CRM/Core/Payment/MJWIPNTrait.php

@@ -9,6 +9,9 @@
  +--------------------------------------------------------------------+
  */
 
+use Civi\Api4\Contribution;
+use Civi\Payment\Exception\PaymentProcessorException;
+
 /**
  * Shared payment IPN functions that should one day be migrated to CiviCRM core
  *
@@ -24,7 +27,7 @@ trait CRM_Core_Payment_MJWIPNTrait {
   /**
    * Do we send an email receipt for each contribution?
    *
-   * @var int
+   * @var int|null
    */
   protected $is_email_receipt = NULL;
 
@@ -34,78 +37,180 @@ trait CRM_Core_Payment_MJWIPNTrait {
    */
   protected $contribution_recur_id = NULL;
 
+  /**
+   * The recurring contribution detail (as retrieved by API4)
+   * @var array
+   */
+  protected $contributionRecur = [];
+
   /**
    *  The IPN event type
    * @var string
    */
   protected $eventType = NULL;
 
+  /**
+   * The IPN event ID
+   * @var string
+   */
+  protected $eventID = NULL;
+
   /**
    * Exit on exceptions (TRUE), or just throw them (FALSE).
+   *
+   * @var bool
    */
   protected $exitOnException = TRUE;
 
   /**
-   * Set the value of is_email_receipt to use when a new contribution is received for a recurring contribution
-   * If not set, we respect the value set on the ContributionRecur entity.
+   * Should we verify (re-retrieve) the object that we have been given.
+   * Usually TRUE when an IPN request is received.
    *
-   * @param int $sendReceipt The value of is_email_receipt
+   * @var bool
    */
-  public function setSendEmailReceipt($sendReceipt) {
-    switch ($sendReceipt) {
-      case 0:
-        $this->is_email_receipt = 0;
-        break;
+  protected $verifyData = TRUE;
 
-      case 1:
-        $this->is_email_receipt = 1;
-        break;
+  /**
+   * The data provided by the IPN
+   *
+   * @var array|Object|string
+   */
+  protected $data;
 
-      default:
-        $this->is_email_receipt = 0;
+  /**
+   *
+   * Set the value of is_email_receipt to use when a new contribution is
+   * received for a recurring contribution. If set to NULL, we use CiviCRM core
+   * logic to determine if a receipt should be sent (typically the recurring
+   * contribution setting).
+   *
+   * @param int|null|bool $sendReceipt The value of is_email_receipt
+   */
+  public function setSendEmailReceipt($sendReceipt) {
+    if (is_null($sendReceipt)) {
+      // Let CiviCRM core decide whether to send a receipt.
+      $this->is_email_receipt = NULL;
+    }
+    elseif ($sendReceipt) {
+      // Explicitly turn on receipts.
+      $this->is_email_receipt = 1;
+    }
+    else {
+      // Explicitly turn off receipts.
+      $this->is_email_receipt = 0;
     }
   }
 
   /**
-   * Get the value of is_email_receipt to use when a new contribution is received for a recurring contribution
-   * If not set, we respect the value set on the ContributionRecur entity.
+   * Get the value of is_email_receipt to use when a new contribution is received.
+   * If NULL we let CiviCRM core decide whether to send a receipt.
    *
-   * @return int
-   * @throws \CiviCRM_API3_Exception
+   * See setSendEmalReceipt() for more details.
+   *
+   * @return int|null
    */
   public function getSendEmailReceipt() {
-    if (isset($this->is_email_receipt)) {
-      return (int) $this->is_email_receipt;
-    }
-    if (!empty($this->contribution_recur_id)) {
-      $this->is_email_receipt = civicrm_api3('ContributionRecur', 'getvalue', [
-        'return' => "is_email_receipt",
-        'id' => $this->contribution_recur_id,
-      ]);
-    }
-    return (int) $this->is_email_receipt;
+    return $this->is_email_receipt;
   }
 
   /**
-   * Get the payment processor
-   *   The $_GET['processor_id'] value is set by CRM_Core_Payment::handlePaymentMethod.
+   * Set and initialise the paymentProcessor object
+   * @param int $paymentProcessorID
    *
-   * @throws \CRM_Core_Exception
    * @throws \Civi\Payment\Exception\PaymentProcessorException
    */
-  protected function getPaymentProcessor() {
-   $paymentProcessorID = CRM_Utils_Request::retrieveValue('processor_id', 'Positive', NULL, FALSE, 'GET');
-   if (!$paymentProcessorID) {
-     $this->exception('Failed to get payment processor ID');
-   }
+  public function setPaymentProcessor($paymentProcessorID) {
     try {
       $this->_paymentProcessor = \Civi\Payment\System::singleton()->getById($paymentProcessorID);
     }
-    catch(Exception $e) {
+    catch (Exception $e) {
       $this->exception('Failed to get payment processor');
     }
   }
 
+  /**
+   * Get the payment processor object
+   */
+  public function getPaymentProcessor() {
+    return $this->_paymentProcessor;
+  }
+
+  /**
+   * @param int $recurID
+   *
+   * @return void
+   */
+  public function setContributionRecurID(int $recurID) {
+    $this->contribution_recur_id = $recurID;
+  }
+
+  /**
+   * @return int|null
+   */
+  public function getContributionRecurID() {
+    return $this->contribution_recur_id;
+  }
+
+  /**
+   * @param bool $verify
+   */
+  public function setVerifyData($verify) {
+    $this->verifyData = $verify;
+  }
+
+  /**
+   * @return bool
+   */
+  public function getVerifyData() {
+    return $this->verifyData;
+  }
+
+  /**
+   * @param string $eventID
+   */
+  public function setEventID($eventID) {
+    $this->eventID = $eventID;
+  }
+
+  /**
+   * @return string
+   */
+  public function getEventID() {
+    return $this->eventID;
+  }
+
+  /**
+   * Set the eventType. Returns TRUE if event is supported. FALSE otherwise.
+   * @param string $eventType
+   *
+   * @return bool
+   */
+  public function setEventType($eventType) {
+    $this->eventType = $eventType;
+    return TRUE;
+  }
+
+  /**
+   * @return string
+   */
+  public function getEventType() {
+    return $this->eventType;
+  }
+
+  /**
+   * @param array|Object|string $data
+   */
+  public function setData($data) {
+    $this->data = $data;
+  }
+
+  /**
+   * @return array|Object
+   */
+  public function getData() {
+    return $this->data;
+  }
+
   /**
    * Check that required params are present
    *
@@ -130,7 +235,7 @@ trait CRM_Core_Payment_MJWIPNTrait {
    * Cancel a subscription (recurring contribution)
    * @param array $params
    *
-   * @throws \CiviCRM_API3_Exception
+   * @throws \CRM_Core_Exception
    * @throws \Civi\Payment\Exception\PaymentProcessorException
    */
   protected function updateRecurCancelled($params) {
@@ -142,7 +247,7 @@ trait CRM_Core_Payment_MJWIPNTrait {
    * Update the subscription (recurring contribution) to a successful status
    * @param array $params
    *
-   * @throws \CiviCRM_API3_Exception
+   * @throws \CRM_Core_Exception
    * @throws \Civi\Payment\Exception\PaymentProcessorException
    */
   private function updateRecurSuccess($params) {
@@ -158,21 +263,23 @@ trait CRM_Core_Payment_MJWIPNTrait {
    * Update the subscription (recurring contribution) to a completed status
    * @param array $params
    *
-   * @throws \CiviCRM_API3_Exception
+   * @throws \CRM_Core_Exception
    * @throws \Civi\Payment\Exception\PaymentProcessorException
    */
   private function updateRecurCompleted($params) {
     $this->checkRequiredParams('updateRecurCompleted', ['id'], $params);
-    $params['contribution_status_id'] = 'Completed';
 
-    civicrm_api3('ContributionRecur', 'create', $params);
+    \Civi\Api4\ContributionRecur::update(FALSE)
+      ->addWhere('id', '=', $params['id'])
+      ->addValue('contribution_status_id:name', 'Completed')
+      ->execute();
   }
 
   /**
    * Update the subscription (recurring contribution) to a failing status
    * @param array $params
    *
-   * @throws \CiviCRM_API3_Exception
+   * @throws \CRM_Core_Exception
    * @throws \Civi\Payment\Exception\PaymentProcessorException
    */
   private function updateRecurFailed($params) {
@@ -194,11 +301,13 @@ trait CRM_Core_Payment_MJWIPNTrait {
   /**
    * Repeat a contribution (call the Contribution.repeattransaction API)
    *
-   * @param array $params
+   * @param array $repeatContributionParams
    *
-   * @throws \CiviCRM_API3_Exception
+   * @return int The new Contribution ID
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\Payment\Exception\PaymentProcessorException
    */
-  private function repeatContribution($params) {
+  private function repeatContribution(array $repeatContributionParams): int {
     $this->checkRequiredParams(
       'repeatContribution',
       [
@@ -208,16 +317,16 @@ trait CRM_Core_Payment_MJWIPNTrait {
         'receive_date',
         'order_reference',
         'trxn_id',
-        'total_amount',
+        //'total_amount',
       ],
-      $params
+      $repeatContributionParams
     );
     // Optional Params: fee_amount
 
     // Creat contributionParams for Contribution.repeattransaction and set some values
-    $contributionParams = $params;
+    $contributionParams = $repeatContributionParams;
     // Status should be pending if we have a successful payment
-    switch ($params['contribution_status_id']) {
+    switch ($contributionParams['contribution_status_id']) {
       case CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'contribution_status_id', 'Completed'):
         // Create a contribution in Pending state using Contribution.repeattransaction and then complete using Payment.create
         $contributionParams['contribution_status_id'] = 'Pending';
@@ -227,41 +336,59 @@ trait CRM_Core_Payment_MJWIPNTrait {
       default:
         // Failed etc.
         // For any other status create it directly using Contribution.repeattransaction and don't create a payment
-        $contributionParams['contribution_status_id'] = $params['contribution_status_id'];
         $createPayment = FALSE;
     }
 
