package types

import (
	"bytes"
	"crypto/ecdsa"
	"encoding/json"
	"fmt"
	"math/big"
	"math/rand"
	"reflect"
	"testing"
	"time"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/ethereum/go-ethereum/rlp"
)

// The values in those tests are from the Transaction Tests
// at github.com/ethereum/tests.
var (
	testAddr = common.HexToAddress("b94f5374fce5edbc8e2a8697c15331677e6ebf0b")

	emptyTx = NewTransaction(
		0,
		common.HexToAddress("095e7baea6a6c7c4c2dfeb977efac326af552d87"),
		big.NewInt(0), 0, big.NewInt(0),
		nil,
	)

	rightvrsTx, _ = NewTransaction(
		3,
		testAddr,
		big.NewInt(10),
		2000,
		big.NewInt(1),
		common.FromHex("5544"),
	).WithSignature(
		HomesteadSigner{},
		common.Hex2Bytes("98ff921201554726367d2be8c804a7ff89ccf285ebc57dff8ae4c44b9c19ac4a8887321be575c8095f789dd4c743dfe42c1820f9231f98a962b210e3ac2452a301"),
	)

	emptyEip2718Tx = NewTx(&AccessListTx{
		ChainID:  big.NewInt(1),
		Nonce:    3,
		To:       &testAddr,
		Value:    big.NewInt(10),
		Gas:      25000,
		GasPrice: big.NewInt(1),
		Data:     common.FromHex("5544"),
	})

	signedEip2718Tx, _ = emptyEip2718Tx.WithSignature(
		NewEIP2930Signer(big.NewInt(1)),
		common.Hex2Bytes("c9519f4f2b30335884581971573fadf60c6204f59a911df35ee8a540456b266032f1e8e2c5dd761f9e4f88f41c8310aeaba26a8bfcdacfedfa12ec3862d3752101"),
	)
)

func TestDecodeEmptyTypedTx(t *testing.T) {
	input := []byte{0x80}
	var tx Transaction
	err := rlp.DecodeBytes(input, &tx)
	if err != errShortTypedTx {
		t.Fatal("wrong error:", err)
	}
}

func TestTransactionSigHash(t *testing.T) {
	var homestead HomesteadSigner
	if homestead.Hash(emptyTx) != common.HexToHash("c775b99e7ad12f50d819fcd602390467e28141316969f4b57f0626f74fe3b386") {
		t.Errorf("empty transaction hash mismatch, got %x", emptyTx.Hash())
	}
	if homestead.Hash(rightvrsTx) != common.HexToHash("fe7a79529ed5f7c3375d06b26b186a8644e0e16c373d7a12be41c62d6042b77a") {
		t.Errorf("RightVRS transaction hash mismatch, got %x", rightvrsTx.Hash())
	}
}

func TestTransactionEncode(t *testing.T) {
	txb, err := rlp.EncodeToBytes(rightvrsTx)
	if err != nil {
		t.Fatalf("encode error: %v", err)
	}
	should := common.FromHex("f86103018207d094b94f5374fce5edbc8e2a8697c15331677e6ebf0b0a8255441ca098ff921201554726367d2be8c804a7ff89ccf285ebc57dff8ae4c44b9c19ac4aa08887321be575c8095f789dd4c743dfe42c1820f9231f98a962b210e3ac2452a3")
	if !bytes.Equal(txb, should) {
		t.Errorf("encoded RLP mismatch, got %x", txb)
	}
}

func TestEIP2718TransactionSigHash(t *testing.T) {
	s := NewEIP2930Signer(big.NewInt(1))
	if s.Hash(emptyEip2718Tx) != common.HexToHash("49b486f0ec0a60dfbbca2d30cb07c9e8ffb2a2ff41f29a1ab6737475f6ff69f3") {
		t.Errorf("empty EIP-2718 transaction hash mismatch, got %x", s.Hash(emptyEip2718Tx))
	}
	if s.Hash(signedEip2718Tx) != common.HexToHash("49b486f0ec0a60dfbbca2d30cb07c9e8ffb2a2ff41f29a1ab6737475f6ff69f3") {
		t.Errorf("signed EIP-2718 transaction hash mismatch, got %x", s.Hash(signedEip2718Tx))
	}
}

