package storage_test

import (
	"errors"
	"math/big"
	"testing"

	"github.com/nspcc-dev/neo-go/pkg/config/limits"
	"github.com/nspcc-dev/neo-go/pkg/core"
	"github.com/nspcc-dev/neo-go/pkg/core/block"
	"github.com/nspcc-dev/neo-go/pkg/core/interop"
	"github.com/nspcc-dev/neo-go/pkg/core/interop/iterator"
	istorage "github.com/nspcc-dev/neo-go/pkg/core/interop/storage"
	"github.com/nspcc-dev/neo-go/pkg/core/native"
	"github.com/nspcc-dev/neo-go/pkg/core/state"
	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
	"github.com/nspcc-dev/neo-go/pkg/neotest/chain"
	"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
	"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
	"github.com/nspcc-dev/neo-go/pkg/smartcontract/nef"
	"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
	"github.com/nspcc-dev/neo-go/pkg/vm"
	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
	"github.com/stretchr/testify/require"
)

func TestPut(t *testing.T) {
	_, cs, ic, _ := createVMAndContractState(t)

	require.NoError(t, native.PutContractState(ic.DAO, cs))

	initVM := func(t *testing.T, key, value []byte, gas int64) {
		v := ic.SpawnVM()
		v.LoadScript(cs.NEF.Script)
		v.GasLimit = gas
		v.Estack().PushVal(value)
		v.Estack().PushVal(key)
		require.NoError(t, istorage.GetContext(ic))
	}

	t.Run("create, not enough gas", func(t *testing.T) {
		initVM(t, []byte{1}, []byte{2, 3}, 2*native.DefaultStoragePrice)
		err := istorage.Put(ic)
		require.True(t, errors.Is(err, istorage.ErrGasLimitExceeded), "got: %v", err)
	})

	initVM(t, []byte{4}, []byte{5, 6}, 3*native.DefaultStoragePrice)
	require.NoError(t, istorage.Put(ic))

	t.Run("update", func(t *testing.T) {
		t.Run("not enough gas", func(t *testing.T) {
			initVM(t, []byte{4}, []byte{5, 6, 7, 8}, native.DefaultStoragePrice)
			err := istorage.Put(ic)
			require.True(t, errors.Is(err, istorage.ErrGasLimitExceeded), "got: %v", err)
		})
		initVM(t, []byte{4}, []byte{5, 6, 7, 8}, 3*native.DefaultStoragePrice)
		require.NoError(t, istorage.Put(ic))
		initVM(t, []byte{4}, []byte{5, 6}, native.DefaultStoragePrice)
		require.NoError(t, istorage.Put(ic))
	})

	t.Run("check limits", func(t *testing.T) {
		initVM(t, make([]byte, limits.MaxStorageKeyLen), make([]byte, limits.MaxStorageValueLen), -1)
		require.NoError(t, istorage.Put(ic))
	})

	t.Run("bad", func(t *testing.T) {
		t.Run("readonly context", func(t *testing.T) {
			initVM(t, []byte{1}, []byte{1}, -1)
			require.NoError(t, istorage.ContextAsReadOnly(ic))
			require.Error(t, istorage.Put(ic))
		})
		t.Run("big key", func(t *testing.T) {
			initVM(t, make([]byte, limits.MaxStorageKeyLen+1), []byte{1}, -1)
			require.Error(t, istorage.Put(ic))
		})
		t.Run("big value", func(t *testing.T) {
			initVM(t, []byte{1}, make([]byte, limits.MaxStorageValueLen+1), -1)
			require.Error(t, istorage.Put(ic))
		})
	})
}

func TestDelete(t *testing.T) {
	v, cs, ic, _ := createVMAndContractState(t)

	require.NoError(t, native.PutContractState(ic.DAO, cs))
	v.LoadScriptWithHash(cs.NEF.Script, cs.Hash, callflag.All)
	put := func(key, value string, flag int) {
		v.Estack().PushVal(value)
		v.Estack().PushVal(key)
		require.NoError(t, istorage.GetContext(ic))
		require.NoError(t, istorage.Put(ic))
	}
	put("key1", "value1", 0)
	put("key2", "value2", 0)
	put("key3", "value3", 0)

	t.Run("good", func(t *testing.T) {
		v.Estack().PushVal("key1")
		require.NoError(t, istorage.GetContext(ic))
		require.NoError(t, istorage.Delete(ic))
	})
	t.Run("readonly context", func(t *testing.T) {
		v.Estack().PushVal("key2")
		require.NoError(t, istorage.GetReadOnlyContext(ic))
		require.Error(t, istorage.Delete(ic))
	})
	t.Run("readonly context (from normal)", func(t *testing.T) {
		v.Estack().PushVal("key3")
		require.NoError(t, istorage.GetContext(ic))
		require.NoError(t, istorage.ContextAsReadOnly(ic))
		require.Error(t, istorage.Delete(ic))
	})
}