     // Create the new contribution
-    $contributionParams['trxn_id'] = $params['order_reference'];
+    $contributionParams['trxn_id'] = $repeatContributionParams['order_reference'];
     // We send a receipt when adding a payment, not now
     $contributionParams['is_email_receipt'] = FALSE;
-    $contribution = civicrm_api3('Contribution', 'repeattransaction', $contributionParams);
+    try {
+      $contribution = reset(civicrm_api3('Contribution', 'repeattransaction', $contributionParams)['values']);
+    }
+    catch (Exception $e) {
+      // We catch, log, throw again so we have debug details in the logs
+      $message = 'MJWIPNTrait call to repeattransaction failed: ' . $e->getMessage() . '; params: ' . print_r($contributionParams, TRUE);
+      \Civi::log()->error($message);
+      throw new PaymentProcessorException($message);
+    }
+
+    // Get total amount from contribution returned by repeatTransaction (Which came from the recur template Contribution)
+    $repeatContributionParams['total_amount'] = $repeatContributionParams['total_amount'] ?? $contribution['total_amount'];
 
     if ($createPayment) {
-      $paymentParamsKeys = [
+      // Start by passing through all params (we may pass in customdata as well in API4 format)
+      $paymentParams = $repeatContributionParams;
+      // Now map contribution keys to payment keys
+      $paymentParamsMap = [
         'receive_date' => 'trxn_date',
         'order_reference' => 'order_reference',
         'trxn_id' => 'trxn_id',
         'total_amount' => 'total_amount',
         'fee_amount' => 'fee_amount',
       ];
-      foreach ($paymentParamsKeys as $contributionKey => $paymentKey) {
-        if (isset($params[$contributionKey])) {
-          $paymentParams[$paymentKey] = $params[$contributionKey];
+      foreach ($paymentParamsMap as $contributionKey => $paymentKey) {
+        if (isset($contributionParams[$contributionKey])) {
+          unset($paymentParams[$contributionKey]);
+          $paymentParams[$paymentKey] = $contributionParams[$contributionKey];
         }
       }
       $paymentParams['contribution_id'] = $contribution['id'];
+      $paymentParams['payment_processor_id'] = $this->getPaymentProcessor()->getID();
       $paymentParams['is_send_contribution_notification'] = $this->getSendEmailReceipt();
       $paymentParams['skipCleanMoney'] = TRUE;
       civicrm_api3('Mjwpayment', 'create_payment', $paymentParams);
     }
+    return $contribution['id'];
   }
 
   /**
    * @param array $params
    *
-   * @throws \CiviCRM_API3_Exception
+   * @throws \CRM_Core_Exception
    * @throws \Civi\Payment\Exception\PaymentProcessorException
+   *
+   * @deprecated Was used in Stripe until 6.11
    */
   private function updateContribution($params) {
     $this->checkRequiredParams('updateContribution', ['contribution_id'], $params);
@@ -277,15 +404,18 @@ trait CRM_Core_Payment_MJWIPNTrait {
   /**
    * Complete a pending contribution and update associated entities (recur/membership)
    *
-   * @param array $params
+   * @param array $contributionParams
    *
-   * @throws \CiviCRM_API3_Exception
+   * @throws \CRM_Core_Exception
    * @throws \Civi\Payment\Exception\PaymentProcessorException
    */
-  private function updateContributionCompleted($params) {
-    $this->checkRequiredParams('updateContributionCompleted', ['contribution_id', 'trxn_date', 'order_reference', 'trxn_id'], $params);
+  private function updateContributionCompleted(array $contributionParams) {
+    $this->checkRequiredParams('updateContributionCompleted', ['contribution_id', 'trxn_date', 'order_reference', 'trxn_id', 'total_amount'], $contributionParams);
 
-    $paymentParamsKeys = [
+    // Start by passing through all params (we may pass in customdata as well in API4 format)
+    $paymentParams = $contributionParams;
+    // Now map contribution keys to payment keys
+    $paymentParamsMap = [
       'contribution_id' => 'contribution_id',
       'trxn_date' => 'trxn_date',
       'order_reference' => 'order_reference',
@@ -293,9 +423,10 @@ trait CRM_Core_Payment_MJWIPNTrait {
       'total_amount' => 'total_amount',
       'fee_amount' => 'fee_amount',
     ];
-    foreach ($paymentParamsKeys as $contributionKey => $paymentKey) {
-      if (isset($params[$contributionKey])) {
-        $paymentParams[$paymentKey] = $params[$contributionKey];
+    foreach ($paymentParamsMap as $contributionKey => $paymentKey) {
+      if (isset($contributionParams[$contributionKey])) {
+        unset($paymentParams[$contributionKey]);
+        $paymentParams[$paymentKey] = $contributionParams[$contributionKey];
       }
     }
 
@@ -303,18 +434,20 @@ trait CRM_Core_Payment_MJWIPNTrait {
     // But we need to go from Failed to Completed if payment succeeds following a failure.
     // So we check for Failed status and update to Pending so it will transition to Completed.
     // Fixed in 5.29 with https://github.com/civicrm/civicrm-core/pull/17943
+    // Also set cancel_date to NULL because we are setting it for failed payments and UI will still display "greyed
+    // out" if it is set.
     $failedContributionStatus = (int) CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'contribution_status_id', 'Failed');
-    if (isset($params['contribution_status_id']) && ((int) $params['contribution_status_id'] === $failedContributionStatus)) {
-      $sql = "UPDATE civicrm_contribution SET contribution_status_id=%1 WHERE id=%2";
+    if (isset($contributionParams['contribution_status_id']) && ((int) $contributionParams['contribution_status_id'] === $failedContributionStatus)) {
+      $sql = "UPDATE civicrm_contribution SET contribution_status_id=%1,cancel_date=NULL WHERE id=%2";
       $queryParams = [
         1 => [CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'contribution_status_id', 'Pending'), 'Positive'],
-        2 => [$params['contribution_id'], 'Positive'],
+        2 => [$contributionParams['contribution_id'], 'Positive'],
       ];
       CRM_Core_DAO::executeQuery($sql, $queryParams);
     }
     $paymentParams['is_send_contribution_notification'] = $this->getSendEmailReceipt();
     $paymentParams['skipCleanMoney'] = TRUE;
-    $paymentParams['payment_processor_id'] = $this->_paymentProcessor->getID();
+    $paymentParams['payment_processor_id'] = $this->getPaymentProcessor()->getID();
     civicrm_api3('Mjwpayment', 'create_payment', $paymentParams);
   }
 
@@ -323,18 +456,18 @@ trait CRM_Core_Payment_MJWIPNTrait {
    *
    * @param array $params ['contribution_id', 'order_reference'{, cancel_date, cancel_reason}]
    *
-   * @throws \CiviCRM_API3_Exception
+   * @throws \CRM_Core_Exception
    * @throws \Civi\Payment\Exception\PaymentProcessorException
    */
   private function updateContributionFailed($params) {
     $this->checkRequiredParams('updateContributionFailed', ['contribution_id', 'order_reference'], $params);
-    civicrm_api3('Contribution', 'create', [
-      'contribution_status_id' => 'Failed',
-      'id' => $params['contribution_id'],
-      'trxn_id' => $params['order_reference'],
-      'cancel_date' => $params['cancel_date'] ?? NULL,
-      'cancel_reason' => $params['cancel_reason'] ?? NULL,
-    ]);
+    Contribution::update(FALSE)
+      ->addValue('contribution_status_id:name', 'Failed')
+      ->addValue('trxn_id', $params['order_reference'])
+      ->addValue('cancel_date', $params['cancel_date'] ?? '')
+      ->addValue('cancel_reason', $params['cancel_reason'] ?? '')
+      ->addWhere('id', '=', $params['contribution_id'])
+      ->execute();
     // No financial_trxn is created so we don't need to update that.
   }
 
@@ -379,12 +512,25 @@ trait CRM_Core_Payment_MJWIPNTrait {
    * @param array $params
    *
    * @throws \CRM_Core_Exception
-   * @throws \CiviCRM_API3_Exception
    */
   protected function updateContributionRefund($params) {
     $this->checkRequiredParams('updateContributionRefund', ['contribution_id', 'total_amount'], $params);
-    $params['payment_processor_id'] = $this->_paymentProcessor->getID();
-    civicrm_api3('Mjwpayment', 'create_payment', $params);
+    $params['payment_processor_id'] = $this->getPaymentProcessor()->getID();
+
+    $lock = Civi::lockManager()->acquire('data.contribute.contribution.' . $params['contribution_id']);
+    if (!$lock->isAcquired()) {
+      throw new PaymentProcessorException('Could not acquire lock to record refund for contribution: ' . $params['contribution_id']);
+    }
+    // Check if it was already recorded (in case two processes are running the same time - eg. Refund UI + IPN processing).
+    $refundPayment = civicrm_api3('Payment', 'get', [
+      'contribution_id' => $params['contribution_id'],
+      'total_amount' => $params['total_amount'],
+      'trxn_id' => $params['trxn_id'] ?? NULL,
+    ]);
+    if (empty($refundPayment['count'])) {
+      civicrm_api3('Mjwpayment', 'create_payment', $params);
+    }
+    $lock->release();
   }
 
