<?PHP

  /**
   * qcEvents - Ogg-Stream-Reader
   * Copyright (C) 2014 Bernd Holzmueller <bernd@quarxconnect.de>
   * 
   * 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 3 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, see <http://www.gnu.org/licenses/>.
   **/
  
  require_once ('qcEvents/Interface/Consumer.php');
  require_once ('qcEvents/Trait/Hookable.php');
  
  /** 
   * Ogg Streams
   * -----------
   * Read a physical Ogg-Stream and split it into its logical streams
   * 
   * @class qcEvents_Stream_Ogg
   * @extends qcEvents_Event
   * @package qcEvents
   * @revision 02
   * @author Bernd Holzmueller <bernd@quarxconnect.de>
   **/
  class qcEvents_Stream_Ogg implements qcEvents_Interface_Consumer {
    use qcEvents_Trait_Hookable;
    
    /* Quirk-Mode */
    private $tolerateQuirks = false;
    
    /* Perform CRC-Checking */
    private $checkCRC = true;
    
    /* Internal buffer for the stream */
    private $Buffer = '';
    
    /* Internal representation of streams */
    private $Streams = array ();
    
    /* Group-Detection */
    private $streamGroup = array ();
    
    /* Last parsed packet was a stream that started */
    private $streamAdded = false;
    
    /* Initialization-Callback */
    private $initCallback = null;
    
    // {{{ consume
    /**
     * Consume a set of data
     * 
     * @param mixed $Data
     * @param qcEvents_Interface_Source $Source
     * 
     * @access public
     * @return void
     **/
    public function consume ($Data, qcEvents_Interface_Source $Source) {
      // Append to internal buffer
      $this->Buffer .= $Data;
      $l = strlen ($this->Buffer);
      $p = 0;
      unset ($Data);
      
      // Check if we are initializing
      if ($this->initCallback) {
        // Check if the first bytes denote an Ogg-Stream-Packet
        $Status = (substr ($this->Buffer, 0, 4) == 'OggS');
        
        // Check wheter we should accept quirks
        if (!$Status && $this->tolerateQuirks) {
          // Check if there is a stream-header in the buffer (but not at start)
          if (($p = strpos ($this->Buffer, 'OggS', 1)) === false)
            return;
          
          // Override the old status
          $Status = true;
        }
        
        // Raise the initial callback
        if ($Status)
          $this->___raiseCallback ($this->initCallback [0], $Status, $this->initCallback [1]);
        else
          $this->deinitConsumer ($Source);
        
        $this->initCallback = null;
        
        if (!$Status)
          return;
      }
      
      while (($p = strpos ($this->Buffer, 'OggS', $p)) !== false) {
        // Read the Ogg-Header
        # $Version = ord ($this->Buffer [$p + 4]);
        $Type = ord ($this->Buffer [$p + 5]);
        $Position =
          (ord ($this->Buffer [$p +  6])) +
          (ord ($this->Buffer [$p +  7]) << 8) +
          (ord ($this->Buffer [$p +  8]) << 16) +
          (ord ($this->Buffer [$p +  9]) << 24) +
          (ord ($this->Buffer [$p + 10]) * 4294967296) +
          (ord ($this->Buffer [$p + 11]) * 1099511627776) +
          (ord ($this->Buffer [$p + 12]) * 281474976710656) +
          (ord ($this->Buffer [$p + 13]) * 18014398509481984);
        $Serial =
          (ord ($this->Buffer [$p + 14])) +
          (ord ($this->Buffer [$p + 15]) << 8) +
          (ord ($this->Buffer [$p + 16]) << 16) + 
          (ord ($this->Buffer [$p + 17]) << 24);
        $Sequence =
          (ord ($this->Buffer [$p + 18])) +
          (ord ($this->Buffer [$p + 19]) << 8) +
          (ord ($this->Buffer [$p + 20]) << 16) + 
          (ord ($this->Buffer [$p + 21]) << 24);
        $CRC =
          (ord ($this->Buffer [$p + 22])) +
          (ord ($this->Buffer [$p + 23]) << 8) +
          (ord ($this->Buffer [$p + 24]) << 16) + 
          (ord ($this->Buffer [$p + 25]) << 24);
        $Segments = ord ($this->Buffer [$p + 26]);
        
