// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package state

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"math"
	"math/big"
	"math/rand"
	"reflect"
	"strings"
	"sync"
	"testing"
	"testing/quick"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/rawdb"
	"github.com/ethereum/go-ethereum/core/types"
)

// Tests that updating a state trie does not leak any database writes prior to
// actually committing the state.
func TestUpdateLeaks(t *testing.T) {
	// Create an empty state database
	db := rawdb.NewMemoryDatabase()
	state, _ := New(common.Hash{}, NewDatabase(db), nil)

	// Update it with some accounts
	for i := byte(0); i < 255; i++ {
		addr := common.BytesToAddress([]byte{i})
		state.AddBalance(addr, big.NewInt(int64(11*i)))
		state.SetNonce(addr, uint64(42*i))
		if i%2 == 0 {
			state.SetState(addr, common.BytesToHash([]byte{i, i, i}), common.BytesToHash([]byte{i, i, i, i}))
		}
		if i%3 == 0 {
			state.SetCode(addr, []byte{i, i, i, i, i})
		}
	}

	root := state.IntermediateRoot(false)
	if err := state.Database().TrieDB().Commit(root, false, nil); err != nil {
		t.Errorf("can not commit trie %v to persistent database", root.Hex())
	}

	// Ensure that no data was leaked into the database
	it := db.NewIterator(nil, nil)
	for it.Next() {
		t.Errorf("State leaked into database: %x -> %x", it.Key(), it.Value())
	}
	it.Release()
}

// Tests that no intermediate state of an object is stored into the database,
// only the one right before the commit.
func TestIntermediateLeaks(t *testing.T) {
	// Create two state databases, one transitioning to the final state, the other final from the beginning
	transDb := rawdb.NewMemoryDatabase()
	finalDb := rawdb.NewMemoryDatabase()
	transState, _ := New(common.Hash{}, NewDatabase(transDb), nil)
	finalState, _ := New(common.Hash{}, NewDatabase(finalDb), nil)

	modify := func(state *StateDB, addr common.Address, i, tweak byte) {
		state.SetBalance(addr, big.NewInt(int64(11*i)+int64(tweak)))
		state.SetNonce(addr, uint64(42*i+tweak))
		if i%2 == 0 {
			state.SetState(addr, common.Hash{i, i, i, 0}, common.Hash{})
			state.SetState(addr, common.Hash{i, i, i, tweak}, common.Hash{i, i, i, i, tweak})
		}
		if i%3 == 0 {
			state.SetCode(addr, []byte{i, i, i, i, i, tweak})
		}
	}

	// Modify the transient state.
	for i := byte(0); i < 255; i++ {
		modify(transState, common.Address{i}, i, 0)
	}
	// Write modifications to trie.
	transState.IntermediateRoot(false)

	// Overwrite all the data with new values in the transient database.
	for i := byte(0); i < 255; i++ {
		modify(transState, common.Address{i}, i, 99)
		modify(finalState, common.Address{i}, i, 99)
	}

	// Commit and cross check the databases.
	transRoot, err := transState.Commit(false)
	if err != nil {
		t.Fatalf("failed to commit transition state: %v", err)
	}
	if err = transState.Database().TrieDB().Commit(transRoot, false, nil); err != nil {
		t.Errorf("can not commit trie %v to persistent database", transRoot.Hex())
	}

	finalRoot, err := finalState.Commit(false)
	if err != nil {
		t.Fatalf("failed to commit final state: %v", err)
	}
	if err = finalState.Database().TrieDB().Commit(finalRoot, false, nil); err != nil {
		t.Errorf("can not commit trie %v to persistent database", finalRoot.Hex())
	}

	it := finalDb.NewIterator(nil, nil)
	for it.Next() {
		key, fvalue := it.Key(), it.Value()
		tvalue, err := transDb.Get(key)
		if err != nil {
			t.Errorf("entry missing from the transition database: %x -> %x", key, fvalue)
		}
		if !bytes.Equal(fvalue, tvalue) {
			t.Errorf("the value associate key %x is mismatch,: %x in transition database ,%x in final database", key, tvalue, fvalue)
		}
	}
	it.Release()

