package app

import (
	"git.makemake.in/test/mycommon/mylog"
	"io"
	"math/rand"
	"net"
	"sync"
	"time"
)

func Run() {
	rand.Seed(time.Now().UnixNano())

	for name, item := range ProxyMap {
		go listenTcp(name, item)
	}

	select {}
}

func listenTcp(name string, item ProxyItem) {

	listen, err := net.Listen("tcp", item.LocalAddr)
	if err != nil {
		mylog.Errorf("[%s] listen err: %s", name, err)
		return
	}

	mylog.Infof("[%s] listen %s", name, item.LocalAddr)

	for {
		localConn, err := listen.Accept()
		if err != nil {
			mylog.Errorf("conn accept err: %s", item.LocalAddr, err)
			return
		}

		go proxyTcp(localConn, item)
	}
}

func proxyTcp(localConn net.Conn, item ProxyItem) {
	randRemoteAddr := item.RemoteAddr[rand.Intn(len(item.RemoteAddr))]

	remoteConn, err := net.DialTimeout("tcp", randRemoteAddr, time.Second*3)
	if err != nil {
		localConn.Close()
		mylog.Errorf("connect remote err: %s", err)
		return
	}

	mylog.Infof("start proxy %s -> %s", localConn.RemoteAddr(), randRemoteAddr)

	wg0 := &sync.WaitGroup{}
	wg0.Add(2)
	go copyConn(wg0, localConn, remoteConn)
	go copyConn(wg0, remoteConn, localConn)
	wg0.Wait()

	mylog.Infof("stop proxy %s -> %s", localConn.RemoteAddr(), randRemoteAddr)

}

func copyConn(wg0 *sync.WaitGroup, localConn, remoteConn net.Conn) {
	defer func() {
		wg0.Done()
		localConn.Close()
		remoteConn.Close()
	}()

	_, err := io.Copy(remoteConn, localConn)
	if err != nil {
		mylog.Error(err)
	}

}