CRM/Core/Payment/Stripe.php

 <?php
-
 /*
- * Payment Processor class for Stripe
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
  */
 
+use Brick\Money\Money;
+use Brick\Math\RoundingMode;
+use Civi\Api4\ContributionRecur;
+use Civi\Api4\PaymentprocessorWebhook;
+use Civi\Api4\StripeCustomer;
+use CRM_Stripe_ExtensionUtil as E;
+use Civi\Payment\PropertyBag;
+use Stripe\Stripe;
+use Civi\Payment\Exception\PaymentProcessorException;
+use Stripe\StripeObject;
+use Stripe\Webhook;
+
+/**
+ * Class CRM_Core_Payment_Stripe
+ */
 class CRM_Core_Payment_Stripe extends CRM_Core_Payment {
 
+  use CRM_Core_Payment_MJWTrait;
+
   /**
-   * We only need one instance of this object. So we use the singleton
-   * pattern and cache the instance in this variable
-   *
-   * @var object
-   * @static
+   * @var \Stripe\StripeClient
    */
-  static private $_singleton = NULL;
+  public $stripeClient;
 
   /**
-   * Mode of operation: live or test.
+   * @var \Civi\Stripe\Api;
+   */
+  public \Civi\Stripe\Api $api;
+
+  /**
+   * Custom properties used by this payment processor
    *
-   * @var object
+   * @var string[]
    */
-  protected $_mode = NULL;
+  private $customProperties = ['paymentIntentID', 'paymentMethodID', 'setupIntentID'];
 
   /**
    * Constructor
    *
    * @param string $mode
-   *   The mode of operation: live or test.
-   *
-   * @return void
+   *   (deprecated) The mode of operation: live or test.
+   * @param array $paymentProcessor
    */
-  public function __construct($mode, &$paymentProcessor) {
-    $this->_mode = $mode;
-    $this->_islive = ($mode == 'live' ? 1 : 0);
+  public function __construct($mode, $paymentProcessor) {
     $this->_paymentProcessor = $paymentProcessor;
-    $this->_processorName = ts('Stripe');
+    $this->api = new \Civi\Stripe\Api($this);
+
+    if (defined('STRIPE_PHPUNIT_TEST') && isset($GLOBALS['mockStripeClient'])) {
+      // When under test, prefer the mock.
+      $this->stripeClient = $GLOBALS['mockStripeClient'];
+
+    }
+    else {
+      // Normally we create a new stripe client.
+      $secretKey = self::getSecretKey($this->_paymentProcessor);
+      // You can configure only one of live/test so don't initialize StripeClient if keys are blank
+      if (!empty($secretKey)) {
+        $this->setAPIParams();
+        $this->stripeClient = new \Stripe\StripeClient($secretKey);
+      }
+    }
   }
 
   /**
-   * This function checks to see if we have the right config values.
+   * @param array $paymentProcessor
    *
    * @return string
-   *   The error message if any.
+   */
+  public static function getSecretKey($paymentProcessor) {
+    return trim($paymentProcessor['password'] ?? '');
+  }
+
+  /**
+   * @param array $paymentProcessor
    *
-   * @public
+   * @return string
    */
-  public function checkConfig() {
-    $config = CRM_Core_Config::singleton();
-    $error = array();
+  public static function getPublicKey($paymentProcessor) {
+    return trim($paymentProcessor['user_name'] ?? '');
+  }
+
+  /**
+   * @return string
+   */
+  public function getWebhookSecret(): string {
+    return trim($this->_paymentProcessor['signature'] ?? '');
+  }
 
-    if (empty($this->_paymentProcessor['user_name'])) {
-      $error[] = ts('The "Secret Key" is not set in the Stripe Payment Processor settings.');
+  /**
+   * Given a payment processor id, return the public key
+   *
+   * @param $paymentProcessorId
+   *
+   * @return string
+   */
+  public static function getPublicKeyById($paymentProcessorId) {
+    try {
+      $paymentProcessor = civicrm_api3('PaymentProcessor', 'getsingle', [
+        'id' => $paymentProcessorId,
+      ]);
+      $key = self::getPublicKey($paymentProcessor);
     }
+    catch (CRM_Core_Exception $e) {
+      return '';
+    }
+    return $key;
+  }
 
-    if (empty($this->_paymentProcessor['password'])) {
-      $error[] = ts('The "Publishable Key" is not set in the Stripe Payment Processor settings.');
+  /**
+   * Given a payment processor id, return the secret key
+   *
+   * @param $paymentProcessorId
+   *
+   * @return string
+   */
+  public static function getSecretKeyById($paymentProcessorId) {
+    try {
+      $paymentProcessor = civicrm_api3('PaymentProcessor', 'getsingle', [
+        'id' => $paymentProcessorId,
+      ]);
+      $key = self::getSecretKey($paymentProcessor);
     }
+    catch (CRM_Core_Exception $e) {
+      return '';
+    }
+    return $key;
+  }
+
+  /**
+   * This function checks to see if we have the right config values.
+   *
+   * @return null|string
+   *   The error message if any.
+   */
+  public function checkConfig() {
+    $error = [];
 
     if (!empty($error)) {
       return implode('<p>', $error);
@@ -66,155 +155,278 @@ class CRM_Core_Payment_Stripe extends CRM_Core_Payment {
   }
 
   /**
-   * Helper log function.
+   * Override CRM_Core_Payment function
    *
-   * @param string $op
-   *   The Stripe operation being performed.
-   * @param Exception $exception
-   *   The error!
+   * @return string
    */
-  public function logStripeException($op, $exception) {
-    $body = print_r($exception->getJsonBody(), TRUE);
-    CRM_Core_Error::debug_log_message("Stripe_Error {$op}:  <pre> {$body} </pre>");
+  public function getPaymentTypeName() {
+    return 'credit_card';
   }
 
   /**
-   * Check if return from stripeCatchErrors was an error object
-   * that should be passed back to original api caller.
+   * Override CRM_Core_Payment function
    *
-   * @param  $stripeReturn
-   *   The return from a call to stripeCatchErrors
+   * @return string
+   */
+  public function getPaymentTypeLabel() {
+    return E::ts('Stripe');
+  }
+
+  /**
+   * We can use the stripe processor on the backend
    * @return bool
-   *
    */
-  public function isErrorReturn($stripeReturn) {
-      if (is_object($stripeReturn) && get_class($stripeReturn) == 'CRM_Core_Error') {
-        return true;
-      }
-      return false;
+  public function supportsBackOffice() {
+    return TRUE;
+  }
+
+  public function supportsRecurring() {
+    return TRUE;
   }
 
   /**
-   * Run Stripe calls through this to catch exceptions gracefully.
+   * We can edit stripe recurring contributions
+   * @return bool
+   */
+  public function supportsEditRecurringContribution() {
+    return TRUE;
+  }
+
+  /**
+   * Get an array of the fields that can be edited on the recurring contribution.
    *
-   * @param string $op
-   *   Determine which operation to perform.
-   * @param array $params
-   *   Parameters to run Stripe calls on.
+   * Some payment processors support editing the amount and other scheduling details of recurring payments, especially
+   * those which use tokens. Others are fixed. This function allows the processor to return an array of the fields that
+   * can be updated from the contribution recur edit screen.
+   *
+   * The fields are likely to be a subset of these
+   *  - 'amount',
+   *  - 'installments',
+   *  - 'frequency_interval',
+   *  - 'frequency_unit',
+   *  - 'cycle_day',
+   *  - 'next_sched_contribution_date',
+   *  - 'end_date',
+   * - 'failure_retry_day',
    *
-   * @return varies
-   *   Response from gateway.
+   * The form does not restrict which fields from the contribution_recur table can be added (although if the html_type
+   * metadata is not defined in the xml for the field it will cause an error.
+   *
+   * Open question - would it make sense to return membership_id in this - which is sometimes editable and is on that
+   * form (UpdateSubscription).
+   *
+   * @return array
    */
-  public function stripeCatchErrors($op = 'create_customer', $stripe_params, $params, $ignores = array()) {
-    $error_url = $params['stripe_error_url'];
-    $return = FALSE;
-    // Check for errors before trying to submit.
-    try {
-      switch ($op) {
-         case 'create_customer':
-          $return = \Stripe\Customer::create($stripe_params);
-          break;
+  public function getEditableRecurringScheduleFields() {
+    if ($this->supports('changeSubscriptionAmount')) {
+      return ['amount'];
+    }
+    return [];
+  }
 
-        case 'update_customer':
-          $return = \Stripe\Customer::update($stripe_params);
-          break;
+  /**
+   * Does this payment processor support refund?
+   *
+   * @return bool
+   */
+  public function supportsRefund() {
+    return TRUE;
+  }
 
-        case 'charge':
-          $return = \Stripe\Charge::create($stripe_params);
-          break;
+  /**
+   * Can we set a future recur start date?  Stripe allows this but we don't (yet) support it.
+   * @return bool
+   */
+  public function supportsFutureRecurStartDate() {
+    return TRUE;
+  }
 
-        case 'save':
-          $return = $stripe_params->save();
-          break;
+  /**
+   * Is an authorize-capture flow supported.
+   *
+   * @return bool
+   */
+  protected function supportsPreApproval() {
+    return TRUE;
+  }
 
-        case 'create_plan':
-          $return = \Stripe\Plan::create($stripe_params);
-          break;
+  /**
+   * Does this processor support cancelling recurring contributions through code.
+   *
+   * If the processor returns true it must be possible to take action from within CiviCRM
+   * that will result in no further payments being processed.
+   *
+   * @return bool
+   */
+  protected function supportsCancelRecurring() {
+    return TRUE;
+  }
 
-        case 'retrieve_customer':
-          $return = \Stripe\Customer::retrieve($stripe_params);
-          break;
+  /**
+   * Does the processor support the user having a choice as to whether to cancel the recurring with the processor?
+   *
+   * If this returns TRUE then there will be an option to send a cancellation request in the cancellation form.
+   *
+   * This would normally be false for processors where CiviCRM maintains the schedule.
+   *
+   * @return bool
+   */
+  protected function supportsCancelRecurringNotifyOptional() {
+    return TRUE;
+  }
 
-        case 'retrieve_balance_transaction':
-          $return = \Stripe\BalanceTransaction::retrieve($stripe_params);
-          break;
+  /**
+   * Get the amount for the Stripe API formatted in lowest (ie. cents / pennies).
+   *
+   * @param array|PropertyBag $params
+   *
+   * @return string
+   */
+  protected function getAmount($params = []) {
+    $amount = number_format((float) $params['amount'] ?? 0.0, CRM_Utils_Money::getCurrencyPrecision($this->getCurrency($params)), '.', '');
+    // Stripe amount required in cents.
+    $amount = preg_replace('/[^\d]/', '', strval($amount));
+    return $amount;
+  }
 
-        default:
-          $return = \Stripe\Customer::create($stripe_params);
-          break;
-      }
-    }
-    catch (Exception $e) {
-      if (is_a($e, 'Stripe_Error')) {
-        foreach ($ignores as $ignore) {
-          if (is_a($e, $ignore['class'])) {
-            $body = $e->getJsonBody();
-            $error = $body['error'];
-            if ($error['type'] == $ignore['type'] && $error['message'] == $ignore['message']) {
-              return $return;
-            }
-          }
-        }
-      }
+  /**
+   * @param \Civi\Payment\PropertyBag $propertyBag
+   *
+   * @throws \Brick\Money\Exception\UnknownCurrencyException
+   */
+  public function getAmountFormattedForStripeAPI(PropertyBag $propertyBag): string {
+    return Money::of($propertyBag->getAmount(), $propertyBag->getCurrency(), NULL, RoundingMode::HALF_UP)->getMinorAmount()->getIntegralPart();
+  }
 
-      $this->logStripeException($op, $e);
-      $error_message = '';
-      // Since it's a decline, Stripe_CardError will be caught
-      $body = $e->getJsonBody();
-      $err = $body['error'];
+  /**
+   * Set API parameters for Stripe (such as identifier, api version, api key)
+   */
+  public function setAPIParams() {
+    // Use CiviCRM log file
+    Stripe::setLogger(\Civi::log());
+    // Attempt one retry (Stripe default is 0) if we can't connect to Stripe servers
+    Stripe::setMaxNetworkRetries(1);
+    // Set plugin info and API credentials.
+    Stripe::setAppInfo('CiviCRM', CRM_Utils_System::version(), CRM_Utils_System::baseURL());
+    Stripe::setApiKey(self::getSecretKey($this->_paymentProcessor));
+    // With Stripe-php 12 we pin to latest Stripe API
+    // Stripe::setApiVersion(CRM_Stripe_Check::API_VERSION);
+  }
 
-      //$error_message .= 'Status is: ' . $e->getHttpStatus() . "<br />";
-      ////$error_message .= 'Param is: ' . $err['param'] . "<br />";
-      $error_message .= 'Type: ' . $err['type'] . '<br />';
-      $error_message .= 'Code: ' . $err['code'] . '<br />';
-      $error_message .= 'Message: ' . $err['message'] . '<br />';
+  /**
+   * This function parses, sanitizes and extracts useful information from the exception that was thrown.
+   * The goal is that it only returns information that is safe to show to the end-user.
+   *
+   * @see https://stripe.com/docs/api/errors/handling?lang=php
+   *
+   * @param string $op
+   * @param \Exception $e
+   *
+   * @return array $err
+   */
+  public function parseStripeException(string $op, \Exception $e): array {
+    $genericError = ['code' => 9000, 'message' => E::ts('An error occurred')];
+
+    switch (get_class($e)) {
+      case 'Stripe\Exception\CardException':
+        /** @var \Stripe\Exception\CardException $e */
+        // Since it's a decline, \Stripe\Exception\CardException will be caught
+        \Civi::log('stripe')->error($this->getLogPrefix() . $op . ': ' . get_class($e) . ': ' . $e->getMessage() . print_r($e->getJsonBody(),TRUE));
+        $error['code'] = $e->getStripeCode();
+        $error['message'] = $e->getMessage();
+        return $error;
+
+      case 'Stripe\Exception\RateLimitException':
+        // Too many requests made to the API too quickly
+      case 'Stripe\Exception\InvalidRequestException':
+        // Invalid parameters were supplied to Stripe's API
+        switch ($e->getStripeCode()) {
+          case 'payment_intent_unexpected_state':
+            $genericError['message'] = E::ts('An error occurred while processing the payment');
+            break;
+        }
+        // Don't show the actual error code to the end user - we log it so sysadmin can fix it if required.
+        $genericError['code'] = '';
+
+      case 'Stripe\Exception\AuthenticationException':
+        // Authentication with Stripe's API failed
+        // (maybe you changed API keys recently)
+      case 'Stripe\Exception\ApiConnectionException':
+        // Network communication with Stripe failed
+        \Civi::log('stripe')->error($this->getLogPrefix() . $op . ': ' . get_class($e) . ': ' . $e->getMessage());
+        return $genericError;
+
+      case 'Stripe\Exception\ApiErrorException':
+        // Display a very generic error to the user, and maybe send yourself an email
+        // Get the error array. Creat a "fake" error code if error is not set.
+        // The calling code will parse this further.
+        \Civi::log('stripe')->error($this->getLogPrefix() . $op . ': ' . get_class($e) . ': ' . $e->getMessage() . print_r($e->getJsonBody(),TRUE));
+        return $e->getJsonBody()['error'] ?? $genericError;
+
+      case 'Stripe\Exception\PermissionException':
+        // The client is probably setup with a restricted API key and does not have permission to do the requested action.
+        // We should not display the specific error to the end customer but we *do* want the details in the log.
+        // For example, if we have a readonly API key we won't be able to update Stripe customer metadata, but we may choose to continue!
+        \Civi::log('stripe')->warning($this->getLogPrefix() . $op . ': ' . get_class($e) . ': ' . $e->getMessage());
+        $genericError['code'] = $e->getStripeCode();
+        $genericError['message'] = $e->getMessage();
+        return $genericError;
+
+      default:
+        // Something else happened, completely unrelated to Stripe
+        \Civi::log('stripe')->error($this->getLogPrefix() . $op . ' (unknown error): ' . get_class($e) . ': ' . $e->getMessage());
+        return $genericError;
+    }
+  }
 
-      if (is_a($e, 'Stripe_CardError')) {
-        $newnote = civicrm_api3('Note', 'create', array(
-          'sequential' => 1,
-          'entity_id' => $params['contactID'],
-          'contact_id' => $params['contributionID'],
-          'subject' => $err['type'],
-          'note' => $err['code'],
-          'entity_table' => "civicrm_contributions",
-        ));
-      }
+  /**
+   * Create or update a Stripe Plan
+   *
+   * @param \Civi\Payment\PropertyBag $propertyBag
+   * @param integer $amount
+   *
+   * @return \Stripe\Plan
+   */
+  public function createPlan(\Civi\Payment\PropertyBag $propertyBag, int $amount): \Stripe\Plan {
+    $planID = "every-{$propertyBag->getRecurFrequencyInterval()}-{$propertyBag->getRecurFrequencyUnit()}-{$amount}-" . strtolower($propertyBag->getCurrency());
 
-      if (isset($error_url)) {
-      // Redirect to first page of form and present error.
-      CRM_Core_Error::statusBounce("Oops!  Looks like there was an error.  Payment Response:
-        <br /> {$error_message}", $error_url);
-      }
-      else {
-        // Don't have return url - return error object to api
-        $core_err = CRM_Core_Error::singleton();
-        $message = 'Oops!  Looks like there was an error.  Payment Response: <br />' . $error_message;
-        if ($err['code']) {
-          $core_err->push($err['code'], 0, NULL, $message);
-        }
-        else {
-          $core_err->push(9000, 0, NULL, 'Unknown Error: ' . $message);
-        }
-        return $core_err;
+    // Try and retrieve existing plan from Stripe
+    // If this fails, we'll create a new one
+    try {
+      $plan = $this->stripeClient->plans->retrieve($planID);
+    }
+    catch (\Stripe\Exception\InvalidRequestException $e) {
+      if ($e->getStripeCode() === 'resource_missing') {
+        $formattedAmount = CRM_Utils_Money::formatLocaleNumericRoundedByCurrency(($amount / 100), $propertyBag->getCurrency());
+        $productName = "{$propertyBag->getCurrency()}{$formattedAmount} "
+          . ($propertyBag->has('membership_name') ? $propertyBag->getCustomProperty('membership_name') . ' ' : '')
+          . "every {$propertyBag->getRecurFrequencyInterval()} {$propertyBag->getRecurFrequencyUnit()}(s)";
+        $product = $this->stripeClient->products->create([
+          'name' => $productName,
+          'type' => 'service'
+        ]);
+        // Create a new Plan.
+        $stripePlan = [
+          'amount' => $amount,
+          'interval' => $propertyBag->getRecurFrequencyUnit(),
+          'product' => $product->id,
+          'currency' => $propertyBag->getCurrency(),
+          'id' => $planID,
+          'interval_count' => $propertyBag->getRecurFrequencyInterval(),
+        ];
+        $plan = $this->stripeClient->plans->create($stripePlan);
       }
     }
-
-    return $return;
+    return $plan;
   }
 
   /**
    * Override CRM_Core_Payment function
+   *
+   * @return array
    */
-  public function getPaymentFormFields() {
-    return array(
-      'credit_card_type',
-      'credit_card_number',
-      'cvv2',
-      'credit_card_exp_date',
-      'stripe_token',
-      'stripe_pub_key',
-      'stripe_id',
-    );
+  public function getPaymentFormFields(): array {
+    return [];
   }
 
   /**
@@ -225,83 +437,27 @@ class CRM_Core_Payment_Stripe extends CRM_Core_Payment {
    * @return array
    *   field metadata
    */
-  public function getPaymentFormFieldsMetadata() {
-    $creditCardType = array('' => ts('- select -')) + CRM_Contribute_PseudoConstant::creditCard();
-    return array(
-      'credit_card_number' => array(
-        'htmlType' => 'text',
-        'name' => 'credit_card_number',
-        'title' => ts('Card Number'),
-        'cc_field' => TRUE,
-        'attributes' => array(
-          'size' => 20,
-          'maxlength' => 20,
-          'autocomplete' => 'off',
-        ),
-        'is_required' => TRUE,
-      ),
-      'cvv2' => array(
-        'htmlType' => 'text',
-        'name' => 'cvv2',
-        'title' => ts('Security Code'),
-        'cc_field' => TRUE,
-        'attributes' => array(
-          'size' => 5,
-          'maxlength' => 10,
-          'autocomplete' => 'off',
-        ),
-        'is_required' => TRUE,
-      ),
-      'credit_card_exp_date' => array(
-        'htmlType' => 'date',
-        'name' => 'credit_card_exp_date',
-        'title' => ts('Expiration Date'),
-        'cc_field' => TRUE,
-        'attributes' => CRM_Core_SelectValues::date('creditCard'),
-        'is_required' => TRUE,
-        'month_field' => 'credit_card_exp_date_M',
-        'year_field' => 'credit_card_exp_date_Y',
-      ),
+  public function getPaymentFormFieldsMetadata(): array {
+    return [];
+  }
 