	it = transDb.NewIterator(nil, nil)
	for it.Next() {
		key, tvalue := it.Key(), it.Value()
		fvalue, err := finalDb.Get(key)
		if err != nil {
			t.Errorf("extra entry in the transition database: %x -> %x", key, it.Value())
		}
		if !bytes.Equal(fvalue, tvalue) {
			t.Errorf("the value associate key %x is mismatch,: %x in transition database ,%x in final database", key, tvalue, fvalue)
		}
	}
}

// TestCopy tests that copying a StateDB object indeed makes the original and
// the copy independent of each other. This test is a regression test against
// https://github.com/ethereum/go-ethereum/pull/15549.
func TestCopy(t *testing.T) {
	// Create a random state test to copy and modify "independently"
	orig, _ := New(common.Hash{}, NewDatabase(rawdb.NewMemoryDatabase()), nil)

	for i := byte(0); i < 255; i++ {
		obj := orig.GetOrNewStateObject(common.BytesToAddress([]byte{i}))
		obj.AddBalance(big.NewInt(int64(i)))
		orig.updateStateObject(obj)
	}
	orig.Finalise(false)

	// Copy the state
	copy := orig.Copy()

	// Copy the copy state
	ccopy := copy.Copy()

	// modify all in memory
	for i := byte(0); i < 255; i++ {
		origObj := orig.GetOrNewStateObject(common.BytesToAddress([]byte{i}))
		copyObj := copy.GetOrNewStateObject(common.BytesToAddress([]byte{i}))
		ccopyObj := ccopy.GetOrNewStateObject(common.BytesToAddress([]byte{i}))

		origObj.AddBalance(big.NewInt(2 * int64(i)))
		copyObj.AddBalance(big.NewInt(3 * int64(i)))
		ccopyObj.AddBalance(big.NewInt(4 * int64(i)))

		orig.updateStateObject(origObj)
		copy.updateStateObject(copyObj)
		ccopy.updateStateObject(copyObj)
	}

	// Finalise the changes on all concurrently
	finalise := func(wg *sync.WaitGroup, db *StateDB) {
		defer wg.Done()
		db.Finalise(true)
	}

	var wg sync.WaitGroup
	wg.Add(3)
	go finalise(&wg, orig)
	go finalise(&wg, copy)
	go finalise(&wg, ccopy)
	wg.Wait()

	// Verify that the three states have been updated independently
	for i := byte(0); i < 255; i++ {
		origObj := orig.GetOrNewStateObject(common.BytesToAddress([]byte{i}))
		copyObj := copy.GetOrNewStateObject(common.BytesToAddress([]byte{i}))
		ccopyObj := ccopy.GetOrNewStateObject(common.BytesToAddress([]byte{i}))

		if want := big.NewInt(3 * int64(i)); origObj.Balance().Cmp(want) != 0 {
			t.Errorf("orig obj %d: balance mismatch: have %v, want %v", i, origObj.Balance(), want)
		}
		if want := big.NewInt(4 * int64(i)); copyObj.Balance().Cmp(want) != 0 {
			t.Errorf("copy obj %d: balance mismatch: have %v, want %v", i, copyObj.Balance(), want)
		}
		if want := big.NewInt(5 * int64(i)); ccopyObj.Balance().Cmp(want) != 0 {
			t.Errorf("copy obj %d: balance mismatch: have %v, want %v", i, ccopyObj.Balance(), want)
		}
	}
}

func TestSnapshotRandom(t *testing.T) {
	config := &quick.Config{MaxCount: 1000}
	err := quick.Check((*snapshotTest).run, config)
	if cerr, ok := err.(*quick.CheckError); ok {
		test := cerr.In[0].(*snapshotTest)
		t.Errorf("%v:\n%s", test.err, test)
	} else if err != nil {
		t.Error(err)
	}
}