   /**
@@ -406,14 +552,14 @@ trait CRM_Core_Payment_MJWIPNTrait {
    * @throws \Civi\Payment\Exception\PaymentProcessorException
    */
   protected function exception($message) {
-    $label = method_exists($this->_paymentProcessor, 'getPaymentProcessorLabel') ? $this->_paymentProcessor->getPaymentProcessorLabel() : __CLASS__;
+    $label = method_exists($this->getPaymentProcessor(), 'getPaymentProcessorLabel') ? $this->getPaymentProcessor()->getPaymentProcessorLabel() : __CLASS__;
     $errorMessage = $label . ' Exception: Event: ' . $this->eventType . ' Error: ' . $message;
     Civi::log()->error($errorMessage);
     if ($this->exitOnException) {
       http_response_code(400);
       exit(1);
     } else {
-      Throw new \Civi\Payment\Exception\PaymentProcessorException($message);
+      Throw new PaymentProcessorException($message);
     }
   }
 

CRM/Mjwshared/BAO/PaymentprocessorWebhook.php

+<?php
+use CRM_Mjwshared_ExtensionUtil as E;
+
+class CRM_Mjwshared_BAO_PaymentprocessorWebhook extends CRM_Mjwshared_DAO_PaymentprocessorWebhook {
+
+}

CRM/Mjwshared/Check.php

@@ -16,24 +16,102 @@ use CRM_Mjwshared_ExtensionUtil as E;
  */
 class CRM_Mjwshared_Check {
 
-  public static function checkRequirements(&$messages) {
-    self::checkExtensionWorldpay($messages);
-    self::checkExtensionMinifier($messages);
-    self::checkExtensionContributiontransactlegacy($messages);
-  }
+  const MIN_VERSION_SWEETALERT = '1.5';
+
+  /**
+   * @var array
+   */
+  private array $messages;
 
   /**
+   * CRM_Mjwshared_Check constructor.
+   *
    * @param array $messages
    *
-   * @throws \CiviCRM_API3_Exception
    */
-  private static function checkExtensionWorldpay(&$messages) {
+  public function __construct($messages) {
+    $this->messages = $messages;
+  }
+
+  /**
+   * @return array
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\API\Exception\UnauthorizedException
+   */
+  public function checkRequirements() {
+    $this->checkExtensionWorldpay();
+    // $this->checkExtensionMinifier();
+    $this->checkExtensionContributiontransactlegacy();
+    $this->checkIfSeparateMembershipPaymentEnabled();
+    $this->checkExtensionSweetalert();
+    $this->checkMultidomainJobs();
+    $this->checkPaymentprocessorWebhooks();
+    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 checkExtensionWorldpay() {
     $extensions = civicrm_api3('Extension', 'get', [
       'full_name' => 'uk.co.nfpservice.onlineworldpay',
     ]);
 
     if (!empty($extensions['id']) && ($extensions['values'][$extensions['id']]['status'] === 'installed')) {
-      $messages[] = new CRM_Utils_Check_Message(
+      $this->messages[] = new CRM_Utils_Check_Message(
         __FUNCTION__ . 'mjwshared_incompatible',
         E::ts('You have the uk.co.nfpservice.onlineworldpay extension installed.
         There are multiple versions of this extension on various sites and the source code has not been released.
@@ -46,17 +124,15 @@ class CRM_Mjwshared_Check {
   }
 
   /**
-   * @param array $messages
-   *
-   * @throws \CiviCRM_API3_Exception
+   * @throws \CRM_Core_Exception
    */
-  private static function checkExtensionMinifier(&$messages) {
+  private function checkExtensionMinifier() {
     $extensionName = 'minifier';
     $extensions = civicrm_api3('Extension', 'get', [
       'full_name' => $extensionName,
     ]);
 
-    if (empty($extensions['id']) || ($extensions['values'][$extensions['id']]['status'] !== 'installed')) {
+    if (empty($extensions['count']) || ($extensions['values'][$extensions['id']]['status'] !== 'installed')) {
       $message = new CRM_Utils_Check_Message(
         __FUNCTION__ . 'mjwshared_recommended',
         E::ts('It is recommended that you download and install the <strong><a href="https://civicrm.org/extensions/minifier">minifier</a></strong> extension.
@@ -71,19 +147,17 @@ class CRM_Mjwshared_Check {
         'href',
         ['path' => 'civicrm/admin/extensions', 'query' => ['action' => 'update', 'id' => $extensionName, 'key' => $extensionName]]
       );
-      $messages[] = $message;
+      $this->messages[] = $message;
     }
   }
 
   /**
-   * @param array $messages
-   *
-   * @throws \CiviCRM_API3_Exception
+   * @throws \CRM_Core_Exception
    */
-  private static function checkExtensionContributiontransactlegacy(&$messages) {
+  private function checkExtensionContributiontransactlegacy() {
     $extensionName = 'contributiontransactlegacy';
-    // Only on Drupal - do we have webform_civicrm installed?
-    if (function_exists('module_exists')) {
+    // Only on Drupal 7 (webform_civicrm 7.x-5.x) - do we have webform_civicrm installed?
+    if (function_exists('module_exists') && CRM_Core_Config::singleton()->userFramework === 'Drupal') {
       $extensions = civicrm_api3('Extension', 'get', [
         'full_name' => $extensionName,
       ]);
@@ -104,11 +178,183 @@ class CRM_Mjwshared_Check {
           'href',
           ['path' => 'civicrm/admin/extensions', 'query' => ['action' => 'update', 'id' => $extensionName, 'key' => $extensionName]]
         );
-        $messages[] = $message;
+        $this->messages[] = $message;
       }
     }
   }
 
+  /**
+   * We don't support "Separate Membership Payment" configuration
+   *
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\API\Exception\UnauthorizedException
+   */
+  private function checkIfSeparateMembershipPaymentEnabled() {
+    $separateMembershipPaymentNotSupportedProcessors = ['Stripe', 'Globalpayments'];
+    $membershipBlocks = civicrm_api3('MembershipBlock', 'get', [
+      'is_separate_payment' => 1,
+      'is_active' => 1,
+    ]);
+    if ($membershipBlocks['count'] > 0) {
+      $contributionPagesToCheck = [];
+      foreach ($membershipBlocks['values'] as $blockDetails) {
+        if ($blockDetails['entity_table'] !== 'civicrm_contribution_page') {
+          continue;
+        }
+        $contributionPagesToCheck[] = $blockDetails['entity_id'];
+      }
+      $paymentProcessorIDs = \Civi\Api4\PaymentProcessor::get(FALSE)
+        ->addJoin('PaymentProcessorType AS payment_processor_type', 'INNER', ['payment_processor_type_id', '=', 'payment_processor_type.id'])
+        ->addWhere('payment_processor_type.name', 'IN', $separateMembershipPaymentNotSupportedProcessors)
+        ->execute()
+        ->column('id');
+
+      if (!empty($contributionPagesToCheck)) {
+        $contributionPages = civicrm_api3('ContributionPage', 'get', [
+          'return' => ['payment_processor'],
+          'id' => ['IN' => $contributionPagesToCheck],
+          'is_active' => 1,
+        ]);
+        foreach ($contributionPages['values'] as $contributionPage) {
+          $enabledPaymentProcessors = is_array($contributionPage['payment_processor'])
+              ? $contributionPage['payment_processor'] : explode(CRM_Core_DAO::VALUE_SEPARATOR, $contributionPage['payment_processor']);
+          foreach ($enabledPaymentProcessors as $enabledID) {
+            if (in_array($enabledID, $paymentProcessorIDs)) {
+              $message = new CRM_Utils_Check_Message(
+                __FUNCTION__ . 'mjwshared_requirements',
+                E::ts('You need to disable "Separate Membership Payment" or disable the payment processors: %2 on contribution page %1 because it is not supported and will not work.
+                See <a href="https://lab.civicrm.org/extensions/stripe/-/issues/134">Stripe#134</a>.',
+                  [
+                    1 => $contributionPage['id'],
+                    2 => implode(', ', $separateMembershipPaymentNotSupportedProcessors),
+                  ]),
+                E::ts('Payments: Invalid configuration'),
+                \Psr\Log\LogLevel::ERROR,
+                'fa-money'
+              );
+              $this->messages[] = $message;
+              return;
+            }
+          }
+        }
+      }
+    }
+  }
 