-      'credit_card_type' => array(
-        'htmlType' => 'select',
-        'name' => 'credit_card_type',
-        'title' => ts('Card Type'),
-        'cc_field' => TRUE,
-        'attributes' => $creditCardType,
-        'is_required' => FALSE,
-      ),
-      'stripe_token' => array(
-        'htmlType' => 'hidden',
-        'name' => 'stripe_token',
-        'title' => 'Stripe Token',
-        'attributes' => array(
-          'id' => 'stripe-token',
-        ),
-        'cc_field' => TRUE,
-        'is_required' => TRUE,
-      ),
-      'stripe_id' => array(
-        'htmlType' => 'hidden',
-        'name' => 'stripe_id',
-        'title' => 'Stripe ID',
-        'attributes' => array(
-          'id' => 'stripe-id',
-        ),
-        'cc_field' => TRUE,
-        'is_required' => TRUE,
-      ),
-      'stripe_pub_key' => array(
-        'htmlType' => 'hidden',
-        'name' => 'stripe_pub_key',
-        'title' => 'Stripe Public Key',
-        'attributes' => array(
-          'id' => 'stripe-pub-key',
-        ),
-        'cc_field' => TRUE,
-        'is_required' => TRUE,
-      ),
-    );
+  /**
+   * Get billing fields required for this processor.
+   *
+   * We apply the existing default of returning fields only for payment processor type 1. Processors can override to
+   * alter.
+   *
+   * @param int $billingLocationID
+   *
+   * @return array
+   */
+  public function getBillingAddressFields($billingLocationID = NULL): array {
+    if ((boolean) \Civi::settings()->get('stripe_nobillingaddress')) {
+      return [];
+    }
+    else {
+      return parent::getBillingAddressFields($billingLocationID);
+    }
   }
 
   /**
@@ -312,586 +468,844 @@ class CRM_Core_Payment_Stripe extends CRM_Core_Payment {
    * @return array
    *    Array of metadata for address fields.
    */
-  public function getBillingAddressFieldsMetadata($billingLocationID = NULL) {
-    $metadata = parent::getBillingAddressFieldsMetadata($billingLocationID);
-    if (!$billingLocationID) {
-      // Note that although the billing id is passed around the forms the idea that it would be anything other than
-      // the result of the function below doesn't seem to have eventuated.
-      // So taking this as a param is possibly something to be removed in favour of the standard default.
-      $billingLocationID = CRM_Core_BAO_LocationType::getBilling();
+  public function getBillingAddressFieldsMetadata($billingLocationID = NULL): array {
+    if ((boolean) \Civi::settings()->get('stripe_nobillingaddress')) {
+      return [];
     }
+    else {
+      $metadata = parent::getBillingAddressFieldsMetadata($billingLocationID);
+      if (!$billingLocationID) {
+        // Note that although the billing id is passed around the forms the idea that it would be anything other than
+        // the result of the function below doesn't seem to have eventuated.
+        // So taking this as a param is possibly something to be removed in favour of the standard default.
+        $billingLocationID = CRM_Core_BAO_LocationType::getBilling();
+      }
 
-    // Stripe does not require the state/county field
-    if (!empty($metadata["billing_state_province_id-{$billingLocationID}"]['is_required'])) {
-      $metadata["billing_state_province_id-{$billingLocationID}"]['is_required'] = FALSE;
-    }
+      // Stripe does not require some of the billing fields but users may still choose to fill them in.
+      $nonRequiredBillingFields = [
+        "billing_state_province_id-{$billingLocationID}",
+        "billing_postal_code-{$billingLocationID}"
+      ];
+      foreach ($nonRequiredBillingFields as $fieldName) {
+        if (!empty($metadata[$fieldName]['is_required'])) {
+          $metadata[$fieldName]['is_required'] = FALSE;
+        }
+      }
 
-    return $metadata;
+      return $metadata;
+    }
   }
 
   /**
-   * Implementation of hook_civicrm_buildForm().
+   * Set default values when loading the (payment) form
    *
-   * @param $form - reference to the form object
+   * @param \CRM_Core_Form $form
    */
   public function buildForm(&$form) {
-    if ($form->isSubmitted()) return;
+    // Don't use \Civi::resources()->addScriptFile etc as they often don't work on AJAX loaded forms (eg. participant backend registration)
+    $context = [];
+    if (class_exists('Civi\Formprotection\Forms')) {
+      $context = \Civi\Formprotection\Forms::getContextFromQuickform($form);
+    }
 
-    $stripe_ppid = CRM_Utils_Array::value('id', $form->_paymentProcessor);
-    $stripe_key = self::stripe_get_key($stripe_ppid);
+    $motoEnabled = CRM_Core_Permission::check('allow stripe moto payments')
+      && (
+        (in_array('backend', \Civi::settings()->get('stripe_moto')) && $form->isBackOffice)
+        || (in_array('frontend', \Civi::settings()->get('stripe_moto')) && !$form->isBackOffice)
+      );
+    $jsVars = [
+      'id' => $form->_paymentProcessor['id'],
+      'currency' => $this->getDefaultCurrencyForForm($form),
+      'billingAddressID' => CRM_Core_BAO_LocationType::getBilling(),
+      'publishableKey' => CRM_Core_Payment_Stripe::getPublicKeyById($form->_paymentProcessor['id']),
+      'paymentProcessorTypeID' => $form->_paymentProcessor['payment_processor_type_id'],
+      'locale' => CRM_Stripe_Api::mapCiviCRMLocaleToStripeLocale(),
+      'apiVersion' => CRM_Stripe_Check::API_VERSION,
+      'csrfToken' => NULL,
+      'country' => \Civi::settings()->get('stripe_country'),
+      'moto' => $motoEnabled,
+      'disablelink' => \Civi::settings()->get('stripe_cardelement_disablelink'),
+    ];
+    if (class_exists('\Civi\Firewall\Firewall')) {
+      $firewall = new \Civi\Firewall\Firewall();
+      $jsVars['csrfToken'] = $firewall->generateCSRFToken($context);
+    }
 
-    // Set ddi_reference
-    $defaults = array();
-    $defaults['stripe_id'] = $stripe_ppid;
-    $defaults['stripe_pub_key'] = $stripe_key;
-    $form->setDefaults($defaults);
+    // Add CSS via region (it won't load on drupal webform if added via \Civi::resources()->addStyleFile)
+    CRM_Core_Region::instance('billing-block')->add([
+      'styleUrl' => \Civi::service('asset_builder')->getUrl(
+        'elements.css',
+        [
+          'path' => E::path('css/elements.css'),
+          'mimetype' => 'text/css',
+        ]
+      ),
+      'weight' => -1,
+    ]);
+    CRM_Core_Region::instance('billing-block')->add([
+      'scriptFile' => [
+        E::LONG_NAME,
+        'js/civicrmStripe.js',
+      ],
+      // Load after other scripts on form (default = 1)
+      'weight' => 100,
+    ]);
+
+    // Add the future recur start date functionality
+    CRM_Stripe_Recur::buildFormFutureRecurStartDate($form, $this, $jsVars);
+
+    \Civi::resources()->addVars(E::SHORT_NAME, $jsVars);
+    // Assign to smarty so we can add via Card.tpl for drupal webform and other situations where jsVars don't get loaded on the form.
+    // This applies to some contribution page configurations as well.
+    $form->assign('stripeJSVars', $jsVars);
+    CRM_Core_Region::instance('billing-block')->add([
+      'template' => E::path('templates/CRM/Core/Payment/Stripe/Card.tpl'),
+      'weight' => -1,
+    ]);
+
+    // Enable JS validation for forms so we only (submit) create a paymentIntent when the form has all fields validated.
+    $form->assign('isJsValidate', TRUE);
   }
 
   /**
-   * Given a payment processor id, return the pub key.
+   * Function to action pre-approval if supported
+   *
+   * @param array $params
+   *   Parameters from the form
+   *
+   * This function returns an array which should contain
+   *   - pre_approval_parameters (this will be stored on the calling form & available later)
+   *   - redirect_url (if set the browser will be redirected to this.
+   *
+   * @return array
    */
-  public function stripe_get_key($stripe_ppid) {
-    try {
-      $result = civicrm_api3('PaymentProcessor', 'getvalue', array(
-        'return' => "password",
-        'id' => $stripe_ppid,
-      ));
-    }
-    catch (CiviCRM_API3_Exception $e) {
-      return NULL;
+  public function doPreApproval(&$params) {
+    foreach ($this->customProperties as $property) {
+      $preApprovalParams[$property] = CRM_Utils_Request::retrieveValue($property, 'String', NULL, FALSE, 'POST');
     }
-    return $result;
+    return ['pre_approval_parameters' => $preApprovalParams ?? []];
   }
 
   /**
-   * Return the CiviCRM version we're running.
+   * Get any details that may be available to the payment processor due to an approval process having happened.
+   *
+   * In some cases the browser is redirected to enter details on a processor site. Some details may be available as a
+   * result.
+   *
+   * @param array $storedDetails
+   *
+   * @return array
    */
-  public function get_civi_version() {
-    $version = civicrm_api3('Domain', 'getvalue', array(
-      'return' => "version",
-      'current_domain' => true,
-    ));
-    return $version;
+  public function getPreApprovalDetails($storedDetails) {
+    return $storedDetails ?? [];
   }
 
   /**
+   * Process payment
    * Submit a payment using Stripe's PHP API:
    * https://stripe.com/docs/api?lang=php
+   * Payment processors should set payment_status_id/payment_status.
    *
-   * @param array $params
+   * @param array|PropertyBag $paymentParams
    *   Assoc array of input parameters for this transaction.
+   * @param string $component
    *
    * @return array
-   *   The result in a nice formatted array (or an error object).
+   *   Result array
    *
-   * @public
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
    */
-  public function doDirectPayment(&$params) {
-    // Let a $0 transaction pass.
-    if (empty($params['amount']) || $params['amount'] == 0) {
-      return $params;
+  public function doPayment(&$paymentParams, $component = 'contribute') {
+    /* @var \Civi\Payment\PropertyBag $propertyBag */
+    $propertyBag = PropertyBag::cast($paymentParams);
+
+    $zeroAmountPayment = $this->processZeroAmountPayment($propertyBag);
+    if ($zeroAmountPayment) {
+      return $zeroAmountPayment;
     }
+    $propertyBag = $this->beginDoPayment($propertyBag);
+
+    $isRecur = ($propertyBag->getIsRecur() && $this->getRecurringContributionId($propertyBag));
 
-    // Get proper entry URL for returning on error.
-    if (!(array_key_exists('qfKey', $params))) {
-      // Probably not called from a civicrm form (e.g. webform) -
-      // will return error object to original api caller.
-      $params['stripe_error_url'] = $error_url = null;
+    // Now try to retrieve the payment "token". One of setupIntentID, paymentMethodID, paymentIntentID is required (in that order)
+    $paymentMethodID = NULL;
+    $propertyBag = $this->getTokenParameter('setupIntentID', $propertyBag, FALSE);
+    if ($propertyBag->has('setupIntentID')) {
+      $setupIntentID = $propertyBag->getCustomProperty('setupIntentID');
+      $setupIntent = $this->stripeClient->setupIntents->retrieve($setupIntentID);
+      $paymentMethodID = $setupIntent->payment_method;
     }
     else {
-      $qfKey = $params['qfKey'];
-      $parsed_url = parse_url($params['entryURL']);
-      $url_path = substr($parsed_url['path'], 1);
-      $params['stripe_error_url'] = $error_url = CRM_Utils_System::url($url_path,
-      $parsed_url['query'] . "&_qf_Main_display=1&qfKey={$qfKey}", FALSE, NULL, FALSE);
+      $propertyBag = $this->getTokenParameter('paymentMethodID', $propertyBag, FALSE);
+      if ($propertyBag->has('paymentMethodID')) {
+        $paymentMethodID = $propertyBag->getCustomProperty('paymentMethodID');
+      }
+      else {
+        $propertyBag = $this->getTokenParameter('paymentIntentID', $propertyBag, TRUE);
+      }
     }
 
-    // Set plugin info and API credentials.
-    \Stripe\Stripe::setAppInfo('CiviCRM', CRM_Utils_System::version(), CRM_Utils_System::baseURL());
-    \Stripe\Stripe::setApiKey($this->_paymentProcessor['user_name']);
+    // We didn't actually use this hook with Stripe, but it was useful to trigger so listeners could see raw params
+    // passing $propertyBag instead of $params now allows some things to be altered
+    $newParams = [];
+    CRM_Utils_Hook::alterPaymentProcessorParams($this, $propertyBag, $newParams);
 
-    // Stripe amount required in cents.
-    $amount = number_format($params['amount'], 2, '.', '');
-    $amount = (int) preg_replace('/[^\d]/', '', strval($amount));
+    $amountFormattedForStripe = $this->getAmountFormattedForStripeAPI($propertyBag);
 
-    // Use Stripe.js instead of raw card details.
-    if (!empty($params['stripe_token'])) {
-      $card_token = $params['stripe_token'];
-    }
-    else if(!empty(CRM_Utils_Array::value('stripe_token', $_POST, NULL))) {
-      $card_token = CRM_Utils_Array::value('stripe_token', $_POST, NULL);
+    $stripeCustomer = $this->getStripeCustomer($propertyBag);
+
+    $customerParams = [
+      'contact_id' => $propertyBag->getContactID(),
+    ];
+
+    // Attach the paymentMethod to the customer and set as default for new invoices
+    if (isset($paymentMethodID)) {
+      $paymentMethod = $this->stripeClient->paymentMethods->retrieve($paymentMethodID);
+      $paymentMethod->attach(['customer' => $stripeCustomer->id]);
+      $customerParams['invoice_settings']['default_payment_method'] = $paymentMethodID;
     }
-    else {
-      CRM_Core_Error::statusBounce(ts('Unable to complete payment! Please this to the site administrator with a description of what you were trying to do.'));
-      Civi::log()->debug('Stripe.js token was not passed!  Report this message to the site administrator. $params: ' . print_r($params, TRUE));
-    }
-
-    // Check for existing customer, create new otherwise.
-    // Possible email fields.
-    $email_fields = array(
-      'email',
-      'email-5',
-      'email-Primary',
-    );
-
-    // Possible contact ID fields.
-    $contact_id_fields = array(
-      'contact_id',
-      'contactID',
-    );
-
-    // Find out which email field has our yummy value.
-    foreach ($email_fields as $email_field) {
-      if (!empty($params[$email_field])) {
-        $email = $params[$email_field];
-        break;
+
+    CRM_Stripe_BAO_StripeCustomer::updateMetadata($customerParams, $this, $stripeCustomer->id);
+
+    // Handle recurring payments in doRecurPayment().
+    if ($isRecur) {
+      // We're processing a recurring payment - for recurring payments we first saved a paymentMethod via the browser js.
+      // Now we use that paymentMethod to setup a stripe subscription and take the first payment.
+      // This is where we save the customer card
+      // @todo For a recurring payment we have to save the card. For a single payment we'd like to develop the
+      //   save card functionality but should not save by default as the customer has not agreed.
+      if (empty($paymentMethodID)) {
+        \Civi::log('stripe')->error($this->getLogPrefix() . 'recur payment but missing paymentmethod. Check form config');
+        throw new PaymentProcessorException('Payment form is not configured correctly!');
       }
+      return $this->doRecurPayment($propertyBag, $amountFormattedForStripe, $stripeCustomer);
     }
 
-    // We didn't find an email, but never fear - this might be a backend contrib.
-    // We can look for a contact ID field and get the email address.
-    if (empty($email)) {
-      foreach ($contact_id_fields as $cid_field) {
-        if (!empty($params[$cid_field])) {
-          $email = civicrm_api3('Contact', 'getvalue', array(
-            'id' => $params[$cid_field],
-            'return' => 'email',
-          ));
-          break;
-        }
+    $intentParams = [
+      'customer' => $stripeCustomer->id,
+      'description' => $this->getDescription($propertyBag, 'description'),
+    ];
+    $intentParams['statement_descriptor_suffix'] = $this->getDescription($propertyBag, 'statement_descriptor_suffix');
+    $intentParams['statement_descriptor'] = $this->getDescription($propertyBag, 'statement_descriptor');
+
+    if (!$propertyBag->has('paymentIntentID') && !empty($paymentMethodID)) {
+      // We came in via a flow that did not know the amount before submit (eg. multiple event participants)
+      // We need to create a paymentIntent
+      $stripePaymentIntent = new CRM_Stripe_PaymentIntent($this);
+      $stripePaymentIntent->setDescription($this->getDescription($propertyBag));
+      $stripePaymentIntent->setReferrer($_SERVER['HTTP_REFERER'] ?? '');
+      $stripePaymentIntent->setExtraData($propertyBag->has('extra_data') ? $propertyBag->getCustomProperty('extra_data') : '');
+
+      $paymentIntentParams = [
+        'paymentMethodID' => $paymentMethodID,
+        'customer' => $stripeCustomer->id,
+        'capture' => FALSE,
+        'amount' => $propertyBag->getAmount(),
+        'currency' => $propertyBag->getCurrency(),
+      ];
+      $processIntentResult = $stripePaymentIntent->processPaymentIntent($paymentIntentParams);
+      if ($processIntentResult->ok) {
+        $paymentIntentID = $processIntentResult->data['paymentIntent']['id'];
+      }
+      else {
+        \Civi::log('stripe')->error('Attempted to create paymentIntent from paymentMethod during doPayment failed: ' . print_r($processIntentResult, TRUE));
       }
     }
 
-    // We still didn't get an email address?!  /ragemode on
-    if (empty($email)) {
-      CRM_Core_Error::fatal(ts('No email address found.  Please report this issue.'));
+    // This is where we actually charge the customer
+    try {
+      if (empty($paymentIntentID)) {
+        $paymentIntentID = $propertyBag->getCustomProperty('paymentIntentID');
+      }
+      $intent = $this->stripeClient->paymentIntents->retrieve($paymentIntentID);
+      if ($intent->amount != $this->getAmountFormattedForStripeAPI($propertyBag)) {
+        $intentParams['amount'] = $this->getAmountFormattedForStripeAPI($propertyBag);
+      }
+      $intent = $this->stripeClient->paymentIntents->update($intent->id, $intentParams);
+    }
+    catch (Exception $e) {
+      $parsedError = $this->parseStripeException('doPayment', $e);
+      $this->handleError($parsedError['code'], $parsedError['message'], $this->getErrorUrl($propertyBag), FALSE);
     }
 
-    // Prepare escaped query params.
-    $query_params = array(
-      1 => array($email, 'String'),
-      2 => array($this->_paymentProcessor['id'], 'Integer'),
-    );
-
-    $customer_query = CRM_Core_DAO::singleValueQuery("SELECT id
-      FROM civicrm_stripe_customers
-      WHERE email = %1 AND is_live = '{$this->_islive}' AND processor_id = %2", $query_params);
-
-    /****
-     * If for some reason you cannot use Stripe.js and you are aware of PCI Compliance issues,
-     * here is the alternative to Stripe.js:
-     ****/
-
-    /*
-      // Get Cardholder's full name.
-      $cc_name = $params['first_name'] . " ";
-      if (strlen($params['middle_name']) > 0) {
-        $cc_name .= $params['middle_name'] . " ";
-      }
-      $cc_name .= $params['last_name'];
+    // @fixme FROM HERE we are using $params ONLY - SET things if required ($propertyBag is not used beyond here)
+    $params = $this->getPropertyBagAsArray($propertyBag);
+    $params = $this->processPaymentIntent($params, $intent);
 
-      // Prepare Card details in advance to use for new Stripe Customer object if we need.
-      $card_details = array(
-        'number' => $params['credit_card_number'],
-        'exp_month' => $params['month'],
-        'exp_year' => $params['year'],
-        'cvc' => $params['cvv2'],
-        'name' => $cc_name,
-        'address_line1' => $params['street_address'],
-        'address_state' => $params['state_province'],
-        'address_zip' => $params['postal_code'],
-      );
-    */
-
-    // drastik - Uncomment this for Drupal debugging to dblog.
-    /*
-     $zz = print_r(get_defined_vars(), TRUE);
-     $debug_code = '<pre>' . $zz . '</pre>';
-     watchdog('Stripe', $debug_code);
-    */
-
-    // Customer not in civicrm_stripe database.  Create a new Customer in Stripe.
-    if (!isset($customer_query)) {
-      $sc_create_params = array(
-        'description' => 'Donor from CiviCRM',
-        'card' => $card_token,
-        'email' => $email,
-      );
+    // For a single charge there is no stripe invoice, we set OrderID to the ChargeID.
+    if (empty($this->getPaymentProcessorOrderID())) {
+      $this->setPaymentProcessorOrderID($this->getPaymentProcessorTrxnID());
+    }
 
