Cherry pick PR#50805 into trunk (#50814)

plugins/woocommerce/includes/admin/settings/class-wc-settings-products.php

@@ -446,6 +446,20 @@ class WC_Settings_Products extends WC_Settings_Page {
 					),
 				),
 
+				array(
+					'title'    => __( 'Count partial downloads', 'woocommerce' ),
+					'desc'     => __( 'Count downloads even if only part of a file is fetched.', 'woocommerce' ),
+					'id'       => 'woocommerce_downloads_count_partial',
+					'type'     => 'checkbox',
+					'default'  => 'yes',
+					'desc_tip' => sprintf(
+						/* Translators: 1: opening link tag 2: closing link tag. */
+						__( 'Repeat fetches made within a reasonable window of time (by default, 30 minutes) will not be counted twice. This is a generally reasonably way to enforce download limits in relation to ranged requests. %1$sLearn more.%2$s', 'woocommerce' ),
+						'<a href="https://woocommerce.com/document/digital-downloadable-product-handling/">',
+						'</a>'
+					),
+				),
+
 				array(
 					'type' => 'sectionend',
 					'id'   => 'digital_download_options',

plugins/woocommerce/includes/class-wc-download-handler.php

@@ -8,12 +8,19 @@
  * @version 2.2.0
  */
 
+use Automattic\WooCommerce\Internal\Traits\AccessiblePrivateMethods;
 defined( 'ABSPATH' ) || exit;
 
 /**
  * Download handler class.
  */
 class WC_Download_Handler {
+	use AccessiblePrivateMethods;
+
+	/**
+	 * The hook used for deferred tracking of partial download attempts.
+	 */
+	public const TRACK_DOWNLOAD_CALLBACK = 'track_partial_download';
 
 	/**
 	 * Hook in methods.
@@ -25,6 +32,7 @@ class WC_Download_Handler {
 		add_action( 'woocommerce_download_file_redirect', array( __CLASS__, 'download_file_redirect' ), 10, 2 );
 		add_action( 'woocommerce_download_file_xsendfile', array( __CLASS__, 'download_file_xsendfile' ), 10, 2 );
 		add_action( 'woocommerce_download_file_force', array( __CLASS__, 'download_file_force' ), 10, 2 );
+		self::add_action( self::TRACK_DOWNLOAD_CALLBACK, array( __CLASS__, 'track_download' ), 10, 3 );
 	}
 
 	/**
@@ -135,9 +143,13 @@ class WC_Download_Handler {
 		// Track the download in logs and change remaining/counts.
 		$current_user_id = get_current_user_id();
 		$ip_address      = WC_Geolocation::get_ip_address();
-		if ( ! $download_range['is_range_request'] ) {
+
-			$download->track_download( $current_user_id > 0 ? $current_user_id : null, ! empty( $ip_address ) ? $ip_address : null );
+		self::track_download(
-		}
+			$download,
+			$current_user_id > 0 ? $current_user_id : null,
+			! empty( $ip_address ) ? $ip_address : null,
+			$download_range['is_range_request']
+		);
 
