package dao

import (
	"encoding/binary"
	"errors"
	"testing"

	"github.com/nspcc-dev/neo-go/internal/random"
	"github.com/nspcc-dev/neo-go/pkg/core/block"
	"github.com/nspcc-dev/neo-go/pkg/core/state"
	"github.com/nspcc-dev/neo-go/pkg/core/storage"
	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
	"github.com/nspcc-dev/neo-go/pkg/io"
	"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
	"github.com/nspcc-dev/neo-go/pkg/util"
	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
	"github.com/stretchr/testify/require"
)

func TestPutGetAndDecode(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), false, false)
	serializable := &TestSerializable{field: random.String(4)}
	hash := []byte{1}
	err := dao.Put(serializable, hash)
	require.NoError(t, err)

	gotAndDecoded := &TestSerializable{}
	err = dao.GetAndDecode(gotAndDecoded, hash)
	require.NoError(t, err)
}

// TestSerializable structure used in testing.
type TestSerializable struct {
	field string
}

func (t *TestSerializable) EncodeBinary(writer *io.BinWriter) {
	writer.WriteString(t.field)
}

func (t *TestSerializable) DecodeBinary(reader *io.BinReader) {
	t.field = reader.ReadString()
}

func TestPutGetAppExecResult(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), false, false)
	hash := random.Uint256()
	appExecResult := &state.AppExecResult{
		Container: hash,
		Execution: state.Execution{
			Trigger: trigger.Application,
			Events:  []state.NotificationEvent{},
			Stack:   []stackitem.Item{},
		},
	}
	err := dao.AppendAppExecResult(appExecResult, nil)
	require.NoError(t, err)
	gotAppExecResult, err := dao.GetAppExecResults(hash, trigger.All)
	require.NoError(t, err)
	require.Equal(t, []state.AppExecResult{*appExecResult}, gotAppExecResult)
}

func TestPutGetStorageItem(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), false, false)
	id := int32(random.Int(0, 1024))
	key := []byte{0}
	storageItem := state.StorageItem{}
	err := dao.PutStorageItem(id, key, storageItem)
	require.NoError(t, err)
	gotStorageItem := dao.GetStorageItem(id, key)
	require.Equal(t, storageItem, gotStorageItem)
}

func TestDeleteStorageItem(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), false, false)
	id := int32(random.Int(0, 1024))
	key := []byte{0}
	storageItem := state.StorageItem{}
	err := dao.PutStorageItem(id, key, storageItem)
	require.NoError(t, err)
	err = dao.DeleteStorageItem(id, key)
	require.NoError(t, err)
	gotStorageItem := dao.GetStorageItem(id, key)
	require.Nil(t, gotStorageItem)
}

func TestGetBlock_NotExists(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), false, false)
	hash := random.Uint256()
	block, err := dao.GetBlock(hash)
	require.Error(t, err)
	require.Nil(t, block)
}

func TestPutGetBlock(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), false, false)
	b := &block.Block{
		Header: block.Header{
			Script: transaction.Witness{
				VerificationScript: []byte{byte(opcode.PUSH1)},
				InvocationScript:   []byte{byte(opcode.NOP)},
			},
		},
	}
	hash := b.Hash()
	err := dao.StoreAsBlock(b, nil)
	require.NoError(t, err)
	gotBlock, err := dao.GetBlock(hash)
	require.NoError(t, err)
	require.NotNil(t, gotBlock)
}

func TestGetVersion_NoVersion(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), false, false)
	version, err := dao.GetVersion()
	require.Error(t, err)
	require.Equal(t, "", version.Value)
}

func TestGetVersion(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), false, false)
	expected := Version{
		StoragePrefix:     0x42,
		P2PSigExtensions:  true,
		StateRootInHeader: true,
		Value:             "testVersion",
	}
	err := dao.PutVersion(expected)
	require.NoError(t, err)
	actual, err := dao.GetVersion()
	require.NoError(t, err)
	require.Equal(t, expected, actual)

	t.Run("invalid", func(t *testing.T) {
		dao := NewSimple(storage.NewMemoryStore(), false, false)
		require.NoError(t, dao.Store.Put(storage.SYSVersion.Bytes(), []byte("0.1.2\x00x")))

