package rpc

import (
	"context"
	"errors"
	"math/big"
	"reflect"
	"testing"
	"time"

	"github.com/prysmaticlabs/prysm/shared/event"

	ptypes "github.com/gogo/protobuf/types"
	"github.com/golang/mock/gomock"
	"github.com/prysmaticlabs/prysm/beacon-chain/db"
	"github.com/prysmaticlabs/prysm/beacon-chain/internal"
	pbp2p "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
	pb "github.com/prysmaticlabs/prysm/proto/beacon/rpc/v1"
	"github.com/prysmaticlabs/prysm/shared/params"
	"github.com/prysmaticlabs/prysm/shared/testutil"
	logTest "github.com/sirupsen/logrus/hooks/test"
)

type faultyPOWChainService struct {
	chainStartFeed *event.Feed
}

func (f *faultyPOWChainService) HasChainStartLogOccurred() (bool, uint64, error) {
	return false, uint64(time.Now().Unix()), nil
}
func (f *faultyPOWChainService) ChainStartFeed() *event.Feed {
	return f.chainStartFeed
}
func (f *faultyPOWChainService) LatestBlockNumber() *big.Int {
	return big.NewInt(0)
}

type mockPOWChainService struct {
	chainStartFeed    *event.Feed
	latestBlockNumber *big.Int
}

func (m *mockPOWChainService) HasChainStartLogOccurred() (bool, uint64, error) {
	return true, uint64(time.Unix(0, 0).Unix()), nil
}
func (m *mockPOWChainService) ChainStartFeed() *event.Feed {
	return m.chainStartFeed
}
func (m *mockPOWChainService) LatestBlockNumber() *big.Int {
	return m.latestBlockNumber
}

func TestWaitForChainStart_ContextClosed(t *testing.T) {
	hook := logTest.NewGlobal()
	ctx, cancel := context.WithCancel(context.Background())
	beaconServer := &BeaconServer{
		ctx: ctx,
		powChainService: &faultyPOWChainService{
			chainStartFeed: new(event.Feed),
		},
	}
	exitRoutine := make(chan bool)
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()
	mockStream := internal.NewMockBeaconService_WaitForChainStartServer(ctrl)
	go func(tt *testing.T) {
		if err := beaconServer.WaitForChainStart(&ptypes.Empty{}, mockStream); err != nil {
			tt.Errorf("Could not call RPC method: %v", err)
		}
		<-exitRoutine
	}(t)
	cancel()
	exitRoutine <- true
	testutil.AssertLogsContain(t, hook, "RPC context closed, exiting goroutine")
}

func TestWaitForChainStart_AlreadyStarted(t *testing.T) {
	beaconServer := &BeaconServer{
		ctx: context.Background(),
		powChainService: &mockPOWChainService{
			chainStartFeed: new(event.Feed),
		},
	}
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()
	mockStream := internal.NewMockBeaconService_WaitForChainStartServer(ctrl)
	mockStream.EXPECT().Send(
		&pb.ChainStartResponse{
			Started:     true,
			GenesisTime: uint64(time.Unix(0, 0).Unix()),
		},
	).Return(nil)
	if err := beaconServer.WaitForChainStart(&ptypes.Empty{}, mockStream); err != nil {
		t.Errorf("Could not call RPC method: %v", err)
	}
}

func TestWaitForChainStart_NotStartedThenLogFired(t *testing.T) {
	hook := logTest.NewGlobal()
	beaconServer := &BeaconServer{
		ctx:            context.Background(),
		chainStartChan: make(chan time.Time, 1),
		powChainService: &faultyPOWChainService{
			chainStartFeed: new(event.Feed),
		},
	}
	exitRoutine := make(chan bool)
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()
	mockStream := internal.NewMockBeaconService_WaitForChainStartServer(ctrl)
	mockStream.EXPECT().Send(
		&pb.ChainStartResponse{
			Started:     true,
			GenesisTime: uint64(time.Unix(0, 0).Unix()),
		},
	).Return(nil)
	go func(tt *testing.T) {
		if err := beaconServer.WaitForChainStart(&ptypes.Empty{}, mockStream); err != nil {
			tt.Errorf("Could not call RPC method: %v", err)
		}
		<-exitRoutine
	}(t)
	beaconServer.chainStartChan <- time.Unix(0, 0)
	exitRoutine <- true
	testutil.AssertLogsContain(t, hook, "Sending ChainStart log and genesis time to connected validator clients")
}

func TestLatestAttestation_ContextClosed(t *testing.T) {
	hook := logTest.NewGlobal()
	mockOperationService := &mockOperationService{}
	ctx, cancel := context.WithCancel(context.Background())
	beaconServer := &BeaconServer{
		ctx:              ctx,
		operationService: mockOperationService,
	}
	exitRoutine := make(chan bool)
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()
	mockStream := internal.NewMockBeaconService_LatestAttestationServer(ctrl)
	go func(tt *testing.T) {
		if err := beaconServer.LatestAttestation(&ptypes.Empty{}, mockStream); err != nil {
			tt.Errorf("Could not call RPC method: %v", err)
		}
		<-exitRoutine
	}(t)
	cancel()
	exitRoutine <- true
	testutil.AssertLogsContain(t, hook, "RPC context closed, exiting goroutine")
}

