package main

import ("bufio"
	"strings"
	"net"
	"net/url"
	"net/http"
	"io/ioutil")

func panicOnErr(err error, msg string) {
	if err != nil {
		panic(msg+":"+err.Error())
	}
}

func byDial(req *http.Request) (*http.Response,error) {
	port := ""
	if ! strings.Contains(req.URL.Host,":") {
		port = ":80"
	}
	c,err := net.Dial("tcp",req.URL.Host+port)
	panicOnErr(err,"dial")

	req.Write(c)

	resp,err := http.ReadResponse(bufio.NewReader(c),req)
	panicOnErr(err,"read resp")

	return resp,nil
}

func byTransport(req *http.Request) (*http.Response,error) {

	resp,err := http.DefaultTransport.RoundTrip(req)
	panicOnErr(err,"read resp")

	return resp,nil
}

func byClient(req *http.Request) (*http.Response,error) {
	client := &http.Client{}
	return client.Do(req)
}
func reqBy(u *url.URL,f func(*http.Request)(*http.Response,error)) string {

	req,err := http.NewRequest("GET",u.String(),nil)
	panicOnErr(err,"newreq")

	resp,err := f(req)
	panicOnErr(err,"read resp")
	defer resp.Body.Close()

	b,err := ioutil.ReadAll(resp.Body)
	panicOnErr(err,"readall")

	return resp.Status+"\n'''"+string(b[:50])+"'''\n"
}

func main() {
	m := map[string]func(*http.Request)(*http.Response,error){
		"client":byClient,
		"transport":byTransport,
		"dial":byDial,
	}
	for _,urlStr := range []string{"http://tip.golang.org","http://t.co/UZqlvMMQ"} {
		println("GET",urlStr)
		u,err := url.Parse(urlStr)
		panicOnErr(err,"parse")
		for name,f := range m {
			println(name+":",reqBy(u,f))
		}
		println("====")
	}
}