package sync

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

	"github.com/gogo/protobuf/proto"
	pb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
	"github.com/prysmaticlabs/go-ssz"
	mockChain "github.com/prysmaticlabs/prysm/beacon-chain/blockchain/testing"
	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
	db "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
	"github.com/prysmaticlabs/prysm/beacon-chain/operations/slashings"
	"github.com/prysmaticlabs/prysm/beacon-chain/p2p"
	p2ptest "github.com/prysmaticlabs/prysm/beacon-chain/p2p/testing"
	mockSync "github.com/prysmaticlabs/prysm/beacon-chain/sync/initial-sync/testing"
	"github.com/prysmaticlabs/prysm/shared/bls"
	"github.com/prysmaticlabs/prysm/shared/bytesutil"
	"github.com/prysmaticlabs/prysm/shared/params"
	"github.com/prysmaticlabs/prysm/shared/testutil"
)

func TestSubscribe_ReceivesValidMessage(t *testing.T) {
	p2p := p2ptest.NewTestP2P(t)
	r := Service{
		ctx:         context.Background(),
		p2p:         p2p,
		initialSync: &mockSync.Sync{IsSyncing: false},
	}
	topic := "/eth2/voluntary_exit"
	var wg sync.WaitGroup
	wg.Add(1)

	r.subscribe(topic, r.noopValidator, func(_ context.Context, msg proto.Message) error {
		m := msg.(*pb.SignedVoluntaryExit)
		if m.Exit == nil || m.Exit.Epoch != 55 {
			t.Errorf("Unexpected incoming message: %+v", m)
		}
		wg.Done()
		return nil
	})
	r.chainStarted = true

	p2p.ReceivePubSub(topic, &pb.SignedVoluntaryExit{Exit: &pb.VoluntaryExit{Epoch: 55}})

	if testutil.WaitTimeout(&wg, time.Second) {
		t.Fatal("Did not receive PubSub in 1 second")
	}
}

func TestSubscribe_ReceivesAttesterSlashing(t *testing.T) {
	p2p := p2ptest.NewTestP2P(t)
	ctx := context.Background()
	d := db.SetupDB(t)
	defer db.TeardownDB(t, d)
	chainService := &mockChain.ChainService{}
	r := Service{
		ctx:          ctx,
		p2p:          p2p,
		initialSync:  &mockSync.Sync{IsSyncing: false},
		slashingPool: slashings.NewPool(),
		chain:        chainService,
		db:           d,
	}
	topic := "/eth2/attester_slashing"
	var wg sync.WaitGroup
	wg.Add(1)
	params.OverrideBeaconConfig(params.MinimalSpecConfig())
	r.subscribe(topic, r.noopValidator, func(ctx context.Context, msg proto.Message) error {
		r.attesterSlashingSubscriber(ctx, msg)
		wg.Done()
		return nil
	})
	beaconState, privKeys := testutil.DeterministicGenesisState(t, params.BeaconConfig().MinGenesisActiveValidatorCount)
	chainService.State = beaconState
	r.chainStarted = true
	attesterSlashing, err := testutil.GenerateAttesterSlashingForValidator(
		beaconState,
		privKeys[1],
		1, /* validator index */
	)
	if err != nil {
		t.Fatalf("Error generating attester slashing")
	}
	r.db.SaveState(ctx, beaconState, bytesutil.ToBytes32(attesterSlashing.Attestation_1.Data.BeaconBlockRoot))
	p2p.ReceivePubSub(topic, attesterSlashing)

	if testutil.WaitTimeout(&wg, time.Second) {
		t.Fatal("Did not receive PubSub in 1 second")
	}
	as := r.slashingPool.PendingAttesterSlashings(ctx)
	if len(as) != 1 {
		t.Errorf("Expected attester slashing: %v to be added to slashing pool. got: %v", attesterSlashing, as[0])
	}
}