func TestFind(t *testing.T) {
	v, contractState, context, _ := createVMAndContractState(t)

	arr := []stackitem.Item{
		stackitem.NewBigInteger(big.NewInt(42)),
		stackitem.NewByteArray([]byte("second")),
		stackitem.Null{},
	}
	rawArr, err := stackitem.Serialize(stackitem.NewArray(arr))
	require.NoError(t, err)
	rawArr0, err := stackitem.Serialize(stackitem.NewArray(arr[:0]))
	require.NoError(t, err)
	rawArr1, err := stackitem.Serialize(stackitem.NewArray(arr[:1]))
	require.NoError(t, err)

	skeys := [][]byte{{0x01, 0x02}, {0x02, 0x01}, {0x01, 0x01},
		{0x04, 0x00}, {0x05, 0x00}, {0x06}, {0x07}, {0x08},
		{0x09, 0x12, 0x34}, {0x09, 0x12, 0x56},
	}
	items := []state.StorageItem{
		[]byte{0x01, 0x02, 0x03, 0x04},
		[]byte{0x04, 0x03, 0x02, 0x01},
		[]byte{0x03, 0x04, 0x05, 0x06},
		[]byte{byte(stackitem.ByteArrayT), 2, 0xCA, 0xFE},
		[]byte{0xFF, 0xFF},
		rawArr,
		rawArr0,
		rawArr1,
		[]byte{111},
		[]byte{222},
	}

	require.NoError(t, native.PutContractState(context.DAO, contractState))

	id := contractState.ID

	for i := range skeys {
		context.DAO.PutStorageItem(id, skeys[i], items[i])
	}

	testFind := func(t *testing.T, prefix []byte, opts int64, expected []stackitem.Item) {
		v.Estack().PushVal(opts)
		v.Estack().PushVal(prefix)
		v.Estack().PushVal(stackitem.NewInterop(&istorage.Context{ID: id}))

		err := istorage.Find(context)
		require.NoError(t, err)

		var iter *stackitem.Interop
		require.NotPanics(t, func() { iter = v.Estack().Pop().Interop() })

		for i := range expected { // sorted indices with mathing prefix
			v.Estack().PushVal(iter)
			require.NoError(t, iterator.Next(context))
			require.True(t, v.Estack().Pop().Bool())

			v.Estack().PushVal(iter)
			if expected[i] == nil {
				require.Panics(t, func() { _ = iterator.Value(context) })
				return
			}
			require.NoError(t, iterator.Value(context))
			require.Equal(t, expected[i], v.Estack().Pop().Item())
		}

		v.Estack().PushVal(iter)
		require.NoError(t, iterator.Next(context))
		require.False(t, v.Estack().Pop().Bool())
	}

	t.Run("normal invocation", func(t *testing.T) {
		testFind(t, []byte{0x01}, istorage.FindDefault, []stackitem.Item{
			stackitem.NewStruct([]stackitem.Item{
				stackitem.NewByteArray(skeys[2]),
				stackitem.NewByteArray(items[2]),
			}),
			stackitem.NewStruct([]stackitem.Item{
				stackitem.NewByteArray(skeys[0]),
				stackitem.NewByteArray(items[0]),
			}),
		})
	})

	t.Run("keys only", func(t *testing.T) {
		testFind(t, []byte{0x01}, istorage.FindKeysOnly, []stackitem.Item{
			stackitem.NewByteArray(skeys[2]),
			stackitem.NewByteArray(skeys[0]),
		})
	})
	t.Run("remove prefix", func(t *testing.T) {
		testFind(t, []byte{0x01}, istorage.FindKeysOnly|istorage.FindRemovePrefix, []stackitem.Item{
			stackitem.NewByteArray(skeys[2][1:]),
			stackitem.NewByteArray(skeys[0][1:]),
		})
		testFind(t, []byte{0x09, 0x12}, istorage.FindKeysOnly|istorage.FindRemovePrefix, []stackitem.Item{
			stackitem.NewByteArray(skeys[8][2:]),
			stackitem.NewByteArray(skeys[9][2:]),
		})
	})
	t.Run("values only", func(t *testing.T) {
		testFind(t, []byte{0x01}, istorage.FindValuesOnly, []stackitem.Item{
			stackitem.NewByteArray(items[2]),
			stackitem.NewByteArray(items[0]),
		})
	})
	t.Run("deserialize values", func(t *testing.T) {
		testFind(t, []byte{0x04}, istorage.FindValuesOnly|istorage.FindDeserialize, []stackitem.Item{
			stackitem.NewByteArray(items[3][2:]),
		})
		t.Run("invalid", func(t *testing.T) {
			v.Estack().PushVal(istorage.FindDeserialize)
			v.Estack().PushVal([]byte{0x05})
			v.Estack().PushVal(stackitem.NewInterop(&istorage.Context{ID: id}))
			err := istorage.Find(context)
			require.NoError(t, err)

