package main

import (
	"flag"
	"fmt"
	"log"
	"net/http"
	"net/http/httputil"
	"net/url"
)

func main() {
	var listenAddr string
	var targetAddr string

	flag.StringVar(&listenAddr, "l", "", "Listen address")
	flag.StringVar(&targetAddr, "t", "", "Target address")
	flag.Parse()

	if listenAddr == "" || targetAddr == "" {
		flag.Usage()
		return
	}

	mux := http.NewServeMux()

	u, err := url.Parse(targetAddr)
	if err != nil {
		fmt.Println("URL error:", err)
		return
	}

	rproxy := httputil.NewSingleHostReverseProxy(u)

	fmt.Println("Listening at:", listenAddr)
	mux.HandleFunc("/", LogHandler(rproxy.ServeHTTP))

	err = http.ListenAndServe(listenAddr, mux)
	if err != nil {
		fmt.Println("Err:", err)
	}

}

type qlogHandler struct {
	http.ResponseWriter
	statusCode int
}

func (q *qlogHandler) WriteHeader(statusCode int) {
	q.statusCode = statusCode
	q.ResponseWriter.WriteHeader(statusCode)
}
func LogHandler(next http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		l := &qlogHandler{w, 200}
		next(l, r)
		log.Printf("%d - %s %s", l.statusCode, r.Method, r.URL)
	}
}