        // Determine end of segment-table
        $PS = $PE = $p + 27 + $Segments;
        
        if ($PE > $l)
          break;
        
        // Read the segment-table
        for ($i = $p + 27; $i < $PS; $i++)
          $PE += ord ($this->Buffer [$i]);
        
        if ($PE > $l)
          break;
        
        // Check the CRC
        if ($this->checkCRC) {
          $Page = substr ($this->Buffer, $p, $PE - $p);
          
          // Remove the current CRC-Value
          $Page [22] = "\x00";
          $Page [23] = "\x00";
          $Page [24] = "\x00";
          $Page [25] = "\x00";
          
          if ($CRC != $this->crc ($Page)) {
            // Bail out an error
            $this->___callback ('oggCRCError');
            
            // Just move to the next possible OggS-Marker
            $p -= 4;
           
            continue;
          }
        }
        
        // Check if a new stream is started
        if (($Type & 0x02) == 0x02) {
          // Create the stream
          if (!isset ($this->Streams [$Serial])) {
             $this->Streams [$Serial] = array (
              'Sequence' => $Sequence,
              'Position' => 0,
              'Buffer' => '',
            );
            $this->streamGroup [$Serial] = $Serial;
            
            $this->___callback ('oggStreamStarted', $Serial);
            
          // Check if the stream is already started
          } else
            trigger_error ('Starting a stream that is already started?!');
          
          $this->streamAdded = true;
        
        // Handle stream-group-detection
        } elseif ($this->streamAdded) {
          // Check if this is a group
          if (count ($this->Streams) > 1)
            $this->___callback ('oggStreamGroupStarted', $tihs->streamGroup);
          
          $this->streamAdded = false;
        }
        
        // Make sure we have a stream
        if (!isset ($this->Streams [$Serial])) {
          trigger_error ('Packet without stream started');
          
          $p = $PE;
          
          continue;
        }
        
        // Check if a packet is missing
        if ($Sequence - $this->Streams [$Serial]['Sequence'] > 1)
          for ($i = $this->Streams [$Serial]['Sequence'] + 1; $i < $Sequence; $i++)
            $this->___callback ('oggStreamPacketLost', $Serial, $i);
        
        $this->Streams [$Serial]['Sequence'] = $Sequence;
        
        // Extract the payload
        $Payload = substr ($this->Buffer, $PS, $PE - $PS);
        
        // Check if this is final packet of a stream
        if (($Type & 0x04) == 0x04) {
          // Write out the last packet
          if (($Type & 0x01) == 0x01) {
            if (strlen ($this->Streams [$Serial]['Buffer']) > 0) {
              $Payload = $this->Streams [$Serial]['Buffer'] . $Payload;
              $Position = $this->Streams [$Serial]['Position'];
            } else
              trigger_error ('Continue-Packet without buffered data');
          
          // Flush the buffer
          } elseif (strlen ($this->Streams [$Serial]['Buffer']) > 0)
             $this->___callback ('oggStreamPacket', $Serial, $this->Streams [$Serial]['Position'], $this->Streams [$Serial]['Buffer']);
          
          // Write out the last packet
          $this->___callback ('oggStreamPacket', $Serial, $Position, $Payload);
          
          // Fire a callback
          $this->___callback ('oggStreamFinished', $Serial);
          
          // Remove the stream
          unset ($this->Streams [$Serial]);
          
          // Check if there are no more streams active an we were a group
          if ((count ($this->Streams) == 0) && (count ($this->streamGroup) > 1))
            $this->___callback ('oggStreamGroupFinished', $tihs->streamGroup);
          
          $this->streamGroup = array ();
        