		_, err := dao.GetVersion()
		require.Error(t, err)
	})
	t.Run("old format", func(t *testing.T) {
		dao := NewSimple(storage.NewMemoryStore(), false, false)
		require.NoError(t, dao.Store.Put(storage.SYSVersion.Bytes(), []byte("0.1.2")))

		version, err := dao.GetVersion()
		require.NoError(t, err)
		require.Equal(t, "0.1.2", version.Value)
	})
}

func TestGetCurrentHeaderHeight_NoHeader(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), false, false)
	height, err := dao.GetCurrentBlockHeight()
	require.Error(t, err)
	require.Equal(t, uint32(0), height)
}

func TestGetCurrentHeaderHeight_Store(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), false, false)
	b := &block.Block{
		Header: block.Header{
			Script: transaction.Witness{
				VerificationScript: []byte{byte(opcode.PUSH1)},
				InvocationScript:   []byte{byte(opcode.NOP)},
			},
		},
	}
	err := dao.StoreAsCurrentBlock(b, nil)
	require.NoError(t, err)
	height, err := dao.GetCurrentBlockHeight()
	require.NoError(t, err)
	require.Equal(t, uint32(0), height)
}

func TestStoreAsTransaction(t *testing.T) {
	t.Run("P2PSigExtensions off", func(t *testing.T) {
		dao := NewSimple(storage.NewMemoryStore(), false, false)
		tx := transaction.New([]byte{byte(opcode.PUSH1)}, 1)
		hash := tx.Hash()
		err := dao.StoreAsTransaction(tx, 0, nil)
		require.NoError(t, err)
		err = dao.HasTransaction(hash)
		require.NotNil(t, err)
	})

	t.Run("P2PSigExtensions on", func(t *testing.T) {
		dao := NewSimple(storage.NewMemoryStore(), false, true)
		conflictsH := util.Uint256{1, 2, 3}
		tx := transaction.New([]byte{byte(opcode.PUSH1)}, 1)
		tx.Attributes = []transaction.Attribute{
			{
				Type:  transaction.ConflictsT,
				Value: &transaction.Conflicts{Hash: conflictsH},
			},
		}
		hash := tx.Hash()
		err := dao.StoreAsTransaction(tx, 0, nil)
		require.NoError(t, err)
		err = dao.HasTransaction(hash)
		require.True(t, errors.Is(err, ErrAlreadyExists))
		err = dao.HasTransaction(conflictsH)
		require.True(t, errors.Is(err, ErrHasConflicts))
	})
}

func BenchmarkStoreAsTransaction(b *testing.B) {
	dao := NewSimple(storage.NewMemoryStore(), false, true)
	tx := transaction.New([]byte{byte(opcode.PUSH1)}, 1)
	tx.Attributes = []transaction.Attribute{
		{
			Type: transaction.ConflictsT,
			Value: &transaction.Conflicts{
				Hash: util.Uint256{1, 2, 3},
			},
		},
		{
			Type: transaction.ConflictsT,
			Value: &transaction.Conflicts{
				Hash: util.Uint256{4, 5, 6},
			},
		},
		{
			Type: transaction.ConflictsT,
			Value: &transaction.Conflicts{
				Hash: util.Uint256{7, 8, 9},
			},
		},
	}
	_ = tx.Hash()

	b.ResetTimer()
	b.ReportAllocs()
	for n := 0; n < b.N; n++ {
		err := dao.StoreAsTransaction(tx, 1, nil)
		if err != nil {
			b.FailNow()
		}
	}
}

func TestMakeStorageItemKey(t *testing.T) {
	var id int32 = 5

	expected := []byte{byte(storage.STStorage), 0, 0, 0, 0, 1, 2, 3}
	binary.LittleEndian.PutUint32(expected[1:5], uint32(id))
	actual := makeStorageItemKey(storage.STStorage, id, []byte{1, 2, 3})
	require.Equal(t, expected, actual)

	expected = expected[0:5]
	actual = makeStorageItemKey(storage.STStorage, id, nil)
	require.Equal(t, expected, actual)

	expected = []byte{byte(storage.STTempStorage), 0, 0, 0, 0, 1, 2, 3}
	binary.LittleEndian.PutUint32(expected[1:5], uint32(id))
	actual = makeStorageItemKey(storage.STTempStorage, id, []byte{1, 2, 3})
	require.Equal(t, expected, actual)
}

func TestPutGetStateSyncPoint(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), true, false)

	// empty store
	_, err := dao.GetStateSyncPoint()
	require.Error(t, err)

	// non-empty store
	var expected uint32 = 5
	require.NoError(t, dao.PutStateSyncPoint(expected))
	actual, err := dao.GetStateSyncPoint()
	require.NoError(t, err)
	require.Equal(t, expected, actual)
}

func TestPutGetStateSyncCurrentBlockHeight(t *testing.T) {
	dao := NewSimple(storage.NewMemoryStore(), true, false)

	// empty store
	_, err := dao.GetStateSyncCurrentBlockHeight()
	require.Error(t, err)

	// non-empty store
	var expected uint32 = 5
	require.NoError(t, dao.PutStateSyncCurrentBlockHeight(expected))
	actual, err := dao.GetStateSyncCurrentBlockHeight()
	require.NoError(t, err)
	require.Equal(t, expected, actual)
}