-      $stripe_customer = $this->stripeCatchErrors('create_customer', $sc_create_params, $params);
+    // For contribution workflow we have a contributionId so we can set parameters directly.
+    // For events/membership workflow we have to return the parameters and they might get set...
+    return $this->endDoPayment($params);
+  }
 
-      // Store the relationship between CiviCRM's email address for the Contact & Stripe's Customer ID.
-      if (isset($stripe_customer)) {
-        if ($this->isErrorReturn($stripe_customer)) {
-          return $stripe_customer;
-        }
-        // Prepare escaped query params.
-        $query_params = array(
-          1 => array($email, 'String'),
-          2 => array($stripe_customer->id, 'String'),
-          3 => array($this->_paymentProcessor['id'], 'Integer'),
-        );
+  /**
+   * @param \Civi\Payment\PropertyBag $propertyBag
+   *
+   * @return \Stripe\Customer|PropertySpy
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   */
+  protected function getStripeCustomer(\Civi\Payment\PropertyBag $propertyBag) {
+    if (!$propertyBag->has('email')) {
+      // @fixme: Check if we still need to call the getBillingEmail function - eg. how does it handle "email-Primary".
+      $email = $this->getBillingEmail($propertyBag);
+      $propertyBag->setEmail($email);
+    }
 
-        CRM_Core_DAO::executeQuery("INSERT INTO civicrm_stripe_customers
-          (email, id, is_live, processor_id) VALUES (%1, %2, '{$this->_islive}', %3)", $query_params);
-      }
-      else {
-        CRM_Core_Error::fatal(ts('There was an error saving new customer within Stripe.  Is Stripe down?'));
-      }
+    // See if we already have a stripe customer
+    $customerParams = [
+      'contact_id' => $propertyBag->getContactID(),
+      'processor_id' => $this->getPaymentProcessor()['id'],
+      'email' => $propertyBag->getEmail(),
+      'currency' => mb_strtolower($propertyBag->getCurrency()),
+      // Include this to allow redirect within session on payment failure
+      'error_url' => $this->getErrorUrl($propertyBag),
+    ];
+
+    // Get the Stripe Customer:
+    //   1. Look for an existing customer.
+    //   2. If no customer (or a deleted customer found), create a new one.
+    //   3. If existing customer found, update the metadata that Stripe holds for this customer.
+
+    // Customers can only be billed for subscriptions in a single currency. currency field was added in 6.10
+    // So we look for a customer with matching currency and if not check for an empty currency (if customer was created before 6.10)
+    $stripeCustomer = StripeCustomer::get(FALSE)
+      ->addWhere('contact_id', '=', $customerParams['contact_id'])
+      ->addWhere('processor_id', '=', $customerParams['processor_id'])
+      ->addClause('OR', ['currency', 'IS EMPTY'], ['currency', '=', $customerParams['currency']])
+      ->addOrderBy('currency', 'DESC')
+      ->execute()->first();
+
+    // Customer not in civicrm database.  Create a new Customer in Stripe.
+    if (empty($stripeCustomer)) {
+      $stripeCustomerObject = CRM_Stripe_Customer::create($customerParams, $this);
     }
     else {
-      // Customer was found in civicrm_stripe database, fetch from Stripe.
-      $stripe_customer = $this->stripeCatchErrors('retrieve_customer', $customer_query, $params);
-      if (!empty($stripe_customer)) {
-        if ($this->isErrorReturn($stripe_customer)) {
-          return $stripe_customer;
-        }
-        // Avoid the 'use same token twice' issue while still using latest card.
-        if (!empty($params['selectMembership'])
-          && $params['selectMembership']
-          && empty($params['contributionPageID'])
-        ) {
-          // This is a Contribution form w/ Membership option and charge is
-          // coming through for the 2nd time.  Don't need to update customer again.
+      $shouldDeleteStripeCustomer = $shouldCreateNewStripeCustomer = FALSE;
+      // Customer was found in civicrm database, fetch from Stripe.
+      try {
+        $stripeCustomerObject = $this->stripeClient->customers->retrieve($stripeCustomer['customer_id']);
+        $shouldDeleteStripeCustomer = $stripeCustomerObject->isDeleted();
+      } catch (Exception $e) {
+        $err = $this->parseStripeException('retrieve_customer', $e);
+        \Civi::log('stripe')->error($this->getLogPrefix() . 'Failed to retrieve Stripe Customer: ' . $err['code']);
+        $shouldDeleteStripeCustomer = TRUE;
+      }
+
+      if (empty($stripeCustomer['currency'])) {
+        // We have no currency set for the customer in the CiviCRM database
+        if ($stripeCustomerObject->currency === $customerParams['currency']) {
+          // We can use this customer but we need to update the currency in the civicrm database
+          StripeCustomer::update(FALSE)
+            ->addValue('currency', $stripeCustomerObject->currency)
+            ->addWhere('id', '=', $stripeCustomer['id'])
+            ->execute();
         }
         else {
-          $stripe_customer->card = $card_token;
-          $response = $this->stripeCatchErrors('save', $stripe_customer, $params);
-            if (isset($response) && $this->isErrorReturn($response)) {
-              return $response;
-            }
+          // We need to create a new customer
+          $shouldCreateNewStripeCustomer = TRUE;
         }
       }
-      else {
-        // Customer was found in civicrm_stripe database, but unable to be
-        // retrieved from Stripe.  Was he deleted?
-        $sc_create_params = array(
-          'description' => 'Donor from CiviCRM',
-          'card' => $card_token,
-          'email' => $email,
-        );
-
-        $stripe_customer = $this->stripeCatchErrors('create_customer', $sc_create_params, $params);
-
-        // Somehow a customer ID saved in the system no longer pairs
-        // with a Customer within Stripe.  (Perhaps deleted using Stripe interface?).
-        // Store the relationship between CiviCRM's email address for the Contact & Stripe's Customer ID.
-        if (isset($stripe_customer)) {
-          /*if ($this->isErrorReturn($stripe_customer)) {
-            return $stripe_customer;
-          }*/
-          // Delete whatever we have for this customer.
-          $query_params = array(
-            1 => array($email, 'String'),
-            2 => array($this->_paymentProcessor['id'], 'Integer'),
-          );
-          CRM_Core_DAO::executeQuery("DELETE FROM civicrm_stripe_customers
-            WHERE email = %1 AND is_live = '{$this->_islive}' AND processor_id = %2", $query_params);
-
-          // Create new record for this customer.
-          $query_params = array(
-            1 => array($email, 'String'),
-            2 => array($stripe_customer->id, 'String'),
-            3 => array($this->_paymentProcessor['id'], 'Integer'),
-          );
-          CRM_Core_DAO::executeQuery("INSERT INTO civicrm_stripe_customers (email, id, is_live, processor_id)
-            VALUES (%1, %2, '{$this->_islive}, %3')", $query_params);
-        }
-        else {
-          // Customer was found in civicrm_stripe database, but unable to be
-          // retrieved from Stripe, and unable to be created in Stripe.  What luck :(
-          CRM_Core_Error::fatal(ts('There was an error saving new customer within Stripe.  Is Stripe down?'));
+
+      if ($shouldDeleteStripeCustomer) {
+        // Customer was deleted, delete it.
+        CRM_Stripe_Customer::delete($customerParams);
+      }
+      if ($shouldDeleteStripeCustomer || $shouldCreateNewStripeCustomer) {
+        try {
+          $stripeCustomerObject = CRM_Stripe_Customer::create($customerParams, $this);
+        } catch (Exception $e) {
+          // We still failed to create a customer
+          $err = $this->parseStripeException('create_customer', $e);
+          throw new PaymentProcessorException('Failed to create Stripe Customer: ' . $err['code']);
         }
       }
     }
+    return $stripeCustomerObject;
+  }
+
+  /**
+   * @param \Civi\Payment\PropertyBag $propertyBag
+   *
+   * @return bool
+   */
+  private function isPaymentForEventAdditionalParticipants(\Civi\Payment\PropertyBag $propertyBag): bool {
+    if ($propertyBag->getter('additional_participants', TRUE)) {
+      return TRUE;
+    }
+    return FALSE;
+  }
+
+  /**
+   * Submit a recurring payment using Stripe's PHP API:
+   * https://stripe.com/docs/api?lang=php
+   *
+   * @param \Civi\Payment\PropertyBag $propertyBag
+   *   PropertyBag for this transaction.
+   * @param int $amountFormattedForStripe
+   *   Transaction amount in cents.
+   * @param \Stripe\Customer $stripeCustomer
+   *   Stripe customer object generated by Stripe API.
+   *
+   * @return array
+   *   The result in a nice formatted array (or an error object).
+   *
+   * @throws \CRM_Core_Exception
+   */
+  public function doRecurPayment(\Civi\Payment\PropertyBag $propertyBag, int $amountFormattedForStripe, $stripeCustomer): array {
+    // Make sure recurFrequencyInterval is set (default to 1 if not)
+    if (!$propertyBag->has('recurFrequencyInterval') || $propertyBag->getRecurFrequencyInterval() === 0) {
+      $propertyBag->setRecurFrequencyInterval(1);
+    }
+
+    $params = $this->getPropertyBagAsArray($propertyBag);
+
+    // @fixme FROM HERE we are using $params array (but some things are READING from $propertyBag)
+
+    // @fixme: Split this out into "$returnParams"
+    // We set payment status as pending because the IPN will set it as completed / failed
+    $params = $this->setStatusPaymentPending($params);
+
+    $required = NULL;
+    if (empty($this->getRecurringContributionId($propertyBag))) {
+      $required = 'contributionRecurID';
+    }
+
+    if (!$propertyBag->has('recurFrequencyUnit')) {
+      $required = 'recurFrequencyUnit';
+    }
+    if ($required) {
+      Civi::log()->error($this->getLogPrefix() . 'doRecurPayment: Missing mandatory parameter: ' . $required);
+      throw new CRM_Core_Exception($this->getLogPrefix() . 'doRecurPayment: Missing mandatory parameter: ' . $required);
+    }
+
+    // Create the stripe plan
+    $plan = self::createPlan($propertyBag, $amountFormattedForStripe);
+
+    // Attach the Subscription to the Stripe Customer.
+    $subscriptionParams = [
+      'proration_behavior' => 'none',
+      'plan' => $plan->id,
+      'metadata' => ['Description' => $propertyBag->getDescription()],
+      'expand' => ['latest_invoice.payment_intent'],
+      'customer' => $stripeCustomer->id,
+      'off_session' => TRUE,
+    ];
+    // This is the parameter that specifies the start date for the subscription.
+    // If omitted the subscription will start immediately.
+    $billingCycleAnchor = $this->getRecurBillingCycleDay($params);
+    if ($billingCycleAnchor) {
+      $subscriptionParams['billing_cycle_anchor'] = $billingCycleAnchor;
+    }
+
+    // Create the stripe subscription for the customer
+    $stripeSubscription = $this->stripeClient->subscriptions->create($subscriptionParams);
+    $this->setPaymentProcessorSubscriptionID($stripeSubscription->id);
+
+    $nextScheduledContributionDate = $this->calculateNextScheduledDate($params);
+    $contributionRecur = ContributionRecur::update(FALSE)
+      ->addWhere('id', '=', $this->getRecurringContributionId($propertyBag))
+      ->addValue('processor_id', $this->getPaymentProcessorSubscriptionID())
+      ->addValue('auto_renew', 1)
+      ->addValue('next_sched_contribution_date', $nextScheduledContributionDate)
+      ->addValue('cycle_day', date('d', strtotime($nextScheduledContributionDate)));
+
+    if ($propertyBag->has('recurInstallments') && ($propertyBag->getRecurInstallments() > 0)) {
+      // We set an end date if installments > 0
+      if (empty($params['receive_date'])) {
+        $params['receive_date'] = date('YmdHis');
+      }
+      $contributionRecur
+        ->addValue('end_date', $this->calculateEndDate($params))
+        ->addValue('installments', $propertyBag->getRecurInstallments());
+    }
 
-    // Prepare the charge array, minus Customer/Card details.
-    if (empty($params['description'])) {
-      $params['description'] = ts('CiviCRM backend contribution');
+    if ($stripeSubscription->status === 'incomplete') {
+      $contributionRecur->addValue('contribution_status_id:name', 'Failed');
     }
-    else {
-      $params['description'] = ts('CiviCRM # ') . $params['description'];
+    // Update the recurring payment
+    $contributionRecur->execute();
+
+    if ($stripeSubscription->status === 'incomplete') {
+      // For example with test card 4000000000000341 (Attaching this card to a Customer object succeeds, but attempts to charge the customer fail)
+      \Civi::log('stripe')->warning($this->getLogPrefix() . 'subscription status=incomplete. ID:' . $stripeSubscription->id);
+      throw new PaymentProcessorException('Payment failed');
     }
 
-    // Stripe charge.
-    $stripe_charge = array(
-      'amount' => $amount,
-      'currency' => strtolower($params['currencyID']),
-      'description' => $params['description'] . ' # Invoice ID: ' . CRM_Utils_Array::value('invoiceID', $params),
-    );
+    // For a recurring (subscription) with future start date we might not have an invoice yet.
+    if (!empty($stripeSubscription->latest_invoice)) {
+      // Get the paymentIntent for the latest invoice
+      $intent = $stripeSubscription->latest_invoice['payment_intent'];
+      $params = $this->processPaymentIntent($params, $intent);
 
-    // Use Stripe Customer if we have a valid one.  Otherwise just use the card.
-    if (!empty($stripe_customer->id)) {
-      $stripe_charge['customer'] = $stripe_customer->id;
+      // Set the OrderID (invoice) and TrxnID (charge)
+      $this->setPaymentProcessorOrderID($stripeSubscription->latest_invoice['id']);
+      if (!empty($stripeSubscription->latest_invoice['charge'])) {
+        $this->setPaymentProcessorTrxnID($stripeSubscription->latest_invoice['charge']);
+      }
     }
     else {
-      $stripe_charge['card'] = $card_token;
+      // Update the paymentIntent in the CiviCRM database for later tracking
+      // If we are not starting the recurring series immediately we probably have a "setupIntent" which needs confirming
+      $intentParams = [
+        'stripe_intent_id' => $intent->id ?? $stripeSubscription->pending_setup_intent ?? $propertyBag->getCustomProperty('paymentMethodID'),
+        'payment_processor_id' => $this->_paymentProcessor['id'],
+        'contribution_id' =>  $params['contributionID'] ?? NULL,
+        'identifier' => $params['qfKey'] ?? NULL,
+        'contact_id' => $params['contactID'],
+      ];
+      try {
+        $intentParams['id'] = civicrm_api3('StripePaymentintent', 'getvalue', ['stripe_intent_id' => $propertyBag->getCustomProperty('paymentMethodID'), 'return' => 'id']);
+      }
+      catch (Exception $e) {
+        // Do nothing, we should already have a StripePaymentintent record but we don't so we'll create one.
+      }
+
+      if (empty($intentParams['contribution_id'])) {
+        $intentParams['flags'][] = 'NC';
+      }
+      CRM_Stripe_BAO_StripePaymentintent::create($intentParams);
+      // Set the orderID (trxn_id) to the subscription ID because we don't yet have an invoice.
+      // The IPN will change it to the invoice_id and then the charge_id
+      $this->setPaymentProcessorOrderID($stripeSubscription->id);
     }
 
-    // Handle recurring payments in doRecurPayment().
-    if (CRM_Utils_Array::value('is_recur', $params) && $params['contributionRecurID']) {
-      return $this->doRecurPayment($params, $amount, $stripe_customer);
-    }
-
-    // Fire away!  Check for errors before trying to submit.
-    $stripe_response = $this->stripeCatchErrors('charge', $stripe_charge, $params);
-    if (!empty($stripe_response)) {
-      if ($this->isErrorReturn($stripe_response)) {
-        return $stripe_response;
-      }
-      // Success!  Return some values for CiviCRM.
-      $params['trxn_id'] = $stripe_response->id;
-      // Return fees & net amount for Civi reporting.
-      // Uses new Balance Trasaction object.
-      $balance_transaction = $this->stripeCatchErrors('retrieve_balance_transaction', $stripe_response->balance_transaction, $params);
-      if (!empty($balance_transaction)) {
-        if ($this->isErrorReturn($balance_transaction)) {
-          return $balance_transaction;
-        }
-        $params['fee_amount'] = $balance_transaction->fee / 100;
-        $params['net_amount'] = $balance_transaction->net / 100;
+    return $this->endDoPayment($params);
+  }
+
+  /**
+   * Get the billing cycle day (timestamp)
+   * @param array $params
+   *
+   * @return int|null
+   */
+  private function getRecurBillingCycleDay($params) {
+    if (isset($params['receive_date'])) {
+      $receiveDateTimestamp = strtotime($params['receive_date']);
+      // If `receive_date` was set to "now" it will be in the past (by a few seconds) by the time we actually send it to Stripe.
+      if ($receiveDateTimestamp > strtotime('now')) {
+        // We've specified a receive_date in the future, use it!
+        return $receiveDateTimestamp;
       }
     }
-    else {
-      // There was no response from Stripe on the create charge command.
-      if (isset($error_url)) {
-        CRM_Core_Error::statusBounce('Stripe transaction response not recieved!  Check the Logs section of your stripe.com account.', $error_url);
+    // Either we had no receive_date or receive_date was in the past (or "now" when form was submitted).
+    return NULL;
+  }
+
+  /**
+   * This performs the processing and recording of the paymentIntent for both recurring and non-recurring payments
+   * @param array $params
+   * @param \Stripe\PaymentIntent $intent
+   *
+   * @return array $params
+   */
+  private function processPaymentIntent($params, $intent) {
+    $email = $this->getBillingEmail($params, $params['contactID']);
+
+    try {
+      if ($intent->status === 'requires_confirmation') {
+        $intent->confirm();
       }
-      else {
-        // Don't have return url - return error object to api
-        $core_err = CRM_Core_Error::singleton();
-        $core_err->push(9000, 0, NULL, 'Stripe transaction response not recieved!  Check the Logs section of your stripe.com account.');
-        return $core_err;
+
+      switch ($intent->status) {
+        case 'requires_capture':
+          $intent->capture();
+        case 'succeeded':
+          // Return fees & net amount for Civi reporting.
+          if (!empty($intent->charges)) {
+            // Stripe API version < 2022-11-15
+            $stripeCharge = $intent->charges->data[0];
+          }
+          elseif (!empty($intent->latest_charge)) {
+            // Stripe API version 2022-11-15
+            $stripeCharge = $this->stripeClient->charges->retrieve($intent->latest_charge);
+          }
+          try {
+            $stripeBalanceTransaction = $this->stripeClient->balanceTransactions->retrieve($stripeCharge->balance_transaction);
+          }
+          catch (Exception $e) {
+            $err = $this->parseStripeException('retrieve_balance_transaction', $e);
+            throw new PaymentProcessorException('Failed to retrieve Stripe Balance Transaction: ' . $err['code']);
+          }
+          if (($stripeCharge['currency'] !== $stripeBalanceTransaction->currency)
+              && (!empty($stripeBalanceTransaction->exchange_rate))) {
+            $params['fee_amount'] = CRM_Stripe_Api::currencyConversion($stripeBalanceTransaction->fee, $stripeBalanceTransaction['exchange_rate'], $stripeCharge['currency']);
+          }
+          else {
+            // We must round to currency precision otherwise payments may fail because Contribute BAO saves but then
+            // can't retrieve because it tries to use the full unrounded number when it only got saved with 2dp.
+            $params['fee_amount'] = round($stripeBalanceTransaction->fee / 100, CRM_Utils_Money::getCurrencyPrecision($stripeCharge['currency']));
+          }
+          // Success!
+          // Set the desired contribution status which will be set later (do not set on the contribution here!)
+          $params = $this->setStatusPaymentCompleted($params);
+          // Transaction ID is always stripe Charge ID.
+          $this->setPaymentProcessorTrxnID($stripeCharge->id);
+
+        case 'requires_action':
+          // We fall through to this in requires_capture / requires_action so we always set a receipt_email
+          if ((boolean) \Civi::settings()->get('stripe_oneoffreceipt')) {
+            // Send a receipt from Stripe - we have to set the receipt_email after the charge has been captured,
+            //   as the customer receives an email as soon as receipt_email is updated and would receive two if we updated before capture.
+            $this->stripeClient->paymentIntents->update($intent->id, ['receipt_email' => $email]);
+          }
+          break;
       }
     }
+    catch (Exception $e) {
+      $this->handleError($e->getCode(), $e->getMessage(), $params['error_url'] ?? '');
+    }
+    finally {
+      // Always update the paymentIntent in the CiviCRM database for later tracking
+      $intentParams = [
+        'stripe_intent_id' => $intent->id,
+        'payment_processor_id' => $this->_paymentProcessor['id'],
+        'status' => $intent->status,
+        'contribution_id' =>  $params['contributionID'] ?? NULL,
+        'description' => $this->getDescription($params, 'description'),
+        'identifier' => $params['qfKey'] ?? NULL,
+        'contact_id' => $params['contactID'],
+        'extra_data' => ($errorMessage ?? '') . ';' . ($email ?? ''),
+      ];
+      if (empty($intentParams['contribution_id'])) {
+        $intentParams['flags'][] = 'NC';
+      }
+      CRM_Stripe_BAO_StripePaymentintent::create($intentParams);
+    }
 
