/**
  * Handle WC API requests where we need to run a reference transaction API operation
  *
  * @since 2.0
  */
 public static function handle_wc_api()
 {
     if (!isset($_GET['action'])) {
         return;
     }
     switch ($_GET['action']) {
         // called when the customer is returned from PayPal after authorizing their payment, used for retrieving the customer's checkout details
         case 'create_billing_agreement':
             // bail if no token
             if (!isset($_GET['token'])) {
                 return;
             }
             // get token to retrieve checkout details with
             $token = esc_attr($_GET['token']);
             try {
                 $express_checkout_details_response = self::get_api()->get_express_checkout_details($token);
                 // Make sure the billing agreement was accepted
                 if (1 == $express_checkout_details_response->get_billing_agreement_status()) {
                     $order = $express_checkout_details_response->get_order();
                     if (is_null($order)) {
                         throw new Exception(__('Unable to find order for PayPal billing agreement.', 'woocommerce-subscriptions'));
                     }
                     // we need to process an initial payment
                     if ($order->get_total() > 0 && !wcs_is_subscription($order)) {
                         $billing_agreement_response = self::get_api()->do_express_checkout($token, $order, array('payment_action' => 'Sale', 'payer_id' => $express_checkout_details_response->get_payer_id()));
                     } else {
                         $billing_agreement_response = self::get_api()->create_billing_agreement($token);
                     }
                     if ($billing_agreement_response->has_api_error()) {
                         throw new Exception($billing_agreement_response->get_api_error_message(), $billing_agreement_response->get_api_error_code());
                     }
                     // We're changing the payment method for a subscription, make sure we update it before updating the billing agreement ID so that an old PayPal subscription can be cancelled if the existing payment method is also PayPal
                     if (wcs_is_subscription($order)) {
                         WC_Subscriptions_Change_Payment_Gateway::update_payment_method($order, 'paypal');
                         $redirect_url = add_query_arg('utm_nooverride', '1', $order->get_view_order_url());
                     }
                     // Make sure PayPal is set as the payment method on the order and subscription
                     $available_gateways = WC()->payment_gateways->get_available_payment_gateways();
                     $payment_method = isset($available_gateways[self::instance()->get_id()]) ? $available_gateways[self::instance()->get_id()] : false;
                     $order->set_payment_method($payment_method);
                     // Store the billing agreement ID on the order and subscriptions
                     wcs_set_paypal_id($order, $billing_agreement_response->get_billing_agreement_id());
                     foreach (wcs_get_subscriptions_for_order($order, array('order_type' => 'any')) as $subscription) {
                         $subscription->set_payment_method($payment_method);
                         wcs_set_paypal_id($subscription, $billing_agreement_response->get_billing_agreement_id());
                     }
                     if (!wcs_is_subscription($order)) {
                         if (0 == $order->get_total()) {
                             $order->payment_complete();
                         } else {
                             self::process_subscription_payment_response($order, $billing_agreement_response);
                         }
                         $redirect_url = add_query_arg('utm_nooverride', '1', $order->get_checkout_order_received_url());
                     }
                     // redirect customer to order received page
                     wp_safe_redirect(esc_url_raw($redirect_url));
                 } else {
                     wp_safe_redirect(WC()->cart->get_cart_url());
                 }
             } catch (Exception $e) {
                 wc_add_notice(__('An error occurred, please try again or try an alternate form of payment.', 'woocommerce-subscriptions'), 'error');
                 wp_redirect(WC()->cart->get_cart_url());
             }
             exit;
         case 'reference_transaction_account_check':
             exit;
     }
 }
 /**
  * Cancel a specific PayPal Standard Subscription Profile with PayPal.
  *
  * Used when switching payment methods with PayPal Standard to make sure that
  * the old subscription's profile ID is cancelled, not the new one.