        // Handle normal packets
        } elseif (($Type & 0x01) == 0x01) {
          if (strlen ($this->Streams [$Serial]['Buffer']) == 0) {
            trigger_error ('Continue-Packet without data on buffer');
            
            $this->Streams [$Serial]['Position'] = $Position;
          }
          
          $this->Streams [$Serial]['Buffer'] .= $Payload;
        } else {
          // Write out pending packets
          if (strlen ($this->Streams [$Serial]['Buffer']) > 0)
            $this->___callback ('oggStreamPacket', $Serial, $this->Streams [$Serial]['Position'], $this->Streams [$Serial]['Buffer']);
          
          // Put the new packet onto buffer
          $this->Streams [$Serial]['Position'] = $Position;
          $this->Streams [$Serial]['Buffer'] = $Payload;
        }
        
        // Move forward
        $p = $PE;
      }
      
      // Truncate the buffer
      if ($p > 0)
        $this->Buffer = substr ($this->Buffer, $p);
    }
    // }}}
    
    // {{{ close
    /**
     * Close this event-interface
     * 
     * @param callable $Callback (optional) Callback to raise once the interface is closed
     * @param mixed $Private (optional) Private data to pass to the callback
     * 
     * @access public
     * @return void
     **/
    public function close (callable $Callback = null, $Private = null) {
      # TODO: Unpipe from our parent source/stream
      
      // Raise a callback for this
      $this->___callback ('oggFinished');
      
      // Reset our state
      $this->resetState ();
    }
    // }}}
    
    // {{{ crc
    /**
     * Calculate Ogg-CRC
     * 
     * @param string $Data
     * 
     * @access private
     * @return int
     **/
    private function crc ($Data) {
      static $lookup = array (
        0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9,
        0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005,
        0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
        0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
        0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9,
        0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
        0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011,
        0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd,
        0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
        0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
        0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81,
        0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
        0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49,
        0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
        0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
        0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d,
        0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae,
        0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
        0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
        0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca,
        0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
        0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02,
        0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066,
        0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
        0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e,
        0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692,
        0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
        0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a,
        0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
        0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
        0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686,
        0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a,
        0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
        0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
        0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f,
        0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
        0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47,
        0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b,
        0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
        0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
        0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7,
        0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
        0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f,
        0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
        0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
        0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b,
        0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f,
        0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
        0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
        0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
        0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
        0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24,
        0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30,
        0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
        0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088,
        0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654,
        0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
        0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c,
        0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
        0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
        0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0,
        0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c,
        0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
        0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
      );
      
      $reg = 0;
      $len = strlen ($Data);
     
      for ($i = 0; $i < $len; $i++)   
        $reg = ($reg << 8) ^ $lookup [(($reg >> 24) & 0xff) ^ ord ($Data [$i])];
      
      return $reg;
    }
    // }}}
    
    // {{{ initConsumer
    /**
     * Setup ourself to consume data from a source
     * 
     * @param qcEvents_Interface_Source $Source
     * @param callable $Callback (optional) Callback to raise once the pipe is ready
     * @param mixed $Private (optional) Any private data to pass to the callback
     * 
     * The callback will be raised in the form of
     * 
     *   function (qcEvents_Interface_Consumer $Self, bool $Status, mixed $Private = null) { }
     * 
     * @access public
     * @return callable
     **/
    public function initConsumer (qcEvents_Interface_Source $Source, callable $Callback = null, $Private = null) {
      // Reset ourself first
      $this->resetState ();
      
      // Raise a callback for this
      $this->___callback ('eventPiped', $Source);
      
      // Store the requested callback
      $this->initCallback = array ($Callback, $Private);
    }
    // }}}
    
