processPayment method

  1. @override
Future<PaymentResponse> processPayment(
  1. String checkoutUrl
)
override

Processes a payment by opening the provided checkout URL in a webview.

The implementation should:

  • Open the checkout URL in a platform-appropriate webview
  • Handle Paystack's callback mechanisms (redirects, postMessage, etc.)
  • Return a PaymentResponse based on the payment outcome

checkoutUrl The Paystack checkout URL to load in the webview

Returns a PaymentResponse containing the payment result

Implementation

@override
Future<PaymentResponse> processPayment(String checkoutUrl) async {
  // Extract reference from checkout URL
  final uri = Uri.parse(checkoutUrl);
  final reference =
      uri.queryParameters['reference'] ??
      uri.queryParameters['trxref'] ??
      'linux_webview_${DateTime.now().millisecondsSinceEpoch}';

  try {
    // Call platform method to show webview (opens in browser) with timeout
    final result = await _channel
        .invokeMethod<Map<dynamic, dynamic>>('showWebView', {
          'checkoutUrl': checkoutUrl,
        })
        .timeout(
          const Duration(minutes: 10),
          onTimeout: () {
            throw PaystackError(
              message:
                  'Payment timeout - user took too long to complete payment',
              code: 'PAYMENT_TIMEOUT',
            );
          },
        );

    if (result == null) {
      throw PaystackError(message: 'No response from webview');
    }

    final castedResult = result.cast<String, dynamic>();
    if (castedResult['status'] != 'success') {
      throw PaystackError.fromApiResponse(castedResult);
    }

    // Parse the payment result
    final data = castedResult['data'] as Map<String, dynamic>;
    final paymentReference = data['reference'] as String? ?? reference;
    final status = data['status'] as String? ?? 'success';

    return PaymentResponse(
      reference: paymentReference,
      status: _parsePaymentStatus(status),
      amount: 0, // Would be determined from verification
      currency: Currency.ngn, // Would be determined from verification
      paymentMethod: PaymentMethod.card, // Would be determined from payment
      gatewayResponse: data['message'] as String? ?? 'Payment completed',
    );
  } on PlatformException catch (e) {
    throw PaystackError(
      message: e.message ?? 'Webview payment failed',
      code: e.code,
    );
  } on TimeoutException {
    throw PaystackError(
      message: 'Payment timeout - user took too long to complete payment',
      code: 'PAYMENT_TIMEOUT',
    );
  } catch (_) {
    throw PaystackError(
      message: 'Unexpected error during payment',
      code: 'WEBVIEW_ERROR',
    );
  }
}