// A snapshotTest checks that reverting StateDB snapshots properly undoes all changes
// captured by the snapshot. Instances of this test with pseudorandom content are created
// by Generate.
//
// The test works as follows:
//
// A new state is created and all actions are applied to it. Several snapshots are taken
// in between actions. The test then reverts each snapshot. For each snapshot the actions
// leading up to it are replayed on a fresh, empty state. The behaviour of all public
// accessor methods on the reverted state must match the return value of the equivalent
// methods on the replayed state.
type snapshotTest struct {
	addrs     []common.Address // all account addresses
	actions   []testAction     // modifications to the state
	snapshots []int            // actions indexes at which snapshot is taken
	err       error            // failure details are reported through this field
}

type testAction struct {
	name   string
	fn     func(testAction, *StateDB)
	args   []int64
	noAddr bool
}

// newTestAction creates a random action that changes state.
func newTestAction(addr common.Address, r *rand.Rand) testAction {
	actions := []testAction{
		{
			name: "SetBalance",
			fn: func(a testAction, s *StateDB) {
				s.SetBalance(addr, big.NewInt(a.args[0]))
			},
			args: make([]int64, 1),
		},
		{
			name: "AddBalance",
			fn: func(a testAction, s *StateDB) {
				s.AddBalance(addr, big.NewInt(a.args[0]))
			},
			args: make([]int64, 1),
		},
		{
			name: "SetNonce",
			fn: func(a testAction, s *StateDB) {
				s.SetNonce(addr, uint64(a.args[0]))
			},
			args: make([]int64, 1),
		},
		{
			name: "SetState",
			fn: func(a testAction, s *StateDB) {
				var key, val common.Hash
				binary.BigEndian.PutUint16(key[:], uint16(a.args[0]))
				binary.BigEndian.PutUint16(val[:], uint16(a.args[1]))
				s.SetState(addr, key, val)
			},
			args: make([]int64, 2),
		},
		{
			name: "SetCode",
			fn: func(a testAction, s *StateDB) {
				code := make([]byte, 16)
				binary.BigEndian.PutUint64(code, uint64(a.args[0]))
				binary.BigEndian.PutUint64(code[8:], uint64(a.args[1]))
				s.SetCode(addr, code)
			},
			args: make([]int64, 2),
		},
		{
			name: "CreateAccount",
			fn: func(a testAction, s *StateDB) {
				s.CreateAccount(addr)
			},
		},
		{
			name: "Suicide",
			fn: func(a testAction, s *StateDB) {
				s.Suicide(addr)
			},
		},
		{
			name: "AddRefund",
			fn: func(a testAction, s *StateDB) {
				s.AddRefund(uint64(a.args[0]))
			},
			args:   make([]int64, 1),
			noAddr: true,
		},
		{
			name: "AddLog",
			fn: func(a testAction, s *StateDB) {
				data := make([]byte, 2)
				binary.BigEndian.PutUint16(data, uint16(a.args[0]))
				s.AddLog(&types.Log{Address: addr, Data: data})
			},
			args: make([]int64, 1),
		},
		{
			name: "AddPreimage",
			fn: func(a testAction, s *StateDB) {
				preimage := []byte{1}
				hash := common.BytesToHash(preimage)
				s.AddPreimage(hash, preimage)
			},
			args: make([]int64, 1),
		},
	}
	action := actions[r.Intn(len(actions))]
	var nameargs []string
	if !action.noAddr {
		nameargs = append(nameargs, addr.Hex())
	}
	for i := range action.args {
		action.args[i] = rand.Int63n(100)
		nameargs = append(nameargs, fmt.Sprint(action.args[i]))
	}
	action.name += strings.Join(nameargs, ", ")
	return action
}