     return $params;
   }
 
   /**
-   * Submit a recurring payment using Stripe's PHP API:
-   * https://stripe.com/docs/api?lang=php
+   * Submit a refund payment
    *
    * @param array $params
    *   Assoc array of input parameters for this transaction.
-   * @param int $amount
-   *   Transaction amount in USD cents.
-   * @param object $stripe_customer
-   *   Stripe customer object generated by Stripe API.
    *
    * @return array
-   *   The result in a nice formatted array (or an error object).
-   *
-   * @public
-   */
-  public function doRecurPayment(&$params, $amount, $stripe_customer) {
-    // Get recurring contrib properties.
-    $frequency = $params['frequency_unit'];
-    $frequency_interval = (empty($params['frequency_interval']) ? 1 : $params['frequency_interval']);
-    $currency = strtolower($params['currencyID']);
-    if (isset($params['installments'])) {
-      $installments = $params['installments'];
-    }
-
-    // This adds some support for CiviDiscount on recurring contributions and changes the default behavior to discounting
-    // only the first of a recurring contribution set instead of all. (Intro offer) The Stripe procedure for discounting the
-    // first payment of subscription entails creating a negative invoice item or negative balance first,
-    // then creating the subscription at 100% full price. The customers first Stripe invoice will reflect the
-    // discount. Subsequent invoices will be at the full undiscounted amount.
-    // NB: Civi currently won't send a $0 charge to a payproc extension, but it should in this case. If the discount is >
-    // the cost of initial payment, we still send the whole discount (or giftcard) as a negative balance.
-    // Consider not selling giftards greater than your least expensive auto-renew membership until we can override this.
-    // TODO: add conditonals that look for $param['intro_offer'] (to give admins the choice of default behavior) and
-    // $params['trial_period'].
-
-    if (!empty($params['discountcode'])) {
-      $discount_code = $params['discountcode'];
-      $discount_object = civicrm_api3('DiscountCode', 'get', array(
-         'sequential' => 1,
-         'return' => "amount,amount_type",
-         'code' => $discount_code,
-          ));
-       // amount_types: 1 = percentage, 2 = fixed, 3 = giftcard
-       if ((!empty($discount_object['values'][0]['amount'])) && (!empty($discount_object['values'][0]['amount_type']))) {
-         $discount_type = $discount_object['values'][0]['amount_type'];
-         if ( $discount_type == 1 ) {
-         // Discount is a percentage. Avoid ugly math and just get the full price using price_ param.
-           foreach($params as $key=>$value){
-             if("price_" == substr($key,0,6)){
-               $price_param = $key;
-               $price_field_id = substr($key,strrpos($key,'_') + 1);
-             }
-           }
-           if (!empty($params[$price_param])) {
-             $priceFieldValue = civicrm_api3('PriceFieldValue', 'get', array(
-               'sequential' => 1,
-               'return' => "amount",
-               'id' => $params[$price_param],
-               'price_field_id' => $price_field_id,
-              ));
-           }
-           if (!empty($priceFieldValue['values'][0]['amount'])) {
-              $priceset_amount = $priceFieldValue['values'][0]['amount'];
-              $full_price = $priceset_amount * 100;
-              $discount_in_cents = $full_price - $amount;
-              // Set amount to full price.
-              $amount = $full_price;
-           }
-        } else if ( $discount_type >= 2 ) {
-        // discount is fixed or a giftcard. (may be > amount).
-          $discount_amount = $discount_object['values'][0]['amount'];
-          $discount_in_cents = $discount_amount * 100;
-          // Set amount to full price.
-          $amount =  $amount + $discount_in_cents;
-        }
-     }
-        // Apply the disount through a negative balance.
-       $stripe_customer->account_balance = -$discount_in_cents;
-       $stripe_customer->save();
-     }
-
-    // Tying a plan to a membership (or priceset->membership) makes it possible
-    // to automatically change the users membership level with subscription upgrade/downgrade.
-    // An amount is not enough information to distinguish a membership related recurring
-    // contribution from a non-membership related one.
-    $membership_type_tag = '';
-    $membership_name = '';
-    if (isset($params['selectMembership'])) {
-      $membership_type_id = $params['selectMembership'][0];
-      $membership_type_tag = 'membertype_' . $membership_type_id . '-';
-      $membershipType = civicrm_api3('MembershipType', 'get', array(
-       'sequential' => 1,
-       'return' => "name",
-       'id' => $membership_type_id,
-      ));
-      $membership_name = $membershipType['values'][0]['name'];
-    }
-
-    // Currently plan_id is a unique db key. Therefore test plans of the
-    // same name as a live plan fail to be added with a DB error Already exists,
-    // which is a problem for testing.  This appends 'test' to a test
-    // plan to avoid that error.
-    $is_live = $this->_islive;
-    $mode_tag = '';
-    if ( $is_live == 0 ) {
-      $mode_tag = '-test';
-    }
-    $plan_id = "{$membership_type_tag}every-{$frequency_interval}-{$frequency}-{$amount}-{$currency}{$mode_tag}";
-
-    // Prepare escaped query params.
-    $query_params = array(
-      1 => array($plan_id, 'String'),
-    );
-
-
-    // Prepare escaped query params.
-    $query_params = array(
-      1 => array($plan_id, 'String'),
-      2 => array($this->_paymentProcessor['id'], 'Integer'),
-    );
-
-    $stripe_plan_query = CRM_Core_DAO::singleValueQuery("SELECT plan_id
-      FROM civicrm_stripe_plans
-      WHERE plan_id = %1 AND is_live = '{$this->_islive}' AND processor_id = %2", $query_params);
-
-    if (!isset($stripe_plan_query)) {
-      $formatted_amount = number_format(($amount / 100), 2);
-      $product = \Stripe\Product::create(array(
-        "name" => "CiviCRM {$membership_name} every {$frequency_interval} {$frequency}(s) {$formatted_amount}{$currency}{$mode_tag}",
-        "type" => "service"
-      ));
-      // Create a new Plan.
-      $stripe_plan = array(
-        'amount' => $amount,
-        'interval' => $frequency,
-        'product' => $product->id,
-        'currency' => $currency,
-        'id' => $plan_id,
-        'interval_count' => $frequency_interval,
-      );
-
-      $ignores = array(
-        array(
-          'class' => 'Stripe_InvalidRequestError',
-          'type' => 'invalid_request_error',
-          'message' => 'Plan already exists.',
-        ),
-      );
-      $this->stripeCatchErrors('create_plan', $stripe_plan, $params, $ignores);
-      // Prepare escaped query params.
-      $query_params = array(
-        1 => array($plan_id, 'String'),
-        2 => array($this->_paymentProcessor['id'], 'Integer'),
-      );
-      CRM_Core_DAO::executeQuery("INSERT INTO civicrm_stripe_plans (plan_id, is_live, processor_id)
-        VALUES (%1, '{$this->_islive}', %2)", $query_params);
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   * @throws \Brick\Money\Exception\UnknownCurrencyException
+   */
+  public function doRefund(&$params) {
+    $requiredParams = ['trxn_id', 'amount'];
+    foreach ($requiredParams as $required) {
+      if (!isset($params[$required])) {
+        $message = $this->getLogPrefix() . 'doRefund: Missing mandatory parameter: ' . $required;
+        Civi::log()->error($message);
+        throw new PaymentProcessorException($message);
+      }
     }
 
-    // As of Feb. 2014, Stripe handles multiple subscriptions per customer, even
-    // ones of the exact same plan. To pave the way for that kind of support here,
-    // were using subscription_id as the unique identifier in the
-    // civicrm_stripe_subscription table, instead of using customer_id to derive
-    // the invoice_id.  The proposed default behavor should be to always create a
-    // new subscription. Upgrade/downgrades keep the same subscription id in Stripe
-    // and we mirror this behavior by modifing our recurring contribution when this happens.
-    // For now, updating happens in Webhook.php as a result of modifiying the subscription
-    // in the UI at stripe.com. Eventually we'll initiating subscription changes
-    // from within Civi and Stripe.php. The Webhook.php code should still be relevant.
+    $propertyBag = PropertyBag::cast($params);
 
-    // Attach the Subscription to the Stripe Customer.
-    $cust_sub_params = array(
-      'prorate' => FALSE,
-      'plan' => $plan_id,
-    );
-    $stripe_response = $stripe_customer->subscriptions->create($cust_sub_params);
-    $subscription_id = $stripe_response->id;
-    $recuring_contribution_id = $params['contributionRecurID'];
-
-    // Prepare escaped query params.
-    $query_params = array(
-      1 => array($subscription_id, 'String'),
-      2 => array($stripe_customer->id, 'String'),
-      3 => array($recuring_contribution_id, 'String'),
-      4 => array($this->_paymentProcessor['id'], 'Integer'),
-    );
-
-    // Insert the Stripe Subscription info.
-
-    // Let end_time be NULL if installments are ongoing indefinitely
-    if (empty($installments)) {
-      CRM_Core_DAO::executeQuery("INSERT INTO civicrm_stripe_subscriptions
-        (subscription_id, customer_id, contribution_recur_id, processor_id, is_live )
-        VALUES (%1, %2, %3, %4,'{$this->_islive}')", $query_params);
-    } else {
-      // Calculate timestamp for the last installment.
-      $end_time = strtotime("+{$installments} {$frequency}");
-      // Add the end time to the query params.
-      $query_params[5] = array($end_time, 'Integer');
-      CRM_Core_DAO::executeQuery("INSERT INTO civicrm_stripe_subscriptions
-        (subscription_id, customer_id, contribution_recur_id, processor_id, end_time, is_live)
-        VALUES (%1, %2, %3, %4, %5, '{$this->_islive}')", $query_params);
+    $refundParams = [
+      'charge' => $params['trxn_id'],
+    ];
+    $refundParams['amount'] = $this->getAmountFormattedForStripeAPI($propertyBag);
+    try {
+      $refund = $this->stripeClient->refunds->create($refundParams);
+      // Stripe does not refund fees - see https://support.stripe.com/questions/understanding-fees-for-refunded-payments
+      // $fee = $this->getFeeFromBalanceTransaction($refund['balance_transaction'], $refund['currency']);
+    }
+    catch (Exception $e) {
+      $this->handleError($e->getCode(), $e->getMessage());
     }
 
-    //  Don't return a $params['trxn_id'] here or else recurring membership contribs will be set
-    //  "Completed" prematurely.  Webhook.php does that.
+    switch ($refund->status) {
+      case 'pending':
+        $refundStatus = CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'contribution_status_id', 'Pending');
+        $refundStatusName = 'Pending';
+        break;
 
-    return $params;
+      case 'succeeded':
+        $refundStatus = CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'contribution_status_id', 'Completed');
+        $refundStatusName = 'Completed';
+        break;
 
+      case 'failed':
+        $refundStatus = CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'contribution_status_id', 'Failed');
+        $refundStatusName = 'Failed';
+        break;
+
+      case 'canceled':
+        $refundStatus = CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'contribution_status_id', 'Cancelled');
+        $refundStatusName = 'Cancelled';
+        break;
+    }
+
+    $refundParams = [
+      'refund_trxn_id' => $refund->id,
+      'refund_status_id' => $refundStatus,
+      'refund_status' => $refundStatusName,
+      'fee_amount' => 0,
+    ];
+    return $refundParams;
   }
 
   /**
-   * Transfer method not in use.
-   *
-   * @param array $params
-   *   Name value pair of contribution data.
+   * Get a description field
+   * @param array|PropertyBag $params
+   * @param string $type
+   *   One of description, statement_descriptor, statement_descriptor_suffix
    *
-   * @return void
+   * @return string
+   */
+  protected function getDescription($params, string $type = 'description'): string {
+    /* @var \Civi\Payment\PropertyBag $propertyBag */
+    $propertyBag = PropertyBag::cast($params);
+
+    # See https://stripe.com/docs/statement-descriptors
+    # And note: both the descriptor and the descriptor suffix must have at
+    # least one alphabetical character - so we ensure that all returned
+    # statement descriptors minimally have an "X".
+    $disallowed_characters = ['<', '>', '\\', "'", '"', '*'];
+
+    $contactContributionID = $propertyBag->getContactID() . 'X' . ($propertyBag->has('contributionID') ? $propertyBag->getContributionID() : 'XX');
+    switch ($type) {
+      // For statement_descriptor / statement_descriptor_suffix:
+      // 1. Get it from the setting if defined.
+      // 2. Generate it from the contact/contribution ID + description (event/contribution title).
+      // 3. Set it to the current "domain" name in CiviCRM.
+      // 4. If we end up with a blank descriptor Stripe will reject it - https://lab.civicrm.org/extensions/stripe/-/issues/293
+      //   so we set it to ".".
+      case 'statement_descriptor':
+        $description = trim(\Civi::settings()->get('stripe_statementdescriptor'));
+        if (empty($description)) {
+          $description = trim("{$contactContributionID} {$propertyBag->getDescription()}");
+          if (empty($description)) {
+            $description = \Civi\Api4\Domain::get(FALSE)
+              ->setCurrentDomain(TRUE)
+              ->addSelect('name')
+              ->execute()
+              ->first()['name'];
+          }
+        }
+        $description = str_replace($disallowed_characters, '', $description);
+        if (empty($description)) {
+          $description = 'X';
+        }
+        return substr($description, 0, 22);
+
+      case 'statement_descriptor_suffix':
+        $description = trim(\Civi::settings()->get('stripe_statementdescriptorsuffix'));
+        if (empty($description)) {
+          $description = trim("{$contactContributionID} {$propertyBag->getDescription()}");
+          if (empty($description)) {
+            $description = \Civi\Api4\Domain::get(FALSE)
+              ->setCurrentDomain(TRUE)
+              ->addSelect('name')
+              ->execute()
+              ->first()['name'];
+          }
+        }
+        $description = str_replace($disallowed_characters, '', $description);
+        if (empty($description)) {
+          $description = 'X';
+        }
+        return substr($description,0,12);
+
+      default:
+        // The (paymentIntent) full description has no restriction on characters that are allowed/disallowed.
+        return "{$propertyBag->getDescription()} " . $contactContributionID . " #" . ($propertyBag->has('invoiceID') ? $propertyBag->getInvoiceID() : '');
+    }
+  }
+
+  /**
+   * Calculate the end_date for a recurring contribution based on the number of installments
+   * @param $params
    *
-   * @access public
+   * @return string
+   * @throws \CRM_Core_Exception
+   */
+  public function calculateEndDate($params) {
+    $requiredParams = ['receive_date', 'recurInstallments', 'recurFrequencyInterval', 'recurFrequencyUnit'];
+    foreach ($requiredParams as $required) {
+      if (!isset($params[$required])) {
+        $message = $this->getLogPrefix() . 'calculateEndDate: Missing mandatory parameter: ' . $required;
+        Civi::log()->error($message);
+        throw new CRM_Core_Exception($message);
+      }
+    }
+
+    switch ($params['recurFrequencyUnit']) {
+      case 'day':
+        $frequencyUnit = 'D';
+        break;
+
+      case 'week':
+        $frequencyUnit = 'W';
+        break;
+
+      case 'month':
+        $frequencyUnit = 'M';
+        break;
+
+      case 'year':
+        $frequencyUnit = 'Y';
+        break;
+    }
+
+    $numberOfUnits = $params['recurInstallments'] * $params['recurFrequencyInterval'];
+    $endDate = new DateTime($params['receive_date']);
+    $endDate->add(new DateInterval("P{$numberOfUnits}{$frequencyUnit}"));
+    return $endDate->format('Ymd') . '235959';
+  }
+
+  /**
+   * Calculate the end_date for a recurring contribution based on the number of installments
+   * @param $params
    *
+   * @return string
+   * @throws \CRM_Core_Exception
    */
-  public function doTransferCheckout(&$params, $component) {
-    CRM_Core_Error::fatal(ts('Use direct billing instead of Transfer method.'));
+  public function calculateNextScheduledDate($params) {
+    $requiredParams = ['recurFrequencyInterval', 'recurFrequencyUnit'];
+    foreach ($requiredParams as $required) {
+      if (!isset($params[$required])) {
+        $message = $this->getLogPrefix() . 'calculateNextScheduledDate: Missing mandatory parameter: ' . $required;
+        Civi::log()->error($message);
+        throw new CRM_Core_Exception($message);
+      }
+    }
+    if (empty($params['receive_date']) && empty($params['next_sched_contribution_date'])) {
+      $startDate = date('YmdHis');
+    }
+    elseif (!empty($params['next_sched_contribution_date'])) {
+      if ($params['next_sched_contribution_date'] < date('YmdHis')) {
+        $startDate = $params['next_sched_contribution_date'];
+      }
+    }
+    else {
+      $startDate = $params['receive_date'];
+    }
+
+    switch ($params['recurFrequencyUnit']) {
+      case 'day':
+        $frequencyUnit = 'D';
+        break;
+
+      case 'week':
+        $frequencyUnit = 'W';
+        break;
+
+      case 'month':
+        $frequencyUnit = 'M';
+        break;
+
+      case 'year':
+        $frequencyUnit = 'Y';
+        break;
+    }
+
+    $numberOfUnits = $params['recurFrequencyInterval'];
+    $endDate = new DateTime($startDate);
+    $endDate->add(new DateInterval("P{$numberOfUnits}{$frequencyUnit}"));
+    return $endDate->format('Ymd');
   }
 