// This test checks signature operations on access list transactions.
func TestEIP2930Signer(t *testing.T) {

	var (
		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
		keyAddr = crypto.PubkeyToAddress(key.PublicKey)
		signer1 = NewEIP2930Signer(big.NewInt(1))
		signer2 = NewEIP2930Signer(big.NewInt(2))
		tx0     = NewTx(&AccessListTx{Nonce: 1})
		tx1     = NewTx(&AccessListTx{ChainID: big.NewInt(1), Nonce: 1})
		tx2, _  = SignNewTx(key, signer2, &AccessListTx{ChainID: big.NewInt(2), Nonce: 1})
	)

	tests := []struct {
		tx             *Transaction
		signer         Signer
		wantSignerHash common.Hash
		wantSenderErr  error
		wantSignErr    error
		wantHash       common.Hash // after signing
	}{
		{
			tx:             tx0,
			signer:         signer1,
			wantSignerHash: common.HexToHash("846ad7672f2a3a40c1f959cd4a8ad21786d620077084d84c8d7c077714caa139"),
			wantSenderErr:  ErrInvalidChainId,
			wantHash:       common.HexToHash("1ccd12d8bbdb96ea391af49a35ab641e219b2dd638dea375f2bc94dd290f2549"),
		},
		{
			tx:             tx1,
			signer:         signer1,
			wantSenderErr:  ErrInvalidSig,
			wantSignerHash: common.HexToHash("846ad7672f2a3a40c1f959cd4a8ad21786d620077084d84c8d7c077714caa139"),
			wantHash:       common.HexToHash("1ccd12d8bbdb96ea391af49a35ab641e219b2dd638dea375f2bc94dd290f2549"),
		},
		{
			// This checks what happens when trying to sign an unsigned tx for the wrong chain.
			tx:             tx1,
			signer:         signer2,
			wantSenderErr:  ErrInvalidChainId,
			wantSignerHash: common.HexToHash("367967247499343401261d718ed5aa4c9486583e4d89251afce47f4a33c33362"),
			wantSignErr:    ErrInvalidChainId,
		},
		{
			// This checks what happens when trying to re-sign a signed tx for the wrong chain.
			tx:             tx2,
			signer:         signer1,
			wantSenderErr:  ErrInvalidChainId,
			wantSignerHash: common.HexToHash("846ad7672f2a3a40c1f959cd4a8ad21786d620077084d84c8d7c077714caa139"),
			wantSignErr:    ErrInvalidChainId,
		},
	}

	for i, test := range tests {
		sigHash := test.signer.Hash(test.tx)
		if sigHash != test.wantSignerHash {
			t.Errorf("test %d: wrong sig hash: got %x, want %x", i, sigHash, test.wantSignerHash)
		}
		sender, err := Sender(test.signer, test.tx)
		if err != test.wantSenderErr {
			t.Errorf("test %d: wrong Sender error %q", i, err)
		}
		if err == nil && sender != keyAddr {
			t.Errorf("test %d: wrong sender address %x", i, sender)
		}
		signedTx, err := SignTx(test.tx, test.signer, key)
		if err != test.wantSignErr {
			t.Fatalf("test %d: wrong SignTx error %q", i, err)
		}
		if signedTx != nil {
			if signedTx.Hash() != test.wantHash {
				t.Errorf("test %d: wrong tx hash after signing: got %x, want %x", i, signedTx.Hash(), test.wantHash)
			}
		}
	}
}

func TestEIP2718TransactionEncode(t *testing.T) {
	// RLP representation
	{
		have, err := rlp.EncodeToBytes(signedEip2718Tx)
		if err != nil {
			t.Fatalf("encode error: %v", err)
		}
		want := common.FromHex("b86601f8630103018261a894b94f5374fce5edbc8e2a8697c15331677e6ebf0b0a825544c001a0c9519f4f2b30335884581971573fadf60c6204f59a911df35ee8a540456b2660a032f1e8e2c5dd761f9e4f88f41c8310aeaba26a8bfcdacfedfa12ec3862d37521")
		if !bytes.Equal(have, want) {
			t.Errorf("encoded RLP mismatch, got %x", have)
		}
	}
	// Binary representation
	{
		have, err := signedEip2718Tx.MarshalBinary()
		if err != nil {
			t.Fatalf("encode error: %v", err)
		}
		want := common.FromHex("01f8630103018261a894b94f5374fce5edbc8e2a8697c15331677e6ebf0b0a825544c001a0c9519f4f2b30335884581971573fadf60c6204f59a911df35ee8a540456b2660a032f1e8e2c5dd761f9e4f88f41c8310aeaba26a8bfcdacfedfa12ec3862d37521")
		if !bytes.Equal(have, want) {
			t.Errorf("encoded RLP mismatch, got %x", have)
		}
	}
}

