woocommerce-product-dependencies.php

<?php
/**
 * Plugin Name: WooCommerce Product Dependencies
 * Plugin URI: https://somewherewarm.com/
 * Description: Restrict access to WooCommerce products, depending on the ownership and/or purchase of other, required products.
 * Version: 2.0.0
 * Author: SomewhereWarm
 * Author URI: https://somewherewarm.com/
 *
 * Text Domain: woocommerce-product-dependencies
 * Domain Path: /languages/
 *
 * Requires at least: 6.2
 * Tested up to: 6.6
 *
 * WC requires at least: 8.2
 * WC tested up to: 9.0
 *
 * License: GNU General Public License v3.0
 * License URI: http://www.gnu.org/licenses/gpl-3.0.html
 */
class WC_Product_Dependencies {

	/**
	 * The single instance of the class.
	 * @var WC_Product_Dependencies
	 *
	 * @since 1.1.0
	 */
	protected static $_instance = null;

	/**
	 * Required WC version.
	 * @var string
	 */
	private $required = '8.2';

	/**
	 * Product Dependencies version.
	 */
	public $version = '2.0.0';

	/**
	 * 'Ownership' dependency type code.
	 */
	const DEPENDENCY_TYPE_OWNERSHIP = 1;

	/**
	 * 'Purchase' dependency type code.
	 */
	const DEPENDENCY_TYPE_PURCHASE = 2;

	/**
	 * 'Either' dependency type code.
	 */
	const DEPENDENCY_TYPE_EITHER = 3;

	/**
	 * Main WC_Product_Dependencies instance.
	 *
	 * Ensures only one instance of WC_Product_Dependencies is loaded or can be loaded - @see 'WC_Product_Dependencies()'.
	 *
	 * @since  1.1.0
	 *
	 * @static
	 * @return WC_Product_Dependencies - Main instance
	 */
	public static function instance() {
		if ( is_null( self::$_instance ) ) {
			self::$_instance = new self();
		}
		return self::$_instance;
	}

	/**
	 * Cloning is forbidden.
	 *
	 * @since 1.1.0
	 */
	public function __clone() {
		_doing_it_wrong( __FUNCTION__, __( 'Foul!', 'woocommerce-product-dependencies' ), '1.1.0' );
	}

	/**
	 * Unserializing instances of this class is forbidden.
	 *
	 * @since 1.1.0
	 */
	public function __wakeup() {
		_doing_it_wrong( __FUNCTION__, __( 'Foul!', 'woocommerce-product-dependencies' ), '1.1.0' );
	}

	/**
	 * Fire in the hole!
	 */
	public function __construct() {

		// Load plugin on 'plugins_loaded' hook.
		add_action( 'plugins_loaded', array( $this, 'plugins_loaded' ) );
	}

	/**
	 * The plugin url
	 * @return string
	 */
	public function plugin_url() {
		return plugins_url( basename( plugin_dir_path( __FILE__ ) ), basename(__FILE__) );
	}

	/**
	 * Initialize.
	 *
	 * @return void
	 */
	public function plugins_loaded() {

		// Core compatibility functions.
		require_once( 'class-wc-pd-core-compatibility.php' );

		if ( ! function_exists( 'WC' ) || ! WC_PD_Core_Compatibility::is_wc_version_gte_8_2() ) {
			return;
		}

		// Helper functions.
		require_once( 'class-wc-pd-helpers.php' );

		// Declare HPOS compatibility.
		add_action( 'before_woocommerce_init', array( $this, 'declare_hpos_compatibility' ) );

		// Init textdomain.
		add_action( 'init', array( $this, 'init') );

		// Validate add-to-cart action.
		add_filter( 'woocommerce_add_to_cart_validation', array( $this, 'add_to_cart_validation' ), 10, 3 );

		// Validate products in cart.
		add_action( 'woocommerce_check_cart_items', array( $this, 'check_cart_items' ), 1 );

		if ( is_admin() ) {

			// Admin jQuery.
			add_action( 'admin_enqueue_scripts', array( $this, 'dependencies_admin_scripts' ) );

			// Save admin options.
			add_action( 'woocommerce_admin_process_product_object', array( $this, 'process_product_data' ) );

			// Add the "Dependencies" tab in Product Data.
			add_action( 'woocommerce_product_data_tabs', array( $this, 'dependencies_product_data_tab' ) );

