if(oggz_get_next_page_7 (oggz, &og) < 0)
      return OGGZ_READ_EMPTY; /* eof. leave uninitialized */

    serialno = ogg_page_serialno (&og);
    reader->current_serialno = serialno; /* XXX: maybe not necessary */

    stream = oggz_get_stream (oggz, serialno);

    if (stream == NULL) {
      /* new stream ... check bos etc. */
      if ((stream = oggz_add_stream (oggz, serialno)) == NULL) {
        /* error -- could not add stream */
        return -7;
      }

      /* identify stream type */
      oggz_auto_identify(oggz, &og, serialno);
    }
    else if (oggz_stream_get_content(oggz, serialno) == OGGZ_CONTENT_ANXDATA)
    {
      /*
       * re-identify ANXDATA streams as these are now content streams
       */
      oggz_auto_identify(oggz, &og, serialno);
    }
    
    os = &stream->ogg_stream;

    {
      ogg_int64_t granulepos;

      granulepos = ogg_page_granulepos (&og);
      stream->page_granulepos = granulepos;

      if ((oggz->metric || stream->metric) && granulepos != -1) {
       reader->current_unit = oggz_get_unit (oggz, serialno, granulepos);
      } else if (granulepos == 0) {
       reader->current_unit = 0;
      }
    }

    if (stream->read_page) {
      cb_ret =
        stream->read_page (oggz, &og, serialno, stream->read_page_user_data);
    } else if (reader->read_page) {
      cb_ret =
        reader->read_page (oggz, &og, serialno, reader->read_page_user_data);
    }

#if 0
    /* bitrate tracking; add the header's bytes here, the body bytes
       are done by packet above */
    vf->bittrack+=og.header_len*8;
#endif

    ogg_stream_pagein(os, &og);
  }

  return cb_ret;
}

long
oggz_read (OGGZ * oggz, long n)
{
  OggzReader * reader;
  char * buffer;
  long bytes, bytes_read = 1, remaining = n, nread = 0;
  int cb_ret = 0;

  if (oggz == NULL) return OGGZ_ERR_BAD_OGGZ;

  if (oggz->flags & OGGZ_WRITE) {
    return OGGZ_ERR_INVALID;
  }

  if ((cb_ret = oggz->cb_next) != OGGZ_CONTINUE) {
    oggz->cb_next = 0;
    return oggz_map_return_value_to_error (cb_ret);
  }

  reader = &oggz->x.reader;

  cb_ret = oggz_read_sync (oggz);

#if 0
  if (cb_ret == OGGZ_READ_EMPTY) {
    /* If there's nothing to read yet, don't return 0 (eof) */
    if (reader->current_unit == 0) cb_ret = 0;
    else {
#if 0
      printf ("oggz_read: EMPTY, current_unit %ld != 0\n",
              reader->current_unit);
      return 0;
#endif
    }
  }
#endif

  while (cb_ret != OGGZ_STOP_ERR && cb_ret != OGGZ_STOP_OK &&
         bytes_read > 0 && remaining > 0) {
    bytes = MIN (remaining, CHUNKSIZE);
    buffer = ogg_sync_buffer (&reader->ogg_sync, bytes);
    if ((bytes_read = (long) oggz_io_read (oggz, buffer, bytes)) == 0) {
      /* schyeah! */
    }
    if (bytes_read == OGGZ_ERR_SYSTEM) {
      return OGGZ_ERR_SYSTEM;
    }

    if (bytes_read > 0) {
      ogg_sync_wrote (&reader->ogg_sync, bytes_read);
      
      remaining -= bytes_read;
      nread += bytes_read;
      
      cb_ret = oggz_read_sync (oggz);
    }
  }

  if (cb_ret == OGGZ_STOP_ERR) oggz_purge (oggz);

  /* Don't return 0 unless it's actually an EOF condition */
  if (nread == 0) {
    switch (bytes_read) {
    case OGGZ_ERR_IO_AGAIN:
    case OGGZ_ERR_SYSTEM:
      return bytes_read; break;
    default: break;
    }

    if (cb_ret == OGGZ_READ_EMPTY) {
      return 0;
    } else {
      return oggz_map_return_value_to_error (cb_ret);
    }

  } else {
    if (cb_ret == OGGZ_READ_EMPTY) cb_ret = OGGZ_CONTINUE;
    oggz->cb_next = cb_ret;
  }

  return nread;
}

/* generic */
long
oggz_read_input (OGGZ * oggz, unsigned char * buf, long n)
{
  OggzReader * reader;
  char * buffer;
  long bytes, remaining = n, nread = 0;
  int cb_ret = 0;

  if (oggz == NULL) return OGGZ_ERR_BAD_OGGZ;

  if (oggz->flags & OGGZ_WRITE) {
    return OGGZ_ERR_INVALID;
  }

  if ((cb_ret = oggz->cb_next) != OGGZ_CONTINUE) {
    oggz->cb_next = 0;
    return oggz_map_return_value_to_error (cb_ret);
  }

  reader = &oggz->x.reader;

  cb_ret = oggz_read_sync (oggz);

#if 0
  if (cb_ret == OGGZ_READ_EMPTY) {
    /* If there's nothing to read yet, don't return 0 (eof) */
    if (reader->current_unit == 0) cb_ret = 0;
    else return 0;
  }
#endif

  while (cb_ret != OGGZ_STOP_ERR && cb_ret != OGGZ_STOP_OK  &&
         /* !oggz->eos && */ remaining > 0) {
    bytes = MIN (remaining, 4096);
    buffer = ogg_sync_buffer (&reader->ogg_sync, bytes);
    memcpy (buffer, buf, bytes);
    ogg_sync_wrote (&reader->ogg_sync, bytes);

    buf += bytes;
    remaining -= bytes;
    nread += bytes;

    cb_ret = oggz_read_sync (oggz);
  }

  if (cb_ret == OGGZ_STOP_ERR) oggz_purge (oggz);

  if (nread == 0) {
    /* Don't return 0 unless it's actually an EOF condition */
    if (cb_ret == OGGZ_READ_EMPTY) {
      return OGGZ_ERR_STOP_OK;
    } else {
      return oggz_map_return_value_to_error (cb_ret);
    }
  } else {
    if (cb_ret == OGGZ_READ_EMPTY) cb_ret = OGGZ_CONTINUE;
    oggz->cb_next = cb_ret;
  }

  return nread;
}


#else /* OGGZ_CONFIG_READ */

#include <ogg/ogg.h>
#include "oggz_private.h"

OGGZ *
oggz_read_init (OGGZ * oggz)
{
  return NULL;
}

OGGZ *
oggz_read_close (OGGZ * oggz)
{
  return NULL;
}

int
oggz_set_read_callback (OGGZ * oggz, long serialno,
                        OggzReadPacket read_packet, void * user_data)
{
  return OGGZ_ERR_DISABLED;
}

long
oggz_read (OGGZ * oggz, long n)
{
  return OGGZ_ERR_DISABLED;
}

long
oggz_read_input (OGGZ * oggz, unsigned char * buf, long n)
{
  return OGGZ_ERR_DISABLED;
}

#endif