From a0e872f12e7b1bf855a1e4d645ba68d12af4fb83 Mon Sep 17 00:00:00 2001
From: Seamus Lee <seamuslee001@gmail.com>
Date: Mon, 13 Jul 2020 14:38:20 +1000
Subject: [PATCH] [REF] permit negative payments to be made against completed
 payments

Add in unit test for adding additional refund payment to contribution already refunded and also adding a negative payment to a contribution that is negative already
---
 CRM/Financial/BAO/Payment.php        | 11 ++++++++--
 tests/phpunit/api/v3/PaymentTest.php | 32 ++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/CRM/Financial/BAO/Payment.php b/CRM/Financial/BAO/Payment.php
index e13837e996..2b93c545e1 100644
--- a/CRM/Financial/BAO/Payment.php
+++ b/CRM/Financial/BAO/Payment.php
@@ -487,6 +487,9 @@ class CRM_Financial_BAO_Payment {
     if ($outstandingBalance !== 0.0) {
       $ratio = $params['total_amount'] / $outstandingBalance;
     }
+    elseif ($params['total_amount'] < 0) {
+      $ratio = $params['total_amount'] / (float) CRM_Core_BAO_FinancialTrxn::getTotalPayments($params['contribution_id'], TRUE);
+    }
     else {
       // Help we are making a payment but no money is owed. We won't allocate the overpayment to any line item.
       $ratio = 0;
@@ -496,12 +499,16 @@ class CRM_Financial_BAO_Payment {
       $lineItems[$lineItemID]['id'] = $lineItemID;
       $lineItems[$lineItemID]['paid'] = self::getAmountOfLineItemPaid($lineItemID);
       $lineItems[$lineItemID]['balance'] = $lineItem['subTotal'] - $lineItems[$lineItemID]['paid'];
-
       if (!empty($lineItemOverrides)) {
         $lineItems[$lineItemID]['allocation'] = $lineItemOverrides[$lineItemID] ?? NULL;
       }
       else {
-        $lineItems[$lineItemID]['allocation'] = $lineItems[$lineItemID]['balance'] * $ratio;
+        if (empty($lineItems[$lineItemID]['balance']) && !empty($ratio) && $params['total_amount'] < 0) {
+          $lineItems[$lineItemID]['allocation'] = $lineItem['subTotal'] * $ratio;
+        }
+        else {
+          $lineItems[$lineItemID]['allocation'] = $lineItems[$lineItemID]['balance'] * $ratio;
+        }
       }
     }
     return $lineItems;
diff --git a/tests/phpunit/api/v3/PaymentTest.php b/tests/phpunit/api/v3/PaymentTest.php
index 4ae47f9200..5c36bde5d2 100644
--- a/tests/phpunit/api/v3/PaymentTest.php
+++ b/tests/phpunit/api/v3/PaymentTest.php
@@ -183,6 +183,7 @@ class api_v3_PaymentTest extends CiviUnitTestCase {
       ],
     ];
     $this->checkPaymentResult($payment, $expectedResult);
+    $this->callAPISuccess('Payment', 'create', ['total_amount' => '-20', 'contribution_id' => $contributionID2]);
     $this->validateAllPayments();
   }
 
@@ -213,6 +214,37 @@ class api_v3_PaymentTest extends CiviUnitTestCase {
     ]);
   }
 
+  /**
+   * Test full refund when no payment has actually been record.
+   */
+  public function testFullRefundWithPaymentAlreadyRefunded() {
+    $params1 = [
+      'contact_id' => $this->_individualId,
+      'trxn_id' => 111111,
+      'total_amount' => 10,
+    ];
+    $contributionID1 = $this->contributionCreate($params1);
+    $paymentParams = ['contribution_id' => $contributionID1];
+    $this->callAPISuccess('Payment', 'create', ['total_amount' => '-10', 'contribution_id' => $contributionID1]);
+    $payment = $this->callAPISuccess('payment', 'get', $paymentParams);
+    $this->callAPISuccess('Payment', 'create', ['total_amount' => '-10', 'contribution_id' => $contributionID1]);
+    $payment = $this->callAPISuccess('payment', 'get', $paymentParams);
+    $this->validateAllPayments();
+  }
+
+  public function testNegativePaymentWithNegativeContribution() {
+    $params1 = [
+      'contact_id' => $this->_individualId,
+      'trxn_id' => 111111,
+      'total_amount' => -10,
+    ];
+    $contributionID1 = $this->contributionCreate($params1);
+    $this->callAPISuccess('Payment', 'create', ['total_amount' => '-20', 'contribution_id' => $contributionID1]);
+    $paymentParams = ['contribution_id' => $contributionID1];
+    $payment = $this->callAPISuccess('payment', 'get', $paymentParams);
+    $this->validateAllPayments();
+  }
+
   /**
    * Test email receipt for partial payment.
    *
-- 
2.25.1