			var iter *stackitem.Interop
			require.NotPanics(t, func() { iter = v.Estack().Pop().Interop() })

			v.Estack().PushVal(iter)
			require.NoError(t, iterator.Next(context))

			v.Estack().PushVal(iter)
			require.Panics(t, func() { _ = iterator.Value(context) })
		})
	})
	t.Run("PickN", func(t *testing.T) {
		testFind(t, []byte{0x06}, istorage.FindPick0|istorage.FindValuesOnly|istorage.FindDeserialize, arr[:1])
		testFind(t, []byte{0x06}, istorage.FindPick1|istorage.FindValuesOnly|istorage.FindDeserialize, arr[1:2])
		// Array with 0 elements.
		testFind(t, []byte{0x07}, istorage.FindPick0|istorage.FindValuesOnly|istorage.FindDeserialize,
			[]stackitem.Item{nil})
		// Array with 1 element.
		testFind(t, []byte{0x08}, istorage.FindPick1|istorage.FindValuesOnly|istorage.FindDeserialize,
			[]stackitem.Item{nil})
		// Not an array, but serialized ByteArray.
		testFind(t, []byte{0x04}, istorage.FindPick1|istorage.FindValuesOnly|istorage.FindDeserialize,
			[]stackitem.Item{nil})
	})

	t.Run("normal invocation, empty result", func(t *testing.T) {
		testFind(t, []byte{0x03}, istorage.FindDefault, nil)
	})

	t.Run("invalid options", func(t *testing.T) {
		invalid := []int64{
			istorage.FindKeysOnly | istorage.FindValuesOnly,
			^istorage.FindAll,
			istorage.FindKeysOnly | istorage.FindDeserialize,
			istorage.FindPick0,
			istorage.FindPick0 | istorage.FindPick1 | istorage.FindDeserialize,
			istorage.FindPick0 | istorage.FindPick1,
		}
		for _, opts := range invalid {
			v.Estack().PushVal(opts)
			v.Estack().PushVal([]byte{0x01})
			v.Estack().PushVal(stackitem.NewInterop(&istorage.Context{ID: id}))
			require.Error(t, istorage.Find(context))
		}
	})
	t.Run("invalid type for storage.Context", func(t *testing.T) {
		v.Estack().PushVal(istorage.FindDefault)
		v.Estack().PushVal([]byte{0x01})
		v.Estack().PushVal(stackitem.NewInterop(nil))

		require.Error(t, istorage.Find(context))
	})

	t.Run("invalid id", func(t *testing.T) {
		invalidID := id + 1

		v.Estack().PushVal(istorage.FindDefault)
		v.Estack().PushVal([]byte{0x01})
		v.Estack().PushVal(stackitem.NewInterop(&istorage.Context{ID: invalidID}))

		require.NoError(t, istorage.Find(context))
		require.NoError(t, iterator.Next(context))
		require.False(t, v.Estack().Pop().Bool())
	})
}

// Helper functions to create VM, InteropContext, TX, Account, Contract.

func createVM(t testing.TB) (*vm.VM, *interop.Context, *core.Blockchain) {
	chain, _ := chain.NewSingle(t)
	ic, err := chain.GetTestVM(trigger.Application, &transaction.Transaction{}, &block.Block{})
	require.NoError(t, err)
	v := ic.SpawnVM()
	return v, ic, chain
}

func createVMAndContractState(t testing.TB) (*vm.VM, *state.Contract, *interop.Context, *core.Blockchain) {
	script := []byte("testscript")
	m := manifest.NewManifest("Test")
	ne, err := nef.NewFile(script)
	require.NoError(t, err)
	contractState := &state.Contract{
		ContractBase: state.ContractBase{
			NEF:      *ne,
			Hash:     hash.Hash160(script),
			Manifest: *m,
			ID:       123,
		},
	}

	v, context, chain := createVM(t)
	return v, contractState, context, chain
}