package forkchoice_test

import (
	"context"
	_ "embed"
	"fmt"
	"testing"

	"github.com/ledgerwatch/erigon/cl/antiquary/tests"
	"github.com/ledgerwatch/erigon/cl/cltypes/solid"
	"github.com/ledgerwatch/erigon/cl/phase1/core/state"
	"github.com/ledgerwatch/erigon/cl/phase1/forkchoice"
	"github.com/ledgerwatch/erigon/cl/phase1/forkchoice/fork_graph"
	"github.com/ledgerwatch/erigon/cl/pool"
	"github.com/ledgerwatch/erigon/cl/transition"
	"github.com/spf13/afero"

	libcommon "github.com/ledgerwatch/erigon-lib/common"

	"github.com/ledgerwatch/erigon/cl/clparams"
	"github.com/ledgerwatch/erigon/cl/cltypes"
	"github.com/ledgerwatch/erigon/cl/utils"
	"github.com/stretchr/testify/require"
)

//go:embed test_data/anchor_state.ssz_snappy
var anchorStateEncoded []byte

//go:embed test_data/block_0x3af8b5b42ca135c75b32abb32b3d71badb73695d3dc638bacfb6c8b7bcbee1a9.ssz_snappy
var block3aEncoded []byte

//go:embed test_data/block_0xc2788d6005ee2b92c3df2eff0aeab0374d155fa8ca1f874df305fa376ce334cf.ssz_snappy
var blockc2Encoded []byte

//go:embed test_data/block_0xd4503d46e43df56de4e19acb0f93b3b52087e422aace49a7c3816cf59bafb0ad.ssz_snappy
var blockd4Encoded []byte

//go:embed test_data/attestation_0xfb924d35b2888d9cd70e6879c1609e6cad7ea3b028a501967747d96e49068cb6.ssz_snappy
var attestationEncoded []byte

// this is consensus spec test altair/forkchoice/ex_ante/ex_ante_attestations_is_greater_than_proposer_boost_with_boost
func TestForkChoiceBasic(t *testing.T) {
	expectedCheckpoint := solid.NewCheckpointFromParameters(libcommon.HexToHash("0x564d76d91f66c1fb2977484a6184efda2e1c26dd01992e048353230e10f83201"), 0)