+  /**
+   * @throws \CRM_Core_Exception
+   */
+  private function checkExtensionSweetalert() {
+    // sweetalert: recommended. If installed requires min version
+    $extensionName = 'sweetalert';
+    $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__ . 'mjwshared_recommended',
+        E::ts('It is recommended that you install the <strong><a href="https://civicrm.org/extensions/sweetalert">sweetalert</a></strong> extension.
+        This allows extensions such as Stripe to show useful messages to the user when processing payment.
+        If this is not installed it will fallback to the browser "alert" message but you will
+        not see some messages (such as <em>we are pre-authorizing your card</em> and <em>please wait</em>) and the feedback to the user will not be as helpful.'),
+        E::ts('Recommended Extension: sweetalert'),
+        \Psr\Log\LogLevel::NOTICE,
+        'fa-lightbulb-o'
+      );
+      $message->addAction(
+        E::ts('Install now'),
+        NULL,
+        'href',
+        ['path' => 'civicrm/admin/extensions', 'query' => ['action' => 'update', 'id' => $extensionName, 'key' => $extensionName]]
+      );
+      $this->messages[] = $message;
+      return;
+    }
+    if (isset($extensions['id']) && $extensions['values'][$extensions['id']]['status'] === 'installed') {
+      $this->requireExtensionMinVersion($extensionName, self::MIN_VERSION_SWEETALERT, $extensions['values'][$extensions['id']]['version']);
+    }
+  }
+
+  /**
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\API\Exception\UnauthorizedException
+   */
+  private function checkMultidomainJobs() {
+    $domains = \Civi\Api4\Domain::get(FALSE)
+      ->execute();
+    if ($domains->count() <= 1) {
+      return;
+    }
+
+    $jobs = civicrm_api3('Job', 'get', [
+      'api_action' => "process_paymentprocessor_webhooks",
+      'api_entity' => "job",
+    ])['values'];
+
+    $domainMissingJob = [];
+    foreach ($domains as $domain) {
+      foreach ($jobs as $job) {
+        if ((int) $job['domain_id'] === $domain['id']) {
+          // We found a job for this domain.
+          continue 2;
+        }
+      }
+      $domainMissingJob[$domain['id']] = "{$domain['id']}: {$domain['name']}";
+    }
+
+    if (!empty($domainMissingJob)) {
+      $domainMessage = '<ul><li>' . implode('</li><li>', $domainMissingJob) . '</li></ul>';
+      $message = new CRM_Utils_Check_Message(
+        __FUNCTION__ . 'mjwshared_multidomain',
+        E::ts('You have multiple domains configured and some domains are missing the scheduled job "Job.process_paymentprocessor_webhooks": %1',
+          [1 => $domainMessage]
+        ),
+        E::ts('Payments: Multidomain scheduled jobs'),
+        \Psr\Log\LogLevel::WARNING,
+        'fa-code'
+      );
+      $this->messages[] = $message;
+    }
+  }
+
+  /**
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\API\Exception\UnauthorizedException
+   */
+  private function checkPaymentprocessorWebhooks() {
+    $paymentprocessorWebhooksProcessingCount = \Civi\Api4\PaymentprocessorWebhook::get(FALSE)
+      ->addSelect('row_count')
+      ->addWhere('status', '=', 'processing')
+      ->addWhere('created_date', '<', 'now-1hour')
+      ->addOrderBy('created_date', 'DESC')
+      ->execute()
+      ->countMatched();
+
+    if ($paymentprocessorWebhooksProcessingCount > 0) {
+      $paymentprocessorWebhookProcessors = \Civi\Api4\PaymentprocessorWebhook::get(FALSE)
+        ->addSelect('id', 'payment_processor_id:label')
+        ->addWhere('status', '=', 'processing')
+        ->addWhere('created_date', '<', 'now-1hour')
+        ->addOrderBy('created_date', 'DESC')
+        ->addGroupBy('payment_processor_id')
+        ->execute()
+        ->indexBy('payment_processor_id:label')
+        ->getArrayCopy();
+      $message = new CRM_Utils_Check_Message(
+        __FUNCTION__ . 'mjwshared_paymentprocessorwebhooks',
+        E::ts('You have %1 payment processor webhooks in "processing" status for %2 payment processors.
+        This means that the system started processing them but something went wrong that can\'t be fixed automatically.
+        Please check and identify the problem. Then you can mark them for retry.',
+          [1 => $paymentprocessorWebhooksProcessingCount, 2 => implode(',', array_keys($paymentprocessorWebhookProcessors))]
+        ),
+        E::ts('Payment Processor Webhooks: Processing failed'),
+        \Psr\Log\LogLevel::ERROR,
+        'fa-code'
+      );
+      $message->addAction('Check now', FALSE, 'href', ['path' => 'civicrm/a#/paymentprocessorWebhook']);
+      $this->messages[] = $message;
+    }
+  }
 
 }

CRM/Mjwshared/DAO/PaymentprocessorWebhook.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 $payment_processor_id 
+ * @property string $event_id 
+ * @property string $trigger 
+ * @property string $created_date 
+ * @property string $processed_date 
+ * @property string $status 
+ * @property string $identifier 
+ * @property string $message 
+ * @property string $data 
+ */
+class CRM_Mjwshared_DAO_PaymentprocessorWebhook extends CRM_Mjwshared_DAO_Base {
+
+  /**
+   * Required by older versions of CiviCRM (<5.74).
+   * @var string
+   */
+  public static $_tableName = 'civicrm_paymentprocessor_webhook';
+
+}

CRM/Mjwshared/Form/PaymentRefund.php

+<?php
+
+use Civi\Api4\LineItem;
+use Civi\Api4\Membership;
+use Civi\Api4\Participant;
+use Civi\Api4\PaymentProcessor;
+use Civi\Payment\Exception\PaymentProcessorException;
+use CRM_Mjwshared_ExtensionUtil as E;
+use Brick\Money\Money;
+use Brick\Money\Context\DefaultContext;
+use Brick\Math\RoundingMode;
+
+
+/**
+ * Form controller class
+ *
+ * @see https://docs.civicrm.org/dev/en/latest/framework/quickform/
+ */
+class CRM_Mjwshared_Form_PaymentRefund extends CRM_Core_Form {
+
+  /**
+   * @var int $paymentID
+   */
+  private $paymentID;
+
+  /**
+   * @var int $contributionID
+   */
+  private $contributionID;
+
+  /**
+   * @var array $financialTrxn
+   */
+  private $financialTrxn;
+
+  public function buildQuickForm() {
+    if (!CRM_Core_Permission::check('edit contributions')) {
+      CRM_Core_Error::statusBounce(ts('You do not have permission to access this page.'));
+    }
+
+    $this->addFormRule(['CRM_Mjwshared_Form_PaymentRefund', 'formRule'], $this);
+
+    $this->setTitle('Refund payment');
+
+    $this->paymentID = CRM_Utils_Request::retrieveValue('payment_id', 'Positive', NULL, FALSE, 'REQUEST');
+    if (!$this->paymentID) {
+      CRM_Core_Error::statusBounce('Payment not found!');
+    }
+
+    $this->contributionID = CRM_Utils_Request::retrieveValue('contribution_id', 'Positive', NULL, FALSE, 'REQUEST');
+    if (!$this->contributionID) {
+      CRM_Core_Error::statusBounce('Contribution not found!');
+    }
+
+    $financialTrxn = reset(civicrm_api3('Mjwpayment', 'get_payment', [
+      'financial_trxn_id' => $this->paymentID,
+    ])['values']);
+    if ((int)$financialTrxn['contribution_id'] !== $this->contributionID) {
+      CRM_Core_Error::statusBounce('Contribution / Payment does not match');
+    }
+    $financialTrxn['order_reference'] = $financialTrxn['order_reference'] ?? NULL;
+
+    $paymentProcessor = PaymentProcessor::get(FALSE)
+      ->addWhere('id', '=', $financialTrxn['payment_processor_id'])
+      ->execute()
+      ->first();
+    $financialTrxn['payment_processor_title'] = $paymentProcessor['title'] ?? $paymentProcessor['name'];
+
+    $this->assign('paymentInfo', $financialTrxn);
+    $this->financialTrxn = $financialTrxn;
+
+    $this->add('hidden', 'payment_id');
+    $this->add('hidden', 'contribution_id');
+
+    $participantIDs = $membershipIDs = [];
+
+    $lineItems = LineItem::get(FALSE)
+      ->addWhere('contribution_id', '=', $this->contributionID)
+      ->execute();
+    foreach ($lineItems as $lineItemDetails) {
+      switch ($lineItemDetails['entity_table']) {
+        case 'civicrm_participant':
+          $participantIDs[] = $lineItemDetails['entity_id'];
+          break;
+
+        case 'civicrm_membership':
+          $membershipIDs[] = $lineItemDetails['entity_id'];
+          break;
+      }
+    }
+    if (!empty($participantIDs)) {
+      $participantsForAssign = [];
+      $this->set('participant_ids', $participantIDs);
+      $participants = Participant::get()
+        ->addSelect('*', 'event_id.title', 'status_id:label', 'contact_id.display_name')
+        ->addWhere('id', 'IN', $participantIDs)
+        ->execute();
+      foreach ($participants->getArrayCopy() as $participant) {
+        $participant['status'] = $participant['status_id:label'];
+        $participant['event_title'] = $participant['event_id.title'];
+        $participant['display_name'] = $participant['contact_id.display_name'];
+        $participantsForAssign[] = $participant;
+      }
+      $this->addYesNo('cancel_participants', E::ts('Do you want to cancel these registrations when you refund the payment?'), NULL, TRUE);
+    }
+    $this->assign('participants', $participantsForAssign ?? NULL);
+
+    if (!empty($membershipIDs)) {
+      $membershipsForAssign = [];
+      $this->set('membership_ids', $membershipIDs);
+      $memberships = Membership::get(FALSE)
+        ->addSelect('*', 'membership_type_id:label', 'status_id:label', 'contact_id.display_name')
+        ->addWhere('id', 'IN', $membershipIDs)
+        ->execute();
+      foreach ($memberships->getArrayCopy() as $membership) {
+        $membership['status'] = $membership['status_id:label'];
+        $membership['type'] = $membership['membership_type_id:label'];
+        $membership['display_name'] = $membership['contact_id.display_name'];
+        $membershipsForAssign[] = $membership;
+      }
+      $this->addYesNo('cancel_memberships', E::ts('Do you want to cancel these memberships when you refund the payment?'), NULL, TRUE);
+    }
+    $this->assign('memberships', $membershipsForAssign ?? NULL);
+
+    $this->addMoney('refund_amount',
+      ts('Refund Amount'),
+      TRUE,
+      [],
+      TRUE, 'currency', $financialTrxn['currency'], TRUE
+    );
+
+    $this->addButtons([
+      [
+        'type' => 'submit',
+        'name' => ts('Refund'),
+        'isDefault' => TRUE,
+      ],
+      [
+        'type' => 'cancel',
+        'name' => ts('Cancel'),
+      ],
+    ]);
+  }
+
+  public function setDefaultValues() {
+    if ($this->paymentID) {
+      $this->_defaults['payment_id'] = $this->paymentID;
+      $this->set('payment_id', $this->paymentID);
+      $this->_defaults['contribution_id'] = $this->contributionID;
+      $this->set('contribution_id', $this->contributionID);
+      $this->_defaults['refund_amount'] = $this->financialTrxn['total_amount'];
+    }
+    return $this->_defaults;
+  }
+
+  /**
+   * Global form rule.
+   *
+   * @param array $fields
+   *   The input form values.
+   * @param array $files
+   *   The uploaded files if any.
+   * @param CRM_Core_Form $form
+   *
+   * @return bool|array
+   *   true if no errors, else array of errors
+   */
+  public static function formRule($fields, $files, $form) {
+    $errors = [];
+
+    $formValues = $form->getSubmitValues();
+    $paymentID = $form->get('payment_id');
+
+    $payment = reset(civicrm_api3('Mjwpayment', 'get_payment', ['id' => $paymentID])['values']);
+
+    // Check refund amount
+    $refundAmount = Money::of($formValues['refund_amount'], $payment['currency'], new DefaultContext(), RoundingMode::CEILING);
+    $paymentAmount = Money::of($payment['total_amount'], $payment['currency'], new DefaultContext(), RoundingMode::CEILING);
+
+    if ($refundAmount->isGreaterThan($paymentAmount)) {
+      $errors['refund_amount'] = 'Cannot refund more than the original amount';
+    }
+    if ($refundAmount->isNegativeOrZero()) {
+      $errors['refund_amount'] = 'Cannot refund zero or negative amount';
+    }
+
+    return $errors;
+  }
+
+  public function postProcess() {
+    $formValues = $this->getSubmitValues();
+    $paymentID = $this->get('payment_id');
+    $participantIDs = $this->get('participant_ids');
+    $cancelParticipants = $formValues['cancel_participants'] ?? FALSE;
+    $membershipIDs = $this->get('membership_ids');
+    $cancelMemberships = $formValues['cancel_memberships'] ?? FALSE;
+
+    try {
+      $payment = reset(civicrm_api3('Mjwpayment', 'get_payment', ['id' => $paymentID])['values']);
+
+      // Check refund amount
+      $refundAmount = Money::of($formValues['refund_amount'], $payment['currency'], new DefaultContext(), RoundingMode::CEILING);
+      $paymentAmount = Money::of($payment['total_amount'], $payment['currency'], new DefaultContext(), RoundingMode::CEILING);
+
+      if ($refundAmount->isGreaterThan($paymentAmount)) {
+        throw new PaymentProcessorException('Cannot refund more than the original amount');
+      }
+      if ($refundAmount->isNegativeOrZero()) {
+        throw new PaymentProcessorException('Cannot refund zero or negative amount');
+      }
+
+      $refundParams = [
+        'payment_processor_id' => $payment['payment_processor_id'],
+        'amount' => $refundAmount->getAmount()->toFloat(),
+        'currency' => $payment['currency'],
+        'trxn_id' => $payment['trxn_id'],
+      ];
+      $refund = reset(civicrm_api3('PaymentProcessor', 'Refund', $refundParams)['values']);
+      if ($refund['refund_status'] === 'Completed') {
+        $refundPaymentParams = [
+          'contribution_id' => $payment['contribution_id'],
+          'trxn_id' => $refund['refund_trxn_id'],
+          'order_reference' => $payment['order_reference'] ?? NULL,
+          'total_amount' => 0 - abs($refundAmount->getAmount()->toFloat()),
+          'fee_amount' => 0 - abs($refund['fee_amount']),
+          'payment_processor_id' => $payment['payment_processor_id'],
+        ];
+
+        $lock = Civi::lockManager()->acquire('data.contribute.contribution.' . $refundPaymentParams['contribution_id']);
+        if (!$lock->isAcquired()) {
+          throw new PaymentProcessorException('Could not acquire lock to record refund for contribution: ' . $refundPaymentParams['contribution_id']);
+        }
+        $refundPayment = civicrm_api3('Payment', 'get', [
+          'contribution_id' => $refundPaymentParams['contribution_id'],
+          'total_amount' => $refundPaymentParams['total_amount'],
+          'trxn_id' => $refundPaymentParams['trxn_id'],
+        ]);
+        if (empty($refundPayment['count'])) {
+          // Record the refund in CiviCRM
+          civicrm_api3('Mjwpayment', 'create_payment', $refundPaymentParams);
+        }
+        $lock->release();
+        $message = E::ts('Refund was processed successfully.');
+
+        if ($cancelParticipants && !empty($participantIDs)) {
+          foreach ($participantIDs as $participantID) {
+            civicrm_api3('Participant', 'create', [
+              'id' => $participantID,
+              'status_id' => 'Cancelled',
+            ]);
+          }
+          $message .= ' ' . E::ts('Cancelled %1 participant registration(s).', [1 => count($participantIDs)]);
+        }
+
+        if ($cancelMemberships && !empty($membershipIDs)) {
+          Membership::update(FALSE)
+            ->addValue('status_id.name', 'Cancelled')
+            ->addWhere('id', 'IN', $membershipIDs)
+            ->execute();
+          $message .= ' ' . E::ts('Cancelled %1 membership(s).', [1 => count($membershipIDs)]);
+        }
+
+        CRM_Core_Session::setStatus($message, 'Refund processed', 'success');
+      }
+      else {
+        CRM_Core_Error::statusBounce("Refund status '{$refund['refund_status']}'is not supported at this time and was not recorded in CiviCRM.");
+      }
+    } catch (Exception $e) {
+      CRM_Core_Error::statusBounce($e->getMessage(), NULL, 'Refund failed');
+    }
+  }
+
+}

