package obfsvpn_test

import (
	"context"
	"io"
	"testing"
	"time"

	"gitlab.com/yawning/obfs4.git/common/ntor"

	"0xacab.org/leap/obfsvpn"
)

func TestRoundTrip(t *testing.T) {
	pair, err := ntor.NewKeypair(false)
	if err != nil {
		t.Fatalf("error generating keys: %v", err)
	}
	nodeID, err := ntor.NewNodeID(make([]byte, ntor.NodeIDLength))
	if err != nil {
		t.Fatalf("error creating node ID: %v", err)
	}
	lc := obfsvpn.ListenConfig{
		NodeID:     nodeID,
		PrivateKey: pair.Private(),
		StateDir:   t.TempDir(),
	}
	ln, err := lc.Listen(context.Background(), "tcp", ":0")
	if err != nil {
		t.Fatalf("error listening for incoming connection: %v", err)
	}

	const (
		clientSend  = `Though they broke my legs, they gave me a crutch to walk.`
		serverReply = `Her Majesty's a pretty nice girl, but she's pretty much obsolete.`
	)

	errs := make(chan error)
	serverRecv := make([]byte, len(clientSend))
	go func() {
		conn, err := ln.Accept()
		if err != nil {
			errs <- err
			return
		}
		_, err = conn.Read(serverRecv)
		if err != nil {
			errs <- err
			return
		}
		_, err = io.WriteString(conn, serverReply)
		if err != nil {
			errs <- err
			return
		}
	}()

	select {
	case err := <-errs:
		t.Fatalf("error accepting connection: %v", err)
	default:
	}
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	d := obfsvpn.Dialer{
		NodeID:    nodeID,
		PublicKey: pair.Public(),
	}
	conn, err := d.Dial(ctx, "tcp", ln.Addr().String())
	if err != nil {
		t.Fatalf("error dialing connection: %v", err)
	}
	_, err = io.WriteString(conn, clientSend)
	if err != nil {
		t.Fatalf("error writing client side: %v", err)
	}
	select {
	case err := <-errs:
		t.Fatalf("error reading server side: %v", err)
	default:
	}
	clientRecv := make([]byte, len(serverReply))
	_, err = conn.Read(clientRecv)
	if err != nil {
		t.Fatalf("error reading client side: %v", err)
	}
	select {
	case err := <-errs:
		t.Fatalf("error writing server side: %v", err)
	default:
	}

	if s := string(clientRecv); s != serverReply {
		t.Fatalf("wrong response from server: want=%q, got=%q", serverReply, s)
	}
	if s := string(serverRecv); s != clientSend {
		t.Fatalf("wrong request from client: want=%q, got=%q", clientSend, s)
	}
}