package blockchain

import (
	"context"
	"testing"
	"time"

	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
	"github.com/prysmaticlabs/prysm/shared/params"
	"github.com/prysmaticlabs/prysm/shared/testutil"
	"github.com/prysmaticlabs/prysm/shared/testutil/require"
)

func TestAttestationCheckPtState_FarFutureSlot(t *testing.T) {
	helpers.ClearCache()
	beaconDB := testDB.SetupDB(t)

	chainService := setupBeaconChain(t, beaconDB)
	chainService.genesisTime = time.Now()

	e := helpers.MaxSlotBuffer/params.BeaconConfig().SlotsPerEpoch + 1
	_, err := chainService.AttestationPreState(context.Background(), &ethpb.Attestation{Data: &ethpb.AttestationData{Target: &ethpb.Checkpoint{Epoch: e}}})
	require.ErrorContains(t, "exceeds max allowed value relative to the local clock", err)
}

func TestVerifyLMDFFGConsistent_NotOK(t *testing.T) {
	ctx := context.Background()
	beaconDB := testDB.SetupDB(t)

	cfg := &Config{BeaconDB: beaconDB, ForkChoiceStore: protoarray.New(0, 0, [32]byte{})}
	service, err := NewService(ctx, cfg)
	require.NoError(t, err)

	b32 := testutil.NewBeaconBlock()
	b32.Block.Slot = 32
	require.NoError(t, service.beaconDB.SaveBlock(ctx, b32))
	r32, err := b32.Block.HashTreeRoot()
	require.NoError(t, err)
	b33 := testutil.NewBeaconBlock()
	b33.Block.Slot = 33
	b33.Block.ParentRoot = r32[:]
	require.NoError(t, service.beaconDB.SaveBlock(ctx, b33))
	r33, err := b33.Block.HashTreeRoot()
	require.NoError(t, err)

	wanted := "FFG and LMD votes are not consistent"
	a := testutil.NewAttestation()
	a.Data.Target.Epoch = 1
	a.Data.Target.Root = []byte{'a'}
	a.Data.BeaconBlockRoot = r33[:]
	require.ErrorContains(t, wanted, service.VerifyLmdFfgConsistency(context.Background(), a))
}

func TestVerifyLMDFFGConsistent_OK(t *testing.T) {
	ctx := context.Background()
	beaconDB := testDB.SetupDB(t)

	cfg := &Config{BeaconDB: beaconDB, ForkChoiceStore: protoarray.New(0, 0, [32]byte{})}
	service, err := NewService(ctx, cfg)
	require.NoError(t, err)

	b32 := testutil.NewBeaconBlock()
	b32.Block.Slot = 32
	require.NoError(t, service.beaconDB.SaveBlock(ctx, b32))
	r32, err := b32.Block.HashTreeRoot()
	require.NoError(t, err)
	b33 := testutil.NewBeaconBlock()
	b33.Block.Slot = 33
	b33.Block.ParentRoot = r32[:]
	require.NoError(t, service.beaconDB.SaveBlock(ctx, b33))
	r33, err := b33.Block.HashTreeRoot()
	require.NoError(t, err)

	a := testutil.NewAttestation()
	a.Data.Target.Epoch = 1
	a.Data.Target.Root = r32[:]
	a.Data.BeaconBlockRoot = r33[:]
	err = service.VerifyLmdFfgConsistency(context.Background(), a)
	require.NoError(t, err, "Could not verify LMD and FFG votes to be consistent")
}