module.ab-redirect.php

<?php

define("QUICK_CACHE_ALLOWED", false); 
define("DONOTCACHEPAGE", true); 
define('DONOTCACHCEOBJECT', true); 
define('DONOTCDN', true); 

if ( file_exists ( './../../../../wp-load.php' ) )
{
	include_once ( './../../../../wp-load.php' );
}
else if ( file_exists ( './../../../../../wp-load.php' ) )
{
	include_once ( './../../../../../wp-load.php' );
}

class LP_Variation_Rotation {

	static $permalink_name;
	static $post_id;
	static $last_loaded_variation;
	static $variations; 
	static $marker;
	static $next_marker;
	static $destination_url;
	
	/**
	 *  	Executes Class 
	 */
	public function __construct() {
	
		self::load_variables();
		//self::run_debug();
		self::redirect();		
		
	}
	
	/**
	 *  	Loads Static Variables
	 */
	private static function load_variables()
	{	
		self::$permalink_name = (isset($_GET['permalink_name'])) ?  sanitize_text_field($_GET['permalink_name']) : null;
		self::$post_id = self::load_post_id();
		self::$last_loaded_variation = ( isset( $_COOKIE['lp-loaded-variation-'.self::$permalink_name] ) ) ? $_COOKIE['lp-loaded-variation-'.self::$permalink_name] : null;
		self::$variations = self::load_variations();
		self::$marker = self::load_marker();
		self::$next_marker = self::discover_next_variation();
		self::$destination_url = self::build_destination_url();
	}
	
	/**
	 *  	Debug Information - Prints Class Variable Data 
	 */
	static function run_debug() {
		print_r($this);exit;
	}
	
	/**
	 *  	Loads the ID of the Landing Page 
	 */
	static function load_post_id() {
		global $wpdb;
		
		$post_id = $wpdb->get_var( $wpdb->prepare( "SELECT ID FROM $wpdb->posts WHERE post_name = %s AND post_type='landing-page'", self::$permalink_name ));
		
		return $post_id;
		
	}
	
	/**
	 *  	Loads an Array of Active Variations Associated with Landing Page 
	 */
	static function load_variations() {
		
		$live_variations = array();
		
		$variations_string = get_post_meta( self::$post_id , 'lp-ab-variations' , true );	
		$variations = explode(',',$variations_string);
		$variations = array_filter($variations,'is_numeric');
		
		/* Check the Status of Each Variation and Keep Live Ones */
		foreach ($variations as $key=>$vid) {
		
			if ($vid==0) {
				$variation_status = get_post_meta( self::$post_id , 'lp_ab_variation_status' , true );
			} else 	{
				$variation_status = get_post_meta( self::$post_id , 'lp_ab_variation_status-'.$vid , true );
			}

			if (!is_numeric($variation_status) || $variation_status==1) {
				$live_variations[] = $vid;
			}
			
		}		
		
		return $live_variations;		
	}
	
	/**
	 *  	Loads Variation ID of Last Variation Loaded 
	 */
	static function load_marker() {
		
		$marker = get_post_meta( self::$post_id , 'lp-ab-variations-marker' , true );
		
		if ( !is_numeric($marker) || !in_array( $marker , self::$variations ) ) {

			$marker = current(self::$variations);
		}
		
		return $marker;
	}
	
	/**
	 *  	Discovers Next Variation in Line 
	 */
	static function discover_next_variation() {
	
		/* Set Pointer to Correct Location in Variations Array */
		while ( self::$marker != current( self::$variations) ) {
			next(self::$variations);
		}
		
		/* Discover the next variation in the array */
		next(self::$variations);
		
		/* If the pointer is empty then reset array */
		if ( !is_numeric(current( self::$variations ) ) ) {
			reset( self::$variations );
		}
		
		/* Save as Historical Data */		
		update_post_meta( self::$post_id , 'lp-ab-variations-marker' , current( self::$variations ) );
		
		return current( self::$variations );
		
	}
	
	/**
	 *  	Builds Redirect URL & Stores Cookie Data 
	 */
	static function build_destination_url() {
		
		/* Load Base URL */
		$url = get_permalink(self::$post_id);
		$old_params = null;
		
		/* Keep GET Params */
		foreach ($_GET as $key=>$value) {
			if ($key != "permalink_name"){
				$old_params .= "&$key=" . $value;
			}
		}
		
		/* Build Final URL and Set Memory Cookies */
		$url = $url."?lp-variation-id=".self::$next_marker.$old_params;
		
		/* Set Memory Cookies */
		setcookie('lp-loaded-variation-'.self::$permalink_name , $url , time()+ 60 * 60 * 24 * 30 , "/" );
		setcookie( 'lp-variation-id' , self::$next_marker , time()+3600 , "/" );
		
		return $url;
	}

	/**
	 *  	Redirects to Correct Variation
	 */
	static function redirect() {
		header("Location: ".self::$destination_url , false );
		exit;
	}
}

$VariationRoation = new LP_Variation_Rotation;