			// Add the "Dependencies" tab content in Product Data.
			add_action( 'woocommerce_product_data_panels', array( $this, 'dependencies_product_data_panel' ) );
		}
	}

	/**
	 * Init textdomain.
	 *
	 * @return void
	 */
	public function init() {
		load_plugin_textdomain( 'woocommerce-product-dependencies', false, dirname( plugin_basename( __FILE__ ) ) . '/languages/' );
	}

	/**
	 * Declare HPOS( Custom Order tables) compatibility.
	 *
	 */
	public function declare_hpos_compatibility() {

		if ( ! class_exists( 'Automattic\WooCommerce\Utilities\FeaturesUtil' ) ) {
			return;
		}

		\Automattic\WooCommerce\Utilities\FeaturesUtil::declare_compatibility( 'custom_order_tables', plugin_basename( __FILE__ ), true );
	}

	/**
	 * Include scripts.
	 */
	public function dependencies_admin_scripts() {

		$suffix = defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ? '' : '.min';

		wp_register_script( 'wc-pd-writepanels', $this->plugin_url() . '/assets/js/wc-pd-writepanels' . $suffix . '.js', array(), $this->version );

		$screen    = get_current_screen();
		$screen_id = $screen ? $screen->id : '';

		if ( in_array( $screen_id, array( 'product' ) ) ) {
			wp_enqueue_script( 'wc-pd-writepanels' );
		}

	}

	/**
	 * Validates a product when adding to cart.
	 *
	 * @param  boolean  $add
	 * @param  int      $item_id
	 * @param  int      $quantity
	 * @return boolean
	 */
	public function add_to_cart_validation( $add, $item_id, $quantity ) {
		return $add && $this->evaluate_dependencies( $item_id );
	}

	/**
	 * Validates cart contents.
	 */
	public function check_cart_items() {

		$cart_items = WC()->cart->cart_contents;

		foreach ( $cart_items as $cart_item ) {
			$product = $cart_item[ 'data' ];
			$this->evaluate_dependencies( $product );
		}
	}

	/**
	 * Check conditions.
	 *
	 * @param  mixed  $item
	 * @return boolean
	 */
	public function evaluate_dependencies( $item ) {

		if ( is_a( $item, 'WC_Product' ) ) {

			if ( $item->is_type( 'variation' ) ) {
				$product_id = $item->get_parent_id();
				$product    = wc_get_product( $product_id );
			} else {
				$product_id = $item->get_id();
				$product    = $item;
			}

		} else {
			$product_id = absint( $item );
			$product    = wc_get_product( $product_id );
		}

		if ( ! $product ) {
			return;
		}

		$tied_product_ids          = $this->get_tied_product_ids( $product );
		$tied_category_ids         = $this->get_tied_category_ids( $product );
		$dependency_selection_type = $this->get_dependency_selection_type( $product );
		$dependency_notice         = $this->get_dependency_notice( $product );

		$product_title      = $product->get_title();
		$tied_products      = array();
		$dependencies_exist = false;

		// Ensure dependencies exist.
		if ( 'product_ids' === $dependency_selection_type ) {

			if ( ! empty( $tied_product_ids ) ) {
				foreach ( $tied_product_ids as $id ) {

					$tied_product = wc_get_product( $id );

					if ( $tied_product ) {
						$tied_products[ $id ] = $tied_product;
						$dependencies_exist   = true;
					}
				}
			}

		} else {

			if ( ! empty( $tied_category_ids ) ) {

				$product_categories   = (array) get_terms( 'product_cat', array( 'get' => 'all' ) );
				$product_category_ids = wp_list_pluck( $product_categories, 'term_id' );
				$tied_category_ids    = array_intersect( $product_category_ids, $tied_category_ids );
				$dependencies_exist   = sizeof( $tied_category_ids ) > 0;
			}
		}

		if ( $dependencies_exist ) {

			$purchase_dependency_result  = false;
			$ownership_dependency_result = false;

			$purchased_product_ids = array();
			$purchased_cat_ids     = array();

			$dependency_type         = $this->get_dependency_type( $product );
			$dependency_relationship = $this->get_dependency_relationship( $product );