func TestLatestAttestation_FaultyServer(t *testing.T) {
	mockOperationService := &mockOperationService{}
	ctx, cancel := context.WithCancel(context.Background())
	beaconServer := &BeaconServer{
		ctx:                 ctx,
		operationService:    mockOperationService,
		incomingAttestation: make(chan *pbp2p.Attestation, 0),
	}
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	exitRoutine := make(chan bool)
	attestation := &pbp2p.Attestation{}

	mockStream := internal.NewMockBeaconService_LatestAttestationServer(ctrl)
	mockStream.EXPECT().Send(attestation).Return(errors.New("something wrong"))
	// Tests a faulty stream.
	go func(tt *testing.T) {
		if err := beaconServer.LatestAttestation(&ptypes.Empty{}, mockStream); err.Error() != "something wrong" {
			tt.Errorf("Faulty stream should throw correct error, wanted 'something wrong', got %v", err)
		}
		<-exitRoutine
	}(t)

	beaconServer.incomingAttestation <- attestation
	cancel()
	exitRoutine <- true
}

func TestLatestAttestation_SendsCorrectly(t *testing.T) {
	hook := logTest.NewGlobal()
	operationService := &mockOperationService{}
	ctx, cancel := context.WithCancel(context.Background())
	beaconServer := &BeaconServer{
		ctx:                 ctx,
		operationService:    operationService,
		incomingAttestation: make(chan *pbp2p.Attestation, 0),
	}
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	exitRoutine := make(chan bool)
	attestation := &pbp2p.Attestation{}
	mockStream := internal.NewMockBeaconService_LatestAttestationServer(ctrl)
	mockStream.EXPECT().Send(attestation).Return(nil)
	// Tests a good stream.
	go func(tt *testing.T) {
		if err := beaconServer.LatestAttestation(&ptypes.Empty{}, mockStream); err != nil {
			tt.Errorf("Could not call RPC method: %v", err)
		}
		<-exitRoutine
	}(t)
	beaconServer.incomingAttestation <- attestation
	cancel()
	exitRoutine <- true

	testutil.AssertLogsContain(t, hook, "Sending attestation to RPC clients")
}

func TestPendingDeposits_ReturnsErrorOnUnknownBlockNum(t *testing.T) {
	p := &mockPOWChainService{
		latestBlockNumber: nil,
	}
	bs := BeaconServer{powChainService: p}

	_, err := bs.PendingDeposits(context.Background(), nil)
	if err.Error() != "latest PoW block number is unknown" {
		t.Errorf("Received unexpected error: %v", err)
	}
}

func TestPendingDeposits_ReturnsDepositsOutsideEth1FollowWindow(t *testing.T) {
	p := &mockPOWChainService{
		latestBlockNumber: big.NewInt(int64(10 + params.BeaconConfig().Eth1FollowDistance)),
	}
	d := &db.BeaconDB{}

	// Using the merkleTreeIndex as the block number for this test...
	readyDeposits := []*pbp2p.Deposit{
		{
			MerkleTreeIndex: 1,
		},
		{
			MerkleTreeIndex: 2,
		},
	}

	recentDeposits := []*pbp2p.Deposit{
		{
			MerkleTreeIndex: params.BeaconConfig().Eth1FollowDistance + 100,
		},
		{
			MerkleTreeIndex: params.BeaconConfig().Eth1FollowDistance + 101,
		},
	}
	ctx := context.Background()
	for _, dp := range append(recentDeposits, readyDeposits...) {
		d.InsertPendingDeposit(ctx, dp, big.NewInt(int64(dp.MerkleTreeIndex)))
	}

	bs := &BeaconServer{
		beaconDB:        d,
		powChainService: p,
	}

	result, err := bs.PendingDeposits(ctx, nil)
	if err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(result.PendingDeposits, readyDeposits) {
		t.Errorf("Received unexpected list of deposits: %+v, wanted: %+v", result, readyDeposits)
	}

	// It should also return the recent deposits after their follow window.
	p.latestBlockNumber = big.NewInt(0).Add(p.latestBlockNumber, big.NewInt(10000))
	allResp, err := bs.PendingDeposits(ctx, nil)
	if err != nil {
		t.Fatal(err)
	}
	if len(allResp.PendingDeposits) != len(recentDeposits)+len(readyDeposits) {
		t.Errorf(
			"Received unexpected number of pending deposits: %d, wanted: %d",
			len(allResp.PendingDeposits),
			len(recentDeposits)+len(readyDeposits),
		)
	}
}