// Generate returns a new snapshot test of the given size. All randomness is
// derived from r.
func (*snapshotTest) Generate(r *rand.Rand, size int) reflect.Value {
	// Generate random actions.
	addrs := make([]common.Address, 50)
	for i := range addrs {
		addrs[i][0] = byte(i)
	}
	actions := make([]testAction, size)
	for i := range actions {
		addr := addrs[r.Intn(len(addrs))]
		actions[i] = newTestAction(addr, r)
	}
	// Generate snapshot indexes.
	nsnapshots := int(math.Sqrt(float64(size)))
	if size > 0 && nsnapshots == 0 {
		nsnapshots = 1
	}
	snapshots := make([]int, nsnapshots)
	snaplen := len(actions) / nsnapshots
	for i := range snapshots {
		// Try to place the snapshots some number of actions apart from each other.
		snapshots[i] = (i * snaplen) + r.Intn(snaplen)
	}
	return reflect.ValueOf(&snapshotTest{addrs, actions, snapshots, nil})
}

func (test *snapshotTest) String() string {
	out := new(bytes.Buffer)
	sindex := 0
	for i, action := range test.actions {
		if len(test.snapshots) > sindex && i == test.snapshots[sindex] {
			fmt.Fprintf(out, "---- snapshot %d ----\n", sindex)
			sindex++
		}
		fmt.Fprintf(out, "%4d: %s\n", i, action.name)
	}
	return out.String()
}

func (test *snapshotTest) run() bool {
	// Run all actions and create snapshots.
	var (
		state, _     = New(common.Hash{}, NewDatabase(rawdb.NewMemoryDatabase()), nil)
		snapshotRevs = make([]int, len(test.snapshots))
		sindex       = 0
	)
	for i, action := range test.actions {
		if len(test.snapshots) > sindex && i == test.snapshots[sindex] {
			snapshotRevs[sindex] = state.Snapshot()
			sindex++
		}
		action.fn(action, state)
	}
	// Revert all snapshots in reverse order. Each revert must yield a state
	// that is equivalent to fresh state with all actions up the snapshot applied.
	for sindex--; sindex >= 0; sindex-- {
		checkstate, _ := New(common.Hash{}, state.Database(), nil)
		for _, action := range test.actions[:test.snapshots[sindex]] {
			action.fn(action, checkstate)
		}
		state.RevertToSnapshot(snapshotRevs[sindex])
		if err := test.checkEqual(state, checkstate); err != nil {
			test.err = fmt.Errorf("state mismatch after revert to snapshot %d\n%v", sindex, err)
			return false
		}
	}
	return true
}

// checkEqual checks that methods of state and checkstate return the same values.
func (test *snapshotTest) checkEqual(state, checkstate *StateDB) error {
	for _, addr := range test.addrs {
		var err error
		checkeq := func(op string, a, b interface{}) bool {
			if err == nil && !reflect.DeepEqual(a, b) {
				err = fmt.Errorf("got %s(%s) == %v, want %v", op, addr.Hex(), a, b)
				return false
			}
			return true
		}
		// Check basic accessor methods.
		checkeq("Exist", state.Exist(addr), checkstate.Exist(addr))
		checkeq("HasSuicided", state.HasSuicided(addr), checkstate.HasSuicided(addr))
		checkeq("GetBalance", state.GetBalance(addr), checkstate.GetBalance(addr))
		checkeq("GetNonce", state.GetNonce(addr), checkstate.GetNonce(addr))
		checkeq("GetCode", state.GetCode(addr), checkstate.GetCode(addr))
		checkeq("GetCodeHash", state.GetCodeHash(addr), checkstate.GetCodeHash(addr))
		checkeq("GetCodeSize", state.GetCodeSize(addr), checkstate.GetCodeSize(addr))
		// Check storage.
		if obj := state.getStateObject(addr); obj != nil {
			state.ForEachStorage(addr, func(key, value common.Hash) bool {
				return checkeq("GetState("+key.Hex()+")", checkstate.GetState(addr, key), value)
			})
			checkstate.ForEachStorage(addr, func(key, value common.Hash) bool {
				return checkeq("GetState("+key.Hex()+")", checkstate.GetState(addr, key), value)
			})
		}
		if err != nil {
			return err
		}
	}

