<?php
	/**
	 * The file contains a base class for all metaboxe.
	 *
	 * @author Alex Kovalev <alex.kovalevv@gmail.com>
	 * @copyright (c) 2018, Webcraftic Ltd
	 *
	 * @package factory-metaboxes
	 * @since 1.0.0
	 */

	// Exit if accessed directly
	if( !defined('ABSPATH') ) {
		exit;
	}

	if( !class_exists('Wbcr_FactoryMetaboxes413_Metabox') ) {

		/**
		 * The base class for all metaboxes.
		 *
		 * @link http://codex.wordpress.org/Function_Reference/add_meta_box
		 * @since 1.0.0
		 */
		abstract class Wbcr_FactoryMetaboxes413_Metabox {

			/**
			 * Id of the metabox.
			 * Be default, the current class name is used.
			 *
			 * @since 1.0.0
			 * @var string
			 */
			public $id = null;

			/**
			 * A visible title of the metabox.
			 *
			 * @since 1.0.0
			 * @var string
			 */
			public $title = '';

			/**
			 * The part of the page where the edit screen
			 * section should be shown ('normal', 'advanced', or 'side').
			 *
			 * @since 1.0.0
			 * @var string
			 */
			public $context = 'normal';

			/**
			 * The priority within the context where the boxes
			 * should show ('high', 'core', 'default' or 'low')
			 *
			 * @since 1.0.0
			 * @var string
			 */
			public $priority = 'default';

			/**
			 * Post types for which a metabox should be shown.
			 *
			 * @since 1.0.0
			 * @var array
			 */
			public $post_types = array();

			/**
			 * Scripts that should be include on the page where the metabox will be shown.
			 *
			 * @since 1.0.0
			 * @var Wbcr_Factory463_ScriptList
			 */
			public $scripts;

			/**
			 * Styles that should be include on the page where the metabox will be shown.
			 *
			 * @since 1.0.0
			 * @var Wbcr_Factory463_StyleList
			 */
			public $styles;

			/**
			 * Stores a state of assets (connected of not).
			 *
			 * @since 1.0.0
			 * @var bool
			 */
			protected $is_connected = false;

			/**
			 * Creates a new instance of a metabox.
			 * @param Wbcr_Factory463_Plugin $plugin
			 */
			public function __construct(Wbcr_Factory463_Plugin $plugin)
			{
				$this->plugin = $plugin;
				$this->id = empty($this->id)
					? get_class($this)
					: $this->id;
			}

			/**
			 * Adds a new post type where the metabox should appear.
			 *
			 * @since 1.0.0
			 * @param string $typeName
			 */
			public function addPostType($typeName)
			{
				if( !in_array($typeName, $this->post_types) ) {
					$this->post_types[] = $typeName;
				}
			}

			/**
			 * Configures a metabox.
			 *
			 * @since 1.0.0
			 * @param Factory463_ScriptList $scripts A set of scripts to include.
			 * @param Factory463_StyleList $styles A set of style to include.
			 * @return void
			 */
			public function configure($scripts, $styles)
			{
				// method must be overriden in the derived classed.
			}

			/**
			 * Registers this metabox to show.
			 *
			 * @since 1.0.0
			 * @return void
			 */
			public function connect()
			{
				if( $this->is_connected ) {
					return;
				}
				$this->is_connected = true;

				$this->scripts = $this->plugin->newScriptList();
				$this->styles = $this->plugin->newStyleList();

				$this->configure($this->scripts, $this->styles);
				$this->includeScriptsAndStyles();
			}

			/**
			 * Includes scripts and styles for a metabox.
			 *
			 * @since 1.0.0
			 * @return void
			 */
			public function includeScriptsAndStyles()
			{
				global $post;

				if( $this->scripts->isEmpty() && $this->styles->isEmpty() ) {
					return;
				}
				if( !in_array($post->post_type, $this->post_types) ) {
					return;
				}

				$this->scripts->connect();
				$this->styles->connect();
			}

			/**
			 * Saves metabox data.
			 *
			 * @since 1.0.0
			 * @param int $post_id
			 * @return int
			 */
			public function actionSavePost($post_id)
			{

				$post_type = $_POST['post_type'];

				if( !in_array($post_type, $this->post_types) ) {
					return $post_id;
				}

				// verify the nonce before proceeding
				$className = strtolower(get_class($this));
				$nonceName = $className . '_factory_nonce';
				$nonceValue = $className . '_factory';

				if( !isset($_POST[$nonceName]) || !wp_verify_nonce($_POST[$nonceName], $nonceValue) ) {
					return $post_id;
				}

				if( wp_is_post_revision($post_id) ) {
					return $post_id;
				}

				// get the post type object.
				$post_type = get_post_type_object($post_type);

				// check if the current user has permission to edit the post.
				if( !current_user_can($post_type->cap->edit_post, $post_id) ) {
					return $post_id;
				}

				// all right, save data.
				$this->save($post_id);
			}

			/**
			 * Shows content of a metabox.
			 *
			 * @since 1.0.0
			 * @return void
			 */
			public function show()
			{
				// security nonce
				$className = strtolower(get_class($this));
				wp_nonce_field($className . '_factory', $className . '_factory_nonce');

				ob_start();
				$this->html();
				$content = ob_get_clean();

				echo $content;
			}

			/**
			 * [virtual] Prints html content of a metabox.
			 *
			 * The method must be overridden in the derived classes.
			 *
			 * @since 1.0.0
			 * @return void
			 */
			public function html()
			{
				echo 'Define the method "html" in your metabox class.';
			}

			/**
			 * [virtual] Saves metabox data.
			 *
			 * The method must be overridden in the derived classes.
			 *
			 * @since 1.0.0
			 * @param int $post_id
			 * @return void
			 */
			public function save($post_id)
			{
			}
		}
	}