package app

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

var (
	wg = &sync.WaitGroup{}
)

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

	for name, item := range ProxyMap {
		wg.Add(1)
		go listenTcp(name, item)
	}

	wg.Wait()
}

func listenTcp(name string, item ProxyItem) {
	defer wg.Done()

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

		go proxyTcp(conn, item)
	}
}

func proxyTcp(conn net.Conn, item ProxyItem) {

	randRemoteAddr := item.RemoteAddr[rand.Intn(len(item.RemoteAddr))]

	remoteConn, err := net.Dial("tcp", randRemoteAddr)
	if err != nil {
		mylog.Errorf("connect remote err: %s\n", err)
		return
	}

	go copyConn(randRemoteAddr, conn, remoteConn)

}

func copyConn(addr string, conn, remoteConn net.Conn) {
	mylog.Infof("start proxy: %s", addr)

	wg2 := &sync.WaitGroup{}
	wg2.Add(2)

	go func() {
		_, err := io.Copy(conn, remoteConn)
		if err != nil {
			mylog.Error(err)
			return
		}
		wg2.Done()
	}()

	go func() {
		_, err := io.Copy(remoteConn, conn)
		if err != nil {
			mylog.Error(err)
			return
		}
		wg2.Done()
	}()

	wg2.Wait()

	mylog.Infof("stop proxy: %s", addr)

}