  *
  * @param WC_Subscription A subscription object
  * @param string A PayPal Subscription Profile ID
  * @since 2.0
  */
 protected static function cancel_subscription($subscription, $old_paypal_subscriber_id)
 {
     // No need to cancel billing agreements
     if (wcs_is_paypal_profile_a($old_paypal_subscriber_id, 'billing_agreement')) {
         return;
     }
     $current_profile_id = wcs_get_paypal_id($subscription->id);
     // Update the subscription using the old profile ID
     wcs_set_paypal_id($subscription, $old_paypal_subscriber_id);
     // Call update_subscription_status() directly as we don't want the notes added by WCS_PayPal_Status_Manager::cancel_subscription()
     WCS_PayPal_Status_Manager::update_subscription_status($subscription, 'Cancel');
     // Restore the current profile ID
     wcs_set_paypal_id($subscription, $current_profile_id);
 }
 /**
  * Process a PayPal Standard Subscription IPN request
  *
  * @param array $transaction_details Post data after wp_unslash
  * @since 2.0
  */
 protected function process_ipn_request($transaction_details)
 {
     // Get the subscription ID and order_key with backward compatibility
     $subscription_id_and_key = self::get_order_id_and_key($transaction_details, 'shop_subscription');
     $subscription = wcs_get_subscription($subscription_id_and_key['order_id']);
     $subscription_key = $subscription_id_and_key['order_key'];
     // We have an invalid $subscription, probably because invoice_prefix has changed since the subscription was first created, so get the subscription by order key
     if (!isset($subscription->id)) {
         $subscription = wcs_get_subscription(wc_get_order_id_by_order_key($subscription_key));
     }
     if (empty($subscription)) {
         WC_Gateway_Paypal::log('Subscription IPN Error: Could not find matching Subscription.');
         exit;
     }
     if ($subscription->order_key != $subscription_key) {
         WC_Gateway_Paypal::log('Subscription IPN Error: Subscription Key does not match invoice.');
         exit;
     }
     $is_renewal_sign_up_after_failure = false;
     // If the invoice ID doesn't match the default invoice ID and contains the string '-wcsfrp-', the IPN is for a subscription payment to fix up a failed payment
     if (in_array($transaction_details['txn_type'], array('subscr_signup', 'subscr_payment')) && false !== strpos($transaction_details['invoice'], '-wcsfrp-')) {
         $renewal_order = wc_get_order(substr($transaction_details['invoice'], strrpos($transaction_details['invoice'], '-') + 1));
         // check if the failed signup has been previously recorded
         if ($renewal_order->id != get_post_meta($subscription->id, '_paypal_failed_sign_up_recorded', true)) {
             $is_renewal_sign_up_after_failure = true;
         }
     }
     // If the invoice ID doesn't match the default invoice ID and contains the string '-wcscpm-', the IPN is for a subscription payment method change
     if ('subscr_signup' == $transaction_details['txn_type'] && false !== strpos($transaction_details['invoice'], '-wcscpm-')) {
         $is_payment_change = true;
     } else {
         $is_payment_change = false;
     }
     if ($is_renewal_sign_up_after_failure || $is_payment_change) {
         // Store the old profile ID on the order (for the first IPN message that comes through)
         $existing_profile_id = wcs_get_paypal_id($subscription);
         if (empty($existing_profile_id) || $existing_profile_id !== $transaction_details['subscr_id']) {
             update_post_meta($subscription->id, '_old_paypal_subscriber_id', $existing_profile_id);
             update_post_meta($subscription->id, '_old_payment_method', $subscription->payment_method);
         }
     }
     // Ignore IPN messages when the payment method isn't PayPal
     if ('paypal' != $subscription->payment_method) {
         // The 'recurring_payment_suspended' transaction is actually an Express Checkout transaction type, but PayPal also send it for PayPal Standard Subscriptions suspended by admins at PayPal, so we need to handle it *if* the subscription has PayPal as the payment method, or leave it if the subscription is using a different payment method (because it might be using PayPal Express Checkout or PayPal Digital Goods)
         if ('recurring_payment_suspended' == $transaction_details['txn_type']) {
             WC_Gateway_Paypal::log('"recurring_payment_suspended" IPN ignored: recurring payment method is not "PayPal". Returning to allow another extension to process the IPN, like PayPal Digital Goods.');
             return;
         } elseif (false === $is_renewal_sign_up_after_failure && false === $is_payment_change) {