			$tied_product_ids = array_keys( $tied_products );
			$has_multiple     = 'product_ids' === $dependency_selection_type ? sizeof( $tied_products ) > 1 : sizeof( $tied_category_ids ) > 1;
			$tied_ids         = 'product_ids' === $dependency_selection_type ? $tied_product_ids : $tied_category_ids;
			$owned_ids        = array();

			// Check cart.
			if ( in_array( $dependency_type, array( self::DEPENDENCY_TYPE_PURCHASE, self::DEPENDENCY_TYPE_EITHER ) ) ) {

				$cart_contents = WC()->cart->cart_contents;
				$item_id       = $product_id;

				foreach ( $cart_contents as $cart_item ) {

					$product_id   = $cart_item[ 'product_id' ];
					$variation_id = $cart_item[ 'variation_id' ];

					if ( $product_id === $item_id || $variation_id === $item_id ) {
						continue;
					}

					if ( 'product_ids' === $dependency_selection_type ) {

						if ( in_array( $product_id, $tied_product_ids ) || in_array( $variation_id, $tied_product_ids ) ) {

							if ( 'or' === $dependency_relationship ) {
								$purchase_dependency_result = true;
								break;
							} else {
								$purchased_product_ids = array_unique( array_merge( $purchased_product_ids, array_filter( array( $product_id, $variation_id ) ) ) );
							}
						}

					} else {

						$cart_item_product = $cart_item[ 'data' ]->is_type( 'variation' ) ? wc_get_product( $cart_item[ 'data' ]->get_parent_id() ) : $cart_item[ 'data' ];
						$cart_item_cat_ids = $cart_item_product->get_category_ids();

						$matching_cat_ids  = array_intersect( $cart_item_cat_ids, $tied_category_ids );

						if ( sizeof( $matching_cat_ids ) ) {

							if ( 'or' === $dependency_relationship ) {
								$purchase_dependency_result = true;
								break;
							} else {
								$purchased_cat_ids     = array_unique( array_merge( $purchased_cat_ids, array_filter( $matching_cat_ids ) ) );
								$purchased_product_ids = array_unique( array_merge( $purchased_product_ids, array_filter( array( $product_id, $variation_id ) ) ) );
							}
						}
					}
				}

				$purchased_ids = 'product_ids' === $dependency_selection_type ? $purchased_product_ids : $purchased_cat_ids;

				if ( 'and' === $dependency_relationship ) {
					if ( sizeof( $purchased_ids ) >= sizeof( $tied_ids ) ) {
						$purchase_dependency_result = true;
					}
				}
			}

			// Check ownership.
			if ( in_array( $dependency_type, array( self::DEPENDENCY_TYPE_OWNERSHIP, self::DEPENDENCY_TYPE_EITHER ) ) ) {

				if ( is_user_logged_in() ) {

					$current_user = wp_get_current_user();

					if ( 'category_ids' === $dependency_selection_type ) {
						$tied_product_ids = $this->get_product_ids_in_categories( $tied_category_ids );
					}

					if ( $dependency_type === self::DEPENDENCY_TYPE_EITHER && $purchase_dependency_result ) {

						$ownership_dependency_result = true;

					} else {

						$owned_product_ids = $this->customer_bought_products( $current_user->user_email, $current_user->ID, $tied_product_ids );

						// Find all categories that these products belong to and then compare against the set of required categories.
						if ( 'and' === $dependency_relationship && $has_multiple ) {

							if ( $dependency_type === self::DEPENDENCY_TYPE_EITHER ) {
								$owned_product_ids = array_unique( array_merge( $owned_product_ids, $purchased_product_ids ) );
							}

							if ( 'product_ids' === $dependency_selection_type ) {
								$owned_ids = $owned_product_ids;
							} else {
								$owned_ids = array_unique( wp_get_object_terms( $owned_product_ids, 'product_cat', array( 'fields' => 'ids' ) ) );
							}

							$owned_ids = array_intersect( $owned_ids, $tied_ids );

							$ownership_dependency_result = sizeof( $owned_ids ) >= sizeof( $tied_ids );

							if ( $ownership_dependency_result ) {
								$purchase_dependency_result = true;
							}

						} else {
							$ownership_dependency_result = sizeof( $owned_product_ids );
						}
					}
				}
			}

			$result = $ownership_dependency_result || $purchase_dependency_result;

