package detection

import (
	"context"
	"reflect"
	"testing"

	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
	"github.com/prysmaticlabs/prysm/shared/bytesutil"
	testDB "github.com/prysmaticlabs/prysm/slasher/db/testing"
	status "github.com/prysmaticlabs/prysm/slasher/db/types"
	"github.com/prysmaticlabs/prysm/slasher/detection/attestations"
	"github.com/prysmaticlabs/prysm/slasher/detection/attestations/types"
	"github.com/prysmaticlabs/prysm/slasher/detection/proposals"
	testDetect "github.com/prysmaticlabs/prysm/slasher/detection/testing"
)

func TestDetect_detectAttesterSlashings_Surround(t *testing.T) {
	type testStruct struct {
		name           string
		savedAtts      []*ethpb.IndexedAttestation
		incomingAtt    *ethpb.IndexedAttestation
		slashingsFound int
	}
	tests := []testStruct{
		{
			name: "surrounding vote detected should report a slashing",
			savedAtts: []*ethpb.IndexedAttestation{
				{
					AttestingIndices: []uint64{3},
					Data: &ethpb.AttestationData{
						Source: &ethpb.Checkpoint{Epoch: 9},
						Target: &ethpb.Checkpoint{Epoch: 13},
					},
					Signature: bytesutil.PadTo([]byte{1, 2}, 96),
				},
			},
			incomingAtt: &ethpb.IndexedAttestation{
				AttestingIndices: []uint64{1, 3, 7},
				Data: &ethpb.AttestationData{
					Source: &ethpb.Checkpoint{Epoch: 7},
					Target: &ethpb.Checkpoint{Epoch: 14},
				},
			},
			slashingsFound: 1,
		},
		{
			name: "surrounded vote detected should report a slashing",
			savedAtts: []*ethpb.IndexedAttestation{
				{
					AttestingIndices: []uint64{0, 2, 4, 8},
					Data: &ethpb.AttestationData{
						Source: &ethpb.Checkpoint{Epoch: 6},
						Target: &ethpb.Checkpoint{Epoch: 10},
					},
					Signature: bytesutil.PadTo([]byte{1, 2}, 96),
				},
			},
			incomingAtt: &ethpb.IndexedAttestation{
				AttestingIndices: []uint64{0, 4},
				Data: &ethpb.AttestationData{
					Source: &ethpb.Checkpoint{Epoch: 7},
					Target: &ethpb.Checkpoint{Epoch: 9},
				},
			},
			slashingsFound: 1,
		},
		{
			name: "2 different surrounded votes detected should report 2 slashings",
			savedAtts: []*ethpb.IndexedAttestation{
				{
					AttestingIndices: []uint64{0, 2},
					Data: &ethpb.AttestationData{
						Source: &ethpb.Checkpoint{Epoch: 4},
						Target: &ethpb.Checkpoint{Epoch: 5},
					},
					Signature: bytesutil.PadTo([]byte{1, 2}, 96),
				},
				{
					AttestingIndices: []uint64{4, 8},
					Data: &ethpb.AttestationData{
						Source: &ethpb.Checkpoint{Epoch: 3},
						Target: &ethpb.Checkpoint{Epoch: 4},
					},
					Signature: bytesutil.PadTo([]byte{1, 3}, 96),
				},
			},
			incomingAtt: &ethpb.IndexedAttestation{
				AttestingIndices: []uint64{0, 4},
				Data: &ethpb.AttestationData{
					Source: &ethpb.Checkpoint{Epoch: 2},
					Target: &ethpb.Checkpoint{Epoch: 7},
				},
			},
			slashingsFound: 2,
		},
		{
			name: "2 different surrounding votes detected should report 2 slashings",
			savedAtts: []*ethpb.IndexedAttestation{
				{
					AttestingIndices: []uint64{0, 2},
					Data: &ethpb.AttestationData{
						Source: &ethpb.Checkpoint{Epoch: 4},
						Target: &ethpb.Checkpoint{Epoch: 10},
					},
					Signature: bytesutil.PadTo([]byte{1, 2}, 96),
				},
				{
					AttestingIndices: []uint64{4, 8},
					Data: &ethpb.AttestationData{
						Source: &ethpb.Checkpoint{Epoch: 5},
						Target: &ethpb.Checkpoint{Epoch: 9},
					},
					Signature: bytesutil.PadTo([]byte{1, 3}, 96),
				},
			},
			incomingAtt: &ethpb.IndexedAttestation{
				AttestingIndices: []uint64{0, 4},
				Data: &ethpb.AttestationData{
					Source: &ethpb.Checkpoint{Epoch: 7},
					Target: &ethpb.Checkpoint{Epoch: 8},
				},
			},
			slashingsFound: 2,
		},
		{
			name: "no slashable detected should not report a slashing",
			savedAtts: []*ethpb.IndexedAttestation{
				{
					AttestingIndices: []uint64{0},
					Data: &ethpb.AttestationData{
						Source: &ethpb.Checkpoint{Epoch: 1},
						Target: &ethpb.Checkpoint{Epoch: 2},
					},
					Signature: bytesutil.PadTo([]byte{1, 2}, 96),
				},
			},
			incomingAtt: &ethpb.IndexedAttestation{
				AttestingIndices: []uint64{0},
				Data: &ethpb.AttestationData{
					Source: &ethpb.Checkpoint{Epoch: 0},
					Target: &ethpb.Checkpoint{Epoch: 1},
				},
			},
			slashingsFound: 0,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			db := testDB.SetupSlasherDB(t, false)
			ctx := context.Background()
			ds := Service{
				ctx:                ctx,
				slasherDB:          db,
				minMaxSpanDetector: attestations.NewSpanDetector(db),
			}
			if err := db.SaveIndexedAttestations(ctx, tt.savedAtts); err != nil {
				t.Fatal(err)
			}
			for _, att := range tt.savedAtts {
				if err := ds.minMaxSpanDetector.UpdateSpans(ctx, att); err != nil {
					t.Fatal(err)
				}
			}

