<?php

namespace CevianSelectNamespace\Modules\Header\Lib;

/**
 * Class that builds header object and holds reference to it
 *
 * Class HeaderFactory
 */
class HeaderFactory {
	/**
	 * Instance of current class
	 *
	 * @var
	 */
	private static $instance;
	/**
	 * Instance of HeaderType
	 *
	 * @var
	 */
	private $headerObject;
	
	/**
	 * Private construct because of singletone
	 */
	private function __construct() {
	}
	
	/**
	 * Returns current header object
	 *
	 * @return mixed
	 */
	public function getHeaderObject() {
		return $this->headerObject;
	}
	
	/**
	 * Returns instance of current class
	 *
	 * @return HeaderFactory
	 */
	public static function getInstance() {
		if ( self::$instance == null ) {
			self::$instance = new self();
		}
		
		return self::$instance;
	}
	
	/**
	 * Checks if header object, whether passed as parameter or not, is valid object that extends HeaderType class
	 *
	 * @param null $header_object
	 *
	 * @return bool
	 */
	public function validHeaderObject( $header_object = null ) {
		$header_object = $header_object == null ? $this->headerObject : $header_object;
		
		return is_subclass_of( $header_object, 'CevianSelectNamespace\Modules\Header\Lib\HeaderType' );
	}
	
	/**
	 * Builds header object based on option read from database
	 *
	 * @param string $headerType value read from database
	 * @param array  $headerTypesOption
	 *
	 * @return bool|HeaderType
	 */
	public function build( $headerType, $headerTypesOption ) {
		if ( ! empty( $headerType ) && ! empty( $headerTypesOption ) ) {
			foreach ( $headerTypesOption as $header_type_option_key => $header_type_option_value ) {
				if ( $headerType === $header_type_option_key ) {
					$this->headerObject = new $header_type_option_value;
					
					break;
				}
			}
			
			return $this->headerObject;
		} else {
			return false;
		}
	}
}