			// Show notice.
			if ( false === $result ) {

				if ( ! WC()->session->has_session() ) {
					// Generate a random customer ID.
					WC()->session->set_customer_session_cookie( true );
				}

				if ( $dependency_notice ) {

					wc_add_notice( $dependency_notice, 'error' );

				} else {

					if ( 'product_ids' === $dependency_selection_type ) {

						$required_msg = WC_PD_Helpers::merge_product_titles( $tied_products, $dependency_relationship );

						if ( $has_multiple ) {
							if ( 'and' === $dependency_relationship ) {
								$action_msg   = __( 'all required products', 'woocommerce-product-dependencies' );
								$action_msg_2 = __( 'these products', 'woocommerce-product-dependencies' );
							} else {
								$action_msg = __( 'a required product', 'woocommerce-product-dependencies' );
							}
						} else {
							$action_msg = $required_msg;
						}

					} else {

						$merged_category_titles = WC_PD_Helpers::merge_category_titles( $tied_category_ids, $dependency_relationship );

						if ( $has_multiple ) {
							if ( 'and' === $dependency_relationship ) {
								$required_msg = sprintf( __( 'one or more products from the %s categories', 'woocommerce-product-dependencies' ), $merged_category_titles );
								$action_msg   = __( 'one or more products from all required categories', 'woocommerce-product-dependencies' );
							} else {
								$required_msg = sprintf( __( 'a product from the %s category', 'woocommerce-product-dependencies' ), $merged_category_titles );
								$action_msg   = __( 'a qualifying product', 'woocommerce-product-dependencies' );
							}
						} else {
							$required_msg = sprintf( __( 'a product from the %s category', 'woocommerce-product-dependencies' ), $merged_category_titles );
							$action_msg   = $required_msg;
						}
					}

					if ( $dependency_type === self::DEPENDENCY_TYPE_OWNERSHIP ) {

						if ( is_user_logged_in() ) {
							$msg = __( 'Access to &quot;%1$s&quot; is restricted to customers who have previously purchased %2$s.', 'woocommerce-product-dependencies' );
						} else {
							$msg = __( 'Access to &quot;%1$s&quot; is restricted to customers who have previously purchased %2$s. Please <a href="%3$s">log in</a> to validate ownership and try again.', 'woocommerce-product-dependencies' );
						}

						wc_add_notice( sprintf( $msg, $product_title, $required_msg, wp_login_url() ), 'error' );

					} elseif ( $dependency_type === self::DEPENDENCY_TYPE_EITHER ) {

						if ( is_user_logged_in() ) {

							if ( 'and' === $dependency_relationship && $has_multiple && sizeof( $owned_ids ) ) {

								if ( 'product_ids' === $dependency_selection_type ) {

									$owned_msg  = WC_PD_Helpers::merge_product_titles( array_intersect_key( $tied_products, array_flip( $owned_product_ids ) ), 'and' );
									$action_msg = WC_PD_Helpers::merge_product_titles( array_intersect_key( $tied_products, array_flip( array_diff( $tied_ids, $owned_product_ids ) ) ), 'and' );

								} else {

									$owned_category_titles = WC_PD_Helpers::merge_category_titles( $owned_ids, 'and' );
									$owned_products_msg    = _n( 'a product', 'some products', sizeof( $owned_product_ids ), 'woocommerce-product-dependencies' );
									$owned_msg             = sprintf( _n( '%1$s from the %2$s category', '%1$s from the %2$s categories', sizeof( $owned_category_titles ), 'woocommerce-product-dependencies' ), $owned_products_msg, $owned_category_titles );

									$action_category_titles = WC_PD_Helpers::merge_category_titles( array_diff( $tied_ids, $owned_ids ), 'and' );
									$action_msg             = sprintf( _n( 'one or more products from the %s category', 'one or more products from the %s categories', sizeof( $action_category_titles ), 'woocommerce-product-dependencies' ), $action_category_titles );
								}

								$msg = __( '&quot;%1$s&quot; requires purchasing %2$s. Please add %3$s to your cart and try again (you have already purchased %4$s).', 'woocommerce-product-dependencies' );

								wc_add_notice( sprintf( $msg, $product_title, $required_msg, $action_msg, $owned_msg ), 'error' );

							} else {

								$msg = __( '&quot;%1$s&quot; requires purchasing %2$s. To get access to this product now, please add %3$s to your cart.', 'woocommerce-product-dependencies' );

								wc_add_notice( sprintf( $msg, $product_title, $required_msg, $action_msg ), 'error' );
							}