    // {{{ initStreamConsumer
    /**
     * Setup ourself to consume data from a stream
     * 
     * @param qcEvents_Interface_Source $Source
     * @param callable $Callback (optional) Callback to raise once the pipe is ready
     * @param mixed $Private (optional) Any private data to pass to the callback
     * 
     * The callback will be raised in the form of
     * 
     *   function (qcEvents_Interface_Stream_Consumer $Self, bool $Status, mixed $Private = null) { }
     * 
     * @access public
     * @return callable
     **/
    public function initStreamConsumer (qcEvents_Interface_Stream $Source, callable $Callback = null, $Private = null) {
      // Reset ourself first
      $this->resetState ();
      
      // Raise a callback for this
      $this->___callback ('eventPipedStream', $Source);
      
      // Store the requested callback
      $this->initCallback = array ($Callback, $Private);
    }
    // }}}
    
    // {{{ deinitConsumer
    /** 
     * Callback: A source was removed from this sink
     *    
     * @param qcEvents_Interface_Source $Source
     * @param callable $Callback (optional) Callback to raise once the pipe is ready
     * @param mixed $Private (optional) Any private data to pass to the callback
     * 
     * The callback will be raised in the form of 
     *  
     *   function (qcEvents_Interface_Consumer $Self, bool $Status, mixed $Private = null) { }
     * 
     * @access public
     * @return void
     **/  
    public function deinitConsumer (qcEvents_Interface_Source $Source, callable $Callback = null, $Private = null) {
      // Reset our state   
      $this->resetState ();
      
      // Raise a callback for this
      $this->___callback ('eventUnpiped', $Source);
      $this->___raiseCallback ($Callback, true, $Private);
    } 
    // }}}
    
    // {{{ resetState
    /**
     * Reset our internal state
     * 
     * @access private
     * @return void
     **/
    private function resetState () {
      if ($this->initCallback)
        $this->___raiseCallback ($this->initCallback [0], false, $this->initCallback [1]);
      
      $this->initCallback = null;
      $this->Buffer = '';
      $this->Streams = array ();
      $this->streamGroup = array ();
      $this->streamAdded = false;
    }
    // }}}
    
    
    // {{{ oggFinished
    /**
     * Callback: Finished parsing the Ogg-Stream
     * 
     * @access protected
     * @return void
     **/
    protected function oggFinished () { }
    // }}}
    
    // {{{ oggStreamStarted
    /**
     * Callback: A new logical Ogg-Stream was started
     * 
     * @param int $Serial
     * 
     * @access protected
     * @return void
     **/
    protected function oggStreamStarted ($Serial) { }
    // }}}
    
    // {{{ oggStreamFinished
    /**
     * Callback: A logical Ogg-Stream was finished
     * 
     * @param int $Serial
     * 
     * @access protected
     * @return void
     **/
    protected function oggStreamFinished ($Serial) { }
    // }}}
    
    // {{{ oggStreamGroupStarted
    /**
     * Callback: A grouped stream is ready
     * 
     * @param array $Serials
     * 
     * @access protected
     * @return void
     **/
    protected function oggStreamGroupStarted ($Serials) { }
    // }}}
    
    // {{{ oggStreamGroupFinished
    /**
     * Callback: A grouped stream was finished
     * 
     * @param array $Serials
     * 
     * @remark Do not forget that a stream might be chained!
     * 
     * @access protected
     * @return void
     **/
    protected function oggStreamGroupFinished ($Serials) { }
    // }}}
    
    protected function oggStreamPacket ($Serial, $Position, $Packet) { }
    
    // {{{ oggStreamPacketLost
    /**
     * Callback: A packet on a logical stream is missing
     * 
     * @param int $Serial
     * @param int $Sequence
     * 
     * @access protected
     * @return void
     **/
    protected function oggStreamPacketLost ($Serial, $Sequence) { }
    // }}}
    
    // {{{ oggCRCError
    /**
     * Callback: A CRC-Error happened on the physical stream
     * 
     * @remark No further information is provided as we do not
     *    know what's valid here and what's not
     * 
     * @access protected
     * @return void
     **/
    protected function oggCRCError () {
      trigger_error ('CRC-Error on Ogg-Stream');
    }
    // }}}
  }

?>