<?php
/**
 * Common serialization class. Fixes issues with broken serialized strings
 * typically caused by users migrating sites + running a search/replace MySQL
 * query on the post meta table (therefore breaking Soliloquy + it 'losing'
 * all slides etc).
 *
 * @since 2.3.9.6
 *
 * @package Soliloquy
 * @author  Tim Carr
 */

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class Soliloquy_Serialization_Admin {

	/**
	 * Holds the class object.
	 *
	 * @since 2.3.9.6
	 *
	 * @var object
	 */
	public static $instance;

	/**
	 * Path to the file.
	 *
	 * @since 2.3.9.6
	 *
	 * @var string
	 */
	public $file = __FILE__;

	/**
	 * Holds the base class object.
	 *
	 * @since 2.3.9.6
	 *
	 * @var object
	 */
	public $base;

	/**
	 * Primary class constructor.
	 *
	 * @since 2.3.9.6
	 */
	public function __construct() {
	}

	/**
	 * Fix a serialized string
	 *
	 * @since 2.3.9.6
	 *
	 * @param string $string Serialized string to fix
	 * @return array Unserialized data
	 */
	public function fix_serialized_string( $string ) {

		// Check string is serialised and if it already works return it
		if ( ! preg_match( '/^[aOs]:/', $string ) ) {
			return $string;
		}

		$unserialized_data = @unserialize( $string, [ 'allowed_classes' => false ] );
		if ( $unserialized_data !== false ) {
			return $unserialized_data;
		}

		// String needs fixing - fix it
		$string = preg_replace_callback( '/\bs:(\d+):"(.*?)"/', array( $this, 'fix_str_length' ), $string );

		// Return fixed unserialized data
		return @unserialize( $string, [ 'allowed_classes' => false ] );
	}

	/**
	 * Callback function for replacing the string's length paramter on a broken
	 * serialized string
	 *
	 * @since 2.3.9.6
	 *
	 * @param array $matches preg_replace matches
	 * @return string Replacement string
	 */
	private function fix_str_length( $matches ) {

		$string       = $matches[2];
		$right_length = strlen( $string );
		return 's:' . $right_length . ':"' . $string . '"';
	}

	/**
	 * Returns the singleton instance of the class.
	 *
	 * @since 2.3.9.6
	 *
	 * @return object The Soliloquy_Serialization_Admin object.
	 */
	public static function get_instance() {

		if ( ! isset( self::$instance ) && ! ( self::$instance instanceof Soliloquy_Serialization_Admin ) ) {
			self::$instance = new Soliloquy_Serialization_Admin();
		}

		return self::$instance;
	}
}

// Load the serialization admin class.
$soliloquy_serialization_admin = Soliloquy_Serialization_Admin::get_instance();