						} else {

							$msg = __( '&quot;%1$s&quot; requires purchasing %2$s. If you have previously purchased %3$s, please <a href="%5$s">log in</a> to verify ownership and try again. Alternatively, get access to &quot;%1$s&quot; now by adding %4$s to your cart.', 'woocommerce-product-dependencies' );

							wc_add_notice( sprintf( $msg, $product_title, $required_msg, isset( $action_msg_2 ) ? $action_msg_2 : $action_msg, $action_msg, wp_login_url() ), 'error' );
						}

					} else {

						$msg = __( '&quot;%1$s&quot; is only available in combination with %2$s. To purchase this product, please add %3$s to your cart.', 'woocommerce-product-dependencies' );

						wc_add_notice( sprintf( $msg, $product_title, $required_msg, $action_msg ), 'error' );
					}
				}
			}

			return $result;
		}

		return true;
	}

	/**
	 * Dependency relationship:
	 * - 'or':   Ownership/purchase of any product required.
	 * - 'and':  Ownership/purhase of all products required.
	 *
	 * @param  WC_Product  $product
	 * @return string
	 */
	public function get_dependency_relationship( $product ) {
		return apply_filters( 'wc_pd_dependency_relationship', 'or', $product );
	}

	/**
	 * Returns an array with all dependent product ids.
	 *
	 * @since  1.2.0
	 *
	 * @param  WC_Product  $product
	 * @return array       $dependent_ids
	 */
	public function get_tied_product_ids( $product ) {
		$dependent_ids = $product->get_meta( '_tied_products', true );
		return empty( $dependent_ids ) ? array() : array_unique( $dependent_ids );
	}

	/**
	 * Returns an array with all saved category ids.
	 *
	 * @since  1.2.0
	 *
	 * @param  WC_Product  $product
	 * @return array       $category_ids
	 */
	public function get_tied_category_ids( $product ) {
		$category_ids = $product->get_meta( '_tied_categories', true );
		return empty( $category_ids ) ? array() : array_unique( $category_ids );
	}

	/**
	 * Returns the product dependency selection type.
	 *
	 * @since  1.2.0
	 *
	 * @param  WC_Product  $product
	 * @return string      $selection_type
	 */
	public function get_dependency_selection_type( $product ) {
		$selection_type = $product->get_meta( '_dependency_selection_type', true );
		$selection_type = in_array( $selection_type, array( 'product_ids', 'category_ids' ) ) ? $selection_type : 'product_ids';

		return $selection_type;
	}

	/**
	 * Returns the custom dependency notice.
	 *
	 * @since  1.2.0
	 *
	 * @param  WC_Product  $product
	 * @return string      $notice
	 */
	public function get_dependency_notice( $product ) {
		$notice = $product->get_meta( '_dependency_notice', true );
		return $notice;
	}

	/**
	 * Returns the product dependency type.
	 *
	 * @since  1.2.0
	 *
	 * @param  WC_Product  $product
	 * @return string      $type
	 */
	public function get_dependency_type( $product ) {
		$type = absint( $product->get_meta( '_dependency_type', true ) );
		$type = in_array( $type, array( self::DEPENDENCY_TYPE_OWNERSHIP, self::DEPENDENCY_TYPE_PURCHASE, self::DEPENDENCY_TYPE_EITHER ) ) ? $type : self::DEPENDENCY_TYPE_EITHER;

		return $type;
	}

	/**
	 * Get all product IDs that belong to the specified categories.
	 *
	 * @param  array  $category_ids
	 * @return array
	 */
	private function get_product_ids_in_categories( $category_ids ) {

		$query_results = new WP_Query( array(
			'post_type'   => array( 'product', 'product_variation' ),
			'fields'      => 'ids',
			'tax_query'   => array(
				array(
					'taxonomy' => 'product_cat',
					'field'    => 'term_id',
					'terms'    => $category_ids,
					'operator' => 'IN',
				)
			)
		) );

		return $query_results->posts;
	}

	/**
	 * Re-implementation of 'wc_customer_bought_product' with support for array input.
	 *
	 * @since  1.2.0
	 *
	 * @param  string  $customer_email
	 * @param  int     $user_id
	 * @param  array   $product_ids
	 * @return array
	 */
	private function customer_bought_products( $customer_email, $user_id, $product_ids ) {

		global $wpdb;