	if state.GetRefund() != checkstate.GetRefund() {
		return fmt.Errorf("got GetRefund() == %d, want GetRefund() == %d",
			state.GetRefund(), checkstate.GetRefund())
	}
	if !reflect.DeepEqual(state.GetLogs(common.Hash{}), checkstate.GetLogs(common.Hash{})) {
		return fmt.Errorf("got GetLogs(common.Hash{}) == %v, want GetLogs(common.Hash{}) == %v",
			state.GetLogs(common.Hash{}), checkstate.GetLogs(common.Hash{}))
	}
	return nil
}

func TestTouchDelete(t *testing.T) {
	s := newStateTest()
	s.state.GetOrNewStateObject(common.Address{})
	root, _ := s.state.Commit(false)
	s.state.Reset(root)

	snapshot := s.state.Snapshot()
	s.state.AddBalance(common.Address{}, new(big.Int))

	if len(s.state.journal.dirties) != 1 {
		t.Fatal("expected one dirty state object")
	}
	s.state.RevertToSnapshot(snapshot)
	if len(s.state.journal.dirties) != 0 {
		t.Fatal("expected no dirty state object")
	}
}

// TestCopyOfCopy tests that modified objects are carried over to the copy, and the copy of the copy.
// See https://github.com/ethereum/go-ethereum/pull/15225#issuecomment-380191512
func TestCopyOfCopy(t *testing.T) {
	state, _ := New(common.Hash{}, NewDatabase(rawdb.NewMemoryDatabase()), nil)
	addr := common.HexToAddress("aaaa")
	state.SetBalance(addr, big.NewInt(42))

	if got := state.Copy().GetBalance(addr).Uint64(); got != 42 {
		t.Fatalf("1st copy fail, expected 42, got %v", got)
	}
	if got := state.Copy().Copy().GetBalance(addr).Uint64(); got != 42 {
		t.Fatalf("2nd copy fail, expected 42, got %v", got)
	}
}

// Tests a regression where committing a copy lost some internal meta information,
// leading to corrupted subsequent copies.
//
// See https://github.com/ethereum/go-ethereum/issues/20106.
func TestCopyCommitCopy(t *testing.T) {
	state, _ := New(common.Hash{}, NewDatabase(rawdb.NewMemoryDatabase()), nil)

	// Create an account and check if the retrieved balance is correct
	addr := common.HexToAddress("0xaffeaffeaffeaffeaffeaffeaffeaffeaffeaffe")
	skey := common.HexToHash("aaa")
	sval := common.HexToHash("bbb")

	state.SetBalance(addr, big.NewInt(42)) // Change the account trie
	state.SetCode(addr, []byte("hello"))   // Change an external metadata
	state.SetState(addr, skey, sval)       // Change the storage trie

	if balance := state.GetBalance(addr); balance.Cmp(big.NewInt(42)) != 0 {
		t.Fatalf("initial balance mismatch: have %v, want %v", balance, 42)
	}
	if code := state.GetCode(addr); !bytes.Equal(code, []byte("hello")) {
		t.Fatalf("initial code mismatch: have %x, want %x", code, []byte("hello"))
	}
	if val := state.GetState(addr, skey); val != sval {
		t.Fatalf("initial non-committed storage slot mismatch: have %x, want %x", val, sval)
	}
	if val := state.GetCommittedState(addr, skey); val != (common.Hash{}) {
		t.Fatalf("initial committed storage slot mismatch: have %x, want %x", val, common.Hash{})
	}
	// Copy the non-committed state database and check pre/post commit balance
	copyOne := state.Copy()
	if balance := copyOne.GetBalance(addr); balance.Cmp(big.NewInt(42)) != 0 {
		t.Fatalf("first copy pre-commit balance mismatch: have %v, want %v", balance, 42)
	}
	if code := copyOne.GetCode(addr); !bytes.Equal(code, []byte("hello")) {
		t.Fatalf("first copy pre-commit code mismatch: have %x, want %x", code, []byte("hello"))
	}
	if val := copyOne.GetState(addr, skey); val != sval {
		t.Fatalf("first copy pre-commit non-committed storage slot mismatch: have %x, want %x", val, sval)
	}
	if val := copyOne.GetCommittedState(addr, skey); val != (common.Hash{}) {
		t.Fatalf("first copy pre-commit committed storage slot mismatch: have %x, want %x", val, common.Hash{})
	}