CRM/Mjwshared/Hook.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       |
+ +--------------------------------------------------------------------+
+ */
+
+/**
+ * This class implements hooks for Mjwshared
+ */
+class CRM_Mjwshared_Hook {
+
+  /**
+   * This hook allows modifying recurring contribution parameters
+   *
+   * @param string $type The type of webhook - eg. 'stripe'
+   * @param object $object The object (eg. CRM_Core_Payment_StripeIPN)
+   * @param string $code "Code" to identify what was not matched (eg. customer_not_found)
+   * @param array $result Results returned by hook processing. Depends on the type/code. Eg. for stripe.contribution_not_found return $result['contribution'] = "contribution array from API"
+   *
+   * @return mixed
+   */
+  public static function webhookEventNotMatched(string $type, $object, string $code = '', array &$result = []) {
+    // Wrap in a try/catch to guard against coding errors in extensions.
+    try {
+      return CRM_Utils_Hook::singleton()
+        ->invoke([
+          'type',
+          'object',
+          'code',
+          'result'
+        ], $type, $object, $code, $result, CRM_Utils_Hook::$_nullObject, CRM_Utils_Hook::$_nullObject,
+          'civicrm_webhook_eventNotMatched'
+        );
+    }
+    catch (Exception $e) {
+      \Civi::log()->error("webhookEventNotMatched triggered exception. Type: {$type}; Code: {$code}; Message: " . $e->getMessage());
+      return FALSE;
+    }
+  }
+
+}

CRM/Mjwshared/Upgrader.php

+<?php
+use CRM_Mjwshared_ExtensionUtil as E;
+
+/**
+ * Collection of upgrade steps.
+ */
+class CRM_Mjwshared_Upgrader extends CRM_Extension_Upgrader_Base {
+
+  /**
+   * @return TRUE on success
+   * @throws Exception
+   */
+  public function upgrade_1000() {
+    $this->ctx->log->info('Applying update 1000 - Add civicrm_paymentprocessor_webhook table');
+    if (!CRM_Core_DAO::checkTableExists('civicrm_paymentprocessor_webhook')) {
+      // Note: this SQL installs an old version of this table which will then
+      // be updated by upgrade_1001 It only exists for the sake of people
+      // upgrading from old versions.
+      $this->executeSqlFile('sql/upgrade_1000.sql');
+    }
+    return TRUE;
+  }
+
+  /**
+   * @return TRUE on success
+   * @throws Exception
+  */
+  public function upgrade_1001() {
+    $this->ctx->log->info('Applying update 1001 - alter civicrm_paymentprocessor_webhook table');
+    $this->executeSqlFile('sql/upgrade_1001.sql');
+    return TRUE;
+  }
+
+  public function upgrade_1002() {
+    $this->ctx->log->info('Add indexes to civicrm_paymentprocessor_webhook table');
+    if (!CRM_Core_BAO_SchemaHandler::checkIfIndexExists('civicrm_paymentprocessor_webhook', 'index_processed_date')) {
+      CRM_Core_DAO::executeQuery('ALTER TABLE `civicrm_paymentprocessor_webhook` ADD INDEX `index_processed_date` (`processed_date`)');
+    }
+    if (!CRM_Core_BAO_SchemaHandler::checkIfIndexExists('civicrm_paymentprocessor_webhook', 'index_identifier')) {
+      CRM_Core_DAO::executeQuery('ALTER TABLE `civicrm_paymentprocessor_webhook` ADD INDEX `index_identifier` (`identifier`)');
+    }
+    return TRUE;
+  }
+
+  public function upgrade_1003() {
+    $this->ctx->log->info('Make "message" field not required');
+    CRM_Core_DAO::executeQuery("ALTER TABLE civicrm_paymentprocessor_webhook MODIFY COLUMN `message` varchar(1024) DEFAULT '' COMMENT 'Stores data sent that is needed for processing. JSON suggested.'");
+    return TRUE;
+  }
+}

CRM/Mjwshared/Utils.php

@@ -17,12 +17,12 @@ class CRM_Mjwshared_Utils {
   /**
    * Return the field ID for $fieldName custom field
    *
-   * @param $fieldName
-   * @param $fieldGroup
-   * @param bool $fullString
+   * @param string $fieldName
+   * @param string $fieldGroup
+   * @param bool $fullString If TRUE return "custom_25", If FALSE return "25"
    *
-   * @return mixed
-   * @throws \CiviCRM_API3_Exception
+   * @return int|string
+   * @throws \CRM_Core_Exception
    */
   public static function getCustomByName($fieldName, $fieldGroup, $fullString = TRUE) {
     if (!isset(Civi::$statics[__CLASS__][$fieldGroup][$fieldName])) {

