package p2p

import (
	"context"
	"reflect"
	"sync"
	"testing"
	"time"

	"github.com/gogo/protobuf/proto"
	"github.com/libp2p/go-libp2p-core/network"
	testp2p "github.com/prysmaticlabs/prysm/beacon-chain/p2p/testing"
	testpb "github.com/prysmaticlabs/prysm/proto/testing"
	"github.com/prysmaticlabs/prysm/shared/testutil"
)

func TestService_Send(t *testing.T) {
	p1 := testp2p.NewTestP2P(t)
	p2 := testp2p.NewTestP2P(t)
	p1.Connect(p2)

	svc := &Service{
		host: p1.Host,
		cfg:  &Config{Encoding: "ssz"},
	}

	msg := &testpb.TestSimpleMessage{
		Foo: []byte("hello"),
		Bar: 55,
	}

	// Register testing topic.
	RPCTypeMapping[reflect.TypeOf(msg)] = "/testing/1"

	// Register external listener which will repeat the message back.
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		p2.SetStreamHandler("/testing/1/ssz", func(stream network.Stream) {
			rcvd := &testpb.TestSimpleMessage{}
			if err := svc.Encoding().DecodeWithLength(stream, rcvd); err != nil {
				t.Fatal(err)
			}
			if _, err := svc.Encoding().EncodeWithLength(stream, rcvd); err != nil {
				t.Fatal(err)
			}
			if err := stream.Close(); err != nil {
				t.Error(err)
			}
			wg.Done()
		})
	}()

	stream, err := svc.Send(context.Background(), msg, p2.Host.ID())
	if err != nil {
		t.Fatal(err)
	}

	testutil.WaitTimeout(&wg, 1*time.Second)

	rcvd := &testpb.TestSimpleMessage{}
	if err := svc.Encoding().DecodeWithLength(stream, rcvd); err != nil {
		t.Fatal(err)
	}
	if !proto.Equal(rcvd, msg) {
		t.Errorf("Expected identical message to be received. got %v want %v", rcvd, msg)
	}

}