refactor: refactoring of code

Add graceful shutdown server

internal/middlewares/helpers.go

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2024 Jonas Kaninda
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package middlewares
+
+import (
+	"encoding/json"
+	"net/http"
+	"slices"
+)
+
+func getRealIP(r *http.Request) string {
+	if ip := r.Header.Get("X-Real-IP"); ip != "" {
+		return ip
+	}
+	if ip := r.Header.Get("X-Forwarded-For"); ip != "" {
+		return ip
+	}
+	return r.RemoteAddr
+}
+func allowedOrigin(origins []string, origin string) bool {
+	return slices.Contains(origins, origin)
+}
+
+// RespondWithError is a helper function to handle error responses with flexible content type
+func RespondWithError(w http.ResponseWriter, statusCode int, logMessage string) {
+	message := http.StatusText(statusCode)
+	if len(logMessage) != 0 {
+		message = logMessage
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(statusCode)
+	err := json.NewEncoder(w).Encode(ProxyResponseError{
+		Success: false,
+		Code:    statusCode,
+		Message: message,
+	})
+	if err != nil {
+		return
+	}
+
+}