             WC_Gateway_Paypal::log('IPN ignored, recurring payment method has changed.');
             exit;
         }
     }
     if (isset($transaction_details['ipn_track_id'])) {
         // Make sure the IPN request has not already been handled
         $handled_ipn_requests = get_post_meta($subscription->id, '_paypal_ipn_tracking_ids', true);
         if (empty($handled_ipn_requests)) {
             $handled_ipn_requests = array();
         }
         // The 'ipn_track_id' is not a unique ID and is shared between different transaction types, so create a unique ID by prepending the transaction type
         $ipn_id = $transaction_details['txn_type'] . '_' . $transaction_details['ipn_track_id'];
         if (in_array($ipn_id, $handled_ipn_requests)) {
             WC_Gateway_Paypal::log('Subscription IPN Error: IPN ' . $ipn_id . ' message has already been correctly handled.');
             exit;
         }
     }
     if (isset($transaction_details['txn_id'])) {
         // Make sure the IPN request has not already been handled
         $handled_transactions = get_post_meta($subscription->id, '_paypal_transaction_ids', true);
         if (empty($handled_transactions)) {
             $handled_transactions = array();
         }
         $transaction_id = $transaction_details['txn_id'];
         if (isset($transaction_details['txn_type'])) {
             $transaction_id .= '_' . $transaction_details['txn_type'];
         }
         // The same transaction ID is used for different payment statuses, so make sure we handle it only once. See: http://stackoverflow.com/questions/9240235/paypal-ipn-unique-identifier
         if (isset($transaction_details['payment_status'])) {
             $transaction_id .= '_' . $transaction_details['payment_status'];
         }
         if (in_array($transaction_id, $handled_transactions)) {
             WC_Gateway_Paypal::log('Subscription IPN Error: transaction ' . $transaction_id . ' has already been correctly handled.');
             exit;
         }
     }
     // Save the profile ID if it's not a cancellation/expiration request
     if (isset($transaction_details['subscr_id']) && !in_array($transaction_details['txn_type'], array('subscr_cancel', 'subscr_eot'))) {
         wcs_set_paypal_id($subscription, $transaction_details['subscr_id']);
         if (wcs_is_paypal_profile_a($transaction_details['subscr_id'], 'out_of_date_id') && 'disabled' != get_option('wcs_paypal_invalid_profile_id')) {
             update_option('wcs_paypal_invalid_profile_id', 'yes');
         }
     }
     $is_first_payment = $subscription->get_completed_payment_count() < 1 ? true : false;
     if ($subscription->has_status('switched')) {
         WC_Gateway_Paypal::log('IPN ignored, subscription has been switched.');
         exit;
     }
     switch ($transaction_details['txn_type']) {
         case 'subscr_signup':
             // Store PayPal Details on Subscription and Order
             $this->save_paypal_meta_data($subscription, $transaction_details);
             $this->save_paypal_meta_data($subscription->order, $transaction_details);
             // When there is a free trial & no initial payment amount, we need to mark the order as paid and activate the subscription
             if (!$is_payment_change && !$is_renewal_sign_up_after_failure && 0 == $subscription->order->get_total()) {
                 // Safe to assume the subscription has an order here because otherwise we wouldn't get a 'subscr_signup' IPN
                 $subscription->order->payment_complete();
                 // No 'txn_id' value for 'subscr_signup' IPN messages
                 update_post_meta($subscription->id, '_paypal_first_ipn_ignored_for_pdt', 'true');
             }
             // Payment completed
             if ($is_payment_change) {
                 // Set PayPal as the new payment method
                 WC_Subscriptions_Change_Payment_Gateway::update_payment_method($subscription, 'paypal');
                 // We need to cancel the subscription now that the method has been changed successfully
                 if ('paypal' == get_post_meta($subscription->id, '_old_payment_method', true)) {
                     self::cancel_subscription($subscription, get_post_meta($subscription->id, '_old_paypal_subscriber_id', true));
                 }
                 $subscription->add_order_note(__('IPN subscription payment method changed to PayPal.', 'woocommerce-subscriptions'));
             } else {
                 $subscription->add_order_note(__('IPN subscription sign up completed.', 'woocommerce-subscriptions'));
             }
             if ($is_payment_change) {
