implement TwingleShop integration

api/v3/TwingleShop/Getsingle.php

@@ -0,0 +1,54 @@
+<?php
+use CRM_Twingle_ExtensionUtil as E;
+
+/**
+ * TwingleShop.Getsingle API specification (optional)
+ * This is used for documentation and validation.
+ *
+ * @param array $spec description of fields supported by this API call
+ *
+ * @see https://docs.civicrm.org/dev/en/latest/framework/api-architecture/
+ */
+function _civicrm_api3_twingle_shop_Getsingle_spec(&$spec) {
+  _civicrm_api3_twingle_shop_Get_spec($spec);
+}
+
+/**
+ * TwingleShop.Getsingle API
+ *
+ * @param array $params
+ *
+ * @return array
+ *   API result descriptor
+ *
+ * @see civicrm_api3_create_success
+ *
+ * @throws API_Exception
+ */
+function civicrm_api3_twingle_shop_Getsingle($params) {
+  // Filter for allowed params
+  $allowed_params = [];
+  _civicrm_api3_twingle_shop_Getsingle_spec($allowed_params);
+  $params = array_intersect_key($params, $allowed_params);
+
+  // Check whether any parameters are set
+  if (empty($params)) {
+    return civicrm_api3_create_error(
+      "At least one parameter must be set",
+      ['error_code' => 'missing_parameter', 'params' => $params]
+    );
+  }
+
+  // Find TwingleShop via get API
+  $returnValues = civicrm_api3('TwingleShop', 'get', $params);
+  $count = $returnValues['count'];
+
+  // Check whether only a single TwingleShop is found
+  if ($count != 1) {
+    return civicrm_api3_create_error(
+      "Expected one TwingleShop but found $count",
+      ['error_code' => 'not_found', 'params' => $params]
+    );
+  }
+  return $returnValues['values'][$returnValues['id']];
+}