status('initializing Services_JSON');

$json = new Services_JSON(SERVICES_JSON_LOOSE_TYPE);

// keep track of playlist refresh

$playlist_last_refresh = time();

/**

 * Terminate a request with an error string formatted as JSON.

 * @param string Error message

 */

function json_die($msg)

{

  global $json;

  echo $json->encode(array(

      'mode' => 'error',

      'error' => $msg

    ));

  return true;

}

function ajax_request_handler($httpd)

{

  global $playlist, $mime_types, $json;

  // Set content type

  $httpd->header("Content-type: {$mime_types['js']}");

  // get PATH_INFO

  $pathinfo = @substr(@substr($_SERVER['REQUEST_URI'], 1), @strpos(@substr($_SERVER['REQUEST_URI'], 1), '/')+1);

  if ( empty($pathinfo) )

  {

    return json_die('No action specified on URI');

  }

  $params = explode('/', $pathinfo);

  $action =& $params[0];

  switch ( $action )

  {

    case 'stop':

    case 'next':

    case 'prev':

      echo dcop_action('player', 'stop');

      break;

    case 'play':

      echo dcop_action('player', 'playPause');

      break;

    case 'jump':

      $tid =& $params[1];

      if ( !preg_match('/^[0-9]+$/', $tid) )

      {

        return die_json('Invalid track ID');

      }

      $tid = intval($tid);

      dcop_action('playlist', "playByIndex $tid");

      $return = array(

        'current_track_length' => $playlist[$tid]['length_int'],

        'current_track_pos' => 0

      );

      echo $json->encode($return);

      break;

    case 'volume':

      $volume =& $params[1];

      if ( !preg_match('/^[0-9]+$/', $volume) )

      {

        return die_json('Invalid track ID');

      }

      $volume = intval($volume);

      dcop_action('player', "setVolume $volume");

      $return = array(

        'volume' => $volume

        );

      echo $json->encode($return);

      break;

    case 'refresh':

      global $playlist_last_refresh, $playlist, $playlist_last_md5;

      if ( $playlist_last_refresh + 60 < time() )

      {

        rebuild_playlist();

      }

      $current_track = dcop_action('playlist', 'getActiveIndex');

      $return = array(

          'is_playing' => dcop_action('player', 'isPlaying'),

          'current_track' => $current_track,

          'volume' => dcop_action('player', 'getVolume'),

          // include the MD5 of the playlist so that if it changes, the

          // client can refresh (otherwise things get madly corrupted)

          'playlist_hash' => $playlist_last_md5

        );

      if ( isset($playlist[$current_track]) )

      {

        $return['current_track_length'] = $playlist[$current_track]['length_int'];

        $return['current_track_pos'] = dcop_action('player', 'trackCurrentTime');

      }

      echo $json->encode($return);

      break;

    default:

      return json_die("Undefined action: $action");

  }

}