                 WC_Gateway_Paypal::log('IPN subscription payment method changed for subscription ' . $subscription->id);
             } else {
                 WC_Gateway_Paypal::log('IPN subscription sign up completed for subscription ' . $subscription->id);
             }
             break;
         case 'subscr_payment':
             if (!$is_first_payment && !$is_renewal_sign_up_after_failure) {
                 // Generate a renewal order to record the payment (and determine how much is due)
                 $renewal_order = wcs_create_renewal_order($subscription);
                 // Set PayPal as the payment method (we can't use $renewal_order->set_payment_method() here as it requires an object we don't have)
                 $available_gateways = WC()->payment_gateways->get_available_payment_gateways();
                 $renewal_order->set_payment_method($available_gateways['paypal']);
             }
             if ('completed' == strtolower($transaction_details['payment_status'])) {
                 // Store PayPal Details
                 $this->save_paypal_meta_data($subscription, $transaction_details);
                 // Subscription Payment completed
                 $subscription->add_order_note(__('IPN subscription payment completed.', 'woocommerce-subscriptions'));
                 WC_Gateway_Paypal::log('IPN subscription payment completed for subscription ' . $subscription->id);
                 // First payment on order, process payment & activate subscription
                 if ($is_first_payment) {
                     $subscription->order->payment_complete($transaction_details['txn_id']);
                     // Store PayPal Details on Order
                     $this->save_paypal_meta_data($subscription->order, $transaction_details);
                     // IPN got here first or PDT will never arrive. Normally PDT would have arrived, so the first IPN would not be the first payment. In case the the first payment is an IPN, we need to make sure to not ignore the second one
                     update_post_meta($subscription->id, '_paypal_first_ipn_ignored_for_pdt', 'true');
                     // Ignore the first IPN message if the PDT should have handled it (if it didn't handle it, it will have been dealt with as first payment), but set a flag to make sure we only ignore it once
                 } elseif ($subscription->get_completed_payment_count() == 1 && '' !== WCS_PayPal::get_option('identity_token') && 'true' != get_post_meta($subscription->id, '_paypal_first_ipn_ignored_for_pdt', true) && false === $is_renewal_sign_up_after_failure) {
                     WC_Gateway_Paypal::log('IPN subscription payment ignored for subscription ' . $subscription->id . ' due to PDT previously handling the payment.');
                     update_post_meta($subscription->id, '_paypal_first_ipn_ignored_for_pdt', 'true');
                     // Process the payment if the subscription is active
                 } elseif (!$subscription->has_status(array('cancelled', 'expired', 'switched', 'trash'))) {
                     // We don't need to reactivate the subscription because Subs didn't suspend it
                     remove_action('woocommerce_subscription_activated_paypal', __CLASS__ . '::reactivate_subscription');
                     if (true === $is_renewal_sign_up_after_failure && is_object($renewal_order)) {
                         update_post_meta($subscription->id, '_paypal_failed_sign_up_recorded', $renewal_order->id);
                         // We need to cancel the old subscription now that the method has been changed successfully
                         if ('paypal' == get_post_meta($subscription->id, '_old_payment_method', true)) {
                             $profile_id = get_post_meta($subscription->id, '_old_paypal_subscriber_id', true);
                             // Make sure we don't cancel the current profile
                             if ($profile_id !== $transaction_details['subscr_id']) {
                                 self::cancel_subscription($subscription, $profile_id);
                             }
                             $subscription->add_order_note(__('IPN subscription failing payment method changed.', 'woocommerce-subscriptions'));
                         }
                     }
                     $renewal_order->payment_complete($transaction_details['txn_id']);
                     $renewal_order->add_order_note(__('IPN subscription payment completed.', 'woocommerce-subscriptions'));
                     wcs_set_paypal_id($renewal_order, $transaction_details['subscr_id']);
                     add_action('woocommerce_subscription_activated_paypal', __CLASS__ . '::reactivate_subscription');
