<?php
namespace StockholmQodeMembership\Lib;

/**
 * Class ShortcodeLoader
 * @package StockholmQodeMembership\Lib
 */
class ShortcodeLoader {
	/**
	 * @var private instance of current class
	 */
	private static $instance;
	/**
	 * @var array
	 */
	private $loadedShortcodes = array();

	/**
	 * Private constuct because of Singletone
	 */
	private function __construct() {
	}

	/**
	 * Private sleep because of Singletone
	 */
	private function __wakeup() {
	}

	/**
	 * Private clone because of Singletone
	 */
	private function __clone() {
	}

	/**
	 * Returns current instance of class
	 * @return ShortcodeLoader
	 */
	public static function getInstance() {
		if ( self::$instance == null ) {
			return new self;
		}

		return self::$instance;
	}

	/**
	 * Adds new shortcode. Object that it takes must implement ShortcodeInterface
	 *
	 * @param ShortcodeInterface $shortcode
	 */
	private function addShortcode( ShortcodeInterface $shortcode ) {
		if ( ! array_key_exists( $shortcode->getBase(), $this->loadedShortcodes ) ) {
			$this->loadedShortcodes[ $shortcode->getBase() ] = $shortcode;
		}
	}

	/**
	 * Adds all shortcodes.
	 *
	 * @see ShortcodeLoader::addShortcode()
	 */
	private function addShortcodes() {
		$shortcodes_class_name = apply_filters('stockholm_qode_filter_membership_add_vc_shortcode', $shortcodes_class_name = array());
		sort($shortcodes_class_name);

		if(!empty($shortcodes_class_name)) {
			foreach($shortcodes_class_name as $shortcode_class_name) {
				$this->addShortcode(new $shortcode_class_name);
			}
		}
	}

	/**
	 * Calls ShortcodeLoader::addShortcodes and than loops through added shortcodes and calls render method
	 * of each shortcode object
	 */
	public function load() {

		$this->addShortcodes();

		foreach ( $this->loadedShortcodes as $shortcode ) {
			add_shortcode( $shortcode->getBase(), array( $shortcode, 'render' ) );
		}

	}
}