<?php
/**
 * Jet_Engine_Relations_Hierarchy manager
 */

// If this file is called directly, abort.
if ( ! defined( 'WPINC' ) ) {
	die;
}

if ( ! class_exists( 'Jet_Engine_Relations_Hierarchy' ) ) {

	/**
	 * Define Jet_Engine_Relations_Hierarchy class
	 */
	class Jet_Engine_Relations_Hierarchy {

		private $_hierarchy = array();

		/**
		 * Constructor for the class
		 */
		public function __construct() {
			add_filter( 'jet-engine/listings/macros-list', array( $this, 'register_grand_parent_child_macros' ) );
			//add_action( 'wp_loaded', array( $this, 'test_relations' ) );
		}

		public function test_relations() {
			$this->get_grandparent( 'kingdom', 'entity' );
			$this->get_grandchild( 'entity', 'kingdom' );
		}

		/**
		 * Add %get_grandparent% and %get_grandchild%
		 * @return [type] [description]
		 */
		public function register_grand_parent_child_macros( $macros = array() ) {

			$macros['get_grandparent'] = array(
				'label' => esc_html__( 'Get grandparent', 'jet-engine' ),
				'cb'    => array( $this, 'get_grandparent_macros' ),
				'args'  => array(
					'post_type' => array(
						'label'   => __( 'Post type', 'jet-engine' ),
						'type'    => 'select',
						'options' => jet_engine()->listings->get_post_types_for_options(),
					),
				),
			);

			$macros['get_grandchild'] = array(
				'label' => esc_html__( 'Get grandchild', 'jet-engine' ),
				'cb'    => array( $this, 'get_grandchild_macros' ),
				'args'  => array(
					'post_type' => array(
						'label'   => __( 'Post type', 'jet-engine' ),
						'type'    => 'select',
						'options' => jet_engine()->listings->get_post_types_for_options(),
					),
				),
			);

			return $macros;

		}

		/**
		 * Has hierarchy
		 *
		 * @return boolean [description]
		 */
		public function has_hierarchy() {
			return ! empty( $this->_hierarchy );
		}

		/**
		 * Handler for %get_grandparent% macros
		 * @param  [type] $value          [description]
		 * @param  [type] $from_post_type [description]
		 * @return [type]                 [description]
		 */
		public function get_grandparent_macros( $value, $from_post_type ) {

			$ids = $this->get_grandparent( $from_post_type );

			if ( empty( $ids ) ) {
				$ids = array( 0 );
			}

			return implode( ',', $ids );
		}

		/**
		 * Handler for %get_grandchild% macros
		 * @param  [type] $value          [description]
		 * @param  [type] $from_post_type [description]
		 * @return [type]                 [description]
		 */
		public function get_grandchild_macros( $value, $from_post_type ) {

			$ids = $this->get_grandchild( $from_post_type );

			if ( empty( $ids ) ) {
				$ids = array( 0 );
			}

			return implode( ',', $ids );

		}

		/**
		 * Returns grandparent posts for current post type
		 *
		 * @param  [type] $value     [description]
		 * @param  [type] $post_type [description]
		 * @return [type]            [description]
		 */
		public function get_grandparent( $from_post_type, $current = null, $post_id = null ) {

			if ( ! $current ) {
				$current = get_post_type();
			}

			if ( ! $post_id ) {
				$post_id = get_the_ID();
			}

			$grandparent = $from_post_type;

			if ( ! $current ) {
				return;
			}

			if ( empty( $this->_hierarchy ) ) {
				return;
			}

			$trail = $this->get_trail_data( $grandparent, $current );

			if ( empty( $trail['post_types'] ) ) {
				return;
			}

			if ( 1 === count( $trail['keys'] ) && 2 === count( $trail['post_types'] ) ) {
				$posts = jet_engine()->relations->get_related_posts( array(
					'post_type_1' => $from_post_type,
					'post_type_2' => $current,
					'from'        => $from_post_type,
				) );
			}

			$posts = $this->get_posts_by_trail( $post_id, $trail, 'up', $grandparent );

			if ( is_array( $posts ) ) {
				return $posts;
			} else {
				return array();
			}