		$results = apply_filters( 'wc_pd_pre_customer_bought_products', null, $customer_email, $user_id, $product_ids );

		if ( null !== $results ) {
			return $results;
		}

		$transient_name = 'wc_cbp_' . md5( $customer_email . $user_id . WC_Cache_Helper::get_transient_version( 'orders' ) );

		if ( false === ( $results = get_transient( $transient_name ) ) ) {

			$customer_data = array( $user_id );

			if ( $user_id ) {

				$user = get_user_by( 'id', $user_id );

				if ( isset( $user->user_email ) ) {
					$customer_data[] = $user->user_email;
				}
			}

			if ( is_email( $customer_email ) ) {
				$customer_data[] = $customer_email;
			}

			$customer_data = array_map( 'esc_sql', array_filter( array_unique( $customer_data ) ) );
			$statuses      = array_map( 'esc_sql', wc_get_is_paid_statuses() );

			if ( sizeof( $customer_data ) == 0 ) {
				return false;
			}

			$results = $wpdb->get_col( "
				SELECT im.meta_value FROM {$wpdb->posts} AS p
				INNER JOIN {$wpdb->postmeta} AS pm ON p.ID = pm.post_id
				INNER JOIN {$wpdb->prefix}woocommerce_order_items AS i ON p.ID = i.order_id
				INNER JOIN {$wpdb->prefix}woocommerce_order_itemmeta AS im ON i.order_item_id = im.order_item_id
				WHERE p.post_status IN ( 'wc-" . implode( "','wc-", $statuses ) . "' )
				AND pm.meta_key IN ( '_billing_email', '_customer_user' )
				AND im.meta_key IN ( '_product_id', '_variation_id' )
				AND im.meta_value != 0
				AND pm.meta_value IN ( '" . implode( "','", $customer_data ) . "' )
			" );

			$results = array_map( 'absint', $results );

			set_transient( $transient_name, $results, DAY_IN_SECONDS * 30 );
		}

		return array_intersect( $results, $product_ids );
	}

	/*
	|--------------------------------------------------------------------------
	| Admin Filters.
	|--------------------------------------------------------------------------
	*/

	/**
	 * Add Product Data tab.
	 *
	 * @return void
	 */
	public function dependencies_product_data_panel_tab() {
		echo '<li class="tied_products_tab related_product_options linked_product_options"><a href="#tied_products_data">' . __( 'Dependencies', 'woocommerce-product-dependencies' ) . '</a></li>';
	}

	/**
	 * Add the "Product Dependencies" panel tab.
	 *
	 * @param  array  $tabs
	 * @return array
	 */
	public function dependencies_product_data_tab( $tabs ) {

		$tabs[ 'dependencies' ] = array(
			'label'  => __( 'Dependencies', 'woocommerce-product-dependencies' ),
			'target' => 'tied_products_data',
			'class'  => array( 'show_if_simple', 'show_if_variable', 'show_if_bundle', 'show_if_composite', 'linked_product_options', 'show_if_booking', 'show_if_phive_booking' )
		);

		return $tabs;
	}

	/**
	 * Add Product Data tab section.
	 *
	 * @return void
	 */
	public function dependencies_product_data_panel() {

		global $post, $product_object;

		if ( empty( $product_object ) || ! is_a( $product_object, 'WC_Product' ) ) {
			$product_object = wc_get_product( $post->ID );
		}

		if ( ! $product_object ) {
			return;
		}

		$tied_products      = $this->get_tied_product_ids( $product_object );
		$tied_categories    = $this->get_tied_category_ids( $product_object );
		$dependency_type    = $this->get_dependency_type( $product_object );
		$selection_type     = $this->get_dependency_selection_type( $product_object );
		$dependency_notice  = $this->get_dependency_notice( $product_object );

		$product_id_options = array();
		$product_categories = (array) get_terms( 'product_cat', array( 'get' => 'all' ) );
		$selection_type     = in_array( $selection_type, array( 'product_ids', 'category_ids' ) ) ? $selection_type : 'product_ids';

		if ( $tied_products ) {
			foreach ( $tied_products as $item_id ) {

				$title = WC_PD_Helpers::get_product_title( $item_id );

				if ( $title ) {
					$product_id_options[ $item_id ] = $title;
				}
			}
		}

		?>
		<div id="tied_products_data" class="panel woocommerce_options_panel wc-metaboxes-wrapper">

