tsk-59: Got the code for MER and added TODO

internal/handler/message_event_response.go

@@ -93,8 +93,43 @@ type GetMessageEventResponseFetchedResponse struct {
 }
 
 func (e *EventResponseHandler) Fetch(w http.ResponseWriter, r *http.Request) {
+	queryParams := r.URL.Query()
+	var userId uuid.UUID
+
+	if _, exists := queryParams["user_id"]; !exists {
+		http.Error(w, "Query params", http.StatusBadRequest)
+		return
+	} else {
+		var err error
+		userId, err = uuid.Parse(queryParams.Get("user_id"))
+		if err != nil {
+			http.Error(w, "Query params", http.StatusBadRequest)
+			return
+		}
+	}
+
 	var statusCode int
 	var resp GetMessageEventResponseFetchedResponse
 
+	if userId == uuid.Nil {
+		statusCode = http.StatusBadRequest
+		resp.Message = "User Id is nil"
+	} else {
+		ctx := r.Context()
+		if sentMessages, err := e.MessageEventResponseStore.GetWithUserId(ctx, userId); err != nil {
+			statusCode = http.StatusInternalServerError
+			resp.Message = err.Error()
+		} else {
+			if len(sentMessages) == 0 {
+				statusCode = http.StatusNotFound
+				resp.Message = "Not MessageEventResponses found"
+			} else {
+				statusCode = http.StatusOK
+				resp.Message = "Successful"
+				resp.Data = sentMessages
+			}
+		}
+	}
+
 	RespondWithJSON(w, statusCode, &resp)
 }