package http

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

func GetClientIP(req *http.Request) net.IP {
	if req == nil {
		return nil
	}
	// cloudflare CDN
	sip := req.Header.Get("CF-Connecting-IP")
	if sip == "" {
		ss := strings.Split(req.Header.Get("X-Forwarded-For"), ",")
		if len(ss) > 0 && ss[0] != "" {
			sip = ss[0]
		}
	}
	if sip == "" {
		sip = req.Header.Get("X-Real-Ip")
	}

	return net.ParseIP(sip)
}