	// Decode test blocks
	block0x3a, block0xc2, block0xd4 := cltypes.NewSignedBeaconBlock(&clparams.MainnetBeaconConfig), cltypes.NewSignedBeaconBlock(&clparams.MainnetBeaconConfig), cltypes.NewSignedBeaconBlock(&clparams.MainnetBeaconConfig)
	require.NoError(t, utils.DecodeSSZSnappy(block0x3a, block3aEncoded, int(clparams.AltairVersion)))
	require.NoError(t, utils.DecodeSSZSnappy(block0xc2, blockc2Encoded, int(clparams.AltairVersion)))
	require.NoError(t, utils.DecodeSSZSnappy(block0xd4, blockd4Encoded, int(clparams.AltairVersion)))
	// decode test attestation
	testAttestation := &solid.Attestation{}
	require.NoError(t, utils.DecodeSSZSnappy(testAttestation, attestationEncoded, int(clparams.AltairVersion)))
	// Initialize forkchoice store
	anchorState := state.New(&clparams.MainnetBeaconConfig)
	require.NoError(t, utils.DecodeSSZSnappy(anchorState, anchorStateEncoded, int(clparams.AltairVersion)))
	pool := pool.NewOperationsPool(&clparams.MainnetBeaconConfig)
	store, err := forkchoice.NewForkChoiceStore(context.Background(), anchorState, nil, nil, pool, fork_graph.NewForkGraphDisk(anchorState, afero.NewMemMapFs()))
	require.NoError(t, err)
	// first steps
	store.OnTick(0)
	store.OnTick(12)
	require.NoError(t, store.OnBlock(block0x3a, false, true))
	// Check if we get correct status (1)
	require.Equal(t, store.Time(), uint64(12))
	require.Equal(t, store.ProposerBoostRoot(), libcommon.HexToHash("0xc9bd7bcb6dfa49dc4e5a67ca75e89062c36b5c300bc25a1b31db4e1a89306071"))
	require.Equal(t, store.JustifiedCheckpoint(), expectedCheckpoint)
	require.Equal(t, store.FinalizedCheckpoint(), expectedCheckpoint)
	headRoot, headSlot, err := store.GetHead()
	require.NoError(t, err)
	require.Equal(t, headRoot, libcommon.HexToHash("0xc9bd7bcb6dfa49dc4e5a67ca75e89062c36b5c300bc25a1b31db4e1a89306071"))
	require.Equal(t, headSlot, uint64(1))
	// process another tick and another block
	store.OnTick(36)
	require.NoError(t, store.OnBlock(block0xc2, false, true))
	// Check if we get correct status (2)
	require.Equal(t, store.Time(), uint64(36))
	require.Equal(t, store.ProposerBoostRoot(), libcommon.HexToHash("0x744cc484f6503462f0f3a5981d956bf4fcb3e57ab8687ed006467e05049ee033"))
	require.Equal(t, store.JustifiedCheckpoint(), expectedCheckpoint)
	require.Equal(t, store.FinalizedCheckpoint(), expectedCheckpoint)
	headRoot, headSlot, err = store.GetHead()
	require.NoError(t, err)
	require.Equal(t, headSlot, uint64(3))
	require.Equal(t, headRoot, libcommon.HexToHash("0x744cc484f6503462f0f3a5981d956bf4fcb3e57ab8687ed006467e05049ee033"))
	// last block
	require.NoError(t, store.OnBlock(block0xd4, false, true))
	require.Equal(t, store.Time(), uint64(36))
	require.Equal(t, store.ProposerBoostRoot(), libcommon.HexToHash("0x744cc484f6503462f0f3a5981d956bf4fcb3e57ab8687ed006467e05049ee033"))
	require.Equal(t, store.JustifiedCheckpoint(), expectedCheckpoint)
	require.Equal(t, store.FinalizedCheckpoint(), expectedCheckpoint)
	headRoot, headSlot, err = store.GetHead()
	require.NoError(t, err)
	require.Equal(t, headSlot, uint64(3))
	require.Equal(t, headRoot, libcommon.HexToHash("0x744cc484f6503462f0f3a5981d956bf4fcb3e57ab8687ed006467e05049ee033"))
	// lastly do attestation
	require.NoError(t, store.OnAttestation(testAttestation, false, false))
	// Try processing a voluntary exit
	err = store.OnVoluntaryExit(&cltypes.SignedVoluntaryExit{
		VoluntaryExit: &cltypes.VoluntaryExit{
			Epoch:          0,
			ValidatorIndex: 0,
		},
	}, true)
	require.NoError(t, err)
	// Try processing a bls execution change exit
	err = store.OnBlsToExecutionChange(&cltypes.SignedBLSToExecutionChange{
		Message: &cltypes.BLSToExecutionChange{
			ValidatorIndex: 0,
		},
	}, true)
	require.NoError(t, err)
	require.Equal(t, len(pool.VoluntaryExistsPool.Raw()), 1)
}

func TestForkChoiceChainBellatrix(t *testing.T) {
	blocks, anchorState, _ := tests.GetBellatrixRandom()

	intermediaryState, err := anchorState.Copy()
	require.NoError(t, err)

	intermediaryBlockRoot := blocks[0].Block.ParentRoot
	for i := 0; i < 35; i++ {
		require.NoError(t, transition.TransitionState(intermediaryState, blocks[i], nil, false))
		intermediaryBlockRoot, err = blocks[i].Block.HashSSZ()
		require.NoError(t, err)
	}
	// Initialize forkchoice store
	pool := pool.NewOperationsPool(&clparams.MainnetBeaconConfig)
	store, err := forkchoice.NewForkChoiceStore(context.Background(), anchorState, nil, nil, pool, fork_graph.NewForkGraphDisk(anchorState, afero.NewMemMapFs()))
	store.OnTick(2000)
	require.NoError(t, err)
	for _, block := range blocks {
		require.NoError(t, store.OnBlock(block, false, true))
	}
	root1, err := blocks[20].Block.HashSSZ()
	require.NoError(t, err)

	rewards, ok := store.BlockRewards(libcommon.Hash(root1))
	require.True(t, ok)
	require.Equal(t, rewards.Attestations, uint64(0x511ad))
	// test randao mix
	mixes := solid.NewHashVector(int(clparams.MainnetBeaconConfig.EpochsPerHistoricalVector))
	require.True(t, store.RandaoMixes(intermediaryBlockRoot, mixes))
	for i := 0; i < mixes.Length(); i++ {
		require.Equal(t, mixes.Get(i), intermediaryState.RandaoMixes().Get(i), fmt.Sprintf("mixes mismatch at index %d, have: %x, expected: %x", i, mixes.Get(i), intermediaryState.RandaoMixes().Get(i)))
	}
	currentIntermediarySyncCommittee, nextIntermediarySyncCommittee, ok := store.GetSyncCommittees(intermediaryBlockRoot)
	require.True(t, ok)

	require.Equal(t, intermediaryState.CurrentSyncCommittee(), currentIntermediarySyncCommittee)
	require.Equal(t, intermediaryState.NextSyncCommittee(), nextIntermediarySyncCommittee)
}