package main

import (
	"context"
	"flag"
	"fmt"
	smux "github.com/libp2p/go-libp2p-core/mux"
	tpt "github.com/libp2p/go-libp2p-core/transport"
	mplex "github.com/libp2p/go-libp2p-mplex"
	direct "github.com/libp2p/go-libp2p-webrtc-direct"
	ma "github.com/multiformats/go-multiaddr"
	"github.com/pion/webrtc/v3"
	"io/ioutil"
)

const listenFlag = "listen"

func main() {
	listening := flag.Bool(listenFlag, false, "Listen for incoming connections.")
	flag.Parse()

	maddr, err := ma.NewMultiaddr("/ip4/127.0.0.1/tcp/9090/http/p2p-webrtc-direct")
	check(err)

	transport := direct.NewTransport(
		webrtc.Configuration{},
		new(mplex.Transport),
	)

	if *listening {
		list, err := transport.Listen(maddr)
		check(err)
		defer list.Close()
		fmt.Println("[listener] Listening")

		for {
			c, err := list.Accept()
			check(err)

			fmt.Println("[listener] Got connection")

			go handleConn(c)
		}
	} else {
		ctx, cancel := context.WithCancel(context.Background())
		defer cancel()

		c, err := transport.Dial(ctx, maddr, "peerA")
		check(err)
		defer c.Close()
		fmt.Println("[dialer] Opened connection")

		s, err := c.OpenStream(context.Background())
		check(err)
		fmt.Println("[dialer] Opened stream")

		_, err = s.Write([]byte("hey, how is it going. I am the dialer"))
		check(err)

		err = s.Close()
		check(err)
	}
}

func handleConn(c tpt.CapableConn) {
	for {
		s, err := c.AcceptStream()
		if err != nil {
			return
		}

		fmt.Println("[listener] Got stream")
		go handleStream(s)
	}
}
func handleStream(s smux.MuxedStream) {
	b, err := ioutil.ReadAll(s)
	check(err)
	fmt.Println("[listener] Received:")
	fmt.Println(string(b))
}

func check(err error) {
	if err != nil {
		panic(err)
	}
}