<?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_View
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */

/**
 * Stream wrapper to convert markup of mostly-PHP templates into PHP prior to 
 * include().
 * 
 * Based in large part on the example at
 * http://www.php.net/manual/en/function.stream-wrapper-register.php
 * 
 * As well as the example provided at:
 *     http://mikenaberezny.com/2006/02/19/symphony-templates-ruby-erb/
 * written by 
 *     Mike Naberezny (@link http://mikenaberezny.com) 
 *     Paul M. Jones  (@link http://paul-m-jones.com)
 *
 * @category   Zend
 * @package    Zend_View
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_View_Stream 
{
    /**
     * Current stream position.
     *
     * @var int
     */
    protected $_pos = 0;

    /**
     * Data for streaming.
     *
     * @var string
     */
    protected $_data;

    /**
     * Stream stats.
     *
     * @var array
     */
    protected $_stat;
    
    /**
     * Opens the script file and converts markup.
     */
    public function stream_open($path, $mode, $options, &$opened_path) 
    {
        // get the view script source
        $path        = str_replace('zend.view://', '', $path);
        $this->_data = file_get_contents($path);
        
        /**
         * If reading the file failed, update our local stat store
         * to reflect the real stat of the file, then return on failure
         */
        if ($this->_data === false) {
            $this->_stat = stat($path);
            return false;
        }

        /**
         * Convert <?= ?> to long-form <?php echo ?> and <? ?> to <?php ?>
         * 
         */
        $this->_data = preg_replace('/\<\?\=/',          "<?php echo ",  $this->_data);
        $this->_data = preg_replace('/<\?(?!xml|php)/s', '<?php ',       $this->_data);
                
        /**
         * file_get_contents() won't update PHP's stat cache, so we grab a stat 
         * of the file to prevent additional reads should the script be 
         * requested again, which will make include() happy.
         */
        $this->_stat = stat($path);

        return true;
    }

    /**
     * Included so that __FILE__ returns the appropriate info
     * 
     * @return array
     */
    public function url_stat()
    {
        return $this->_stat;
    }

    /**
     * Reads from the stream.
     */
    public function stream_read($count) 
    {
        $ret = substr($this->_data, $this->_pos, $count);
        $this->_pos += strlen($ret);
        return $ret;
    }

    
    /**
     * Tells the current position in the stream.
     */
    public function stream_tell() 
    {
        return $this->_pos;
    }

    
    /**
     * Tells if we are at the end of the stream.
     */
    public function stream_eof() 
    {
        return $this->_pos >= strlen($this->_data);
    }

    
    /**
     * Stream statistics.
     */
    public function stream_stat() 
    {
        return $this->_stat;
    }

    
    /**
     * Seek to a specific point in the stream.
     */
    public function stream_seek($offset, $whence) 
    {
        switch ($whence) {
            case SEEK_SET:
                if ($offset < strlen($this->_data) && $offset >= 0) {
                $this->_pos = $offset;
                    return true;
                } else {
                    return false;
                }
                break;

            case SEEK_CUR:
                if ($offset >= 0) {
                    $this->_pos += $offset;
                    return true;
                } else {
                    return false;
                }
                break;

            case SEEK_END:
                if (strlen($this->_data) + $offset >= 0) {
                    $this->_pos = strlen($this->_data) + $offset;
                    return true;
                } else {
                    return false;
                }
                break;

            default:
                return false;
        }
    }
}