   /**
@@ -906,10 +1320,360 @@ class CRM_Core_Payment_Stripe extends CRM_Core_Payment {
   public function validatePaymentInstrument($values, &$errors) {
     // Use $_POST here and not $values - for webform fields are not set in $values, but are in $_POST
     CRM_Core_Form::validateMandatoryFields($this->getMandatoryFields(), $_POST, $errors);
-    if ($this->_paymentProcessor['payment_type'] == 1) {
-      // Don't validate credit card details as they are not passed (and stripe does this for us)
-      //CRM_Core_Payment_Form::validateCreditCard($values, $errors, $this->_paymentProcessor['id']);
+  }
+
+  /**
+   * Attempt to cancel the subscription at Stripe.
+   *
+   * @param \Civi\Payment\PropertyBag $propertyBag
+   *
+   * @return array|null[]
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   */
+  public function doCancelRecurring(PropertyBag $propertyBag) {
+    // By default we always notify the processor and we don't give the user the option
+    // because supportsCancelRecurringNotifyOptional() = FALSE
+    if (!$propertyBag->has('isNotifyProcessorOnCancelRecur')) {
+      // If isNotifyProcessorOnCancelRecur is NOT set then we set our default
+      $propertyBag->setIsNotifyProcessorOnCancelRecur(TRUE);
+    }
+    $notifyProcessor = $propertyBag->getIsNotifyProcessorOnCancelRecur();
+
+    if (!$notifyProcessor) {
+      return ['message' => E::ts('Successfully cancelled the subscription in CiviCRM ONLY.')];
+    }
+
+    if (!$propertyBag->has('recurProcessorID')) {
+      $errorMessage = E::ts('The recurring contribution cannot be cancelled (No reference (processor_id) found).');
+      \Civi::log('stripe')->error($errorMessage);
+      throw new PaymentProcessorException($errorMessage);
+    }
+
+    try {
+      $subscription = $this->stripeClient->subscriptions->retrieve($propertyBag->getRecurProcessorID());
+      if (!$subscription->isDeleted()) {
+        $subscription->cancel();
+      }
+    }
+    catch (Exception $e) {
+      $errorMessage = E::ts('Could not cancel Stripe subscription: %1', [1 => $e->getMessage()]);
+      \Civi::log('stripe')->error($errorMessage);
+      throw new PaymentProcessorException($errorMessage);
+    }
+
+    return ['message' => E::ts('Successfully cancelled the subscription at Stripe.')];
+  }
+
+  /**
+   * Change the amount of the recurring payment.
+   *
+   * @param string $message
+   * @param array $params
+   *
+   * @return bool|object
+   *
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   */
+  public function changeSubscriptionAmount(&$message = '', $params = []) {
+    // We only support the following params: amount
+    try {
+      $propertyBag = $this->beginChangeSubscriptionAmount($params);
+
+      // Get the Stripe subscription
+      $subscription = $this->stripeClient->subscriptions->retrieve($propertyBag->getRecurProcessorID());
+
+      $calculatedItems = $this->api->calculateItemsForSubscription($propertyBag->getRecurProcessorID(), $subscription->items->data);
+      $contributionRecurKey = mb_strtolower($propertyBag->getCurrency()) . "_{$propertyBag->getRecurFrequencyUnit()}_{$propertyBag->getRecurFrequencyInterval()}";
+      if (isset($calculatedItems[$contributionRecurKey])) {
+        $calculatedItem = $calculatedItems[$contributionRecurKey];
+        if (Money::of($calculatedItem['amount'], mb_strtoupper($calculatedItem['currency']))
+          ->isAmountAndCurrencyEqualTo(Money::of($propertyBag->getAmount(), $propertyBag->getCurrency()))) {
+          throw new PaymentProcessorException('Amount is the same as before!');
+        }
+      }
+      else {
+        throw new PaymentProcessorException('Cannot find existing price/plan for this subscription with matching frequency!');
+      }
+
+      // Get the existing Price
+      $existingPrice = $subscription->items->data[0]->price;
+
+      // Check if the Stripe Product already has a Price configured for the new amount
+      $priceToMatch = [
+        'active' => TRUE,
+        'currency' => $subscription->currency,
+        'product' => $existingPrice->product,
+        'type' => 'recurring',
+        'recurring' => [
+          'interval' => $existingPrice->recurring['interval'],
+        ],
+      ];
+      $existingPrices = $this->stripeClient->prices->all($priceToMatch);
+      foreach ($existingPrices as $price) {
+        if ($price->unit_amount === (int) $this->getAmountFormattedForStripeAPI($propertyBag)) {
+          // Yes, we already have a matching price option - use it!
+          $newPriceID = $price->id;
+          break;
+        }
+      }
+      if (empty($newPriceID)) {
+        // We didn't find an existing price that matched for the product. Create a new one.
+        $newPriceParameters = [
+          'currency' => $subscription->currency,
+          'unit_amount' => $this->getAmountFormattedForStripeAPI($propertyBag),
+          'product' => $existingPrice->product,
+          'metadata' => $existingPrice->metadata->toArray(),
+          'recurring' => [
+            'interval' => $existingPrice->recurring['interval'],
+            'interval_count' => $existingPrice->recurring['interval_count'],
+          ],
+        ];
+        $newPriceID = $this->stripeClient->prices->create($newPriceParameters)->id;
+      }
+
+      // Update the Stripe subscription, replacing the existing price with the new one.
+      $this->stripeClient->subscriptions->update($propertyBag->getRecurProcessorID(), [
+        'items' => [
+          [
+            'id' => $subscription->items->data[0]->id,
+            'price' => $newPriceID,
+          ],
+        ],
+        // See https://stripe.com/docs/billing/subscriptions/prorations - we disable this to keep it simple for now.
+        'proration_behavior' => 'none',
+      ]);
+    }
+    catch (Exception $e) {
+      // On ANY failure, throw an exception which will be reported back to the user.
+      \Civi::log()->error('Update Subscription failed for RecurID: ' . $propertyBag->getContributionRecurID() . ' Error: ' . $e->getMessage());
+      throw new PaymentProcessorException('Update Subscription Failed: ' . $e->getMessage(), $e->getCode(), $params);
+    }
+
+    return TRUE;
+  }
+
+  /**
+   * Process incoming payment notification (IPN).
+   *
+   * @throws \CRM_Core_Exception
+   * @throws \Stripe\Exception\UnknownApiErrorException
+   */
+  public function handlePaymentNotification() {
+    // Set default http response to 200
+    http_response_code(200);
+    $rawData = file_get_contents("php://input");
+    $event = json_decode($rawData, TRUE);
+    $ipnClass = new CRM_Core_Payment_StripeIPN($this);
+    $ipnClass->setEventID($event['id']);
+    if (!$ipnClass->setEventType($event['type'])) {
+      // We don't handle this event
+      return;
+    }
+
+    $webhookSecret = $this->getWebhookSecret();
+    if (!empty($webhookSecret)) {
+      $sigHeader = $_SERVER['HTTP_STRIPE_SIGNATURE'];
+      try {
+        Webhook::constructEvent($rawData, $sigHeader, $webhookSecret);
+        $ipnClass->setVerifyData(FALSE);
+        $data = StripeObject::constructFrom($event['data']);
+        $ipnClass->setData($data);
+      } catch (\UnexpectedValueException $e) {
+        // Invalid payload
+        \Civi::log('stripe')->error($this->getLogPrefix() . 'webhook signature validation error: ' . $e->getMessage());
+        http_response_code(400);
+        exit();
+      } catch (\Stripe\Exception\SignatureVerificationException $e) {
+        // Invalid signature
+        \Civi::log('stripe')->error($this->getLogPrefix() . 'webhook signature validation error: ' . $e->getMessage());
+        http_response_code(400);
+        exit();
+      }
+    }
+    else {
+      $ipnClass->setVerifyData(TRUE);
+    }
+
+    $ipnClass->onReceiveWebhook();
+  }
+
+  /**
+   * @param int $paymentProcessorID
+   *   The actual payment processor ID that should be used.
+   * @param $rawData
+   *   The "raw" data, eg. a JSON string that is saved in the civicrm_system_log.context table
+   * @param bool $verifyRequest
+   *   Should we verify the request data with the payment processor (eg. retrieve it again?).
+   * @param null|int $emailReceipt
+   *   Override setting of email receipt if set to 0, 1
+   *
+   * @return bool
+   * @throws \API_Exception
+   * @throws \Civi\API\Exception\UnauthorizedException
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   * @deprecated
+   */
+  public static function processPaymentNotification($paymentProcessorID, $rawData, $verifyRequest = TRUE, $emailReceipt = NULL) {
+    // Set default http response to 200
+    http_response_code(200);
+
+    $event = json_decode($rawData);
+    $paymentProcessorObject = \Civi\Payment\System::singleton()->getById($paymentProcessorID);
+    if (!($paymentProcessorObject instanceof CRM_Core_Payment_Stripe)) {
+      throw new PaymentProcessorException('Failed to get payment processor');
+    }
+    $ipnClass = new CRM_Core_Payment_StripeIPN($paymentProcessorObject);
+    $ipnClass->setEventID($event->id);
+    if (!$ipnClass->setEventType($event->type)) {
+      // We don't handle this event
+      return FALSE;
+    };
+    $ipnClass->setVerifyData($verifyRequest);
+    if (!$verifyRequest) {
+      $ipnClass->setData($event->data);
+    }
+    $ipnClass->setExceptionMode(FALSE);
+    if (isset($emailReceipt)) {
+      $ipnClass->setSendEmailReceipt($emailReceipt);
+    }
+    return $ipnClass->processWebhookEvent()->ok;
+  }
+
+  /**
+   * Called by mjwshared extension's queue processor api3 Job.process_paymentprocessor_webhooks
+   *
+   * The array parameter contains a row of PaymentprocessorWebhook data, which represents a single PaymentprocessorWebhook event
+   *
+   * Return TRUE for success, FALSE if there's a problem
+   */
+  public function processWebhookEvent(array $webhookEvent) :bool {
+    // If there is another copy of this event in the table with a lower ID, then
+    // this is a duplicate that should be ignored. We do not worry if there is one with a higher ID
+    // because that means that while there are duplicates, we'll only process the one with the lowest ID.
+    $duplicates = PaymentprocessorWebhook::get(FALSE)
+      ->selectRowCount()
+      ->addWhere('event_id', '=', $webhookEvent['event_id'])
+      ->addWhere('id', '<', $webhookEvent['id'])
+      ->execute()->count();
+    if ($duplicates) {
+      PaymentprocessorWebhook::update(FALSE)
+        ->addWhere('id', '=', $webhookEvent['id'])
+        ->addValue('status', 'error')
+        ->addValue('message', 'Refusing to process this event as it is a duplicate.')
+        ->execute();
+      return FALSE;
+    }
+
+    $handler = new CRM_Core_Payment_StripeIPN($this);
+    $handler->setEventID($webhookEvent['event_id']);
+    if (!$handler->setEventType($webhookEvent['trigger'])) {
+      // We don't handle this event
+      return FALSE;
     }
+
+    // Populate the data from this webhook.
+    $rawEventData = str_replace('Stripe\StripeObject JSON: ', '', $webhookEvent['data']);
+    $eventData = json_decode($rawEventData, TRUE);
+    $data = StripeObject::constructFrom($eventData);
+    $handler->setData($data);
+
+    // We retrieve/validate/store the webhook data when it is received.
+    $handler->setVerifyData(FALSE);
+    $handler->setExceptionMode(FALSE);
+    return $handler->processQueuedWebhookEvent($webhookEvent);
+  }
+
+  /**
+   * Get help text information (help, description, etc.) about this payment,
+   * to display to the user.
+   *
+   * @param string $context
+   *   Context of the text.
+   *   Only explicitly supported contexts are handled without error.
+   *   Currently supported:
+   *   - contributionPageRecurringHelp (params: is_recur_installments, is_email_receipt)
+   *   - contributionPageContinueText (params: amount, is_payment_to_existing)
+   *   - cancelRecurDetailText:
+   *     params:
+   *       mode, amount, currency, frequency_interval, frequency_unit,
+   *       installments, {membershipType|only if mode=auto_renew},
+   *       selfService (bool) - TRUE if user doesn't have "edit contributions" permission.
+   *         ie. they are accessing via a "self-service" link from an email receipt or similar.
+   *   - cancelRecurNotSupportedText
+   *
+   * @param array $params
+   *   Parameters for the field, context specific.
+   *
+   * @return string
+   */
+  public function getText($context, $params) {
+    $text = parent::getText($context, $params);
+
+    switch ($context) {
+      case 'cancelRecurDetailText':
+        // $params['selfService'] added via https://github.com/civicrm/civicrm-core/pull/17687
+        $params['selfService'] = $params['selfService'] ?? TRUE;
+        if ($params['selfService']) {
+          $text .= ' <br/><strong>' . E::ts('Stripe will be automatically notified and the subscription will be cancelled.') . '</strong>';
+        }
+        else {
+          $text .= ' <br/><strong>' . E::ts("If you select 'Send cancellation request..' then Stripe will be automatically notified and the subscription will be cancelled.") . '</strong>';
+        }
+    }
+    return $text;
+  }
+
+  /**
+   * Get the help text to present on the recurring update page.
+   *
+   * This should reflect what can or cannot be edited.
+   *
+   * @return string
+   */
+  public function getRecurringScheduleUpdateHelpText() {
+    return E::ts('Use this form to change the amount for this recurring contribution. The Stripe subscription will be updated with the new amount.');
+  }
+
+  /*
+   * Sets a mock stripe client object for this object and all future created
+   * instances. This should only be called by phpunit tests.
+   *
+   * Nb. cannot change other already-existing instances.
+   */
+  public function setMockStripeClient($stripeClient) {
+    if (!defined('STRIPE_PHPUNIT_TEST')) {
+      throw new \RuntimeException("setMockStripeClient was called while not in a STRIPE_PHPUNIT_TEST");
+    }
+    $GLOBALS['mockStripeClient'] = $this->stripeClient = $stripeClient;
+  }
+
+  /**
+   * Get the Fee charged by Stripe from the "balance transaction".
+   * If the transaction is declined, there won't be a balance_transaction_id.
+   * We also have to do currency conversion here in case Stripe has converted it internally.
+   *
+   * @param \Stripe\BalanceTransaction|PropertySpy $balanceTransaction
+   * @param
+   *
+   * @return float
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   */
+  public function getFeeFromBalanceTransaction($balanceTransaction, string $currency): float {
+    if ($currency !== $balanceTransaction->currency && !empty($balanceTransaction->exchange_rate)) {
+      $fee = CRM_Stripe_Api::currencyConversion($balanceTransaction->fee, $balanceTransaction->exchange_rate, $currency);
+    } else {
+      // We must round to currency precision otherwise payments may fail because Contribute BAO saves but then
+      // can't retrieve because it tries to use the full unrounded number when it only got saved with 2dp.
+      $fee = round($balanceTransaction->fee / 100, CRM_Utils_Money::getCurrencyPrecision($currency));
+    }
+    return $fee;
+  }
+
+  /**
+   * @return string
+   */
+  public function getLogPrefix(): string {
+    return 'Stripe(' . $this->getID() . '): ';
   }
 
 }

CRM/Core/Payment/StripeCheckout.php

+<?php
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+use CRM_Stripe_ExtensionUtil as E;
+use Civi\Payment\PropertyBag;
+use Civi\Payment\Exception\PaymentProcessorException;
+
+/**
+ * Class CRM_Core_Payment_Stripe
+ */
+class CRM_Core_Payment_StripeCheckout extends CRM_Core_Payment_Stripe {
+
+  use CRM_Core_Payment_MJWTrait;
+
+  /**
+   * Override CRM_Core_Payment function
+   *
+   * @return string
+   */
+  public function getPaymentTypeName() {
+    return 'stripe-checkout';
+  }
+
+  /**
+   * Override CRM_Core_Payment function
+   *
+   * @return string
+   */
+  public function getPaymentTypeLabel() {
+    return E::ts('Stripe Checkout');
+  }
+
+  /**
+   * We can use the stripe processor on the backend
+   *
+   * @return bool
+   */
+  public function supportsBackOffice() {
+    return FALSE;
+  }
+
+  /**
+   * We can edit stripe recurring contributions
+   * @return bool
+   */
+  public function supportsEditRecurringContribution() {
+    return FALSE;
+  }
+
+  public function supportsRecurring() {
+    return TRUE;
+  }
+
+  /**
+   * Does this payment processor support refund?
+   *
+   * @return bool
+   */
+  public function supportsRefund() {
+    return TRUE;
+  }
+
+  /**
+   * Can we set a future recur start date?
+   *
+   * @return bool
+   */
+  public function supportsFutureRecurStartDate() {
+    return FALSE;
+  }
+
+  /**
+   * Is an authorize-capture flow supported.
+   *
+   * @return bool
+   */
+  protected function supportsPreApproval() {
+    return FALSE;
+  }
+
+  /**
+   * Does this processor support cancelling recurring contributions through code.
+   *
+   * If the processor returns true it must be possible to take action from within CiviCRM
+   * that will result in no further payments being processed.
+   *
+   * @return bool
+   */
+  protected function supportsCancelRecurring() {
+    return TRUE;
+  }
+
+  /**
+   * Does the processor support the user having a choice as to whether to cancel the recurring with the processor?
+   *
+   * If this returns TRUE then there will be an option to send a cancellation request in the cancellation form.
+   *
+   * This would normally be false for processors where CiviCRM maintains the schedule.
+   *
+   * @return bool
+   */
+  protected function supportsCancelRecurringNotifyOptional() {
+    return TRUE;
+  }
+
+  /**
+   * Set default values when loading the (payment) form
+   *
+   * @param \CRM_Core_Form $form
+   */
+  public function buildForm(&$form) {}
+
+  /**
+   * Process payment
+   * Submit a payment using Stripe's PHP API:
+   * https://stripe.com/docs/api?lang=php
+   * Payment processors should set payment_status_id/payment_status.
+   *
+   * @param array|PropertyBag $paymentParams
+   *   Assoc array of input parameters for this transaction.
+   * @param string $component
+   *
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   */
+  public function doPayment(&$paymentParams, $component = 'contribute') {
+    /* @var \Civi\Payment\PropertyBag $propertyBag */
+    $propertyBag = \Civi\Payment\PropertyBag::cast($paymentParams);
+
+    $zeroAmountPayment = $this->processZeroAmountPayment($propertyBag);
+    if ($zeroAmountPayment) {
+      return $zeroAmountPayment;
+    }
+    $propertyBag = $this->beginDoPayment($propertyBag);
+
+    // Not sure what the point of this next line is.
+    $this->_component = $component;
+
+    $successUrl = $this->getReturnSuccessUrl($paymentParams['qfKey']);
+    $failUrl = $this->getCancelUrl($paymentParams['qfKey'], NULL);
+    $lineItems = $this->calculateLineItems($paymentParams);
+    $checkoutSession = $this->createCheckoutSession($successUrl, $failUrl, $propertyBag, $lineItems);
+
+    // Allow each CMS to do a pre-flight check before redirecting to Stripe.
+    CRM_Core_Config::singleton()->userSystem->prePostRedirect();
+    CRM_Utils_System::setHttpHeader("HTTP/1.1 303 See Other", '');
+    CRM_Utils_System::redirect($checkoutSession->url);
+  }
+
+  /**
+   * This gathers the line items which are then used in buildCheckoutLineItems()
+   *
+   * @param array|PropertyBag $paymentParams
+   */
+  public function calculateLineItems($paymentParams): array {
+    $lineItems = [];
+    if (!empty($paymentParams['skipLineItem']) || empty($paymentParams['line_item'])) {
+      if (!empty($paymentParams['participants_info'])) {
+        // Events: Multiple participants. Lineitem for each participant is in participantDetail.
+        foreach ($paymentParams['participants_info'] as $participantID => $participantDetail) {
+          $lineItems = array_merge($lineItems, $participantDetail['lineItem']);
+        }
+      }
+      else {
+        // Fallback if no lineitems (some contribution pages)
+        $lineItems = [
+          'priceset' => [
+            'pricesetline' => [
+              'unit_price' => $paymentParams['amount'],
+              // source is available on contribution pages, description on event registration
+              'field_title' => $paymentParams['source'] ?? $paymentParams['description'],
+              'label' => $paymentParams['source'] ?? $paymentParams['description'],
+              'qty' => 1,
+            ],
+          ],
+        ];
+      }
+    }
+    else {
+      $lineItems = $paymentParams['line_item'] ?? [];
+    }
+    return $lineItems;
+  }
+
+  /**
+   * Create a Stripe Checkout Session
+   *
+   * @return \Stripe\Checkout\Session
+   */
+  public function createCheckoutSession(string $successUrl, string $failUrl, PropertyBag $propertyBag, array $lineItems) {
+
+    // Get existing/saved Stripe customer or create a new one
+    $existingStripeCustomer = \Civi\Api4\StripeCustomer::get(FALSE)
+      ->addWhere('contact_id', '=', $propertyBag->getContactID())
+      ->addWhere('processor_id', '=', $this->getPaymentProcessor()['id'])
+      ->execute()
+      ->first();
+    if (empty($existingStripeCustomer)) {
+      $stripeCustomer = $this->getStripeCustomer($propertyBag);
+      $stripeCustomerID = $stripeCustomer->id;
+    }
+    else {
+      $stripeCustomerID = $existingStripeCustomer['customer_id'];
+    }
+
+    // Build the checkout session parameters
+    $checkoutSessionParams = [
+      'line_items' => $this->buildCheckoutLineItems($lineItems, $propertyBag),
+      'mode' => $propertyBag->getIsRecur() ? 'subscription' : 'payment',
+      'success_url' => $successUrl,
+      'cancel_url' => $failUrl,
+      // Nb. We can only specify customer_email|customer, not both.
+      // 'customer_email' => $propertyBag->getEmail(),
+      'customer' => $stripeCustomerID,
+      // 'submit_type' => one of 'auto', pay, book, donate
+      'client_reference_id' => $propertyBag->getInvoiceID(),
+      'payment_method_types' => $this->getSupportedPaymentMethods($propertyBag),
+    ];
+
+    // Stripe Error:
+    // Stripe\Exception\InvalidRequestException: You can not pass `payment_intent_data` in `subscription` mode.
+    if ($propertyBag->getIsRecur()) {
+      $checkoutSessionParams['subscription_data'] = [
+        'description' => $this->getDescription($propertyBag, 'description'),
+      ];
+    }
+    else {
+      $checkoutSessionParams['payment_intent_data'] = [
+        'description' => $this->getDescription($propertyBag, 'description'),
+      ];
+    }
+
+    // Allows you to alter the params passed to StripeCheckout (eg. payment_method_types)
+    CRM_Utils_Hook::alterPaymentProcessorParams($this, $propertyBag, $checkoutSessionParams);
+
+    try {
+      $checkoutSession = $this->stripeClient->checkout->sessions->create($checkoutSessionParams);
+    }
+    catch (Exception $e) {
+      $parsedError = $this->parseStripeException('doPayment', $e);
+      throw new PaymentProcessorException($parsedError['message']);
+    }
+
+    CRM_Stripe_BAO_StripeCustomer::updateMetadata(['contact_id' => $propertyBag->getContactID()], $this, $checkoutSession['customer']);
+
+    return $checkoutSession;
+  }
+
+  /**
+   * @param \Civi\Payment\PropertyBag $propertyBag
+   *
+   * @return array
+   */
+  private function getSupportedPaymentMethods(\Civi\Payment\PropertyBag $propertyBag): array {
+    $paymentMethods = \Civi::settings()->get('stripe_checkout_supported_payment_methods');
+    $result = [];
+    foreach ($paymentMethods as $paymentMethod) {
+      switch ($paymentMethod) {
+        case 'sepa_debit':
+        case 'bancontact':
+          if ($propertyBag->getCurrency() === 'EUR') {
+            $result[] = $paymentMethod;
+          }
+          break;
+
+        case 'us_bank_account':
+          if ($propertyBag->getCurrency() === 'USD') {
+            $result[] = $paymentMethod;
+          }
+          break;
+
+        case 'bacs_debit':
+          if ($propertyBag->getCurrency() === 'GBP') {
+            $result[] = $paymentMethod;
+          }
+          break;
+
+        default:
+          $result[] = $paymentMethod;
+      }
+    }
+    if (empty($result)) {
+      throw new PaymentProcessorException('There are no valid Stripe payment methods enabled for this configuration. Check currency etc.');
+    }
+    return $result;
+  }
+
+  /**
+   * Takes the lineitems passed into doPayment and converts them into an array suitable for passing to Stripe Checkout
+   *
+   * @param array $civicrmLineItems
+   * @param \Civi\Payment\PropertyBag $propertyBag
+   *
+   * @return array
+   * @throws \Brick\Money\Exception\UnknownCurrencyException
+   */
+  private function buildCheckoutLineItems(array $civicrmLineItems, PropertyBag $propertyBag) {
+    foreach ($civicrmLineItems as $priceSetLines) {
+      foreach ($priceSetLines as $lineItem) {
+        $checkoutLineItem = [
+          'price_data' => [
+            'currency' => $propertyBag->getCurrency(),
+            'unit_amount' => $this->getAmountFormattedForStripeAPI(PropertyBag::cast(['amount' => $lineItem['unit_price'], 'currency' => $propertyBag->getCurrency()])),
+            'product_data' => [
+              'name' => $lineItem['field_title'],
+              // An empty label on a contribution page amounts configuration gives an empty $lineItem['label']. StripeCheckout needs it set.
+              'description' => $lineItem['label'] ?: $lineItem['field_title'],
+              //'images' => ['https://example.com/t-shirt.png'],
+            ],
+          ],
+          'quantity' => $lineItem['qty'],
+        ];
+        if ($propertyBag->getIsRecur()) {
+          $checkoutLineItem['price_data']['recurring'] = [
+            'interval' => $propertyBag->getRecurFrequencyUnit(),
+            'interval_count' => $propertyBag->getRecurFrequencyInterval(),
+          ];
+        }
+        $checkoutLineItems[] = $checkoutLineItem;
+      }
+    }
+    return $checkoutLineItems ?? [];
+  }
+
+}