                 }
             } elseif (in_array(strtolower($transaction_details['payment_status']), array('pending', 'failed'))) {
                 // Subscription Payment completed
                 // translators: placeholder is payment status (e.g. "completed")
                 $subscription->add_order_note(sprintf(_x('IPN subscription payment %s.', 'used in order note', 'woocommerce-subscriptions'), $transaction_details['payment_status']));
                 if (!$is_first_payment) {
                     update_post_meta($renewal_order->id, '_transaction_id', $transaction_details['txn_id']);
                     // translators: placeholder is payment status (e.g. "completed")
                     $renewal_order->add_order_note(sprintf(_x('IPN subscription payment %s.', 'used in order note', 'woocommerce-subscriptions'), $transaction_details['payment_status']));
                     $subscription->payment_failed();
                 }
                 WC_Gateway_Paypal::log('IPN subscription payment failed for subscription ' . $subscription->id);
             } else {
                 WC_Gateway_Paypal::log('IPN subscription payment notification received for subscription ' . $subscription->id . ' with status ' . $transaction_details['payment_status']);
             }
             break;
             // Admins can suspend subscription at PayPal triggering this IPN
         // Admins can suspend subscription at PayPal triggering this IPN
         case 'recurring_payment_suspended':
             if (!$subscription->has_status('on-hold')) {
                 // We don't need to suspend the subscription at PayPal because it's already on-hold there
                 remove_action('woocommerce_subscription_on-hold_paypal', __CLASS__ . '::suspend_subscription');
                 $subscription->update_status('on-hold', __('IPN subscription suspended.', 'woocommerce-subscriptions'));
                 add_action('woocommerce_subscription_activated_paypal', __CLASS__ . '::reactivate_subscription');
                 WC_Gateway_Paypal::log('IPN subscription suspended for subscription ' . $subscription->id);
             } else {
                 WC_Gateway_Paypal::log(sprintf('IPN "recurring_payment_suspended" ignored for subscription %d. Subscription already on-hold.', $subscription->id));
             }
             break;
         case 'subscr_cancel':
             // Make sure the subscription hasn't been linked to a new payment method
             if (wcs_get_paypal_id($subscription) != $transaction_details['subscr_id']) {
                 WC_Gateway_Paypal::log('IPN subscription cancellation request ignored - new PayPal Profile ID linked to this subscription, for subscription ' . $subscription->id);
             } else {
                 $subscription->cancel_order(__('IPN subscription cancelled.', 'woocommerce-subscriptions'));
                 WC_Gateway_Paypal::log('IPN subscription cancelled for subscription ' . $subscription->id);
             }
             break;
         case 'subscr_eot':
             // Subscription ended, either due to failed payments or expiration
             WC_Gateway_Paypal::log('IPN EOT request ignored for subscription ' . $subscription->id);
             break;
         case 'subscr_failed':
             // Subscription sign up failed
         // Subscription sign up failed
         case 'recurring_payment_suspended_due_to_max_failed_payment':
             // Subscription sign up failed
             WC_Gateway_Paypal::log('IPN subscription payment failure for subscription ' . $subscription->id);
             // Subscription Payment completed
             $subscription->add_order_note(__('IPN subscription payment failure.', 'woocommerce-subscriptions'));
             $subscription->payment_failed();
             break;
     }
     // Store the transaction IDs to avoid handling requests duplicated by PayPal
     if (isset($transaction_details['ipn_track_id'])) {
         $handled_ipn_requests[] = $ipn_id;
         update_post_meta($subscription->id, '_paypal_ipn_tracking_ids', $handled_ipn_requests);
     }
     if (isset($transaction_details['txn_id'])) {
         $handled_transactions[] = $transaction_id;
         update_post_meta($subscription->id, '_paypal_transaction_ids', $handled_transactions);
     }
     // Log completion
     $log_message = 'IPN subscription request processed for ' . $subscription->id;
     if (isset($ipn_id) && !empty($ipn_id)) {
         $log_message .= sprintf(' (%s)', $ipn_id);
     }
     WC_Gateway_Paypal::log($log_message);
     // Prevent default IPN handling for subscription txn_types
     exit;
 }