 		self::download( $file_path, $download->get_product_id() );
 	}
@@ -695,6 +707,76 @@ class WC_Download_Handler {
 		}
 		wp_die( $message, $title, array( 'response' => $status ) ); // WPCS: XSS ok.
 	}
+
+	/**
+	 * Takes care of tracking download requests, with support for deferring tracking in the case of
+	 * partial (ranged request) downloads.
+	 *
+	 * @param WC_Customer_Download|int $download        The download to be tracked.
+	 * @param int|null                 $user_id         The user ID, if known.
+	 * @param string|null              $user_ip_address The download IP address, if known.
+	 * @param bool                     $defer           If tracking the download should be deferred.
+	 *
+	 * @return void
+	 * @throws Exception If the active version of Action Scheduler is less than 3.6.0.
+	 */
+	private static function track_download( $download, $user_id = null, $user_ip_address = null, bool $defer = false ): void {
+		try {
+			// If we were supplied with an integer, convert it to a download object.
+			$download = new WC_Customer_Download( $download );
+
+			// In simple cases, we can track the download immediately.
+			if ( ! $defer ) {
+				$download->track_download( $user_id, $user_ip_address );
+				return;
+			}
+
+			// Counting of partial downloads may be disabled by the site operator.
+			if ( get_option( 'woocommerce_downloads_count_partial', 'yes' ) !== 'yes' ) {
+				return;
+			}
+
+			/**
+			 * Determines how long the window of time is for tracking unique download attempts, in relation to
+			 * partial (ranged) download requests.
+			 *
+			 * @since 9.2.0
+			 *
+			 * @param int $window_in_seconds      Non-negative number of seconds. Defaults to 1800 (30 minutes).
+			 * @param int $download_permission_id References the download permission being tracked.
+			 */
+			$window = absint( apply_filters( 'woocommerce_partial_download_tracking_window', 30 * MINUTE_IN_SECONDS, $download->get_id() ) );
+
+			// If we do not have Action Scheduler 3.6.0+ (this would be an unexpected scenario) then we cannot
+			// track partial downloads, because we require support for unique actions.
+			if ( version_compare( ActionScheduler_Versions::instance()->latest_version(), '3.6.0', '<' ) ) {
+				throw new Exception( 'Support for unique scheduled actions is not currently available.' );
+			}
+
+			as_schedule_single_action(
+				time() + $window,
+				self::TRACK_DOWNLOAD_CALLBACK,
+				array(
+					$download->get_id(),
+					$user_id,
+					$user_ip_address,
+				),
+				'woocommerce',
+				true
+			);
+		} catch ( Exception $e ) {
+			wc_get_logger()->error(
+				'There was a problem while tracking a product download.',
+				array(
+					'error'    => $e->getMessage(),
+					'id'       => $download->get_id(),
+					'user_id'  => $user_id,
+					'ip'       => $user_ip_address,
+					'deferred' => $defer ? 'yes' : 'no',
+				)
+			);
+		}
+	}
 }
 
 WC_Download_Handler::init();

plugins/woocommerce/tests/php/includes/class-wc-download-handler-tests.php

@@ -74,7 +74,7 @@ class WC_Download_Handler_Tests extends \WC_Unit_Test_Case {
 		$approved_directories->add_approved_directory( 'https://always.trusted' );
 		$approved_directory_rule_id = $approved_directories->add_approved_directory( 'https://new.supplier' );
 
-		$product = WC_Helper_Product::create_downloadable_product(
+		list( $product, $order ) = $this->build_downloadable_product_and_order_one(
 			array(
 				array(
 					'name' => 'Book 1',
@@ -87,12 +87,7 @@ class WC_Download_Handler_Tests extends \WC_Unit_Test_Case {
 			)
 		);
 
-		$customer = WC_Helper_Customer::create_customer();
 		$email         = 'admin@example.org';
-		$order    = WC_Helper_Order::create_order( $customer->get_id(), $product );
-		$order->set_status( 'completed' );
-		$order->save();
-
 		$product_id    = $product->get_id();
 		$downloads     = $product->get_downloads();
 		$download_keys = array_keys( $downloads );
@@ -139,6 +134,111 @@ class WC_Download_Handler_Tests extends \WC_Unit_Test_Case {
 		self::restore_download_handlers();
 	}
 
