<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Media
 * @subpackage ASF
 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com) 
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Metadata.php 177 2010-03-09 13:13:34Z svollbehr $
 */

/**#@+ @ignore */
require_once 'Zend/Media/Asf/Object.php';
/**#@-*/

/**
 * The <i>Metadata Object</i> permits authors to store stream-based metadata in
 * a file. This object supports the same types of metadata information as the
 * <i>Extended Content Description Object</i> except that it also allows a
 * stream number to be specified.
 *
 * @todo       Implement better handling of various types of attributes
 *     according to http://msdn.microsoft.com/en-us/library/aa384495(VS.85).aspx
 * @category   Zend
 * @package    Zend_Media
 * @subpackage ASF
 * @author     Sven Vollbehr <sven@vollbehr.eu>
 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com) 
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Metadata.php 177 2010-03-09 13:13:34Z svollbehr $
 */
final class Zend_Media_Asf_Object_Metadata extends Zend_Media_Asf_Object
{
    /** @var Array */
    private $_descriptionRecords = array();

    /**
     * Constructs the class with given parameters and reads object related data
     * from the ASF file.
     *
     * @param Zend_Io_Reader $reader  The reader object.
     * @param Array          $options The options array.
     */
    public function __construct($reader = null, &$options = array())
    {
        parent::__construct($reader, $options);

        if ($reader === null) {
            return;
        }

        $descriptionRecordsCount = $this->_reader->readUInt16LE();
        for ($i = 0; $i < $descriptionRecordsCount; $i++) {
            $this->_reader->skip(2);
            $descriptionRecord =
                array('streamNumber' => $this->_reader->readUInt16LE());
            $nameLength = $this->_reader->readUInt16LE();
            $dataType = $this->_reader->readUInt16LE();
            $dataLength = $this->_reader->readUInt32LE();
            $descriptionRecord['name'] = iconv
                ('utf-16le', $this->getOption('encoding'),
                 $this->_reader->readString16($nameLength));
            switch ($dataType) {
                case 0: // Unicode string
                    $descriptionRecord['data'] = iconv
                        ('utf-16le', $this->getOption('encoding'),
                         $this->_reader->readString16($dataLength));
                    break;
                case 1: // BYTE array
                    $descriptionRecord['data'] = $this->_reader->read($dataLength);
                    break;
                case 2: // BOOL
                    $descriptionRecord['data'] = $this->_reader->readUInt16LE() == 1;
                    break;
                case 3: // DWORD
                    $descriptionRecord['data'] = $this->_reader->readUInt32LE();
                    break;
                case 4: // QWORD
                    $descriptionRecord['data'] = $this->_reader->readInt64LE();
                    break;
                case 5: // WORD
                    $descriptionRecord['data'] = $this->_reader->readUInt16LE();
                    break;
                default:
                    break;
            }
            $this->_descriptionRecords[] = $descriptionRecord;
        }
    }

    /**
     * Returns the array of description records. Each record consists of the
     * following keys.
     *
     *   o streamNumber -- Specifies the stream number. Valid values are between
     *     1 and 127.
     *
     *   o name -- Specifies the name that uniquely identifies the attribute
     *     being described. Names are case-sensitive.
     *
     *   o data -- Specifies the actual metadata being stored.
     *
     * @return Array
     */
    public function getDescriptionRecords() 
    {
        return $this->_descriptionRecords; 
    }

    /**
     * Sets the array of description records. Each record must consist of the
     * following keys.
     *
     *   o streamNumber -- Specifies the stream number. Valid values are between
     *     1 and 127.
     *
     *   o name -- Specifies the name that uniquely identifies the attribute
     *     being described. Names are case-sensitive.
     *
     *   o data -- Specifies the actual metadata being stored.
     *
     * @param Array $descriptionRecords The array of description records.
     */
    public function setDescriptionRecords($descriptionRecords)
    {
        $this->_descriptionRecords = $descriptionRecords;
    }

    /**
     * Writes the object data.
     *
     * @param Zend_Io_Writer $writer The writer object.
     * @return void
     */
    public function write($writer)
    {
        require_once 'Zend/Io/StringWriter.php';
        $descriptionRecordsCount = count($this->_descriptionRecords);
        $descriptionRecordsWriter = new Zend_Io_StringWriter();
        for ($i = 0; $i < $descriptionRecordsCount; $i++) {
            $descriptionRecordsWriter
                ->writeUInt16LE(0)
                ->writeUInt16LE($this->_descriptionRecords[$i]['streamNumber'])
                ->writeUInt16LE(strlen($name = iconv
                    ($this->getOption('encoding'), 'utf-16le',
                     $this->_descriptionRecords[$i]['name']) . "\0\0"));
            if (is_string($this->_descriptionRecords[$i]['data'])) {
                /* There is no way to distinguish byte arrays from unicode
                 * strings and hence the need for a list of fields of type byte
                 * array */
                static $byteArray = array (
                    ''
                ); // TODO: Add to the list if you encounter one

                if (in_array($name, $byteArray)) {
                    $descriptionRecordsWriter
                        ->writeUInt16LE(1)
                        ->writeUInt32LE
                            (strlen($this->_descriptionRecords[$i]['data']))
                        ->write($name)
                        ->write($this->_descriptionRecords[$i]['data']);
                } else {
                    $value = iconv
                        ($this->getOption('encoding'), 'utf-16le',
                         $this->_descriptionRecords[$i]['data']);
                    $value = ($value ? $value . "\0\0" : '');
                    $descriptionRecordsWriter
                        ->writeUInt16LE(0)
                        ->writeUInt32LE(strlen($value))
                        ->write($name)
                        ->writeString16($value);
                }
            } else if (is_bool($this->_descriptionRecords[$i]['data'])) {
                $descriptionRecordsWriter
                    ->writeUInt16LE(2)
                    ->writeUInt32LE(2)
                    ->write($name)
                    ->writeUInt16LE
                        ($this->_descriptionRecords[$i]['data'] ? 1 : 0);
            } else if (is_int($this->_descriptionRecords[$i]['data'])) {
                $descriptionRecordsWriter
                    ->writeUInt16LE(3)
                    ->writeUInt32LE(4)
                    ->write($name)
                    ->writeUInt32LE($this->_descriptionRecords[$i]['data']);
            } else if (is_float($this->_descriptionRecords[$i]['data'])) {
                $descriptionRecordsWriter
                    ->writeUInt16LE(4)
                    ->writeUInt32LE(8)
                    ->write($name)
                    ->writeInt64LE($this->_descriptionRecords[$i]['data']);
            } else {
                // Invalid value and there is nothing to be done
                require_once 'Zend/Media/Asf/Exception.php';
                throw new Zend_Media_Asf_Exception('Invalid data type');
            }
        }

        $this->setSize
            (24 /* for header */ + 2 + $descriptionRecordsWriter->getSize());

        $writer->writeGuid($this->getIdentifier())
               ->writeInt64LE($this->getSize())
               ->writeUInt16LE($descriptionRecordsCount)
               ->write($descriptionRecordsWriter->toString());
    }
}