		}

		/**
		 * Returns grandchild posts for current post type
		 *
		 * @param  [type] $value     [description]
		 * @param  [type] $post_type [description]
		 * @return [type]            [description]
		 */
		public function get_grandchild( $from_post_type, $current = null, $post_id = null ) {

			if ( ! $current ) {
				$current = get_post_type();
			}

			$grandchild = $from_post_type;

			if ( ! $post_id ) {
				$post_id = get_the_ID();
			}

			if ( ! $current ) {
				return;
			}

			if ( empty( $this->_hierarchy ) ) {
				return;
			}

			$trail = $this->get_trail_data( $current, $grandchild );

			if ( empty( $trail['post_types'] ) ) {
				return;
			}

			if ( 1 === count( $trail['keys'] ) && 2 === count( $trail['post_types'] ) ) {
				$posts = jet_engine()->relations->get_related_posts( array(
					'post_type_1' => $current,
					'post_type_2' => $from_post_type,
					'from'        => $from_post_type,
				) );
			}

			$posts = $this->get_posts_by_trail( $post_id, $trail, 'down', $grandchild );

			if ( is_array( $posts ) ) {
				return $posts;
			} else {
				return array();
			}

		}

		/**
		 * Returns posts by post types and meta keys trail
		 *
		 * @return [type] [description]
		 */
		public function get_posts_by_trail( $post_id, $trail = array(), $dir = 'down', $column = false ) {

			$post_types = $trail['post_types'];
			$keys       = $trail['keys'];
			$post_id    = absint( $post_id );

			if ( 'up' === $dir ) {
				$post_types = array_reverse( $post_types );
				$keys       = array_reverse( $keys );
			}

			$select = "SELECT ";
			$from   = "FROM ";
			$where  = "WHERE ";

			global $wpdb;

			$table = $wpdb->postmeta;

			if ( ! $column ) {
				$glue = ', ';
			} else {
				$glue = '';
			}

			foreach ( $post_types as $index => $post_type ) {

				$show = ( ! $column || ( $column && $post_type === $column ) ) ? true : false;

				if ( 0 === $index ) {
					if ( $show ) {
						$select .= "p1.post_id AS `{$post_type}`";
					}
				} else {
					if ( $show ) {
						$select .= "{$glue}p{$index}.meta_value AS `{$post_type}`";
					}
				}

			}

			foreach ( $keys as $index => $key ) {

				$tableindex = $index + 1;
				$key        = esc_attr( $key );

				if ( 0 === $index ) {
					$from  .= "{$table} AS p1";
					$where .= "p1.post_id = {$post_id} AND p1.meta_key = '{$key}'";
				} else {
					$from  .= " LEFT JOIN {$table} AS p{$tableindex} ON p{$tableindex}.post_id = p{$index}.meta_value";
					$where .= " AND p{$tableindex}.meta_key = '{$key}'";
				}
			}

			$query = $select . ' ' . $from . ' ' . $where . ';';

			if ( $column ) {
				$result = $wpdb->get_col( $query );
			} else {
				$result = $wpdb->get_results( $query );
			}

			return $result;

		}

		/**
		 * Returns trail from post type to post type
		 *
		 * @param  [type] $from [description]
		 * @param  [type] $to   [description]
		 * @return [type]       [description]
		 */
		public function get_trail_data( $from = null, $to = null ) {

			$result = array(
				'post_types' => array(),
				'keys'       => array(),
			);

			foreach ( $this->_hierarchy as $hierarchy ) {
				$post_types = $hierarchy['post_types'];
				$keys       = $hierarchy['trail'];
				$from_index = array_search( $from, $post_types );
				$to_index   = array_search( $to, $post_types );

				if ( false === $from_index || false === $to_index || $to_index < $from_index ) {
					continue;
				}

				$to_index_keys = $to_index - 1;

				$result['post_types'] = array_slice( $post_types, $from_index, ( $to_index - $from_index + 1 ) );
				$result['keys']       = array_slice( $keys, $from_index, ( $to_index_keys - $from_index + 1 ) );

				return $result;

			}

			return $result;
		}

		/**
		 * Create hierarchy description
		 *
		 * @param  [type] $relations [description]
		 * @return [type]            [description]
		 */
		public function create_hierarchy( $relations = array() ) {

			foreach ( $relations as $key => $relation ) {

				if ( empty( $relation['parent_relation'] ) ) {

					$all_relations = $relations;
					unset( $all_relations[ $key ] );

					$this->search_for_children( $key, $relation, $all_relations, $key );

				}

			}

		}

		/**
		 * Add relations to existing hierarcy or create new