func TestSubscribe_ReceivesProposerSlashing(t *testing.T) {
	p2p := p2ptest.NewTestP2P(t)
	ctx := context.Background()
	chainService := &mockChain.ChainService{}
	d := db.SetupDB(t)
	defer db.TeardownDB(t, d)
	r := Service{
		ctx:          ctx,
		p2p:          p2p,
		initialSync:  &mockSync.Sync{IsSyncing: false},
		slashingPool: slashings.NewPool(),
		chain:        chainService,
		db:           d,
	}
	topic := "/eth2/proposer_slashing"
	var wg sync.WaitGroup
	wg.Add(1)
	params.OverrideBeaconConfig(params.MinimalSpecConfig())
	r.subscribe(topic, r.noopValidator, func(ctx context.Context, msg proto.Message) error {
		r.proposerSlashingSubscriber(ctx, msg)
		wg.Done()
		return nil
	})
	beaconState, privKeys := testutil.DeterministicGenesisState(t, params.BeaconConfig().MinGenesisActiveValidatorCount)
	chainService.State = beaconState
	r.chainStarted = true
	proposerSlashing, err := testutil.GenerateProposerSlashingForValidator(
		beaconState,
		privKeys[1],
		1, /* validator index */
	)
	if err != nil {
		t.Fatalf("Error generating proposer slashing")
	}
	root, err := ssz.HashTreeRoot(proposerSlashing.Header_1.Header)
	r.db.SaveState(ctx, beaconState, root)
	p2p.ReceivePubSub(topic, proposerSlashing)

	if testutil.WaitTimeout(&wg, time.Second) {
		t.Fatal("Did not receive PubSub in 1 second")
	}
	ps := r.slashingPool.PendingProposerSlashings(ctx)
	if len(ps) != 1 {
		t.Errorf("Expected proposer slashing: %v to be added to slashing pool. got: %v", proposerSlashing, ps[0])
	}
}

func TestSubscribe_WaitToSync(t *testing.T) {
	p2p := p2ptest.NewTestP2P(t)
	chainService := &mockChain.ChainService{}
	r := Service{
		ctx:           context.Background(),
		p2p:           p2p,
		chain:         chainService,
		stateNotifier: chainService.StateNotifier(),
		initialSync:   &mockSync.Sync{IsSyncing: false},
	}

	topic := "/eth2/beacon_block"
	r.registerSubscribers()
	i := r.stateNotifier.StateFeed().Send(&feed.Event{
		Type: statefeed.Initialized,
		Data: &statefeed.InitializedData{
			StartTime: time.Now(),
		},
	})
	if i == 0 {
		t.Fatal("didn't send genesis time to subscribers")
	}
	b := []byte("sk")
	b32 := bytesutil.ToBytes32(b)
	sk, err := bls.SecretKeyFromBytes(b32[:])
	if err != nil {
		t.Fatal(err)
	}

	msg := &pb.SignedBeaconBlock{
		Block: &pb.BeaconBlock{
			ParentRoot: testutil.Random32Bytes(t),
		},
		Signature: sk.Sign([]byte("data"), 0).Marshal(),
	}
	p2p.ReceivePubSub(topic, msg)
	// wait for chainstart to be sent
	time.Sleep(400 * time.Millisecond)
	if !r.chainStarted {
		t.Fatal("Did not receive chain start event.")
	}

}

func TestSubscribe_HandlesPanic(t *testing.T) {
	p := p2ptest.NewTestP2P(t)
	r := Service{
		ctx: context.Background(),
		p2p: p,
	}

	topic := p2p.GossipTypeMapping[reflect.TypeOf(&pb.SignedVoluntaryExit{})]
	var wg sync.WaitGroup
	wg.Add(1)

	r.subscribe(topic, r.noopValidator, func(_ context.Context, msg proto.Message) error {
		defer wg.Done()
		panic("bad")
	})
	r.chainStarted = true
	p.ReceivePubSub(topic, &pb.SignedVoluntaryExit{Exit: &pb.VoluntaryExit{Epoch: 55}})

	if testutil.WaitTimeout(&wg, time.Second) {
		t.Fatal("Did not receive PubSub in 1 second")
	}
}