Civi/Api4/Action/ContributionRecur/UpdateAmountOnRecurMJW.php

+<?php
+namespace Civi\Api4\Action\ContributionRecur;
+
+use Brick\Money\Money;
+
+/**
+ * This API Action updates the contributionRecur and related entities (templatecontribution/lineitems)
+ *   when a subscription is changed.
+ *
+ */
+class UpdateAmountOnRecurMJW extends \Civi\Api4\Generic\AbstractUpdateAction {
+
+  /**
+   *
+   * Note that the result class is that of the annotation below, not the hint
+   * in the method (which must match the parent class)
+   *
+   * @var \Civi\Api4\Generic\Result $result
+   */
+  public function _run(\Civi\Api4\Generic\Result $result) {
+    if (!array_key_exists('amount', $this->values)) {
+      throw new \CRM_Core_Exception('Must specify amount');
+    }
+    foreach ($this->values as $key => $value) {
+      if ($key !== 'amount') {
+        throw new \CRM_Core_Exception('Only amount can be specified');
+      }
+    }
+
+    // Load the recurs.
+    $recurs = \Civi\Api4\ContributionRecur::get(FALSE)
+      ->setWhere($this->where)
+      ->execute()->indexBy('id');
+
+    foreach ($recurs as $recur) {
+      $subscription = new \Civi\MJW\Payment\Subscription();
+      $subscription->setRecur($recur);
+      if (empty($subscription->getRecur())) {
+        throw new \CRM_Core_Exception('RecurID is not valid!');
+      }
+
+      $newAmount = Money::of($this->values['amount'], $recur['currency']);
+      $recurResults[] = $subscription->updateRecurAndTemplateContributionAmount($newAmount);
+    }
+    $result->exchangeArray($recurResults ?? []);
+    return $result;
+  }
+
+  protected function updateRecords(array $items): array {
+    return $items;
+  }
+}

Civi/Api4/Action/Membership/LinkToRecurMJW.php

+<?php
+namespace Civi\Api4\Action\Membership;
+
+/**
+ * This API Action updates the contributionRecur and related entities (templatecontribution/lineitems)
+ *   when a subscription is changed so they are not linked to a Membership.
+ *
+ */
+class LinkToRecurMJW extends \Civi\Api4\Generic\AbstractUpdateAction {
+
+  /**
+   * @var array field => REQUIRED
+   */
+  private $whereFields = [
+    'id' => TRUE,
+    'contribution_recur_id' => FALSE,
+    'contribution_id' => FALSE,
+  ];
+
+  /**
+   *
+   * Note that the result class is that of the annotation below, not the hint
+   * in the method (which must match the parent class)
+   *
+   * @var \Civi\Api4\Generic\Result $result
+   */
+  public function _run(\Civi\Api4\Generic\Result $result) {
+    if (empty($this->values['id'])) {
+      throw new \CRM_Core_Exception('Must specify Membership ID (id)');
+    }
+    // One of contribution_recur_id or contribution_id is required.
+    if (empty($this->values['contribution_recur_id']) && (empty($this->values['contribution_id']))) {
+      throw new \CRM_Core_Exception('One of contribution_id or contribution_recur_id is required');
+    }
+
+    $membershipProcessor = new \Civi\MJW\Payment\Membership();
+    $entityIDs = $membershipProcessor->linkMembershipToRecur($this->values['id'], $this->values['contribution_id'] ?? NULL, $this->values['contribution_recur_id'] ?? NULL);
+
+    $result->exchangeArray($entityIDs);
+    return $result;
+  }
+
+  protected function updateRecords(array $items): array {
+    return $items;
+  }
+}

Civi/Api4/Action/Membership/UnlinkFromRecurMJW.php

+<?php
+namespace Civi\Api4\Action\Membership;
+
+/**
+ * This API Action updates the contributionRecur and related entities (templatecontribution/lineitems)
+ *   when a subscription is changed so they are not linked to a Membership
+ *
+ */
+class UnlinkFromRecurMJW extends \Civi\Api4\Generic\AbstractUpdateAction {
+
+  /**
+   * @var array field => REQUIRED
+   */
+  private $whereFields = [
+    'id' => TRUE,
+    'contribution_recur_id' => FALSE,
+    'contribution_id' => FALSE,
+  ];
+
+  /**
+   *
+   * Note that the result class is that of the annotation below, not the hint
+   * in the method (which must match the parent class)
+   *
+   * @var \Civi\Api4\Generic\Result $result
+   */
+  public function _run(\Civi\Api4\Generic\Result $result) {
+    if (empty($this->values['id'])) {
+      throw new \CRM_Core_Exception('Must specify Membership ID (id)');
+    }
+
+    $membershipProcessor = new \Civi\MJW\Payment\Membership();
+    $entityIDs = $membershipProcessor->unlinkMembershipFromRecur($this->values['id'], $this->values['contribution_id'] ?? NULL, $this->values['contribution_recur_id'] ?? NULL);
+
+    $result->exchangeArray($entityIDs);
+    return $result;
+  }
+
+  protected function updateRecords(array $items): array {
+    return $items;
+  }
+}

Civi/Api4/Action/PaymentMJW/Create.php

+<?php
+
+namespace Civi\Api4\Action\PaymentMJW;
+
+use CRM_Mjwshared_ExtensionUtil as E;
+use Civi\Api4\CustomField;
+
+/**
+ * This API Action creates a payment. It is based on API3 Payment.create and API3 MJWPayment.create
+ *
+ */
+class Create extends \Civi\Api4\Generic\AbstractCreateAction {
+
+  public static function getCreateFields() {
+    // Basically a copy of _civicrm_api3_payment_create_spec;
+    $fields = [
+      [
+        'name' => 'contribution_id',
+        'required' => TRUE,
+        'description' => E::ts('Contribution ID'),
+        'data_type' => 'Integer',
+        'fk_entity' => 'Contribution',
+        'input_type' => 'EntityRef',
+      ],
+      [
+        'name' => 'total_amount',
+        'required' => TRUE,
+        'description' => E::ts('Total Payment Amount'),
+        'data_type' => 'Float',
+      ],
+      [
+        'name' => 'fee_amount',
+        'description' => E::ts('Fee Amount'),
+        'data_type' => 'Float',
+      ],
+      [
+        'name' => 'payment_processor_id',
+        'data_type' => 'Integer',
+        'description' => E::ts('Payment Processor for this payment'),
+        'fk_entity' => 'PaymentProcessor',
+        'input_type' => 'EntityRef',
+      ],
+      [
+        'name' => 'trxn_date',
+        'description' => E::ts('Payment Date'),
+        'data_type' => 'Datetime',
+        'default' => 'now',
+        'required' => TRUE,
+      ],
+      [
+        'name' => 'is_send_contribution_notification',
+        'description' => E::ts('Send out notifications based on contribution status change?'),
+        'data_type' => 'Boolean',
+        'default' => TRUE,
+      ],
+      [
+        'name' => 'payment_instrument_id',
+        'data_type' => 'Integer',
+        'description' => E::ts('Payment Method (FK to payment_instrument option group values)'),
+        'pseudoconstant' => [
+          'optionGroupName' => 'payment_instrument',
+          'optionEditPath' => 'civicrm/admin/options/payment_instrument',
+        ],
+      ],
+      [
+        'name' => 'card_type_id',
+        'data_type' => 'Integer',
+        'description' => E::ts('Card Type ID (FK to accept_creditcard option group values)'),
+        'pseudoconstant' => [
+          'optionGroupName' => 'accept_creditcard',
+          'optionEditPath' => 'civicrm/admin/options/accept_creditcard',
+        ],
+      ],
+      [
+        'name' => 'trxn_result_code',
+        'data_type' => 'String',
+        'description' => E::ts('Transaction Result Code'),
+      ],
+      [
+        'name' => 'trxn_id',
+        'data_type' => 'String',
+        'description' => E::ts('Transaction ID supplied by external processor. This may not be unique.'),
+      ],
+      [
+        'name' => 'order_reference',
+        'data_type' => 'String',
+        'description' => E::ts('Payment Processor external order reference'),
+      ],
+      [
+        'name' => 'check_number',
+        'data_type' => 'String',
+        'description' => E::ts('Check Number'),
+      ],
+      [
+        'name' => 'pan_truncation',
+        'type' => 'String',
+        'description' => E::ts('PAN Truncation (Last 4 digits of credit card)'),
+      ],
+    ];
+    $customFields = CustomField::get(FALSE)
+      ->addSelect('custom_group_id:name', 'name', 'label', 'data_type')
+      ->addWhere('custom_group_id.extends', '=', 'FinancialTrxn')
+      ->execute();
+    foreach ($customFields as $customField) {
+      $customField['name'] = $customField['custom_group_id:name'] . '.' . $customField['name'];
+      unset($customField['id'], $customField['custom_group_id:name']);
+      $customField['description'] = $customField['label'];
+      $fields[] = $customField;
+    }
+    return $fields;
+  }
+
+  public function fields(): array {
+    return self::getCreateFields();
+  }
+
+  /**
+   *
+   * Note that the result class is that of the annotation below, not the h
+   * in the method (which must match the parent class)
+   *
+   * @var \Civi\Api4\Generic\Result $result
+   */
+  public function _run(\Civi\Api4\Generic\Result $result) {
+    $trxn = \CRM_Financial_BAO_Payment::create($this->values);
+
+    $customFields = CustomField::get(FALSE)
+      ->addSelect('id', 'custom_group_id:name', 'name', 'label', 'data_type')
+      ->addWhere('custom_group_id.extends', '=', 'FinancialTrxn')
+      ->execute();
+    foreach ($customFields as $customField) {
+      $key = $customField['custom_group_id:name'] . '.' . $customField['name'];
+      if (isset($this->values[$key])) {
+        $customParams['custom_' . $customField['id']] = $this->values[$key];
+      }
+    }
+    if (!empty($customParams)) {
+      $customParams['entity_id'] = $trxn->id;
+      civicrm_api3('CustomValue', 'create', $customParams);
+    }
+
+    $result->exchangeArray($trxn);
+    return $result;
+  }
+
+}

