package kv

import (
	"context"
	"testing"

	"github.com/gogo/protobuf/proto"
	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
	"github.com/prysmaticlabs/prysm/shared/bytesutil"
	"github.com/prysmaticlabs/prysm/shared/params"
	"github.com/prysmaticlabs/prysm/shared/testutil"
	"github.com/prysmaticlabs/prysm/shared/testutil/assert"
	"github.com/prysmaticlabs/prysm/shared/testutil/require"
)

func TestStore_JustifiedCheckpoint_CanSaveRetrieve(t *testing.T) {
	db := setupDB(t)
	ctx := context.Background()
	root := bytesutil.ToBytes32([]byte{'A'})
	cp := &ethpb.Checkpoint{
		Epoch: 10,
		Root:  root[:],
	}
	st := testutil.NewBeaconState()
	require.NoError(t, st.SetSlot(1))
	require.NoError(t, db.SaveState(ctx, st, root))
	require.NoError(t, db.SaveJustifiedCheckpoint(ctx, cp))

	retrieved, err := db.JustifiedCheckpoint(ctx)
	require.NoError(t, err)
	assert.Equal(t, true, proto.Equal(cp, retrieved), "Wanted %v, received %v", cp, retrieved)
}

func TestStore_FinalizedCheckpoint_CanSaveRetrieve(t *testing.T) {
	db := setupDB(t)
	ctx := context.Background()

	genesis := bytesutil.ToBytes32([]byte{'G', 'E', 'N', 'E', 'S', 'I', 'S'})
	require.NoError(t, db.SaveGenesisBlockRoot(ctx, genesis))

	blk := testutil.NewBeaconBlock()
	blk.Block.ParentRoot = genesis[:]
	blk.Block.Slot = 40

	root, err := blk.Block.HashTreeRoot()
	require.NoError(t, err)

	cp := &ethpb.Checkpoint{
		Epoch: 5,
		Root:  root[:],
	}

	// a valid chain is required to save finalized checkpoint.
	require.NoError(t, db.SaveBlock(ctx, blk))
	st := testutil.NewBeaconState()
	require.NoError(t, st.SetSlot(1))
	// a state is required to save checkpoint
	require.NoError(t, db.SaveState(ctx, st, root))

	require.NoError(t, db.SaveFinalizedCheckpoint(ctx, cp))

	retrieved, err := db.FinalizedCheckpoint(ctx)
	require.NoError(t, err)
	assert.Equal(t, true, proto.Equal(cp, retrieved), "Wanted %v, received %v", cp, retrieved)
}

func TestStore_JustifiedCheckpoint_DefaultIsZeroHash(t *testing.T) {
	db := setupDB(t)
	ctx := context.Background()

	cp := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
	retrieved, err := db.JustifiedCheckpoint(ctx)
	require.NoError(t, err)
	assert.Equal(t, true, proto.Equal(cp, retrieved), "Wanted %v, received %v", cp, retrieved)
}

func TestStore_FinalizedCheckpoint_DefaultIsZeroHash(t *testing.T) {
	db := setupDB(t)
	ctx := context.Background()

	cp := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
	retrieved, err := db.FinalizedCheckpoint(ctx)
	require.NoError(t, err)
	assert.Equal(t, true, proto.Equal(cp, retrieved), "Wanted %v, received %v", cp, retrieved)
}

func TestStore_FinalizedCheckpoint_StateMustExist(t *testing.T) {
	db := setupDB(t)
	ctx := context.Background()
	cp := &ethpb.Checkpoint{
		Epoch: 5,
		Root:  []byte{'B'},
	}

	require.ErrorContains(t, errMissingStateForCheckpoint.Error(), db.SaveFinalizedCheckpoint(ctx, cp))
}