+	/**
+	 * @testdox The remaining downloads count should iterate accurately.
+	 */
+	public function test_downloads_remaining_count(): void {
+		self::remove_download_handlers();
+		// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_file_put_contents -- Ok for unit tests.
+		file_put_contents( WP_CONTENT_DIR . '/uploads/woocommerce_uploads/supersheet-123.ods', str_pad( '', 100 ) );
+
+		list( $product, $order ) = $this->build_downloadable_product_and_order_one(
+			array(
+				array(
+					'name' => 'Supersheet 123',
+					'file' => content_url( 'uploads/woocommerce_uploads/supersheet-123.ods' ),
+				),
+			)
+		);
+
+		$product_id    = $product->get_id();
+		$downloads     = $product->get_downloads();
+		$download_keys = array_keys( $downloads );
+		$email         = 'admin@example.org';
+		$download      = current( WC_Data_Store::load( 'customer-download' )->get_downloads( array( 'product_id' => $product_id ) ) );
+
+		$download->set_downloads_remaining( 10 );
+		$download->save();
+
+		// phpcs:disable WordPress.Security.NonceVerification.Recommended WordPress.Security.ValidatedSanitizedInput.InputNotValidated
+		$_GET = array(
+			'download_file' => $product_id,
+			'order'         => $order->get_order_key(),
+			'email'         => $email,
+			'uid'           => hash( 'sha256', $email ),
+			'key'           => $download_keys[0],
+		);
+
+		WC_Download_Handler::download_product();
+		$download = new WC_Customer_Download( $download->get_id() );
+		$this->assertEquals(
+			9,
+			$download->get_downloads_remaining(),
+			'In relation to "normal" download requests, we should see a reduction in the downloads remaining count.'
+		);
+
+		// Let's simulate a ranged request (partial download).
+		$_SERVER['HTTP_RANGE'] = 'bytes=10-50';
+		WC_Download_Handler::download_product();
+		$download = new WC_Customer_Download( $download->get_id() );
+		$this->assertEquals(
+			9,
+			$download->get_downloads_remaining(),
+			'In relation to "ranged" (partial) download requests, we should not see an immediate reduction in the downloads remaining count.'
+		);
+
+		// Repeat (HTTP_RANGE is still set).
+		WC_Download_Handler::download_product();
+		$download = new WC_Customer_Download( $download->get_id() );
+		$this->assertEquals(
+			9,
+			$download->get_downloads_remaining(),
+			'In relation to "ranged" (partial) download requests, we should not see an immediate reduction in the downloads remaining count.'
+		);
+
+		// Find the deferred download tracking action.
+		$deferred_download_tracker = current(
+			WC_Queue::instance()->search(
+				array( 'hook' => WC_Download_Handler::TRACK_DOWNLOAD_CALLBACK )
+			)
+		);
+
+		// Let it do it's thing, and confirm that a further decrement happened (of just 1 unit).
+		do_action_ref_array( $deferred_download_tracker->get_hook(), $deferred_download_tracker->get_args() );
+		$download = new WC_Customer_Download( $download->get_id() );
+		$this->assertEquals(
+			8,
+			$download->get_downloads_remaining(),
+			'In relation to "ranged" (partial) download requests, the deferred update to the downloads remaining count functioned as expected.'
+		);
+
+		self::restore_download_handlers();
+	}
+
+	/**
+	 * Creates a downloadable product, and then places (and completes) an order for that
+	 * object.
+	 *
+	 * @param array[] $downloadable_files Array of arrays, with each inner array specifying the 'name' and 'file'.
+	 *
+	 * @return array {
+	 *     WC_Product,
+	 *     WC_Order
+	 * }
+	 */
+	private function build_downloadable_product_and_order_one( array $downloadable_files ): array {
+		$product  = WC_Helper_Product::create_downloadable_product( $downloadable_files );
+		$customer = WC_Helper_Customer::create_customer();
+		$order    = WC_Helper_Order::create_order( $customer->get_id(), $product );
+		$order->set_status( 'completed' );
+		$order->save();
+
+		return array(
+			$product,
+			$order,
+		);
+	}
+
 	/**
 	 * Unregister download handlers to prevent unwanted output and side-effects.
 	 */

plugins/woocommerce/tests/php/includes/settings/class-wc-settings-products-test.php

@@ -148,6 +148,7 @@ class WC_Settings_Products_Test extends WC_Settings_Unit_Test_Case {
 			'woocommerce_downloads_grant_access_after_payment' => 'checkbox',
 			'woocommerce_downloads_add_hash_to_filename'       => 'checkbox',
 			'woocommerce_downloads_deliver_inline'             => 'checkbox',
+			'woocommerce_downloads_count_partial'        => 'checkbox',
 		);
 
 		$this->assertEquals( $expected, $settings_ids_and_types );