			<?php

				woocommerce_wp_select( array(
					'id'      => 'product_dependencies_dropdown',
					'label'   => __( 'Product dependencies', 'woocommerce-product-dependencies' ),
					'options' => array(
						'product_ids'  => __( 'Select products', 'woocommerce-product-dependencies' ),
						'category_ids' => __( 'Select categories', 'woocommerce-product-dependencies' )
					),
					'value'   => $selection_type
				) );
			?>

			<label>
				<?php _e( 'Product dependencies', 'woocommerce-product-dependencies' ); ?>
			</label>

			<div id="product_ids_dependencies_choice" class="form-field">
				<p class="form-field">
					<?php

					?><select id="tied_products" name="tied_products[]" class="wc-product-search" multiple="multiple" style="width: 80%;" data-limit="500" data-action="woocommerce_json_search_products_and_variations" data-placeholder="<?php echo __( 'Search for products and variations&hellip;', 'woocommerce-product-dependencies' ); ?>"><?php

						if ( ! empty( $product_id_options ) ) {

							foreach ( $product_id_options as $product_id => $product_name ) {
								echo '<option value="' . $product_id . '" selected="selected">' . $product_name . '</option>';
							}
						}

						?></select><?php


					echo wc_help_tip( __( 'Restrict product access based on the ownership or purchase of <strong>any</strong> product or variation added to this list.', 'woocommerce-product-dependencies' ) );

					?>
				</p>
			</div>

			<div id="category_ids_dependencies_choice" class="form-field" >
				<p class="form-field">
					<select id="tied_categories" name="tied_categories[]" style="width: 50%" class="multiselect wc-enhanced-select" multiple="multiple" data-placeholder="<?php echo  __( 'Select product categories&hellip;', 'woocommerce-product-dependencies' ); ?>"><?php

						if ( ! empty( $product_categories ) ) {

							foreach ( $product_categories as $product_category ) {
								echo '<option value="' . $product_category->term_id . '" ' . selected( in_array( $product_category->term_id, $tied_categories ), true, false ).'>' . $product_category->name . '</option>';
							}
						}

					?></select>
				</p>
			</div>

			<div class="form-field">
				<p class="form-field">
					<label><?php _e( 'Dependency type', 'woocommerce-product-dependencies' ); ?>
					</label>
					<select name="dependency_type" id="dependency_type" style="min-width:150px;">
						<option value="1" <?php echo $dependency_type == self::DEPENDENCY_TYPE_OWNERSHIP ? 'selected="selected"' : ''; ?>><?php _e( 'Ownership', 'woocommerce-product-dependencies' ); ?></option>
						<option value="2" <?php echo $dependency_type == self::DEPENDENCY_TYPE_PURCHASE ? 'selected="selected"' : ''; ?>><?php _e( 'Purchase', 'woocommerce-product-dependencies' ); ?></option>
						<option value="3" <?php echo $dependency_type == self::DEPENDENCY_TYPE_EITHER ? 'selected="selected"' : ''; ?>><?php _e( 'Either', 'woocommerce-product-dependencies' ); ?></option>
					</select>
				</p>
			</div><?php

				woocommerce_wp_textarea_input( array(
					'id'          => 'dependency_notice',
					'value'       => $dependency_notice,
					'label'       => __( 'Custom notice', 'woocommerce-product-dependencies' ),
					'description' => __( 'Notice to display instead of the default one.', 'woocommerce-product-dependencies' ),
					'desc_tip'    => true
				) );

		?></div>
	<?php
	}

	/**
	 * Save dependencies data. WC >= 2.7.
	 *
	 * @param  WC_Product  $product
	 * @return void
	 */
	public function process_product_data( $product ) {

		if ( ! empty( $_POST[ 'tied_categories' ] ) && is_array( $_POST[ 'tied_categories' ] ) ) {

			$tied_categories = array_map( 'intval', $_POST[ 'tied_categories' ] );

			$product->update_meta_data( '_tied_categories', $tied_categories );

		} else {

			$product->delete_meta_data( '_tied_categories' );
		}

		if ( ! isset( $_POST[ 'tied_products' ] ) || empty( $_POST[ 'tied_products' ] ) ) {