CRM/Core/Payment/StripeIPN.php

+<?php
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+use Civi\Api4\ContributionRecur;
+use Civi\Api4\PaymentprocessorWebhook;
+use Civi\Payment\Exception\PaymentProcessorException;
+
+/**
+ * Class CRM_Core_Payment_StripeIPN
+ */
+class CRM_Core_Payment_StripeIPN {
+
+  use CRM_Core_Payment_MJWIPNTrait;
+
+  /**
+   * @var \CRM_Core_Payment_Stripe Payment processor
+   */
+  protected $_paymentProcessor;
+
+  /**
+   * The data provided by the IPN
+   * Redeclared here to tighten up the var type
+   *
+   * @var \Stripe\StripeObject
+   */
+  protected $data;
+
+  /**
+   * The CiviCRM contact ID that maps to the Stripe customer
+   *
+   * @var int
+   */
+  protected $contactID = NULL;
+
+  // Properties of the event.
+
+  /**
+   * @var string The Stripe Subscription ID
+   */
+  protected $subscription_id = NULL;
+
+  /**
+   * @var string The Stripe Customer ID
+   */
+  protected $customer_id = NULL;
+
+  /**
+   * @var string The Stripe PaymentIntent ID
+   */
+  protected $payment_intent_id = NULL;
+
+  /**
+   * @var string The Stripe Charge ID
+   */
+  protected $charge_id = NULL;
+
+  /**
+   * @var string The stripe Invoice ID (mapped to trxn_id on a contribution for recurring contributions)
+   */
+  protected $invoice_id = NULL;
+
+  /**
+   * @var string The date/time the charge was made
+   */
+  protected $receive_date = NULL;
+
+  /**
+   * @var float The amount paid
+   */
+  protected $amount = 0.0;
+
+  /**
+   * @var float The fee charged by Stripe
+   */
+  protected $fee = 0.0;
+
+  /**
+   * @var array The current contribution (linked to Stripe charge(single)/invoice(subscription)
+   */
+  protected $contribution = NULL;
+
+  /**
+   * @var bool
+   */
+  protected $setInputParametersHasRun = FALSE;
+
+  /**
+   * Normally if any exception is thrown in processing a webhook it is
+   * caught and a simple error logged.
+   *
+   * In a test environment it is often helpful for it to throw the exception instead.
+   *
+   * @var bool.
+   */
+  public $exceptionOnFailure = FALSE;
+
+  /**
+   * Redeclared here to tighten up the var type
+   * Can't define return because unit tests return PropertySpy
+   * Should be \Stripe\StripeObject|PropertySpy with PHP8.0+
+   *
+   * @return \Stripe\StripeObject
+   */
+  public function getData() {
+    return $this->data;
+  }
+
+  public function __construct(?CRM_Core_Payment_Stripe $paymentObject = NULL) {
+    if ($paymentObject !== NULL && !($paymentObject instanceof CRM_Core_Payment_Stripe)) {
+      // This would be a coding error.
+      throw new Exception(__CLASS__ . " constructor requires CRM_Core_Payment_Stripe object (or NULL for legacy use).");
+    }
+    $this->_paymentProcessor = $paymentObject;
+  }
+
+  /**
+   * Returns TRUE if we handle this event type, FALSE otherwise
+   * @param string $eventType
+   *
+   * @return bool
+   */
+  public function setEventType($eventType) {
+    $this->eventType = $eventType;
+    if (!in_array($this->eventType, CRM_Stripe_Webhook::getDefaultEnabledEvents())) {
+      return FALSE;
+    }
+    return TRUE;
+  }
+
+  /**
+   * Set and initialise the paymentProcessor object
+   * @param int $paymentProcessorID
+   *
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   */
+  public function setPaymentProcessor($paymentProcessorID) {
+    try {
+      $this->_paymentProcessor = \Civi\Payment\System::singleton()->getById($paymentProcessorID);
+    }
+    catch (Exception $e) {
+      $this->exception('Failed to get payment processor');
+    }
+  }
+
+  /**
+   * @return string|null
+   */
+  public function getStripeCustomerID() {
+    return $this->customer_id;
+  }
+
+  /**
+   * @return string|null
+   */
+  public function getStripeSubscriptionID() {
+    return $this->subscription_id;
+  }
+
+  /**
+   * @return string|null
+   */
+  public function getStripeInvoiceID() {
+    return $this->invoice_id;
+  }
+
+  /**
+   * @return string|null
+   */
+  public function getStripeChargeID() {
+    return $this->charge_id;
+  }
+
+  /**
+   * Check, decode, validate webhook data and extract some parameters to the class.
+   */
+  public function setInputParameters() {
+    if ($this->setInputParametersHasRun) {
+      return;
+    }
+
+    // If we don't have a webhook signing secret we need to retrieve the event again
+    // to make sure that it is "real" and was not faked.
+    if ($this->getVerifyData()) {
+      /** @var \Stripe\Event $event */
+      $event = $this->getPaymentProcessor()->stripeClient->events->retrieve($this->eventID);
+      $this->setData($event->data);
+    }
+
+    // If we have a webhook signing secret data was already set on the class.
+    $data = $this->getData();
+    if (!is_object($data)) {
+      $this->exception('Invalid input data (not an object)');
+    }
+
+    // When we receive a charge.X webhook event and it has an invoice ID we expand the invoice object
+    //   so that we have the subscription ID.
+    //   We'll receive both invoice.payment_succeeded/failed and charge.succeeded/failed at the same time
+    //   and we need to make sure we don't process them at the same time or we can get deadlocks/race conditions
+    //   that cause processing to fail.
+    if (($data->object instanceof \Stripe\Charge) && !empty($data->object->invoice)) {
+      $data->object = $this->getPaymentProcessor()->stripeClient->charges->retrieve(
+        $this->getData()->object->id,
+        ['expand' => ['invoice']]
+      );
+      $this->setData($data);
+      $this->subscription_id = CRM_Stripe_Api::getObjectParam('subscription_id', $this->getData()->object->invoice);
+      $this->invoice_id = CRM_Stripe_Api::getObjectParam('invoice_id', $this->getData()->object->invoice);
+    }
+    else {
+      $this->subscription_id = $this->retrieve('subscription_id', 'String', FALSE);
+      $this->invoice_id = $this->retrieve('invoice_id', 'String', FALSE);
+    }
+
+    $this->charge_id = $this->retrieve('charge_id', 'String', FALSE);
+    $this->payment_intent_id = $this->retrieve('payment_intent_id', 'String', FALSE);
+    $this->customer_id = $this->retrieve('customer_id', 'String', FALSE);
+
+    $this->setInputParametersHasRun = TRUE;
+  }
+
+  /**
+   * Get a parameter from the Stripe data object
+   *
+   * @param string $name
+   * @param string $type
+   * @param bool $abort
+   *
+   * @return int|mixed|null
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   */
+  public function retrieve($name, $type, $abort = TRUE) {
+    $value = CRM_Stripe_Api::getObjectParam($name, $this->getData()->object);
+    $value = CRM_Utils_Type::validate($value, $type, FALSE);
+    if ($abort && $value === NULL) {
+      echo "Failure: Missing or invalid parameter " . CRM_Utils_Type::escape($name, 'String');
+      $this->exception("Missing or invalid parameter {$name}");
+    }
+    return $value;
+  }
+
+  /**
+   * Get a unique identifier string based on webhook data.
+   *
+   * @return string
+   */
+  private function getWebhookUniqueIdentifier() {
+    return "{$this->payment_intent_id}:{$this->charge_id}:{$this->invoice_id}:{$this->subscription_id}";
+  }
+
+  /**
+   * When CiviCRM receives a Stripe webhook call this method (via handlePaymentNotification()).
+   * This checks the webhook and either queues or triggers processing (depending on existing webhooks in queue)
+   *
+   * Set default to "process immediately". This will get changed to FALSE if we already
+   *   have a pending webhook in the queue or the webhook is flagged for delayed processing.
+   * @param bool $processWebhook
+   *
+   * @return bool
+   * @throws \CRM_Core_Exception
+   * @throws \Stripe\Exception\UnknownApiErrorException
+   */
+  public function onReceiveWebhook($processWebhook = TRUE): bool {
+    if (!in_array($this->eventType, CRM_Stripe_Webhook::getDefaultEnabledEvents())) {
+      // We don't handle this event, return 200 OK so Stripe does not retry.
+      return TRUE;
+    }
+
+    $test = $this->getPaymentProcessor()->getPaymentProcessor()['is_test'] ? '(Test)' : '(Live)';
+    $name = $this->getPaymentProcessor()->getPaymentProcessor()['name'];
+    // Special case if this is the test webhook
+    if (substr($this->getEventID(), -15, 15) === '_00000000000000') {
+      echo "Test webhook from Stripe ({$this->getEventID()}) received successfully by CiviCRM: {$name} {$test}.";
+      exit();
+    }
+
+    // Check, decode, validate webhook data and extract some parameters to the class
+    $this->setInputParameters();
+
+    // If we have both Stripe (elements) and Stripe Checkout setup it is quite likely that
+    //   we have two payment processors with the same private/public key and we'll receive "duplicate" webhooks.
+    // So if we have a Stripe Customer ID with the event check that it matches our payment processor ID as recorded
+    //   in the civicrm_stripe_customers table.
+    if (!empty($this->getStripeCustomerID())) {
+      $stripeCustomers = \Civi\Api4\StripeCustomer::get(FALSE)
+        ->addWhere('customer_id', '=', $this->getStripeCustomerID())
+        ->execute();
+      $eventForThisPaymentProcessor = FALSE;
+      foreach ($stripeCustomers as $stripeCustomer) {
+        if ($stripeCustomer['processor_id'] === $this->getPaymentProcessor()->getID()) {
+          // We have a customer in the database for this processor - continue processing
+          $eventForThisPaymentProcessor = TRUE;
+          break;
+        }
+      }
+      if (!$eventForThisPaymentProcessor) {
+        echo "Event ({$this->getEventID()}) is not for this payment processor - ignoring. CiviCRM: {$name} {$test}.";
+        exit();
+      }
+    }
+
+    // Get a "unique" identifier for this webhook that allows us to match "duplicate/similar" webhooks.
+    $uniqueIdentifier = $this->getWebhookUniqueIdentifier();
+
+    // Get all received webhooks with matching identifier which have not been processed
+    // This returns all webhooks that match the uniqueIdentifier above and have not been processed.
+    // For example this would match both invoice.finalized and invoice.payment_succeeded events which must be
+    // processed sequentially and not simultaneously.
+    $paymentProcessorWebhooks = PaymentprocessorWebhook::get(FALSE)
+      ->addWhere('payment_processor_id', '=', $this->getPaymentProcessor()->getID())
+      ->addWhere('identifier', '=', $uniqueIdentifier)
+      ->addWhere('processed_date', 'IS NULL')
+      ->execute();
+
+    if (empty($paymentProcessorWebhooks->rowCount)) {
+      // We have not received this webhook before.
+      // Some webhooks we always add to the queue and do not process immediately (eg. invoice.finalized)
+      if (in_array($this->eventType, CRM_Stripe_Webhook::getDelayProcessingEvents())) {
+        // Never process the webhook immediately.
+        $processWebhook = FALSE;
+      }
+    }
+    else {
+      // We already have one or more webhooks with matching identifier
+      foreach ($paymentProcessorWebhooks as $paymentProcessorWebhook) {
+        // Does the eventType match our webhook?
+        if ($paymentProcessorWebhook['trigger'] === $this->eventType) {
+          // We have already recorded a webhook with a matching event type and it is awaiting processing.
+          // Exit
+          return TRUE;
+        }
+        if (!in_array($paymentProcessorWebhook['trigger'], CRM_Stripe_Webhook::getDelayProcessingEvents())) {
+          // There is a webhook that is already in the queue not flagged for delayed processing.
+          //   So we cannot process the current webhook immediately and must add it to the queue instead.
+          $processWebhook = FALSE;
+        }
+      }
+      // We have recorded another webhook with matching identifier but different eventType.
+      // There is already a recorded webhook with matching identifier that has not yet been processed.
+      // So we will record this webhook but will not process now (it will be processed later by the scheduled job).
+    }
+
+    $newWebhookEvent = PaymentprocessorWebhook::create(FALSE)
+      ->addValue('payment_processor_id', $this->getPaymentProcessor()->getID())
+      ->addValue('trigger', $this->getEventType())
+      ->addValue('identifier', $uniqueIdentifier)
+      ->addValue('event_id', $this->getEventID())
+      ->addValue('data', $this->getData())
+      ->execute()
+      ->first();
+
+    // Check the number of webhooks to be processed does not exceed connection-limit
+    $toBeProcessedWebhook = PaymentprocessorWebhook::get(FALSE)
+        ->addWhere('payment_processor_id', '=', $this->getPaymentProcessor()->getID())
+        ->addWhere('processed_date', 'IS NULL')
+        ->execute();
+
+    // Limit on webhooks that will be processed immediately. Otherwise we delay execution.
+    $webhookProcessingLimit = (int)\Civi::settings()->get('stripe_webhook_processing_limit');
+    if (!$processWebhook || ($toBeProcessedWebhook->rowCount > $webhookProcessingLimit)) {
+        return TRUE;
+    }
+
+    return $this->processQueuedWebhookEvent($newWebhookEvent);
+  }
+
+  /**
+   * Process a single queued event and update it.
+   *
+   * @param array $webhookEvent
+   *
+   * @return bool TRUE on success.
+   * @throws \API_Exception
+   * @throws \Civi\API\Exception\UnauthorizedException
+   */
+  public function processQueuedWebhookEvent(array $webhookEvent) :bool {
+    $this->setEventID($webhookEvent['event_id']);
+    if (!$this->setEventType($webhookEvent['trigger'])) {
+      // We don't handle this event
+      return FALSE;
+    }
+
+    $this->setExceptionMode(FALSE);
+
+    $processingResult = $this->processWebhookEvent();
+    // Update the stored webhook event.
+    PaymentprocessorWebhook::update(FALSE)
+      ->addWhere('id', '=', $webhookEvent['id'])
+      ->addValue('status', $processingResult->ok ? 'success' : 'error')
+      ->addValue('message', preg_replace('/^(.{250}).*/su', '$1 ...', $processingResult->message))
+      ->addValue('processed_date', 'now')
+      ->execute();
+
+    return $processingResult->ok;
+  }
+
+  /**
+   * Process the given webhook
+   *
+   * @return stdClass
+   * @throws \API_Exception
+   * @throws \Civi\API\Exception\UnauthorizedException
+   */
+  public function processWebhookEvent() :stdClass {
+    $return = (object) ['message' => '', 'ok' => FALSE, 'exception' => NULL];
+
+    try {
+      $this->setInputParameters();
+
+      $webhookEventProcessor = new \Civi\Stripe\Webhook\Events($this->getPaymentProcessor()->getID());
+      $webhookEventProcessor->setEventType($this->getEventType());
+      $webhookEventProcessor->setEventID($this->getEventID());
+      $webhookEventProcessor->setData($this->getData());
+
+      switch ($this->eventType) {
+        case 'checkout.session.completed':
+          $return = $webhookEventProcessor->doCheckoutSessionCompleted();
+          break;
+
+        case 'charge.succeeded':
+        case 'charge.captured':
+          $return = $webhookEventProcessor->doChargeSucceeded();
+          break;
+
+        case 'charge.refunded':
+          $return = $webhookEventProcessor->doChargeRefunded();
+          break;
+
+        case 'charge.failed':
+          $return = $webhookEventProcessor->doChargeFailed();
+          break;
+
+        case 'invoice.payment_failed':
+          $return = $webhookEventProcessor->doInvoicePaymentFailed();
+          break;
+
+        case 'invoice.finalized':
+          $return = $webhookEventProcessor->doInvoiceFinalized();
+          break;
+
+        case 'invoice.paid':
+        case 'invoice.payment_succeeded':
+          $return = $webhookEventProcessor->doInvoicePaid();
+          break;
+
+        case 'customer.subscription.updated':
+          $return = $webhookEventProcessor->doCustomerSubscriptionUpdated();
+          break;
+
+        case 'customer.subscription.deleted':
+          $return = $webhookEventProcessor->doCustomerSubscriptionDeleted();
+          break;
+
+        default:
+          $return->message = $this->eventType . ' - not implemented';
+          $return->ok = TRUE;
+      }
+
+    }
+    catch (Exception $e) {
+      if ($this->exceptionOnFailure) {
+        // Re-throw a modified exception. (Special case for phpunit testing).
+        $return->message = get_class($e) . ": " . $e->getMessage();
+        throw new PaymentProcessorException($return->message, $e->getCode());
+      }
+      else {
+        // Normal use.
+        $return->ok = FALSE;
+        if (($e instanceof \Stripe\Exception\InvalidRequestException) && ($e->getHttpStatus() === 404)) {
+          /** @var \Stripe\Exception\InvalidRequestException $e */
+          // Probably "is no longer available because it's aged out of our retention policy"
+          // We don't need a backtrace
+          $return->message = $e->getMessage();
+        }
+        else {
+          $return->message = $e->getMessage() . "\n" . $e->getTraceAsString();
+        }
+        $return->exception = $e;
+        \Civi::log('stripe')->error("StripeIPN: processWebhookEvent failed. EventID: {$this->eventID} : " . $return->message);
+      }
+    }
+
+    $this->setEventID('');
+    return $return;
+  }
+
+}