Civi/Api4/Action/PriceFieldValue/GetDefaultPriceFieldValueForContributionMJW.php

+<?php
+namespace Civi\Api4\Action\PriceFieldValue;
+
+use Civi\Api4\PriceField;
+use Civi\Api4\PriceFieldValue;
+
+/**
+ * This API Action gets the default price_field_value_id for a contribution
+ *
+ */
+class GetDefaultPriceFieldValueForContributionMJW extends \Civi\Api4\Generic\AbstractQueryAction {
+
+  /**
+   *
+   *  Get the default price_field_id and price_field_value_id for a contribution
+   *
+   * $result = ['price_field_id' = X, 'price_field_value_id' = Y, 'label' = price_field_value.label]
+   *
+   * Note that the result class is that of the annotation below, not the hint
+   * in the method (which must match the parent class)
+   *
+   * @var \Civi\Api4\Generic\Result $result
+   */
+  public function _run(\Civi\Api4\Generic\Result $result) {
+    $priceSetName = 'default_contribution_amount';
+    $priceField = PriceField::get(FALSE)
+      ->addWhere('price_set_id:name', '=', $priceSetName)
+      ->addOrderBy('id', 'ASC')
+      ->execute()
+      ->first();
+    // Now get the relevant PriceFieldValue for the MembershipType.
+    $priceFieldValue = PriceFieldValue::get(FALSE)
+      ->addWhere('price_field_id', '=', $priceField['id'])
+      ->execute()
+      ->first();
+    $results = [
+      'price_field_id' => $priceField['id'],
+      'price_field_value_id' => $priceFieldValue['id'],
+      'label' => $priceFieldValue['label'],
+    ];
+
+    $result->exchangeArray($results);
+    return $result;
+  }
+
+}

Civi/Api4/Action/PriceFieldValue/GetDefaultPriceFieldValueForMembershipMJW.php

+<?php
+namespace Civi\Api4\Action\PriceFieldValue;
+
+use Civi\Api4\PriceField;
+use Civi\Api4\PriceFieldValue;
+
+/**
+ * This API Action gets the default price_field_value_id for the specified membership
+ *
+ * @property int $membershipID
+ */
+class GetDefaultPriceFieldValueForMembershipMJW extends \Civi\Api4\Generic\AbstractAction {
+
+  /**
+   * The Membership ID
+   *
+   * @var int
+   * @required
+   */
+  protected int $membershipID = 0;
+
+  /**
+   *
+   * Get the default price_field_id and price_field_value_id for the membership
+   *
+   * $result = ['price_field_id' = X, 'price_field_value_id' = Y, 'label' = price_field_value.label]
+   *
+   * Note that the result class is that of the annotation below, not the hint
+   * in the method (which must match the parent class)
+   *
+   * @var \Civi\Api4\Generic\Result $result
+   */
+  public function _run(\Civi\Api4\Generic\Result $result) {
+    if (empty($this->membershipID)) {
+      throw new \CRM_Core_Exception('Membership ID is required');
+    }
+    // First we need membership_type_id.member_of_contact_id and membership_type_id to find the PriceFieldValue.
+    $membership = \Civi\Api4\Membership::get(FALSE)
+      ->addSelect('membership_type_id.member_of_contact_id', 'membership_type_id')
+      ->addWhere('id', '=', $this->membershipID)
+      ->execute()
+      ->first();
+
+    // PriceFields and Membership Types...
+    // There is a default PriceSet for contributions with name="default_contribution_amount"
+    // There is a default PriceSet for memberships with name="default_membership_type_amount"
+    // Each MembershipType has a "member_of_contact_id" which gets used as a FK reference in PriceField.name
+    // Each MembershipType has a PriceFieldValue with PriceFieldValue.membership_type_id = Membership Type
+    // Why all this? Well we could (and probably do) have multiple PriceSets that include the same MembershipType but
+    //   different prices. But only one of them will be linked to the default PriceSet.
+    // Confused yet?
+
+    // Get the default price field ID for memberships from the default membership PriceSet and the member_of_contact_id
+    $priceField = PriceField::get(FALSE)
+      ->addWhere('price_set_id:name', '=', 'default_membership_type_amount')
+      ->addWhere('name', '=', $membership['membership_type_id.member_of_contact_id'])
+      ->addOrderBy('id', 'ASC')
+      ->execute()
+      ->first();
+
+    // Now get the relevant PriceFieldValue for the MembershipType.
+    $priceFieldValue = PriceFieldValue::get(FALSE)
+      ->addWhere('price_field_id', '=', $priceField['id'])
+      ->addWhere('membership_type_id', '=', $membership['membership_type_id'])
+      ->execute()
+      ->first();
+
+    $results = [
+      'price_field_id' => $priceField['id'],
+      'price_field_value_id' => $priceFieldValue['id'],
+      'label' => $priceFieldValue['label'],
+    ];
+
+    $result->exchangeArray($results);
+    return $result;
+  }
+
+}

Civi/Api4/PaymentMJW.php

+<?php
+
+namespace Civi\Api4;
+
+/**
+ * A collection of system maintenance/diagnostic utilities.
+ *
+ * @searchable none
+ * @since 5.19
+ * @package Civi\Api4
+ */
+class PaymentMJW extends Generic\AbstractEntity {
+
+  /**
+   * @param bool $checkPermissions
+   * @return Generic\BasicGetFieldsAction
+   */
+  public static function getFields($checkPermissions = TRUE) {
+    return (new Generic\BasicGetFieldsAction(__CLASS__, __FUNCTION__, function() {
+      return [];
+    }))->setCheckPermissions($checkPermissions);
+  }
+
+}

Civi/Api4/PaymentprocessorWebhook.php

+<?php
+namespace Civi\Api4;
+
+/**
+ * PaymentprocessorWebhook entity.
+ *
+ * Provided by the Payment Shared extension.
+ *
+ * @package Civi\Api4
+ */
+class PaymentprocessorWebhook extends Generic\DAOEntity {
+
+}

Civi/MJW/Logger.php

+<?php
+
+namespace Civi\MJW;
+
+
+/**
+ * Abstracts the Civi::log class so that we:
+ *   - Don't have to specify channel each time we log.
+ *   - Automatically log the entityID/name if provided.
+ */
+class Logger {
+
+  /**
+   * The Log channel
+   *
+   * @var string
+   */
+  private string $logChannel = '';
+
+  /**
+   * The entityID/Name
+   *
+   * @var string
+   */
+  private string $logEntity = '';
+
+  public function __construct(string $logChannel, string $logEntity) {
+    $this->logChannel = $logChannel;
+    $this->logEntity = $logEntity;
+  }
+
+  /**
+   * Log an info message with payment processor prefix
+   * @param string $message
+   *
+   * @return void
+   */
+  public function logInfo(string $message) {
+    $this->log('info', $message);
+  }
+
+  /**
+   * Log an error message with payment processor prefix
+   *
+   * @param string $message
+   *
+   * @return void
+   */
+  public function logError(string $message) {
+    $this->log('error', $message);
+  }
+
+  /**
+   * Log a debug message with payment processor prefix
+   *
+   * @param string $message
+   *
+   * @return void
+   */
+  public function logDebug(string $message) {
+    $this->log('debug', $message);
+  }
+
+  /**
+   * @param string $level
+   * @param string $message
+   *
+   * @return void
+   */
+  private function log(string $level, string $message) {
+    $channel = $this->logChannel;
+    $prefix = $channel . '(' . $this->logEntity . '): ';
+    \Civi::log($channel)->$level($prefix . $message);
+  }
+}
\ No newline at end of file

