<?php

if ( ! class_exists( 'WP_Post_Meta_Revisioning' ) ) :

	class WP_Post_Meta_Revisioning {

		/**
		 * Set up the plugin actions
		 */
		public function __construct() {

			// Actions
			//
			// When restoring a revision, also restore that revisions's revisioned meta.
			add_action( 'wp_restore_post_revision', array( $this, '_wp_restore_post_revision_meta' ), 10, 2 );

			// When creating or updating an autosave, save any revisioned meta fields.
			add_action( 'wp_creating_autosave', array( $this, '_wp_autosave_post_revisioned_meta_fields' ) );
			add_action( 'wp_updating_autosave', array( $this, '_wp_autosave_post_revisioned_meta_fields' ) );

			// When creating a revision, also save any revisioned meta.
			add_action( '_wp_put_post_revision', array( $this, '_wp_save_revisioned_meta_fields' ) );


			//Filters
			// When revisioned post meta has changed, trigger a revision save
			add_filter( 'wp_save_post_revision_post_has_changed', array(
				$this,
				'_wp_check_revisioned_meta_fields_have_changed'
			), 10, 3 );

		}

		// Add the reviosioned meta to get_post_metadata for preview meta data
		public function _add_metadata_preview_filter() {
			add_filter( 'get_post_metadata', array( $this, '_wp_preview_meta_filter' ), 10, 4 );
		}

		/**
		 * Autosave the revisioned meta fields.
		 *
		 * Iterates thru the revisioned meta fields and checks each to see if they are set,
		 * and have a changed value. If so, the meta value is saved and attached to the autosave.
		 *
		 * @param Post object $new_autosave The new post being autosaved.
		 */
		public function _wp_autosave_post_revisioned_meta_fields( $new_autosave ) {
			/**
			 * The post data arrives as either $_POST['data']['wp_autosave'] or the $_POST
			 * itself. This sets $posted_data to the correct variable.
			 */
			$posted_data = isset( $_POST['data'] ) ? $_POST['data']['wp_autosave'] : $_POST;
			/**
			 * Go thru the revisioned meta keys and save them as part of the autosave, if
			 * the meta key is part of the posted data, the meta value is not blank and
			 * the the meta value has changes from the last autosaved value.
			 */
			foreach ( $this->_wp_post_revision_meta_keys() as $meta_key ) {

				if ( isset( $posted_data[ $meta_key ] )
				     && '' !== $posted_data[ $meta_key ]
				     && get_post_meta( $new_autosave['ID'], $meta_key, true ) != wp_unslash( $posted_data[ $meta_key ] )
				) {
					/*
					 * Use the underlying delete_metadata() and add_metadata() functions
					 * vs delete_post_meta() and add_post_meta() to make sure we're working
					 * with the actual revision meta.
					 */
					delete_metadata( 'post', $new_autosave['ID'], $meta_key );
					/**
					 * One last check to ensure meta value not empty().
					 */
					if ( ! empty( $posted_data[ $meta_key ] ) ) {
						/**
						 * Add the revisions meta data to the autosave.
						 */
						add_metadata( 'post', $new_autosave['ID'], $meta_key, $posted_data[ $meta_key ] );
					}
				}
			}
		}

		/**
		 * Determine which post meta fields are revisioned for the current post or
		 * a specific revision.
		 *
		 * @access public
		 * @since 4.2.0
		 *
		 * @param int $revision_id The ID of the revision to retrieve post meta fields
		 *                            revisioned for a specific revision. Retrieves current list
		 *                            of keys by default.
		 *
		 * @return array An array of meta keys to be revisioned.
		 */
		public function wp_post_revision_meta_keys_for_revision( $revision_id = null ) {
			$revisioned_meta_keys = array();
			/**
			 * If a revision_id is specified, look for a list of revisioned metas for that revision.
			 */
			if ( null !== $revision_id ) {
				$metas_revisioned = wp_unslash( get_metadata( 'post', $revision_id, '_wp_post_revision_meta_keys' ) );
				if ( 0 !== sizeof( $metas_revisioned[0] ) ) {
					$revisioned_meta_keys = $metas_revisioned;
				}
			} else {
				$revisioned_meta_keys = $this->_wp_post_revision_meta_keys();
			}

			return $revisioned_meta_keys;
		}

		/**
		 * Determine which post meta fields should be revisioned.
		 *
		 * @access public
		 * @since 4.2.0
		 *
		 * @return array An array of meta keys to be revisioned.
		 */
		public function _wp_post_revision_meta_keys() {
			/**
			 * Filter the list of post meta keys to be revisioned.
			 *
			 * @since 4.2.0
			 *
			 * @param array $keys An array of default meta fields to be revisioned.
			 */
			return apply_filters( 'wp_post_revision_meta_keys', array() );
		}