CRM/Stripe/Api.php

+<?php
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+use CRM_Stripe_ExtensionUtil as E;
+
+class CRM_Stripe_Api {
+
+  /**
+   * @param string $name
+   * @param \Stripe\StripeObject $stripeObject
+   *
+   * @return bool|float|int|string|null
+   * @throws \Stripe\Exception\ApiErrorException
+   */
+  public static function getObjectParam($name, $stripeObject) {
+    // object is a string containing the Stripe object name
+    switch ($stripeObject->object) {
+      case 'charge':
+        /** @var \Stripe\Charge $stripeObject */
+        switch ($name) {
+          case 'charge_id':
+            return (string) $stripeObject->id;
+
+          case 'failure_code':
+            return (string) $stripeObject->failure_code;
+
+          case 'failure_message':
+            return (string) $stripeObject->failure_message;
+
+          case 'amount':
+            return (float) $stripeObject->amount / 100;
+
+          case 'refunded':
+            return (bool) $stripeObject->refunded;
+
+          case 'amount_refunded':
+            return (float) $stripeObject->amount_refunded / 100;
+
+          case 'customer_id':
+            return (string) $stripeObject->customer;
+
+          case 'balance_transaction':
+            return (string) $stripeObject->balance_transaction;
+
+          case 'receive_date':
+          case 'created_date':
+            return self::formatDate($stripeObject->created);
+
+          case 'invoice_id':
+            if (!isset($stripeObject->invoice)) {
+              return '';
+            }
+            // Handle both "expanded" and "collapsed" response
+            elseif (is_object($stripeObject->invoice)) {
+              return (string) $stripeObject->invoice->id;
+            }
+            else {
+              return (string) $stripeObject->invoice;
+            }
+
+          case 'captured':
+            return (bool) $stripeObject->captured;
+
+          case 'currency':
+            return self::formatCurrency($stripeObject->currency);
+
+          case 'payment_intent_id':
+            return (string) $stripeObject->payment_intent;
+
+          case 'description':
+            return (string) $stripeObject->description;
+
+          case 'status':
+            // This might be "succeeded", "pending", "failed" (https://stripe.com/docs/api/charges/object#charge_object-status)
+            return (string) $stripeObject->status;
+
+        }
+        break;
+
+      case 'invoice':
+        /** @var \Stripe\Invoice $stripeObject */
+        switch ($name) {
+          case 'charge_id':
+            return (string) $stripeObject->charge;
+
+          case 'invoice_id':
+            return (string) $stripeObject->id;
+
+          case 'receive_date':
+            /*
+             * The "created" date of the invoice does not equal the paid date but it *might* be the same.
+             * We should use the paid_at below or lookup via the charge or paymentintent.
+             * "status_transitions": {
+             * "finalized_at": 1676295806,
+             * "marked_uncollectible_at": null,
+             * "paid_at": 1677591861,
+             * "voided_at": null
+             * },
+             */
+            if (!empty($stripeObject->status_transitions->paid_at)) {
+              return self::formatDate($stripeObject->status_transitions->paid_at);
+            }
+            // Intentionally falls through to invoice_date
+
+          case 'invoice_date':
+            if (!empty($stripeObject->status_transitions->finalized_at)) {
+              return self::formatDate($stripeObject->status_transitions->finalized_at);
+            }
+          // Intentionally falls through to created_date
+
+          case 'created_date':
+            return self::formatDate($stripeObject->created);
+
+          case 'subscription_id':
+            return (string) $stripeObject->subscription;
+
+          case 'amount':
+            return (float) $stripeObject->amount_due / 100;
+
+          case 'amount_paid':
+            return (float) $stripeObject->amount_paid / 100;
+
+          case 'amount_remaining':
+            return (float) $stripeObject->amount_remaining / 100;
+
+          case 'currency':
+            return self::formatCurrency($stripeObject->currency);
+
+          case 'description':
+            return (string) $stripeObject->description;
+
+          case 'customer_id':
+            return (string) $stripeObject->customer;
+
+          case 'failure_message':
+            // This is a coding error, but it looks like the general policy here is to return something. Could otherwise consider throwing an exception.
+            Civi::log()->error("Coding error: CRM_Stripe_Api::getObjectParam failure_message is not a property on a Stripe Invoice object. Please alter your code to fetch the Charge and obtain the failure_message from that.");
+            return '';
+
+          case 'status':
+            return self::mapInvoiceStatusToContributionStatus($stripeObject);
+
+        }
+        break;
+
+      case 'subscription':
+        /** @var \Stripe\Subscription $stripeObject */
+        switch ($name) {
+          case 'frequency_interval':
+          case 'frequency_unit':
+          case 'amount':
+            $plan = [
+              'amount' => 0,
+              'interval' => '',
+              'interval_count' => 0,
+            ];
+            foreach ($stripeObject->items as $item) {
+              if ($item->price->active && ($item->quantity > 0)) {
+                $plan['amount'] += $item->price->unit_amount * $item->quantity;
+                $plan['interval'] = $item->plan->interval;
+                $plan['interval_count'] = $item->plan->interval_count;
+              }
+            }
+
+            switch($name) {
+              case 'frequency_interval':
+                return (int) $plan['interval_count'];
+
+              case 'frequency_unit':
+                return (string) $plan['interval'];
+
+              case 'amount':
+                return (float) $plan['amount'] / 100;
+            }
+            break;
+
+          case 'currency':
+            return self::formatCurrency($stripeObject->currency);
+
+          case 'plan_start':
+            return self::formatDate($stripeObject->start_date);
+
+          case 'cancel_date':
+            return self::formatDate($stripeObject->canceled_at);
+
+          case 'next_sched_contribution_date':
+            return self::formatDate($stripeObject->current_period_end);
+
+          case 'current_period_start':
+            return self::formatDate($stripeObject->current_period_start);
+
+          case 'cycle_day':
+            return date("d", $stripeObject->billing_cycle_anchor);
+
+          case 'subscription_id':
+            return (string) $stripeObject->id;
+
+          case 'status_id':
+            switch ($stripeObject->status) {
+              case \Stripe\Subscription::STATUS_INCOMPLETE:
+                return CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'contribution_status_id', 'Pending');
+
+              case \Stripe\Subscription::STATUS_ACTIVE:
+              case \Stripe\Subscription::STATUS_TRIALING:
+                return CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'contribution_status_id', 'In Progress');
+
+              case \Stripe\Subscription::STATUS_PAST_DUE:
+                return CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'contribution_status_id', 'Overdue');
+
+              case \Stripe\Subscription::STATUS_CANCELED:
+              case \Stripe\Subscription::STATUS_UNPAID:
+              case \Stripe\Subscription::STATUS_INCOMPLETE_EXPIRED:
+              default:
+                return CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'contribution_status_id', 'Cancelled');
+            }
+
+          case 'status':
+            return self::mapSubscriptionStatusToRecurStatus($stripeObject->status);
+
+          case 'customer_id':
+            return (string) $stripeObject->customer;
+        }
+        break;
+
+      case 'checkout.session':
+        /** @var \Stripe\Checkout\Session $stripeObject */
+        switch ($name) {
+          case 'checkout_session_id':
+            return (string) $stripeObject->id;
+
+          case 'client_reference_id':
+            return (string) $stripeObject->client_reference_id;
+
+          case 'customer_id':
+            return (string) $stripeObject->customer;
+
+          case 'invoice_id':
+            return (string) $stripeObject->invoice;
+
+          case 'payment_intent_id':
+            return (string) $stripeObject->payment_intent;
+
+          case 'subscription_id':
+            return (string) $stripeObject->subscription;
+        }
+        break;
+
+      case 'subscription_item':
+        /** @var \Stripe\SubscriptionItem $stripeObject */
+        switch ($name) {
+          default:
+            if (isset($stripeObject->$name)) {
+              return $stripeObject->$name;
+            }
+            \Civi::log('stripe')->error('getObjectParam: Tried to get param "' . $name . '" from "' . $stripeObject->object . '" but it is not set');
+            return NULL;
+          // unit_amount
+        }
+        break;
+
+      case 'price':
+        /** @var \Stripe\Price $stripeObject */
+        switch ($name) {
+          case 'unit_amount':
+            return (float) $stripeObject->unit_amount / 100;
+
+          case 'recurring_interval':
+            // eg. "year"
+            return (string) $stripeObject->recurring->interval ?? '';
+
+          case 'recurring_interval_count':
+            // eg 1
+            return (int) $stripeObject->recurring->interval_count ?? 0;
+
+          default:
+            if (isset($stripeObject->$name)) {
+              return $stripeObject->$name;
+            }
+            \Civi::log('stripe')->error('getObjectParam: Tried to get param "' . $name . '" from "' . $stripeObject->object . '" but it is not set');
+            return NULL;
+          // unit_amount
+        }
+        break;
+
+    }
+
+    return NULL;
+  }
+
+  /**
+   * Return a formatted date from a stripe timestamp or NULL if not set
+   * @param int $stripeTimestamp
+   *
+   * @return string|null
+   */
+  public static function formatDate($stripeTimestamp) {
+    return $stripeTimestamp ? date('YmdHis', $stripeTimestamp) : NULL;
+  }
+
+  /**
+   * @param string $stripeCurrency
+   *
+   * @return string
+   */
+  public static function formatCurrency(string $stripeCurrency): string {
+    return (string) mb_strtoupper($stripeCurrency);
+  }
+
+  /**
+   * Convert amount to a new currency
+   *
+   * @param float $amount
+   * @param float $exchangeRate
+   * @param string $currency
+   *
+   * @return float
+   */
+  public static function currencyConversion($amount, $exchangeRate, $currency) {
+    $amount = ($amount / $exchangeRate) / 100;
+    // We must round to currency precision otherwise payments may fail because Contribute BAO saves but then
+    // can't retrieve because it tries to use the full unrounded number when it only got saved with 2dp.
+    $amount = round($amount, CRM_Utils_Money::getCurrencyPrecision($currency));
+    return $amount;
+  }
+
+  /**
+   * We have to map CiviCRM locales to a specific set of Stripe locales for elements to set the user language correctly.
+   * Reference: https://stripe.com/docs/js/appendix/supported_locales
+   * @param string $civiCRMLocale (eg. en_GB).
+   *
+   * @return string
+   */
+  public static function mapCiviCRMLocaleToStripeLocale($civiCRMLocale = '') {
+    if (empty($civiCRMLocale)) {
+      $civiCRMLocale = CRM_Core_I18n::getLocale();
+    }
+    $localeMap = [
+      'en_AU' => 'en',
+      'en_CA' => 'en',
+      'en_GB' => 'en-GB',
+      'en_US' => 'en',
+      'es_ES' => 'es',
+      'es_MX' => 'es-419',
+      'es_PR' => 'es-419',
+      'fr_FR' => 'fr',
+      'fr_CA' => 'fr-CA',
+      'pt_BR' => 'pt-BR',
+      'pt_PT' => 'pt',
+      'zh_CN' => 'zh',
+      'zh_HK' => 'zh-HK',
+      'zh_TW' => 'zh-TW'
+    ];
+    if (array_key_exists($civiCRMLocale, $localeMap)) {
+      return $localeMap[$civiCRMLocale];
+    }
+    // Most stripe locale codes are two characters which match the first two chars
+    //   of the CiviCRM locale. If it doesn't match the Stripe element will fallback
+    //   to "auto"
+    return substr($civiCRMLocale,0, 2);
+  }
+
+  public static function getListOfSupportedPaymentMethodsCheckout() {
+    return [
+      'card' => E::ts('Card'),
+      // 'acss_debit',
+      // 'affirm',
+      // 'afterpay_clearpay',
+      // 'alipay',
+      'au_becs_debit' => E::ts('BECS Direct Debit payments in Australia'),
+      'bacs_debit' => E::ts('BACS Direct Debit'),
+      'bancontact' => E::ts('Bancontact'),
+      // 'blik',
+      // 'boleto',
+      // 'cashapp',
+      // 'customer_balance',
+      // 'eps',
+      // 'fpx',
+      // 'giropay',
+      // 'grabpay',
+      // 'ideal',
+      // 'klarna',
+      // 'konbini',
+      // 'oxxo',
+      // 'p24',
+      // 'paynow',
+      // 'pix',
+      // 'promptpay',
+      'sepa_debit' => E::ts('SEPA Direct Debit'),
+      // 'sofort',
+      'us_bank_account' => E::ts('ACH Direct Debit'),
+      // 'wechat_pay',
+    ];
+  }
+
+  /**
+   * Map the Stripe Subscription Status to the CiviCRM ContributionRecur status.
+   *
+   * @param string $subscriptionStatus
+   *
+   * @return string
+   */
+  public static function mapSubscriptionStatusToRecurStatus(string $subscriptionStatus): string {
+    $statusMap = [
+      'incomplete' => 'Failed',
+      'incomplete_expired' => 'Failed',
+      'trialing' => 'In Progress',
+      'active' => 'In Progress',
+      'past_due' => 'Overdue',
+      'canceled' => 'Cancelled',
+      'unpaid' => 'Failed',
+      'paused' => 'Pending',
+    ];
+    return $statusMap[$subscriptionStatus] ?? '';
+  }
+
+  /**
+   * Map the Stripe Invoice Status to the CiviCRM Contribution status.
+   * https://stripe.com/docs/invoicing/overview#invoice-statuses
+   *
+   * @param \Stripe\Invoice $invoice
+   *
+   * @return string
+   */
+  public static function mapInvoiceStatusToContributionStatus(\Stripe\Invoice $invoice): string {
+    $statusMap = [
+      'draft' => 'Pending',
+      'open' => 'Pending',
+      'paid' => 'Completed',
+      'void' => 'Cancelled',
+      'uncollectible' => 'Failed',
+    ];
+    if ($invoice->status === 'open' && $invoice->attempted && empty($invoice->next_payment_attempt)) {
+      // An invoice will automatically be retried. If that fails the status will remain "open" but it has effectively failed.
+      // We use attempted + next_payment_attempt to check if it will NOT be retried and then record it as Failed in CiviCRM.
+      return 'Failed';
+    }
+    return $statusMap[$invoice->status] ?? '';
+  }
+
+}

CRM/Stripe/BAO/StripeCustomer.php

+<?php
+
+use Civi\Api4\Contact;
+use Civi\Api4\Email;
+use Civi\Api4\Extension;
+use Civi\Api4\StripeCustomer;
+use Civi\Payment\Exception\PaymentProcessorException;
+use CRM_Stripe_ExtensionUtil as E;
+
+class CRM_Stripe_BAO_StripeCustomer extends CRM_Stripe_DAO_StripeCustomer {
+
+  /**
+   * @param int $contactID
+   * @param array $invoiceSettings
+   * @param string|null $description
+   *
+   * @return array
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\API\Exception\UnauthorizedException
+   */
+  public static function getStripeCustomerMetadata(int $contactID, array $invoiceSettings = [], ?string $description = NULL) {
+    $contact = Contact::get(FALSE)
+      ->addSelect('display_name', 'email_primary.email', 'email_billing.email')
+      ->addWhere('id', '=', $contactID)
+      ->execute()
+      ->first();
+
+    if (version_compare(\CRM_Utils_System::version(), '5.53.0', '<')) {
+      // @todo: Remove when we drop support for CiviCRM < 5.53
+      // APIv4 - Read & write contact primary and billing locations as implicit joins
+      // https://github.com/civicrm/civicrm-core/pull/23972 was added in 5.53
+      $emailResult = Email::get(FALSE)
+        ->addWhere('contact_id', '=', $contactID)
+        ->addOrderBy('is_primary', 'DESC')
+        ->addOrderBy('is_billing', 'DESC')
+        ->execute()
+        ->first();
+      if (!empty($emailResult['email'])) {
+        $contact['email_primary.email'] = $emailResult['email'];
+      }
+    }
+
+    $extVersion = Extension::get(FALSE)
+      ->addWhere('file', '=', E::SHORT_NAME)
+      ->execute()
+      ->first()['version'];
+
+    $stripeCustomerParams = [
+      'name' => $contact['display_name'],
+      // Stripe does not include the Customer Name when exporting payments, just the customer
+      // description, so we stick the name in the description.
+      'description' => $description ?? $contact['display_name'] . ' (CiviCRM)',
+      'metadata' => [
+        'CiviCRM Contact ID' => $contactID,
+        'CiviCRM URL' => CRM_Utils_System::url('civicrm/contact/view', "reset=1&cid={$contactID}", TRUE, NULL, FALSE, FALSE, TRUE),
+        'CiviCRM Version' => CRM_Utils_System::version() . ' ' . $extVersion,
+      ],
+    ];
+    $email = $contact['email_primary.email'] ?? $contact['email_billing.email'] ?? NULL;
+    if ($email) {
+      $stripeCustomerParams['email'] = $email;
+    }
+
+    // This is used for new subscriptions/invoices as the default payment method
+    if (!empty($invoiceSettings)) {
+      $stripeCustomerParams['invoice_settings'] = $invoiceSettings;
+    }
+    return $stripeCustomerParams;
+  }
+
+  /**
+   * @param array $params
+   * @param \CRM_Core_Payment_Stripe $stripe
+   * @param string $stripeCustomerID
+   *
+   * @return string
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   */
+  public static function updateMetadata(array $params, \CRM_Core_Payment_Stripe $stripe, string $stripeCustomerID): string {
+    $requiredParams = ['contact_id'];
+    foreach ($requiredParams as $required) {
+      if (empty($params[$required])) {
+        throw new PaymentProcessorException('Stripe Customer (updateMetadata): Missing required parameter: ' . $required);
+      }
+    }
+
+    $stripeCustomerParams = CRM_Stripe_BAO_StripeCustomer::getStripeCustomerMetadata($params['contact_id'], $params['invoice_settings'] ?? [], $params['description'] ?? NULL);
+
+    try {
+      $stripeCustomer = $stripe->stripeClient->customers->update($stripeCustomerID, $stripeCustomerParams);
+    }
+    catch (Exception $e) {
+      $err = $stripe->parseStripeException('create_customer', $e);
+      if ($e instanceof \Stripe\Exception\PermissionException) {
+        \Civi::log('stripe')->warning($stripe->getLogPrefix() . 'Could not update Stripe Customer metadata for StripeCustomerID: ' . $stripeCustomerID . '; contactID: ' . $params['contact_id']);
+      }
+      else {
+        \Civi::log('stripe')->error($stripe->getLogPrefix() . 'Failed to create Stripe Customer: ' . $err['message'] . '; ' . print_r($err, TRUE));
+        throw new PaymentProcessorException('Failed to update Stripe Customer: ' . $err['code']);
+      }
+    }
+    return $stripeCustomer ?? '';
+  }
+
+  /**
+   * Update the metadata at Stripe for a given contactID
+   *
+   * @param int $contactID
+   *
+   * @return void
+   */
+  public static function updateMetadataForContact(int $contactID): void {
+    $customers = StripeCustomer::get(FALSE)
+      ->addWhere('contact_id', '=', $contactID)
+      ->execute();
+
+    // Could be multiple customer_id's and/or stripe processors
+    foreach ($customers as $customer) {
+      /** @var CRM_Core_Payment_Stripe $stripe */
+      StripeCustomer::updateStripe(FALSE)
+        ->setPaymentProcessorID($customer['processor_id'])
+        ->setContactID($contactID)
+        ->setCustomerID($customer['customer_id'])
+        ->execute()
+        ->first();
+    }
+  }
+
+}

CRM/Stripe/BAO/StripePaymentintent.php

+<?php
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+use CRM_Stripe_ExtensionUtil as E;
+
+class CRM_Stripe_BAO_StripePaymentintent extends CRM_Stripe_DAO_StripePaymentintent {
+
+  public static function getEntityName() {
+    return 'StripePaymentintent';
+  }
+
+  /**
+   * Create a new StripePaymentintent based on array-data
+   *
+   * @param array $params key-value pairs
+   *
+   * @return \CRM_Stripe_BAO_StripePaymentintent
+   */
+  public static function create($params) {
+    $instance = new self;
+    try {
+      if (!empty($params['id'])) {
+        $instance->id = $params['id'];
+      }
+      elseif ($params['stripe_intent_id']) {
+        $instance->id = civicrm_api3('StripePaymentintent', 'getvalue', [
+          'return' => "id",
+          'stripe_intent_id' => $params['stripe_intent_id'],
+        ]);
+      }
+      if ($instance->id) {
+        if ($instance->find()) {
+          $instance->fetch();
+        }
+      }
+    }
+    catch (Exception $e) {
+      // do nothing, we're creating a new one
+    }
+
+    $flags = empty($instance->flags) ? [] : unserialize($instance->flags);
+    if (!empty($params['flags']) && is_array($params['flags'])) {
+      foreach ($params['flags'] as $flag) {
+        if (!in_array($flag, $flags)) {
+          $flags[] = 'NC';
+        }
+      }
+      unset($params['flags']);
+    }
+    $instance->flags = serialize($flags);
+
+    if (!empty($_SERVER['HTTP_REFERER']) && empty($instance->referrer)) {
+      $instance->referrer = $_SERVER['HTTP_REFERER'];
+    }
+
+    $hook = empty($instance->id) ? 'create' : 'edit';
+    CRM_Utils_Hook::pre($hook, self::getEntityName(), $params['id'] ?? NULL, $params);
+    $instance->copyValues($params);
+    $instance->save();
+
+    CRM_Utils_Hook::post($hook, self::getEntityName(), $instance->id, $instance);
+
+    return $instance;
+  }
+}

