Add API for easy programmatic capture

api/order-functions.php

@@ -0,0 +1,46 @@
+<?php
+/**
+ * The API for operations with orders.
+ *
+ * @package WooCommerce\PayPalCommerce\Api
+ *
+ * @phpcs:disable Squiz.Commenting.FunctionCommentThrowTag
+ */
+
+declare(strict_types=1);
+
+namespace WooCommerce\PayPalCommerce\Api;
+
+use Exception;
+use InvalidArgumentException;
+use RuntimeException;
+use WC_Order;
+use WooCommerce\PayPalCommerce\PPCP;
+use WooCommerce\PayPalCommerce\WcGateway\Gateway\PayPalGateway;
+use WooCommerce\PayPalCommerce\WcGateway\Processor\AuthorizedPaymentsProcessor;
+
+/**
+ * Captures the PayPal order.
+ *
+ * @param WC_Order $wc_order The WC order.
+ * @throws InvalidArgumentException When the order cannot be captured.
+ * @throws Exception When the operation fails.
+ */
+function ppcp_capture_order( WC_Order $wc_order ): void {
+	$intent = strtoupper( (string) $wc_order->get_meta( PayPalGateway::INTENT_META_KEY ) );
+
+	if ( $intent !== 'AUTHORIZE' ) {
+		throw new InvalidArgumentException( 'Only orders with "authorize" intent can be captured.' );
+	}
+	$captured = wc_string_to_bool( $wc_order->get_meta( AuthorizedPaymentsProcessor::CAPTURED_META_KEY ) );
+	if ( $captured ) {
+		throw new InvalidArgumentException( 'The order is already captured.' );
+	}
+
+	$authorized_payment_processor = PPCP::container()->get( 'wcgateway.processor.authorized-payments' );
+	assert( $authorized_payment_processor instanceof AuthorizedPaymentsProcessor );
+
+	if ( ! $authorized_payment_processor->capture_authorized_payment( $wc_order ) ) {
+		throw new RuntimeException( 'Capture failed.' );
+	}
+}