TC_037_1, TC037_2: Deduplicate StatusNotifications in RequestQueue

From the OCPP Spec:
> The Charge Point SHOULD NOT send StatusNotification.req PDUs for
> historical status change events that happened while the Charge
> Point was offline.

So, each time we queue another StatusNotification, we drop the
StatusNotifications already in the queue for that connector.

Author: heakins

src/MicroOcpp/Core/Request.cpp

@@ -34,6 +34,10 @@ void Request::setOperation(std::unique_ptr<Operation> msg){
     operation = std::move(msg);
 }
 
+std::unique_ptr<Operation>& Request::getOperation(){
+    return operation;
+}
+
 void Request::setTimeout(unsigned long timeout) {
     this->timeout_period = timeout;
 }

src/MicroOcpp/Core/Request.h

@@ -49,6 +49,7 @@ class Request {
     ~Request();
 
     void setOperation(std::unique_ptr<Operation> msg);
+    std::unique_ptr<Operation>& getOperation();
 
     void setTimeout(unsigned long timeout); //0 = disable timeout
     bool isTimeoutExceeded();

src/MicroOcpp/Core/RequestQueue.cpp

@@ -9,6 +9,7 @@
 #include <MicroOcpp/Core/OcppError.h>
 #include <MicroOcpp/Core/RequestStore.h>
 #include <MicroOcpp/Core/OperationRegistry.h>
+#include <MicroOcpp/Operations/StatusNotification.h>
 
 #include <MicroOcpp/Debug.h>
 
@@ -129,7 +130,21 @@ void RequestQueue::sendRequest(std::unique_ptr<Request> op){
         MO_DBG_ERR("Called with null. Ignore");
         return;
     }
-    
+
+    // Don't queue up multiple StatusNotification messages for the same connectorId
+    if (strcmp(op->getOperationType(), "StatusNotification") == 0)
+    {
+        auto new_status_notification = static_cast<Ocpp16::StatusNotification*>(op->getOperation().get());
+        initiatedRequests->drop_if([&new_status_notification] (const std::unique_ptr<Request>& operation) {
+            if (strcmp(operation->getOperationType(), "StatusNotification")!= 0)
+            {
+                return false;
+            }
+            auto old_status_notification = static_cast<Ocpp16::StatusNotification*>(operation->getOperation().get());
+            return old_status_notification->getConnectorId() == new_status_notification->getConnectorId();
+        });
+    }
+
     initiatedRequests->push_back(std::move(op));
 }
 

src/MicroOcpp/Operations/StatusNotification.h

@@ -35,6 +35,10 @@ class StatusNotification : public Operation {
     void processReq(JsonObject payload) override;
 
     std::unique_ptr<DynamicJsonDocument> createConf() override;
+
+    int getConnectorId() {
+        return connectorId;
+    }
 };
 
 } // namespace Ocpp16