CRM/Stripe/Check.php

+<?php
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+use CRM_Stripe_ExtensionUtil as E;
+
+/**
+ * Class CRM_Stripe_Check
+ */
+class CRM_Stripe_Check {
+
+  /**
+   * @var string
+   */
+  const API_VERSION = \Stripe\Util\ApiVersion::CURRENT;
+  const API_MIN_VERSION = \Stripe\Util\ApiVersion::CURRENT;
+
+  /**
+   * @var string
+   */
+  const MIN_VERSION_MJWSHARED = '1.3';
+  const MIN_VERSION_FIREWALL = '1.5.9';
+
+  /**
+   * @var array
+   */
+  private array $messages;
+
+  /**
+   * constructor.
+   *
+   * @param $messages
+   */
+  public function __construct($messages) {
+    $this->messages = $messages;
+  }
+
+  /**
+   * @return array
+   * @throws \CRM_Core_Exception
+   */
+  public function checkRequirements() {
+    $this->checkExtensionMjwshared();
+    $this->checkExtensionFirewall();
+    $this->checkWebhooks();
+    $this->checkFailedPaymentIntents();
+    return $this->messages;
+  }
+
+  /**
+   * @param string $extensionName
+   * @param string $minVersion
+   * @param string $actualVersion
+   */
+  private function requireExtensionMinVersion(string $extensionName, string $minVersion, string $actualVersion) {
+    $actualVersionModified = $actualVersion;
+    if (substr($actualVersion, -4) === '-dev') {
+      $actualVersionModified = substr($actualVersion, 0, -4);
+      $devMessageAlreadyDefined = FALSE;
+      foreach ($this->messages as $message) {
+        if ($message->getName() === __FUNCTION__ . $extensionName . '_requirements_dev') {
+          // Another extension already generated the "Development version" message for this extension
+          $devMessageAlreadyDefined = TRUE;
+        }
+      }
+      if (!$devMessageAlreadyDefined) {
+        $message = new \CRM_Utils_Check_Message(
+          __FUNCTION__ . $extensionName . '_requirements_dev',
+          E::ts('You are using a development version of %1 extension.',
+            [1 => $extensionName]),
+          E::ts('%1: Development version', [1 => $extensionName]),
+          \Psr\Log\LogLevel::WARNING,
+          'fa-code'
+        );
+        $this->messages[] = $message;
+      }
+    }
+
+    if (version_compare($actualVersionModified, $minVersion) === -1) {
+      $message = new \CRM_Utils_Check_Message(
+        __FUNCTION__ . $extensionName . E::SHORT_NAME . '_requirements',
+        E::ts('The %1 extension requires the %2 extension version %3 or greater but your system has version %4.',
+          [
+            1 => ucfirst(E::SHORT_NAME),
+            2 => $extensionName,
+            3 => $minVersion,
+            4 => $actualVersion
+          ]),
+        E::ts('%1: Missing Requirements', [1 => ucfirst(E::SHORT_NAME)]),
+        \Psr\Log\LogLevel::ERROR,
+        'fa-exclamation-triangle'
+      );
+      $message->addAction(
+        E::ts('Upgrade now'),
+        NULL,
+        'href',
+        ['path' => 'civicrm/admin/extensions', 'query' => ['action' => 'update', 'id' => $extensionName, 'key' => $extensionName]]
+      );
+      $this->messages[] = $message;
+    }
+  }
+
+  /**
+   * @throws \CRM_Core_Exception
+   */
+  private function checkExtensionMjwshared() {
+    // mjwshared: required. Requires min version
+    $extensionName = 'mjwshared';
+    $extensions = civicrm_api3('Extension', 'get', [
+      'full_name' => $extensionName,
+    ]);
+
+    if (empty($extensions['count']) || ($extensions['values'][$extensions['id']]['status'] !== 'installed')) {
+      $message = new CRM_Utils_Check_Message(
+        __FUNCTION__ . E::SHORT_NAME . '_requirements',
+        E::ts('The <em>%1</em> extension requires the <em>Payment Shared</em> extension which is not installed. See <a href="%2" target="_blank">details</a> for more information.',
+          [
+            1 => ucfirst(E::SHORT_NAME),
+            2 => 'https://civicrm.org/extensions/mjwshared',
+          ]
+        ),
+        E::ts('%1: Missing Requirements', [1 => ucfirst(E::SHORT_NAME)]),
+        \Psr\Log\LogLevel::ERROR,
+        'fa-money'
+      );
+      $message->addAction(
+        E::ts('Install now'),
+        NULL,
+        'href',
+        ['path' => 'civicrm/admin/extensions', 'query' => ['action' => 'update', 'id' => $extensionName, 'key' => $extensionName]]
+      );
+      $this->messages[] = $message;
+      return;
+    }
+    if (isset($extensions['id']) && $extensions['values'][$extensions['id']]['status'] === 'installed') {
+      $this->requireExtensionMinVersion($extensionName, self::MIN_VERSION_MJWSHARED, $extensions['values'][$extensions['id']]['version']);
+    }
+  }
+
+  /**
+   * @throws \CRM_Core_Exception
+   */
+  private function checkExtensionFirewall() {
+    $extensionName = 'firewall';
+
+    $extensions = civicrm_api3('Extension', 'get', [
+      'full_name' => $extensionName,
+    ]);
+
+    if (empty($extensions['count']) || ($extensions['values'][$extensions['id']]['status'] !== 'installed')) {
+      $message = new CRM_Utils_Check_Message(
+        __FUNCTION__ . 'stripe_recommended',
+        E::ts('If you are using Stripe to accept payments on public forms (eg. contribution/event registration forms) it is required that you install the <strong><a href="https://lab.civicrm.org/extensions/firewall">firewall</a></strong> extension.
+        Some sites have become targets for spammers who use the payment endpoint to try and test credit cards by submitting invalid payments to your Stripe account.'),
+        E::ts('Required Extension: firewall'),
+        \Psr\Log\LogLevel::ERROR,
+        'fa-lightbulb-o'
+      );
+      $message->addAction(
+        E::ts('Install now'),
+        NULL,
+        'href',
+        ['path' => 'civicrm/admin/extensions', 'query' => ['action' => 'update', 'id' => $extensionName, 'key' => $extensionName]]
+      );
+      $this->messages[] = $message;
+    }
+    if (isset($extensions['id']) && $extensions['values'][$extensions['id']]['status'] === 'installed') {
+      $this->requireExtensionMinVersion($extensionName, CRM_Stripe_Check::MIN_VERSION_FIREWALL, $extensions['values'][$extensions['id']]['version']);
+    }
+  }
+
+  private function checkWebhooks() {
+    // If we didn't install mjwshared yet check requirements but don't crash when checking webhooks
+    if (trait_exists('CRM_Mjwshared_WebhookTrait')) {
+      $webhooks = new CRM_Stripe_Webhook();
+      $webhooks->check($this->messages);
+    }
+  }
+
+  /**
+   * Try to detect if a client is being spammed / credit card fraud.
+   */
+  private function checkFailedPaymentIntents() {
+    // Check for a high volume of failed/pending contributions
+    $count = CRM_Core_DAO::singleValueQuery('SELECT count(*)
+      FROM civicrm_stripe_paymentintent
+      WHERE status = "failed"
+        AND TIMESTAMPDIFF(minute, created_date, NOW()) < 60
+      ORDER BY id DESC
+      LIMIT 1000');
+
+    if ($count > 20) {
+      $message = new CRM_Utils_Check_Message(
+        'stripe_paymentintentspam',
+        E::ts('%1 failed Stripe Payment Intents in the past hour. Please check the logs. They are problably hitting the CiviCRM REST API.', [1 => $count]),
+        E::ts('Stripe - High rate of failed contributions'),
+        \Psr\Log\LogLevel::CRITICAL,
+        'fa-check'
+      );
+      $this->messages[] = $message;
+    }
+    else {
+      $message = new CRM_Utils_Check_Message(
+        'stripe_paymentintentspam',
+        E::ts('%1 failed Stripe Payment Intents in the past hour.', [1 => $count]) . ' ' . E::ts('We monitor this in case someone malicious is testing stolen credit cards on public contribution forms.'),
+        E::ts('Stripe - Failed Stripe Payment Intents'),
+        \Psr\Log\LogLevel::INFO,
+        'fa-check'
+      );
+      $this->messages[] = $message;
+    }
+  }
+
+}

CRM/Stripe/Customer.php

+<?php
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+use Civi\Api4\Contact;
+use Civi\Api4\StripeCustomer;
+use Civi\Payment\Exception\PaymentProcessorException;
+use CRM_Stripe_ExtensionUtil as E;
+
+/**
+ * Class CRM_Stripe_Customer
+ */
+class CRM_Stripe_Customer {
+
+  /**
+   * Find an existing Stripe customer in the CiviCRM database
+   *
+   * @param $params
+   *
+   * @return null|string
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   */
+  public static function find($params) {
+    $requiredParams = ['processor_id'];
+    foreach ($requiredParams as $required) {
+      if (empty($params[$required])) {
+        throw new PaymentProcessorException('Stripe Customer (find): Missing required parameter: ' . $required);
+      }
+    }
+    if (empty($params['contact_id'])) {
+      throw new PaymentProcessorException('Stripe Customer (find): contact_id is required');
+    }
+
+    $result = StripeCustomer::get(FALSE)
+      ->addWhere('contact_id', '=', $params['contact_id'])
+      ->addWhere('processor_id', '=', $params['processor_id'])
+      ->addClause('OR', ['currency', 'IS EMPTY'], ['currency', '=', $params['currency']])
+      ->addSelect('customer_id')
+      ->execute();
+
+    return $result->count() ? $result->first()['customer_id'] : NULL;
+  }
+
+  /**
+   * Find the details (contact_id, processor_id) for an existing Stripe customer in the CiviCRM database
+   *
+   * @param string $stripeCustomerId
+   *
+   * @return array|null
+   */
+  public static function getParamsForCustomerId($stripeCustomerId) {
+    $result = StripeCustomer::get(FALSE)
+      ->addWhere('customer_id', '=', $stripeCustomerId)
+      ->addSelect('contact_id', 'processor_id')
+      ->execute()
+      ->first();
+
+    // Not sure whether this return for no match is needed, but that's what was being returned previously
+    return $result ? $result : ['contact_id' => NULL, 'processor_id' => NULL];
+  }
+
+  /**
+   * Find all the Stripe customers in the CiviCRM database for a given processorId
+   *
+   * @param string $processorId
+   *
+   * @return array|null
+   */
+  public static function getAll($processorId, $options = []) {
+    return civicrm_api4('StripeCustomer', 'get', [
+      'select' => ['customer_id'],
+      'where' => [['processor_id', '=', $processorId]],
+      'checkPermissions' => FALSE,
+    ] + $options, ['customer_id']);
+  }
+
+  /**
+   * @param array $params
+   * @param \CRM_Core_Payment_Stripe $stripe
+   *
+   * @return \Stripe\Customer|\PropertySpy
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   */
+  public static function create(array $params, \CRM_Core_Payment_Stripe $stripe) {
+    $requiredParams = ['contact_id', 'processor_id'];
+    foreach ($requiredParams as $required) {
+      if (empty($params[$required])) {
+        throw new PaymentProcessorException('Stripe Customer (create): Missing required parameter: ' . $required);
+      }
+    }
+
+    $stripeCustomerParams = CRM_Stripe_BAO_StripeCustomer::getStripeCustomerMetadata($params['contact_id'], $params['invoice_settings'] ?? []);
+
+    try {
+      $stripeCustomerObject = $stripe->stripeClient->customers->create($stripeCustomerParams);
+    }
+    catch (Exception $e) {
+      $err = $stripe->parseStripeException('create_customer', $e);
+      \Civi::log('stripe')->error('Failed to create Stripe Customer: ' . $err['message'] . '; ' . print_r($err, TRUE));
+      throw new PaymentProcessorException('Failed to create Stripe Customer: ' . $err['code']);
+    }
+
+    // Store the relationship between CiviCRM's email address for the Contact & Stripe's Customer ID.
+    StripeCustomer::create(FALSE)
+      ->addValue('contact_id', $params['contact_id'])
+      ->addValue('customer_id', $stripeCustomerObject->id)
+      ->addValue('processor_id', $params['processor_id'])
+      ->addValue('currency', $params['currency'])
+      ->execute();
+
+    return $stripeCustomerObject;
+  }
+
+  /**
+   * Delete a Stripe customer from the CiviCRM database
+   *
+   * @param array $params
+   *
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
+   */
+  public static function delete(array $params) {
+    $requiredParams = ['processor_id'];
+    foreach ($requiredParams as $required) {
+      if (empty($params[$required])) {
+        throw new PaymentProcessorException('Stripe Customer (delete): Missing required parameter: ' . $required);
+      }
+    }
+    if (empty($params['contact_id']) && empty($params['customer_id'])) {
+      throw new PaymentProcessorException('Stripe Customer (delete): Missing required parameter: contact_id or customer_id');
+    }
+
+    $delete = StripeCustomer::delete(FALSE)
+      ->addWhere('processor_id', '=', $params['processor_id']);
+
+    if (!empty($params['customer_id'])) {
+      $delete = $delete->addWhere('customer_id', '=', $params['customer_id']);
+    }
+    else {
+      $delete = $delete->addWhere('contact_id', '=', $params['contact_id']);
+    }
+    $delete->execute();
+  }
+
+}

CRM/Stripe/DAO/StripeCustomer.php

+<?php
+
+/**
+ * DAOs provide an OOP-style facade for reading and writing database records.
+ *
+ * DAOs are a primary source for metadata in older versions of CiviCRM (<5.74)
+ * and are required for some subsystems (such as APIv3).
+ *
+ * This stub provides compatibility. It is not intended to be modified in a
+ * substantive way. Property annotations may be added, but are not required.
+ * @property string $id 
+ * @property string $customer_id 
+ * @property string $contact_id 
+ * @property string $processor_id 
+ * @property string $currency 
+ */
+class CRM_Stripe_DAO_StripeCustomer extends CRM_Stripe_DAO_Base {
+
+  /**
+   * Required by older versions of CiviCRM (<5.74).
+   * @var string
+   */
+  public static $_tableName = 'civicrm_stripe_customers';
+
+}

CRM/Stripe/DAO/StripePaymentintent.php

+<?php
+
+/**
+ * DAOs provide an OOP-style facade for reading and writing database records.
+ *
+ * DAOs are a primary source for metadata in older versions of CiviCRM (<5.74)
+ * and are required for some subsystems (such as APIv3).
+ *
+ * This stub provides compatibility. It is not intended to be modified in a
+ * substantive way. Property annotations may be added, but are not required.
+ * @property string $id 
+ * @property string $stripe_intent_id 
+ * @property string $contribution_id 
+ * @property string $payment_processor_id 
+ * @property string $description 
+ * @property string $status 
+ * @property string $identifier 
+ * @property string $contact_id 
+ * @property string $created_date 
+ * @property string $flags 
+ * @property string $referrer 
+ * @property string $extra_data 
+ */
+class CRM_Stripe_DAO_StripePaymentintent extends CRM_Stripe_DAO_Base {
+
+  /**
+   * Required by older versions of CiviCRM (<5.74).
+   * @var string
+   */
+  public static $_tableName = 'civicrm_stripe_paymentintent';
+
+}

CRM/Stripe/Form/UpdateWebhook.php

+<?php
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+use CRM_Stripe_ExtensionUtil as E;
+
+/**
+ * Form controller class
+ *
+ * @see https://wiki.civicrm.org/confluence/display/CRMDOC/QuickForm+Reference
+ */
+class CRM_Stripe_Form_UpdateWebhook extends CRM_Core_Form {
+
+  public function buildQuickForm() {
+    // Defaults.
+    $this->assign('shouldOfferToFix', 0);
+    $this->assign('isStillBad', 0);
+    $this->assign('isAllOk', 0);
+
+    // Run check.
+    $messages = [];
+    $webhooks = new CRM_Stripe_Webhook();
+    $webhooks->check($messages);
+    if (!$messages) {
+      $this->assign('isAllOk', 1);
+    }
+    else {
+      $this->assign('shouldOfferToFix', 1);
+      $this->assignMessages($messages);
+
+      $this->addButtons(array(
+        array(
+          'type' => 'submit',
+          'name' => E::ts('Update / Create webhook'),
+          'isDefault' => TRUE,
+        ),
+      ));
+    }
+
+    // export form elements
+    $this->assign('elementNames', $this->getRenderableElementNames());
+    parent::buildQuickForm();
+  }
+
+  public function postProcess() {
+    $messages = [];
+    $attemptFix = TRUE;
+    $webhooks = new CRM_Stripe_Webhook();
+    $webhooks->check($messages, $attemptFix);
+
+    if ($messages) {
+      $this->assign('isStillBad', 1);
+      $this->assign('shouldOfferToFix', 0);
+      $this->assignMessages($messages);
+    }
+    else {
+      $this->assign('isAllOk', 1);
+      $this->assign('shouldOfferToFix', 0);
+      $this->assign('isStillBad', 0);
+      $this->assign('intro', E::ts('All webhooks update successfully.'));
+    }
+
+    parent::postProcess();
+  }
+
+  /**
+   * @param array $messages
+   */
+  private function assignMessages($messages) {
+    $messagesArray = [];
+    foreach ($messages as $message) {
+      $messagesArray[] = [
+        'title' => $message->getTitle(),
+        'message' => $message->getMessage(),
+      ];
+    }
+    $this->assign('messages', $messagesArray);
+  }
+
+  /**
+   * Get the fields/elements defined in this form.
+   *
+   * @return array (string)
+   */
+  public function getRenderableElementNames() {
+    // The _elements list includes some items which should not be
+    // auto-rendered in the loop -- such as "qfKey" and "buttons".  These
+    // items don't have labels.  We'll identify renderable by filtering on
+    // the 'label'.
+    $elementNames = array();
+    foreach ($this->_elements as $element) {
+      /** @var HTML_QuickForm_Element $element */
+      $label = $element->getLabel();
+      if (!empty($label)) {
+        $elementNames[] = $element->getName();
+      }
+    }
+    return $elementNames;
+  }
+
+}

Civi/Api4/Action/StripeCharge/GetBalanceTransactionDetails.php

+<?php
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+namespace Civi\Api4\Action\StripeCharge;
+
+use Stripe\Event;
+
+/**
+ * @inheritDoc
+ */
+class GetBalanceTransactionDetails extends \Civi\Api4\Generic\AbstractAction {
+
+  /**
+   * Stripe Charge ID
+   *
+   * @var string
+   */
+  protected $chargeID = '';
+
+  /**
+   * The CiviCRM Payment Processor ID
+   *
+   * @var int
+   */
+  protected $paymentProcessorID;
+
+  /**
+   * @param \Civi\Api4\Generic\Result $result
+   *
+   * @return void
+   * @throws \CRM_Core_Exception
+   * @throws \Stripe\Exception\ApiErrorException
+   */
+  public function _run(\Civi\Api4\Generic\Result $result) {
+    if (empty($this->chargeID)) {
+      throw new \CRM_Core_Exception('Missing chargeID');
+    }
+    if (empty($this->paymentProcessorID)) {
+      throw new \CRM_Core_Exception('Missing paymentProcessorID');
+    }
+
+    $stripeApi = new \Civi\Stripe\Api(\Civi\Payment\System::singleton()->getById($this->paymentProcessorID));
+
+    $charge = $stripeApi->getPaymentProcessor()->stripeClient->charges->retrieve($this->chargeID);
+
+    $stripeEvent = new \Stripe\Event();
+    $stripeEvent->object = $charge;
+    $stripeApi->setData($stripeEvent);
+    $balanceTransactionDetails = $stripeApi->getDetailsFromBalanceTransactionByChargeObject($stripeEvent->object);
+
+    $result->exchangeArray($balanceTransactionDetails);
+  }
+
+}