<?php

/**
 * A Class for Fetching Remote JSON data and caching it in a manner that will
 * easily allow other classes to access the data for the purpose of generating
 * notices, updating the sidebar, etc.
 *
 * Everything is stored in local properties to allow the debug method to simply
 * dump the $this item allowing us to see the results of everything that has
 * been processed by this class.
 *
 * @package   SocialWarfare\Functions
 * @copyright Copyright (c) 2018, Warfare Plugins, LLC
 * @license   GPL-3.0+
 * @since     3.1.0 | 27 JUN 2018 | Created
 */
class SWP_JSON_Cache_Handler {


	/**
	 * SWP_Debug_Trait provides useful tool like error handling and a debug
	 * method which outputs the contents of the current object.
	 */
	use SWP_Debug_Trait;


	/**
	 * The fetched from the remote JSON file.
	 *
	 * @var string
	 */
	private $response = '';


	/**
	 * The responsed parsed into an associative array.
	 *
	 * @var array
	 */
	private $parsed_response = array();


	/**
	 * The cached JSON data fetched from the database.
	 *
	 * @var array
	 */
	private $cached_data = array();


	/**
	 * Explicitly define the cache_data property to avoid dynamic property creation.
	 *
	 * @var array
	 */
	private $cache_data = array();


	/**
	 * Instantiate the class object.
	 *
	 * Check if the cache is fresh, if not, ping the JSON file on our server,
	 * parse the results, and store them in an options field in the database.
	 *
	 * @since  3.1.0 | 28 JUN 2018 | Created
	 * @return void
	 */
	public function __construct() {
		if ( false === $this->is_cache_fresh() ) :
			$this->fetch_new_json_data();
			add_action( 'wp_footer', array( $this, 'debug' ) );
		endif;
	}


	/**
	 * Fetch new JSON data.
	 *
	 * @since  3.1.0 | 28 JUN 2018 | Created
	 * @return void
	 */
	private function fetch_new_json_data() {

		if (function_exists('vip_safe_wp_remote_get')) {
			$response = vip_safe_wp_remote_get('https://warfareplugins.com/json_updates.php');
		} else {
			$response = wp_remote_get('https://warfareplugins.com/json_updates.php'); // phpcs:ignore
		}
		$this->response = wp_remote_retrieve_body( $response );

		// Create the cache data array.
		$this->parsed_response = array();

		if ( ! empty( $this->response ) ) :
			$this->parsed_response = json_decode( $this->response, true );
		endif;

		$this->parsed_response['timestamp'] = time();

		// Store the data in the database.
		update_option( 'swp_json_cache', $this->parsed_response, true );
	}


	/**
	 * A method to determin if the cached data is still fresh.
	 *
	 * @since  3.1.0 | 28 JUN 2018 | Created
	 * @return boolean true if fresh, false if expired.
	 */
	private function is_cache_fresh() {

		// If we're debugging, the cache is expired and needs to fetch.
		if ( true === SWP_Utility::debug( 'json_fetch' ) ) :
			return false;
		endif;

		$this->cache_data = get_option( 'swp_json_cache' );

		// If no cached data, the cache is not fresh.
		if ( false === $this->cache_data ) :
			return false;
		endif;

		// Forumlate the timestamps.
		$timestamp           = $this->cache_data['timestamp'];
		$current_time        = time();
		$time_between_checks = ( 6 * 60 * 60 );

		// Compare the timestamps.
		if ( $current_time > $timestamp + $time_between_checks ) :
			return false;
		endif;

		return true;
	}
}