package main

import (
	"errors"
	"net"
	"net/http"
	"net/http/httputil"
	"net/url"
	"strings"
	"time"
)

type Proxy map[string]*url.URL

func (p *Proxy) Decode(value string) error {
	proxy := make(Proxy)

	for _, mapping := range strings.Split(value, ";") {
		parts := strings.Split(mapping, ",")
		for i := range parts {
			parts[i] = strings.TrimSpace(parts[i])
		}

		if parts[0] == "" || len(parts) != 2 {
			return errors.New("bad proxy map")
		}

		url, err := url.Parse(parts[1])
		if err != nil {
			return err
		}

		proxy[parts[0]] = url
	}

	*p = proxy
	return nil
}

func proxyHandler(target *url.URL) *httputil.ReverseProxy {
	p := httputil.NewSingleHostReverseProxy(target)
	p.FlushInterval = 100 * time.Millisecond
	p.Transport = &http.Transport{
		Proxy: http.ProxyFromEnvironment,
		Dial: (&net.Dialer{
			Timeout: 10 * time.Second,
		}).Dial,
	}
	return p
}