Manage products inventory via REST API

mp-product-inventory-rest-api.php

<?php
/*
Plugin Name: MarketPress Manage inventory via REST
Plugin URI: https://premium.wpmudev.org/
Description: Manage products inventory via REST API
Author: Panos Lyrakis @ WPMUDEV
Author URI: https://premium.wpmudev.org/
License: GPLv2 or later
*/
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}
if ( ! class_exists( 'WPMUDEV_MP_Inventory_REST' ) ) {

	class WPMUDEV_MP_Inventory_REST {

		private static $_instance = null;

		public static function get_instance() {
			if( is_null( self::$_instance ) ){
				self::$_instance = new WPMUDEV_MP_Inventory_REST();
			}
			return self::$_instance;
		}

		public function __construct() {

			add_action( 'rest_api_init', array( $this, 'register_mp_routes' ) );
		}

		public function register_mp_routes(){

			register_rest_route( 'mp-store/v1', '/products-inventory', array(
		        'methods'  => WP_REST_Server::READABLE,
		        'callback' => array( $this, 'update_products_inventory' ),
		    ) );

		}



		public function update_products_inventory( $request ){
			
			$products_quantities 	= isset( $_GET[ 'products' ] ) ? $_GET[ 'products' ] : false;

			$products_quantities 	= json_decode( stripcslashes( $products_quantities ) );

	    	if( empty( $products_quantities ) ){
	    		return;
	    	}

			foreach( $products_quantities as $product_id => $quantity ){

	    		$product = new MP_Product( $product_id );
				if ( $product->get_meta( 'inventory_tracking' ) ) {
					$stock = $product->get_stock();
					// Update inventory
					$new_stock = ( $stock - $quantity );
					$product->update_meta( 'inventory', $new_stock );
					$product->update_meta( 'inv_inventory', $new_stock );
					// Send low-stock notification if needed
					if ( $new_stock <= mp_get_setting( 'inventory_threshhold' ) ) {
						$product->low_stock_notification();
					}
					if ( mp_get_setting( 'inventory_remove' ) && $new_stock <= 0 ) {
						// Flag product as out of stock - @version 2.9.5.8
						wp_update_post( array(
							'ID'          => $product->ID,
							'post_status' => 'draft'
						) );
					}
				}
				// Update sales count
				$sales = $product->get_meta( 'mp_sales_count', 0 );
				$sales += $quantity;
				update_post_meta( $product->ID, 'mp_sales_count', $sales );

	    	}

	    	return 'SUCCESS';

		}

	}

	add_action( 'plugins_loaded', function(){
		$GLOBALS['WPMUDEV_MP_Inventory_REST'] = WPMUDEV_MP_Inventory_REST::get_instance();
	}, 10 );

}

/*
HOW TO USE WITH wp_remote_request:

$wp_request_headers = array(
	    'Authorization' => 'Basic ' . base64_encode( 'panos:1234567890' )
	);
	 
	$products_quantities = json_encode( array(
			'97' => 2, // PRODUCT ID => AMOUNT TO SUBTRACT
			'33' => 1
		) );

	$wp_request_url = 'http://site-url.com/wp-json/mp-store/v1/products-inventory/?products=' . $products_quantities;
	 
	$wp_request_post_response = wp_remote_request(
	    $wp_request_url,
	    array(
	        'method'    => 'GET',
	        'headers'   => $wp_request_headers
	    )
	);

	$response_code = wp_remote_retrieve_response_code( $wp_request_post_response ) . ' ' . wp_remote_retrieve_response_message( $wp_request_post_response );

	$response = $wp_request_post_response;

*/