	copyOne.Commit(false)
	if balance := copyOne.GetBalance(addr); balance.Cmp(big.NewInt(42)) != 0 {
		t.Fatalf("first copy post-commit balance mismatch: have %v, want %v", balance, 42)
	}
	if code := copyOne.GetCode(addr); !bytes.Equal(code, []byte("hello")) {
		t.Fatalf("first copy post-commit code mismatch: have %x, want %x", code, []byte("hello"))
	}
	if val := copyOne.GetState(addr, skey); val != sval {
		t.Fatalf("first copy post-commit non-committed storage slot mismatch: have %x, want %x", val, sval)
	}
	if val := copyOne.GetCommittedState(addr, skey); val != sval {
		t.Fatalf("first copy post-commit committed storage slot mismatch: have %x, want %x", val, sval)
	}
	// Copy the copy and check the balance once more
	copyTwo := copyOne.Copy()
	if balance := copyTwo.GetBalance(addr); balance.Cmp(big.NewInt(42)) != 0 {
		t.Fatalf("second copy balance mismatch: have %v, want %v", balance, 42)
	}
	if code := copyTwo.GetCode(addr); !bytes.Equal(code, []byte("hello")) {
		t.Fatalf("second copy code mismatch: have %x, want %x", code, []byte("hello"))
	}
	if val := copyTwo.GetState(addr, skey); val != sval {
		t.Fatalf("second copy non-committed storage slot mismatch: have %x, want %x", val, sval)
	}
	if val := copyTwo.GetCommittedState(addr, skey); val != sval {
		t.Fatalf("second copy post-commit committed storage slot mismatch: have %x, want %x", val, sval)
	}
}

// Tests a regression where committing a copy lost some internal meta information,
// leading to corrupted subsequent copies.
//
// See https://github.com/ethereum/go-ethereum/issues/20106.
func TestCopyCopyCommitCopy(t *testing.T) {
	state, _ := New(common.Hash{}, NewDatabase(rawdb.NewMemoryDatabase()), nil)

	// Create an account and check if the retrieved balance is correct
	addr := common.HexToAddress("0xaffeaffeaffeaffeaffeaffeaffeaffeaffeaffe")
	skey := common.HexToHash("aaa")
	sval := common.HexToHash("bbb")

	state.SetBalance(addr, big.NewInt(42)) // Change the account trie
	state.SetCode(addr, []byte("hello"))   // Change an external metadata
	state.SetState(addr, skey, sval)       // Change the storage trie