			slashings, err := ds.DetectAttesterSlashings(ctx, tt.incomingAtt)
			if err != nil {
				t.Fatal(err)
			}
			if len(slashings) != tt.slashingsFound {
				t.Fatalf("Unexpected amount of slashings found, received %d, expected %d", len(slashings), tt.slashingsFound)
			}
			attsl, err := db.AttesterSlashings(ctx, status.Active)
			if len(attsl) != tt.slashingsFound {
				t.Fatalf("Didnt save slashing to db")
			}
			for _, ss := range slashings {
				slashingAtt1 := ss.Attestation_1
				slashingAtt2 := ss.Attestation_2
				if !isSurrounding(slashingAtt1, slashingAtt2) {
					t.Fatalf(
						"Expected slashing to be valid, received atts %d->%d and %d->%d",
						slashingAtt2.Data.Source.Epoch,
						slashingAtt2.Data.Target.Epoch,
						slashingAtt1.Data.Source.Epoch,
						slashingAtt1.Data.Target.Epoch,
					)
				}
			}
		})
	}
}

func TestDetect_detectAttesterSlashings_Double(t *testing.T) {
	type testStruct struct {
		name           string
		savedAtts      []*ethpb.IndexedAttestation
		incomingAtt    *ethpb.IndexedAttestation
		slashingsFound int
	}
	tests := []testStruct{
		{
			name: "different source, same target, should report a slashing",
			savedAtts: []*ethpb.IndexedAttestation{
				{
					AttestingIndices: []uint64{3},
					Data: &ethpb.AttestationData{
						Source: &ethpb.Checkpoint{Epoch: 3},
						Target: &ethpb.Checkpoint{Epoch: 4},
					},
					Signature: bytesutil.PadTo([]byte{1, 2}, 96),
				},
			},
			incomingAtt: &ethpb.IndexedAttestation{
				AttestingIndices: []uint64{1, 3, 7},
				Data: &ethpb.AttestationData{
					Source: &ethpb.Checkpoint{Epoch: 2},
					Target: &ethpb.Checkpoint{Epoch: 4},
				},
				Signature: bytesutil.PadTo([]byte{1, 2}, 96),
			},
			slashingsFound: 1,
		},
		{
			name: "different histories, same target, should report 2 slashings",
			savedAtts: []*ethpb.IndexedAttestation{
				{
					AttestingIndices: []uint64{1},
					Data: &ethpb.AttestationData{
						Source: &ethpb.Checkpoint{Epoch: 3},
						Target: &ethpb.Checkpoint{Epoch: 4},
					},
					Signature: bytesutil.PadTo([]byte{1, 2}, 96),
				},
				{
					AttestingIndices: []uint64{3},
					Data: &ethpb.AttestationData{
						Source: &ethpb.Checkpoint{Epoch: 1},
						Target: &ethpb.Checkpoint{Epoch: 4},
					},
					Signature: bytesutil.PadTo([]byte{1, 3}, 96),
				},
			},
			incomingAtt: &ethpb.IndexedAttestation{
				AttestingIndices: []uint64{1, 3, 7},
				Data: &ethpb.AttestationData{
					Source: &ethpb.Checkpoint{Epoch: 2},
					Target: &ethpb.Checkpoint{Epoch: 4},
				},
				Signature: bytesutil.PadTo([]byte{1, 4}, 96),
			},
			slashingsFound: 2,
		},
		{
			name: "same source and target, different block root, should report a slashing ",
			savedAtts: []*ethpb.IndexedAttestation{
				{
					AttestingIndices: []uint64{0, 2, 4, 8},
					Data: &ethpb.AttestationData{
						Source:          &ethpb.Checkpoint{Epoch: 2},
						Target:          &ethpb.Checkpoint{Epoch: 4},
						BeaconBlockRoot: bytesutil.PadTo([]byte("good block root"), 32),
					},
					Signature: bytesutil.PadTo([]byte{1, 2}, 96),
				},
			},
			incomingAtt: &ethpb.IndexedAttestation{
				AttestingIndices: []uint64{0, 4},
				Data: &ethpb.AttestationData{
					Source:          &ethpb.Checkpoint{Epoch: 2},
					Target:          &ethpb.Checkpoint{Epoch: 4},
					BeaconBlockRoot: bytesutil.PadTo([]byte("bad block root"), 32),
				},
			},
			slashingsFound: 1,
		},
		{