		/**
		 * Check whether revisioned post meta fields have changed.
		 */
		public function _wp_check_revisioned_meta_fields_have_changed( $post_has_changed, WP_Post $last_revision, WP_Post $post ) {
			foreach ( $this->_wp_post_revision_meta_keys() as $meta_key ) {
				if ( get_post_meta( $post->ID, $meta_key ) != get_post_meta( $last_revision->ID, $meta_key ) ) {
					$post_has_changed = true;
					break;
				}
			}

			return $post_has_changed;
		}

		/**
		 * Save the revisioned meta fields
		 */
		public function _wp_save_revisioned_meta_fields( $revision_id ) {
			$revision = get_post( $revision_id );
			$post_id  = $revision->post_parent;
			// Save revisioned meta fields.
			foreach ( $this->_wp_post_revision_meta_keys() as $meta_key ) {
				$meta_value = get_post_meta( $post_id, $meta_key );

				// Don't save blank meta values
				if ( array_key_exists( 0, $meta_value ) && '' !== $meta_value[0] ) {

					/*
					 * Use the underlying add_metadata() function vs add_post_meta()
					 * to ensure metadata is added to the revision post and not its parent.
					 */
					add_metadata( 'post', $revision_id, $meta_key, $meta_value );
				}
			}
			// Save the revisioned meta keys so we know which meta keys were revisioned
			add_metadata( 'post', $revision_id, '_wp_post_revision_meta_keys', $this->_wp_post_revision_meta_keys() );
		}

		/**
		 * Restore the revisioned meta values for a post
		 */
		public function _wp_restore_post_revision_meta( $post_id, $revision_id ) {
			// Restore revisioned meta fields; first get the keys for this revision
			$metas_revisioned = wp_unslash( get_metadata( 'post', $revision_id, '_wp_post_revision_meta_keys' ) );
			if ( 0 !== sizeof( $metas_revisioned[0] ) ) {
				foreach ( $metas_revisioned[0] as $meta_key ) {
					// Clear any existing metas
					delete_post_meta( $post_id, $meta_key );
					// Get the stored meta, not stored === blank
					$meta_values = get_post_meta( $revision_id, $meta_key, true );
					if ( 0 !== sizeof( $meta_values ) && is_array( $meta_values ) ) {
						foreach ( $meta_values as $meta_value ) {
							add_post_meta( $post_id, $meta_key, $meta_value );
						}
					}
				}
			}
		}

		/**
		 * Filters post meta retrieval to get values from the actual autosave post,
		 * and not its parent.
		 *
		 * Filters revisioned meta keys only.
		 *
		 * @access public
		 * @since 4.2.0
		 *
		 * @param mixed $value Meta value to filter.
		 * @param int $object_id Object ID.
		 * @param string $meta_key Meta key to filter a value for.
		 * @param bool $single Whether to return a single value. Default false.
		 *
		 * @return mixed Original meta value if the meta key isn't revisioned, the object doesn't exist,
		 *               the post type is a revision or the post ID doesn't match the object ID.
		 *               Otherwise, the revisioned meta value is returned for the preview.
		 */
		public function _wp_preview_meta_filter( $value, $object_id, $meta_key, $single ) {

			$post = get_post();
			if ( empty( $post )
			     || $post->ID != $object_id
			     || ! in_array( $meta_key, self::_wp_post_revision_meta_keys() )
			     || 'revision' == $post->post_type
			) {
				return $value;
			}

			// Grab the autosave.
			$preview = wp_get_post_autosave( $post->ID );
			if ( ! is_object( $preview ) ) {
				return $value;
			}

			return get_post_meta( $preview->ID, $meta_key, $single );
		}
	}

endif;

$wp_Post_Meta_Revisioning = new WP_Post_Meta_Revisioning;

//Only works with WordPress version 4.1+
if ( version_compare( $wp_version, '4.1', '>=' ) ) {
	add_filter( 'wp_post_revision_meta_keys', 'quest_pagebuilder_metakeys' );
}


function quest_pagebuilder_metakeys( $meta_keys ) {
	$meta_keys[] = 'pt_pb_sections';

	return $meta_keys;
}