			$product->delete_meta_data( '_tied_products' );

		} elseif ( isset( $_POST[ 'tied_products' ] ) && ! empty( $_POST[ 'tied_products' ] ) ) {

			$tied_ids = $_POST[ 'tied_products' ];

			if ( is_array( $tied_ids ) ) {
				$tied_ids = array_map( 'intval', $tied_ids );
			} else {
				$tied_ids = array_filter( array_map( 'intval', explode( ',', $tied_ids ) ) );
			}

			$product->update_meta_data( '_tied_products', $tied_ids );
		}

		if ( ! empty( $_POST[ 'dependency_type' ] ) ) {
			$product->update_meta_data( '_dependency_type', stripslashes( $_POST[ 'dependency_type' ] ) );
		}

		if ( ! empty( $_POST[ 'product_dependencies_dropdown' ] ) ) {
			$product->update_meta_data( '_dependency_selection_type', stripslashes( $_POST[ 'product_dependencies_dropdown' ] ) );
		}

		if ( ! empty( $_POST[ 'dependency_notice' ] ) ) {
			$product->update_meta_data( '_dependency_notice', wp_kses_post( stripslashes( $_POST[ 'dependency_notice' ] ) ) );
		} else {
			$product->delete_meta_data( '_dependency_notice' );
		}
	}

	/**
	 * Save dependencies meta. WC <= 2.6.
	 *
	 * @param  int      $post_id
	 * @param  WC_Post  $post
	 * @return void
	 */
	public function process_meta( $post_id, $post ) {

		global $post;

		if ( ! empty( $_POST[ 'tied_categories' ] ) && is_array( $_POST[ 'tied_categories' ] ) ) {

			$tied_categories = array_map( 'intval', $_POST[ 'tied_categories' ] );

			update_post_meta( $post_id, '_tied_categories', $tied_categories );

		} else {

			delete_post_meta( $post_id, '_tied_categories' );
		}

		if ( ! isset( $_POST[ 'tied_products' ] ) || empty( $_POST[ 'tied_products' ] ) ) {

			delete_post_meta( $post_id, '_tied_products' );

		} elseif ( isset( $_POST[ 'tied_products' ] ) && ! empty( $_POST[ 'tied_products' ] ) ) {

			$tied_ids = $_POST[ 'tied_products' ];

			if ( is_array( $tied_ids ) ) {
				$tied_ids = array_map( 'intval', $tied_ids );
			} else {
				$tied_ids = array_filter( array_map( 'intval', explode( ',', $tied_ids ) ) );
			}

			update_post_meta( $post_id, '_tied_products', $tied_ids );
		}

		if ( ! empty( $_POST[ 'dependency_type' ] ) ) {
			update_post_meta( $post_id, '_dependency_type', stripslashes( $_POST[ 'dependency_type' ] ) );
		}

		if ( ! empty( $_POST[ 'product_dependencies_dropdown' ] ) ) {
			update_post_meta( $post_id, '_dependency_selection_type', stripslashes( $_POST[ 'product_dependencies_dropdown' ] ) );
		}

		if ( ! empty( $_POST[ 'dependency_notice' ] ) ) {
			update_post_meta( $post_id, '_dependency_notice', wp_kses_post( stripslashes( $_POST[ 'dependency_notice' ] ) ) );
		} else {

			delete_post_meta( $post_id, '_dependency_notice' );
		}
	}

	/*
	|--------------------------------------------------------------------------
	| Deprecated methods.
	|--------------------------------------------------------------------------
	*/

	/**
	 * Check conditions.
	 *
	 * @deprecated  1.1.0
	 *
	 * @param  int  $item_id
	 * @return boolean
	 */
	public function woo_tied_evaluate_access( $id ) {
		_deprecated_function( __METHOD__ . '()', '1.1.0', __CLASS__ . '::evaluate_access()' );
		return WC_Product_Dependencies()->evaluate_dependencies( $id );
	}
}

/**
 * Returns the main instance of WC_Product_Dependencies to prevent the need to use globals.
 *
 * @since  1.1.0
 * @return WC_Product_Dependencies
 */
function WC_Product_Dependencies() {
  return WC_Product_Dependencies::instance();
}

// Backwards compatibility with v1.0.
$GLOBALS[ 'woocommerce_restricted_access' ] = WC_Product_Dependencies();