<?php

namespace ElatedMembership\Lib;

/**
 * Class ShortcodeLoader
 * @package ElatedMembership\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() {
	}
	
	/**
	 * 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( 'eltd_membership_filter_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' ) );
		}
	}
}