#!/usr/bin/env gosh
package main

// SimpleHTTPServer is a simple Go static file server, similar to the Python
// module of the same name, but which supports high concurrency and all the
// other niceties that you get from Go out of the box.
//
// It runs via my `gosh` wrapper for treating simple Go programs as shell
// scripts. See my `gosh` script, or just remove the shebang line at the top
// of this file to `go build` your own version.

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

// LogMiddleware logs all HTTP requests.
func LogMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		res := &ResponseWriter{w, 200}
		next.ServeHTTP(res, r)
		log.Printf("%s %d %s %s\n",
			r.RemoteAddr,
			res.Status,
			r.Method,
			r.RequestURI,
		)
	})
}

// ResponseWriter is my own wrapper around http.ResponseWriter that lets me
// capture its status code, for logging purposes.
type ResponseWriter struct {
	http.ResponseWriter
	Status int
}

// WriteHeader wraps http.WriteHeader to also capture the status code.
func (w *ResponseWriter) WriteHeader(code int) {
	w.ResponseWriter.WriteHeader(code)
	w.Status = code
}

func main() {
	// Command line flag: the port number to listen on.
	port := flag.Int("port", 8000, "The port number to listen on.")
	flag.Parse()

	fmt.Printf("Serving at http://0.0.0.0:%d/\n", *port)
	err := http.ListenAndServe(
		fmt.Sprintf(":%d", *port),
		LogMiddleware(http.FileServer(http.Dir("."))),
	)
	panic(err)
}