package net

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

func ClientIP(request *http.Request) string {
	clientIP := request.Header.Get("X-Forward-For")
	clientIP = strings.TrimSpace(strings.Split(clientIP, ",")[0])
	if clientIP == "" {
		clientIP = strings.TrimSpace(request.Header.Get("X-Real-Ip"))
	}
	if clientIP != "" {
		return clientIP
	}

	if addr := request.Header.Get("X-Appengine-Remote-Addr"); addr != "" {
		return addr
	}

	if ip, _, err := net.SplitHostPort(strings.TrimSpace(request.RemoteAddr)); err == nil {
		return ip
	}

	return ""
}