			name: "same attestation should not report double",
			savedAtts: []*ethpb.IndexedAttestation{
				{
					AttestingIndices: []uint64{0},
					Data: &ethpb.AttestationData{
						Source:          &ethpb.Checkpoint{Epoch: 0},
						Target:          &ethpb.Checkpoint{Epoch: 2},
						BeaconBlockRoot: bytesutil.PadTo([]byte("good block root"), 32),
					},
					Signature: bytesutil.PadTo([]byte{1, 2}, 96),
				},
			},
			incomingAtt: &ethpb.IndexedAttestation{
				AttestingIndices: []uint64{0},
				Data: &ethpb.AttestationData{
					Source:          &ethpb.Checkpoint{Epoch: 0},
					Target:          &ethpb.Checkpoint{Epoch: 2},
					BeaconBlockRoot: bytesutil.PadTo([]byte("good block root"), 32),
				},
			},
			slashingsFound: 0,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			db := testDB.SetupSlasherDB(t, false)
			ctx := context.Background()
			ds := Service{
				ctx:                ctx,
				slasherDB:          db,
				minMaxSpanDetector: attestations.NewSpanDetector(db),
			}
			if err := db.SaveIndexedAttestations(ctx, tt.savedAtts); err != nil {
				t.Fatal(err)
			}
			for _, att := range tt.savedAtts {
				if err := ds.minMaxSpanDetector.UpdateSpans(ctx, att); err != nil {
					t.Fatal(err)
				}
			}

			slashings, err := ds.DetectAttesterSlashings(ctx, tt.incomingAtt)
			if err != nil {
				t.Fatal(err)
			}
			if len(slashings) != tt.slashingsFound {
				t.Fatalf("Unexpected amount of slashings found, received %d, expected %d", len(slashings), tt.slashingsFound)
			}
			savedSlashings, err := db.AttesterSlashings(ctx, status.Active)
			if len(savedSlashings) != tt.slashingsFound {
				t.Fatalf("Did not save slashing to db")
			}

			for _, ss := range slashings {
				slashingAtt1 := ss.Attestation_1
				slashingAtt2 := ss.Attestation_2
				if !isDoubleVote(slashingAtt1, slashingAtt2) {
					t.Fatalf(
						"Expected slashing to be valid, received atts with target epoch %d and %d but not valid",
						slashingAtt2.Data.Target.Epoch,
						slashingAtt1.Data.Target.Epoch,
					)
				}
			}

		})
	}
}

func TestDetect_detectProposerSlashing(t *testing.T) {
	type testStruct struct {
		name        string
		blk         *ethpb.SignedBeaconBlockHeader
		incomingBlk *ethpb.SignedBeaconBlockHeader
		slashing    *ethpb.ProposerSlashing
	}
	blk1slot0, err := testDetect.SignedBlockHeader(testDetect.StartSlot(0), 0)
	if err != nil {
		t.Fatal(err)
	}
	blk2slot0, err := testDetect.SignedBlockHeader(testDetect.StartSlot(0), 0)
	if err != nil {
		t.Fatal(err)
	}
	blk1epoch1, err := testDetect.SignedBlockHeader(testDetect.StartSlot(1), 0)
	if err != nil {
		t.Fatal(err)
	}
	tests := []testStruct{
		{
			name:        "same block sig dont slash",
			blk:         blk1slot0,
			incomingBlk: blk1slot0,
			slashing:    nil,
		},
		{
			name:        "block from different epoch dont slash",
			blk:         blk1slot0,
			incomingBlk: blk1epoch1,
			slashing:    nil,
		},
		{
			name:        "different sig from same slot slash",
			blk:         blk1slot0,
			incomingBlk: blk2slot0,
			slashing:    &ethpb.ProposerSlashing{Header_1: blk2slot0, Header_2: blk1slot0},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			db := testDB.SetupSlasherDB(t, false)
			ctx := context.Background()
			ds := Service{
				ctx:               ctx,
				slasherDB:         db,
				proposalsDetector: proposals.NewProposeDetector(db),
			}
			if err := db.SaveBlockHeader(ctx, tt.blk); err != nil {
				t.Fatal(err)
			}

