package main

import (
	"encoding/json"
	"net/http"
	"os"
)

func GetIP(r *http.Request) string {
	forwarded := r.Header.Get("X-FORWARDED-FOR")
	if forwarded != "" {
		return forwarded
	}
	return r.RemoteAddr
}

func main() {
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte(GetIP(r)))
	})

	http.HandleFunc("/json", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Add("Content-Type", "application/json")
		resp, _ := json.Marshal(map[string]string{
			"ip": GetIP(r),
		})
		w.Write(resp)
	})

	listen := ":8000"
	os.Stdout.Write([]byte("Listening on " + listen))
	http.ListenAndServe(listen, nil)
}