Civi/MJW/Payment/Membership.php

+<?php
+
+namespace Civi\MJW\Payment;
+
+use Civi\Api4\Contribution;
+use Civi\Api4\ContributionRecur;
+use Civi\Api4\LineItem;
+use Civi\Core\Service\AutoService;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * @internal
+ * @service
+ */
+class Membership extends AutoService implements EventSubscriberInterface {
+
+  /**
+   * @return array
+   */
+  public static function getSubscribedEvents() {
+    return [
+      'hook_civicrm_pre' => ['on_hook_civicrm_pre', 150],
+    ];
+  }
+
+  /**
+   * Force setting entity_table / entity_id in LineItem.create (for update)
+   *
+   * @param \Civi\Core\Event\PreEvent $event
+   *
+   * @return void
+   */
+  public function on_hook_civicrm_pre(\Civi\Core\Event\PreEvent $event) {
+    if ($event->entity !== 'LineItem' || $event->action !== 'edit') {
+      return;
+    }
+    // API3 LineItem.create removes entity_table/entity_id before saving.
+    // We add them after LineItem.create removed them but before save!
+    if (isset($event->params['entity_table_force'])) {
+      $event->params['entity_table'] = $event->params['entity_table_force'];
+      unset($event->params['entity_table_force']);
+    }
+    if (isset($event->params['entity_id_force'])) {
+      $event->params['entity_id'] = $event->params['entity_id_force'];
+      unset($event->params['entity_id_force']);
+    }
+  }
+
+  /**
+   * Update and Link Membership to Contribution LineItem and Recur
+   *
+   * @param int $membershipID
+   * @param int|null $contributionID
+   * @param int|null $contributionRecurID
+   *
+   * @return array The various entity IDs
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\API\Exception\UnauthorizedException
+   */
+  public function linkMembershipToRecur(int $membershipID, $contributionID = NULL, $contributionRecurID = NULL): array {
+    // Get contribution ID from the recur if possible
+    if (empty($contributionID) && !empty($contributionRecurID)) {
+      $contributionID = \CRM_Contribute_BAO_ContributionRecur::ensureTemplateContributionExists($contributionRecurID);
+    }
+
+    // First the simple bit! Link the membership to the contributionRecur record if we have one
+    if ($contributionRecurID) {
+      \Civi\Api4\Membership::update(FALSE)
+        ->addWhere('id', '=', $membershipID)
+        ->addValue('contribution_recur_id', $contributionRecurID)
+        ->execute()
+        ->first();
+    }
+
+    // Now we need to update the LineItems on the contribution so that renewals etc. work properly.
+    $priceFieldValues = \Civi\Api4\PriceFieldValue::getDefaultPriceFieldValueForMembershipMJW(FALSE)
+      ->setMembershipID($membershipID)
+      ->execute();
+
+    // Now get the LineItems for the contribution
+    $lineItems = LineItem::get(FALSE)
+      ->addWhere('contribution_id', '=', $contributionID)
+      ->execute();
+    if ($lineItems->count() > 1) {
+      throw new \CRM_Core_Exception('ContributionID: ' . $contributionID . ' has more than one lineitem. Not linking membership as I don\'t know what to do');
+      // @todo: Maybe search them for a LineItem matching this membership type?
+    }
+
+    // Get the membership FinancialType so we can update the Contribution,Recur and LineItem.
+    $membership = \Civi\Api4\Membership::get(FALSE)
+      ->addSelect('membership_type_id.financial_type_id')
+      ->addWhere('id', '=', $membershipID)
+      ->execute()
+      ->first();
+
+    // Update the contributionRecur with the new FinancialType
+    if (!empty($contributionRecurID)) {
+      ContributionRecur::update(FALSE)
+        ->addWhere('id', '=', $contributionRecurID)
+        ->addValue('financial_type_id', $membership['membership_type_id.financial_type_id'])
+        ->execute();
+    }
+    // Update the contribution with the new FinancialType
+    if (!empty($contributionID)) {
+      Contribution::update(FALSE)
+        ->addWhere('id', '=', $contributionID)
+        ->addValue('financial_type_id', $membership['membership_type_id.financial_type_id'])
+        ->execute();
+    }
+
+    // Finally, Update the LineItem to map to a membership
+    civicrm_api3('LineItem', 'create', [
+      'entity_id' => $membershipID,
+      'id' => $lineItems->first()['id'],
+      'entity_table' => 'civicrm_membership',
+      'price_field_id' => $priceFieldValues['price_field_id'],
+      'price_field_value_id' => $priceFieldValues['price_field_value_id'],
+      'label' => $priceFieldValues['label'],
+      'financial_type_id' => $membership['membership_type_id.financial_type_id'],
+      // API3 LineItem.create removes entity_table/entity_id before saving.
+      // We add them here so we can add them back in using hook_civicrm_pre (implemented in on_hook_civicrm_pre).
+      'entity_table_force' => 'civicrm_membership',
+      'entity_id_force' => $membershipID,
+    ]);
+
+    return [
+      'lineItemID' => $lineItems->first()['id'],
+      'contributionRecurID' => $contributionRecurID ?? NULL,
+      'contributionID' => $contributionID,
+      'membershipID' => $membershipID,
+      'action' => 'link',
+    ];
+  }
+
+  /**
+   * Update and Link Membership to Contribution LineItem and Recur
+   *
+   * @param int $membershipID
+   * @param int|null $contributionID
+   * @param int|null $contributionRecurID
+   *
+   * @return array The various entity IDs
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\API\Exception\UnauthorizedException
+   */
+  public function unlinkMembershipFromRecur(int $membershipID, $contributionID = NULL, $contributionRecurID = NULL): array {
+    if (empty($contributionID) && empty($contributionRecurID)) {
+      $contributionRecurID = \Civi\Api4\Membership::get(FALSE)
+        ->addSelect('contribution_recur_id')
+        ->addWhere('id', '=', $membershipID)
+        ->execute()
+        ->first()['contribution_recur_id'];
+      if (empty($contributionRecurID)) {
+        throw new \CRM_Core_Exception('Membership ' . $membershipID . ' does not have a contribution_recur_id. Cannot unlink!');
+      }
+    }
+
+    // Get contribution ID from the recur if possible
+    if (empty($contributionID) && !empty($contributionRecurID)) {
+      $contributionID = \CRM_Contribute_BAO_ContributionRecur::ensureTemplateContributionExists($contributionRecurID);
+    }
+
+    // First the simple bit! Remove the contribution_recur_id from the membership
+    if ($contributionRecurID) {
+      \Civi\Api4\Membership::update(FALSE)
+        ->addWhere('id', '=', $membershipID)
+        ->addValue('contribution_recur_id', NULL)
+        ->execute()
+        ->first();
+    }
+
+    // Now we need to update the LineItems on the contribution so that renewals etc. work properly.
+    $priceFieldValues = \Civi\Api4\PriceFieldValue::getDefaultPriceFieldValueForContributionMJW(FALSE)->execute();
+
+    // Now get the LineItems for the contribution
+    $lineItems = LineItem::get(FALSE)
+      ->addWhere('contribution_id', '=', $contributionID)
+      ->execute();
+    if ($lineItems->count() > 1) {
+      throw new \CRM_Core_Exception('ContributionID: ' . $contributionID . ' has more than one lineitem. Not unlinking membership as I don\'t know what to do');
+      // @todo: Maybe search them for a LineItem matching this membership type?
+    }
+
+    // @todo Maybe change the financial type on contribution/recur to default / "Donation".
+    // But not sure what would be best as we don't have an obvious default (when linking we use Membership financialType).
+
+    // Finally, Update the LineItem to map to a contribution
+    $newLineItem = civicrm_api3('LineItem', 'create', [
+      'entity_id' => $contributionID,
+      'id' => $lineItems->first()['id'],
+      'entity_table' => 'civicrm_contribution',
+      'price_field_id' => $priceFieldValues['price_field_id'],
+      'price_field_value_id' => $priceFieldValues['price_field_value_id'],
+      'label' => $priceFieldValues['label'],
+      // 'financial_type_id' => $membership['membership_type_id.financial_type_id'],
+      // API3 LineItem.create removes entity_table/entity_id before saving.
+      // We add them here so we can add them back in using hook_civicrm_pre (implemented in on_hook_civicrm_pre).
+      'entity_table_force' => 'civicrm_contribution',
+      'entity_id_force' => $contributionID,
+    ]);
+
+    return [
+      'lineItemID' => $lineItems->first()['id'],
+      'contributionRecurID' => $contributionRecurID ?? NULL,
+      'contributionID' => $contributionID,
+      'membershipID' => $membershipID,
+      'action' => 'unlink',
+    ];
+  }
+
+}

Civi/MJW/Payment/Subscription.php

+<?php
+
+namespace Civi\MJW\Payment;
+
+use Brick\Money\Money;
+use Civi\Api4\Contribution;
+use Civi\Api4\ContributionRecur;
+
+class Subscription {
+
+  /**
+   * The ContributionRecur as retrieved by API4.
+   *
+   * @var array
+   */
+  protected array $recur;
+
+  public function setRecur(array $recur) {
+    $this->recur = $recur;
+  }
+
+  public function getRecur(): array {
+    return $this->recur;
+  }
+
+  /**
+   * Updates the ContributionRecur entity, and if a template contribution
+   * exists, update that along with its single line item.
+   *
+   * @param \Brick\Money\Money $newAmount
+   *
+   * @return array
+   * @throws \Brick\Money\Exception\MoneyMismatchException
+   * @throws \Brick\Money\Exception\UnknownCurrencyException
+   * @throws \CRM_Core_Exception
+   * @throws \Civi\API\Exception\UnauthorizedException
+   * @throws \Civi\Core\Exception\DBQueryException
+   */
+  public function updateRecurAndTemplateContributionAmount(Money $newAmount): array {
+    $recur = $this->getRecur();
+    if (empty($recur)) {
+      throw new \CRM_Core_Exception('Must set recur first');
+    }
+
+    // Check if amount is the same
+    if (Money::of($recur['amount'], $recur['currency'])->compareTo($newAmount) === 0) {
+      \Civi::log()->debug('nothing to do. Amount is already the same');
+      return $recur;
+    }
+
+    // Get the template contribution
+    // Calling ensureTemplateContributionExists will *always* return a template contribution
+    //   Either it will have created one or will return the one that already exists.
+    $templateContributionID = \CRM_Contribute_BAO_ContributionRecur::ensureTemplateContributionExists($recur['id']);
+
+    // Now we update the template contribution with the new details
+    // This will automatically update the Contribution LineItems as well.
+    Contribution::update(FALSE)
+      ->addValue('id', $templateContributionID)
+      ->addValue('total_amount', $newAmount->getAmount()->toFloat())
+      ->addWhere('id', '=', $templateContributionID)
+      ->execute()
+      ->first();
+
+    // Update the recur
+    // If we update a template contribution the recur will automatically be updated
+    // (see CRM_Contribute_BAO_Contribution::self_hook_civicrm_post)
+    // We need to make sure we updated the template contribution first because
+    //   CRM_Contribute_BAO_ContributionRecur::self_hook_civicrm_post will also try to update it.
+    $this->setRecur(ContributionRecur::get(FALSE)
+      ->addWhere('id', '=', $recur['id'])
+      ->execute()
+      ->first());
+
+    return $this->getRecur();
+  }
+
+}