/*
 * Copyright (c) 2020 Baidu, Inc.
 *
 * 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 filters

import (
	"net/http"

	"github.com/google/uuid"

	"github.com/baidu/easyfaas/pkg/api"
)

func WithRequestID(handler http.Handler) http.Handler {

	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		rid := r.Header.Get(api.HeaderXRequestID)
		if rid == "" {
			rid = generator()
		}
		r.Header.Add(api.HeaderXRequestID, rid)
		w.Header().Add(api.HeaderXRequestID, rid)

		handler.ServeHTTP(w, r)
	})

}

func generator() string {
	return uuid.New().String()
}