	if balance := state.GetBalance(addr); balance.Cmp(big.NewInt(42)) != 0 {
		t.Fatalf("initial balance mismatch: have %v, want %v", balance, 42)
	}
	if code := state.GetCode(addr); !bytes.Equal(code, []byte("hello")) {
		t.Fatalf("initial code mismatch: have %x, want %x", code, []byte("hello"))
	}
	if val := state.GetState(addr, skey); val != sval {
		t.Fatalf("initial non-committed storage slot mismatch: have %x, want %x", val, sval)
	}
	if val := state.GetCommittedState(addr, skey); val != (common.Hash{}) {
		t.Fatalf("initial committed storage slot mismatch: have %x, want %x", val, common.Hash{})
	}
	// Copy the non-committed state database and check pre/post commit balance
	copyOne := state.Copy()
	if balance := copyOne.GetBalance(addr); balance.Cmp(big.NewInt(42)) != 0 {
		t.Fatalf("first copy balance mismatch: have %v, want %v", balance, 42)
	}
	if code := copyOne.GetCode(addr); !bytes.Equal(code, []byte("hello")) {
		t.Fatalf("first copy code mismatch: have %x, want %x", code, []byte("hello"))
	}
	if val := copyOne.GetState(addr, skey); val != sval {
		t.Fatalf("first copy non-committed storage slot mismatch: have %x, want %x", val, sval)
	}
	if val := copyOne.GetCommittedState(addr, skey); val != (common.Hash{}) {
		t.Fatalf("first copy committed storage slot mismatch: have %x, want %x", val, common.Hash{})
	}
	// Copy the copy and check the balance once more
	copyTwo := copyOne.Copy()
	if balance := copyTwo.GetBalance(addr); balance.Cmp(big.NewInt(42)) != 0 {
		t.Fatalf("second copy pre-commit balance mismatch: have %v, want %v", balance, 42)
	}
	if code := copyTwo.GetCode(addr); !bytes.Equal(code, []byte("hello")) {
		t.Fatalf("second copy pre-commit code mismatch: have %x, want %x", code, []byte("hello"))
	}
	if val := copyTwo.GetState(addr, skey); val != sval {
		t.Fatalf("second copy pre-commit non-committed storage slot mismatch: have %x, want %x", val, sval)
	}
	if val := copyTwo.GetCommittedState(addr, skey); val != (common.Hash{}) {
		t.Fatalf("second copy pre-commit committed storage slot mismatch: have %x, want %x", val, common.Hash{})
	}
	copyTwo.Commit(false)
	if balance := copyTwo.GetBalance(addr); balance.Cmp(big.NewInt(42)) != 0 {
		t.Fatalf("second copy post-commit balance mismatch: have %v, want %v", balance, 42)
	}
	if code := copyTwo.GetCode(addr); !bytes.Equal(code, []byte("hello")) {
		t.Fatalf("second copy post-commit code mismatch: have %x, want %x", code, []byte("hello"))
	}
	if val := copyTwo.GetState(addr, skey); val != sval {
		t.Fatalf("second copy post-commit non-committed storage slot mismatch: have %x, want %x", val, sval)
	}
	if val := copyTwo.GetCommittedState(addr, skey); val != sval {
		t.Fatalf("second copy post-commit committed storage slot mismatch: have %x, want %x", val, sval)
	}
	// Copy the copy-copy and check the balance once more
	copyThree := copyTwo.Copy()
	if balance := copyThree.GetBalance(addr); balance.Cmp(big.NewInt(42)) != 0 {
		t.Fatalf("third copy balance mismatch: have %v, want %v", balance, 42)
	}
	if code := copyThree.GetCode(addr); !bytes.Equal(code, []byte("hello")) {
		t.Fatalf("third copy code mismatch: have %x, want %x", code, []byte("hello"))
	}
	if val := copyThree.GetState(addr, skey); val != sval {
		t.Fatalf("third copy non-committed storage slot mismatch: have %x, want %x", val, sval)
	}
	if val := copyThree.GetCommittedState(addr, skey); val != sval {
		t.Fatalf("third copy committed storage slot mismatch: have %x, want %x", val, sval)
	}
}

// TestDeleteCreateRevert tests a weird state transition corner case that we hit
// while changing the internals of StateDB. The workflow is that a contract is
// self-destructed, then in a follow-up transaction (but same block) it's created
// again and the transaction reverted.
//
// The original StateDB implementation flushed dirty objects to the tries after
// each transaction, so this works ok. The rework accumulated writes in memory
// first, but the journal wiped the entire state object on create-revert.
func TestDeleteCreateRevert(t *testing.T) {
	// Create an initial state with a single contract
	state, _ := New(common.Hash{}, NewDatabase(rawdb.NewMemoryDatabase()), nil)

	addr := toAddr([]byte("so"))
	state.SetBalance(addr, big.NewInt(1))

	root, _ := state.Commit(false)
	state.Reset(root)

	// Simulate self-destructing in one transaction, then create-reverting in another
	state.Suicide(addr)
	state.Finalise(true)

	id := state.Snapshot()
	state.SetBalance(addr, big.NewInt(2))
	state.RevertToSnapshot(id)

