package main

import (
	"flag"
	"fmt"
	"html"
	"log"
	"net/http"
	"sort"
)

func RequestHandler(w http.ResponseWriter, r *http.Request) {

	fmt.Fprintf(w, "\"Host\": %q\n", html.EscapeString(r.Host))
	fmt.Fprintf(w, "\"IP\": %q\n", html.EscapeString(r.RemoteAddr))
	fmt.Fprintf(w, "\"Method\": %q\n", html.EscapeString(r.Method))
	fmt.Fprintf(w, "\"Proto\": %q\n", html.EscapeString(r.Proto))
	fmt.Fprintf(w, "\"URI\": %q\n", html.EscapeString(r.RequestURI))

	keys := make([]string, 0)
	for k, _ := range r.Header {
		keys = append(keys, k)
	}
	sort.Strings(keys)
	for _, k := range keys {
		for _, value := range r.Header[k] {
			fmt.Fprintf(w, "%q: %q\n", html.EscapeString(k), html.EscapeString(value))
		}
	}
}

func main() {

	var (
		host string
		port uint64
	)
	flag.StringVar(&host, "host", "127.0.0.1", "IP address to listen on")
	flag.Uint64Var(&port, "port", 8080, "Port to listen on (default 8080)")
	flag.Parse()

	http.HandleFunc("/", RequestHandler)
	fmt.Printf("Listening on %v port %v (http://%v:%v/)\n", host, port, host, port)
	log.Fatal(http.ListenAndServe(fmt.Sprintf("%s:%d", host, port), nil))
}