			slashing, err := ds.proposalsDetector.DetectDoublePropose(ctx, tt.incomingBlk)
			if err != nil {
				t.Fatal(err)
			}
			if !reflect.DeepEqual(slashing, tt.slashing) {
				t.Errorf("Wanted: %v, received %v", tt.slashing, slashing)
			}
			savedSlashings, err := db.ProposalSlashingsByStatus(ctx, status.Active)
			if tt.slashing != nil && len(savedSlashings) != 1 {
				t.Fatalf("Did not save slashing to db")
			}

			if slashing != nil && !isDoublePropose(slashing.Header_1, slashing.Header_2) {
				t.Fatalf(
					"Expected slashing to be valid, received atts with target epoch %v and %v but not valid",
					slashing.Header_1,
					slashing.Header_2,
				)
			}

		})
	}
}

func TestServer_MapResultsToAtts(t *testing.T) {
	db := testDB.SetupSlasherDB(t, false)
	ctx := context.Background()
	ds := Service{
		ctx:       ctx,
		slasherDB: db,
	}
	// 3 unique results, but 7 validators in total.
	results := []*types.DetectionResult{
		// 3 For the same slashable epoch and same sigs.
		{
			ValidatorIndex: 1,
			SlashableEpoch: 5,
			Kind:           types.DoubleVote,
			SigBytes:       [2]byte{5, 5},
		},
		{
			ValidatorIndex: 2,
			SlashableEpoch: 5,
			Kind:           types.DoubleVote,
			SigBytes:       [2]byte{5, 5},
		},
		{
			ValidatorIndex: 3,
			SlashableEpoch: 5,
			Kind:           types.DoubleVote,
			SigBytes:       [2]byte{5, 5},
		},
		// Different signature.
		{
			ValidatorIndex: 5,
			SlashableEpoch: 5,
			Kind:           types.DoubleVote,
			SigBytes:       [2]byte{3, 5},
		},
		// Different slashable epoch.
		{
			ValidatorIndex: 5,
			SlashableEpoch: 4,
			Kind:           types.DoubleVote,
			SigBytes:       [2]byte{5, 5},
		},
		// Different both.
		{
			ValidatorIndex: 8,
			SlashableEpoch: 6,
			Kind:           types.DoubleVote,
			SigBytes:       [2]byte{2, 1},
		},
		{
			ValidatorIndex: 7,
			SlashableEpoch: 6,
			Kind:           types.DoubleVote,
			SigBytes:       [2]byte{2, 1},
		},
	}
	expectedResultsToAtts := map[[32]byte][]*ethpb.IndexedAttestation{
		resultHash(results[0]): {
			createIndexedAttForResult(results[0]),
			createIndexedAttForResult(results[1]),
			createIndexedAttForResult(results[2]),
		},
		resultHash(results[3]): {
			createIndexedAttForResult(results[3]),
		},
		resultHash(results[4]): {
			createIndexedAttForResult(results[4]),
		},
		resultHash(results[5]): {
			createIndexedAttForResult(results[6]),
			createIndexedAttForResult(results[5]),
		},
	}
	for _, atts := range expectedResultsToAtts {
		if err := ds.slasherDB.SaveIndexedAttestations(ctx, atts); err != nil {
			t.Fatal(err)
		}
	}

	resultsToAtts, err := ds.mapResultsToAtts(ctx, results)
	if err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(expectedResultsToAtts, resultsToAtts) {
		t.Error("Expected map:")
		for key, value := range resultsToAtts {
			t.Errorf("Key %#x: %d atts", key, len(value))
			t.Errorf("%+v", value)
		}
		t.Error("To equal:")
		for key, value := range expectedResultsToAtts {
			t.Errorf("Key %#x: %d atts", key, len(value))
			t.Errorf("%+v", value)
		}
	}
}

func createIndexedAttForResult(result *types.DetectionResult) *ethpb.IndexedAttestation {
	return &ethpb.IndexedAttestation{
		AttestingIndices: []uint64{result.ValidatorIndex},
		Data: &ethpb.AttestationData{
			BeaconBlockRoot: []byte("text block root"),
			Target: &ethpb.Checkpoint{
				Epoch: result.SlashableEpoch,
			},
		},
		Signature: append(result.SigBytes[:], []byte{uint8(result.ValidatorIndex), 4, 5, 6, 7, 8}...),
	}
}