	// Commit the entire state and make sure we don't crash and have the correct state
	root, _ = state.Commit(true)
	state.Reset(root)

	if state.getStateObject(addr) != nil {
		t.Fatalf("self-destructed contract came alive")
	}
}

// TestMissingTrieNodes tests that if the StateDB fails to load parts of the trie,
// the Commit operation fails with an error
// If we are missing trie nodes, we should not continue writing to the trie
func TestMissingTrieNodes(t *testing.T) {

	// Create an initial state with a few accounts
	memDb := rawdb.NewMemoryDatabase()
	db := NewDatabase(memDb)
	var root common.Hash
	state, _ := New(common.Hash{}, db, nil)
	addr := toAddr([]byte("so"))
	{
		state.SetBalance(addr, big.NewInt(1))
		state.SetCode(addr, []byte{1, 2, 3})
		a2 := toAddr([]byte("another"))
		state.SetBalance(a2, big.NewInt(100))
		state.SetCode(a2, []byte{1, 2, 4})
		root, _ = state.Commit(false)
		t.Logf("root: %x", root)
		// force-flush
		state.Database().TrieDB().Cap(0)
	}
	// Create a new state on the old root
	state, _ = New(root, db, nil)
	// Now we clear out the memdb
	it := memDb.NewIterator(nil, nil)
	for it.Next() {
		k := it.Key()
		// Leave the root intact
		if !bytes.Equal(k, root[:]) {
			t.Logf("key: %x", k)
			memDb.Delete(k)
		}
	}
	balance := state.GetBalance(addr)
	// The removed elem should lead to it returning zero balance
	if exp, got := uint64(0), balance.Uint64(); got != exp {
		t.Errorf("expected %d, got %d", exp, got)
	}
	// Modify the state
	state.SetBalance(addr, big.NewInt(2))
	root, err := state.Commit(false)
	if err == nil {
		t.Fatalf("expected error, got root :%x", root)
	}
}

func TestErase(t *testing.T) {
	// Create an initial state with a single contract
	state, _ := New(common.Hash{}, NewDatabase(rawdb.NewMemoryDatabase()), nil)

	addr := toAddr([]byte("so"))
	state.SetBalance(addr, big.NewInt(1))
	skey := common.HexToHash("aaa")
	sval := common.HexToHash("bbb")

	state.SetCode(addr, []byte("hello")) // Change an external metadata
	state.SetState(addr, skey, sval)     // Change the storage trie

	root, _ := state.Commit(false)
	state.Reset(root)

	// Simulate erase and then revert
	id := state.Snapshot()
	state.Erase(addr)
	state.RevertToSnapshot(id)
	root, _ = state.Commit(true)
	state.Reset(root)

	obj := state.getStateObject(addr)
	if code := obj.Code(state.db); !bytes.Equal(code, []byte("hello")) {
		t.Fatal("RevertToSnapshot failed after erase, code mismatch")
	}
	if val := obj.GetState(state.db, skey); val != sval {
		t.Fatal("RevertToSnapshot failed after erase, storage mismatch")
	}

	state.Erase(addr)
	// Commit the entire state and make sure we don't crash and have the correct state
	root, _ = state.Commit(true)
	state.Reset(root)

	obj = state.getStateObject(addr)
	if obj == nil {
		t.Fatal("erase should not delete the account")
	}
	if code := obj.Code(state.db); len(code) > 0 {
		t.Fatal("erase failed to clear the code")
	}
	if val := obj.GetState(state.db, skey); (val != common.Hash{}) {
		t.Fatal("erase not clear the storage")
	}
	if obj.data.Root != emptyRoot {
		t.Fatal("erase not clear the storage")
	}
	if !bytes.Equal(obj.CodeHash(), emptyCodeHash) {
		t.Fatal("erase failed to clear the code hash")
	}
	if obj.Balance().Uint64() != uint64(1) {
		t.Fatal("erase should not change balance")
	}
}
