/* Copyright(C) 2023. Huawei Technologies Co.,Ltd. All rights reserved.
   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 utils offer the some utils for certificate handling
package utils

import (
	"net"
	"net/http"
	"strings"
)

// ClientIP try to get the clientIP
func ClientIP(r *http.Request) string {
	// get forward ip fistly
	var ip string
	xForwardedFor := r.Header.Get("X-Forwarded-For")
	forwardSlice := strings.Split(xForwardedFor, ",")
	if len(forwardSlice) >= 1 {
		if ip = strings.TrimSpace(forwardSlice[0]); ip != "" {
			return ip
		}
	}
	// try get ip from "X-Real-Ip"
	ip = strings.TrimSpace(r.Header.Get("X-Real-Ip"))
	if ip != "" {
		return ip
	}
	var err error
	if ip, _, err = net.SplitHostPort(strings.TrimSpace(r.RemoteAddr)); err == nil {
		return ip
	}
	return ""
}