func decodeTx(data []byte) (*Transaction, error) {
	var tx Transaction
	t, err := &tx, rlp.Decode(bytes.NewReader(data), &tx)
	return t, err
}

func defaultTestKey() (*ecdsa.PrivateKey, common.Address) {
	key, _ := crypto.HexToECDSA("45a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065ff2d8")
	addr := crypto.PubkeyToAddress(key.PublicKey)
	return key, addr
}

func TestRecipientEmpty(t *testing.T) {
	_, addr := defaultTestKey()
	tx, err := decodeTx(common.Hex2Bytes("f8498080808080011ca09b16de9d5bdee2cf56c28d16275a4da68cd30273e2525f3959f5d62557489921a0372ebd8fb3345f7db7b5a86d42e24d36e983e259b0664ceb8c227ec9af572f3d"))
	if err != nil {
		t.Fatal(err)
	}

	from, err := Sender(HomesteadSigner{}, tx)
	if err != nil {
		t.Fatal(err)
	}
	if addr != from {
		t.Fatal("derived address doesn't match")
	}
}

func TestRecipientNormal(t *testing.T) {
	_, addr := defaultTestKey()

	tx, err := decodeTx(common.Hex2Bytes("f85d80808094000000000000000000000000000000000000000080011ca0527c0d8f5c63f7b9f41324a7c8a563ee1190bcbf0dac8ab446291bdbf32f5c79a0552c4ef0a09a04395074dab9ed34d3fbfb843c2f2546cc30fe89ec143ca94ca6"))
	if err != nil {
		t.Fatal(err)
	}

	from, err := Sender(HomesteadSigner{}, tx)
	if err != nil {
		t.Fatal(err)
	}
	if addr != from {
		t.Fatal("derived address doesn't match")
	}
}

func TestTransactionPriceNonceSortLegacy(t *testing.T) {
	testTransactionPriceNonceSort(t, nil)
}

func TestTransactionPriceNonceSort1559(t *testing.T) {
	testTransactionPriceNonceSort(t, big.NewInt(0))
	testTransactionPriceNonceSort(t, big.NewInt(5))
	testTransactionPriceNonceSort(t, big.NewInt(50))
}

// Tests that transactions can be correctly sorted according to their price in
// decreasing order, but at the same time with increasing nonces when issued by
// the same account.
func testTransactionPriceNonceSort(t *testing.T, baseFee *big.Int) {
	// Generate a batch of accounts to start with
	keys := make([]*ecdsa.PrivateKey, 25)
	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
	}
	signer := LatestSignerForChainID(common.Big1)

	// Generate a batch of transactions with overlapping values, but shifted nonces
	groups := map[common.Address]Transactions{}
	expectedCount := 0
	for start, key := range keys {
		addr := crypto.PubkeyToAddress(key.PublicKey)
		count := 25
		for i := 0; i < 25; i++ {
			var tx *Transaction
			gasFeeCap := rand.Intn(50)
			if baseFee == nil {
				tx = NewTx(&LegacyTx{
					Nonce:    uint64(start + i),
					To:       &common.Address{},
					Value:    big.NewInt(100),
					Gas:      100,
					GasPrice: big.NewInt(int64(gasFeeCap)),
					Data:     nil,
				})
			} else {
				tx = NewTx(&DynamicFeeTx{
					Nonce:     uint64(start + i),
					To:        &common.Address{},
					Value:     big.NewInt(100),
					Gas:       100,
					GasFeeCap: big.NewInt(int64(gasFeeCap)),
					GasTipCap: big.NewInt(int64(rand.Intn(gasFeeCap + 1))),
					Data:      nil,
				})
				if count == 25 && int64(gasFeeCap) < baseFee.Int64() {
					count = i
				}
			}
			tx, err := SignTx(tx, signer, key)
			if err != nil {
				t.Fatalf("failed to sign tx: %s", err)
			}
			groups[addr] = append(groups[addr], tx)
		}
		expectedCount += count
	}
	// Sort the transactions and cross check the nonce ordering
	txset := NewTransactionsByPriceAndNonce(signer, groups, baseFee)

	txs := Transactions{}
	for tx := txset.Peek(); tx != nil; tx = txset.Peek() {
		txs = append(txs, tx)
		txset.Shift()
	}
	if len(txs) != expectedCount {
		t.Errorf("expected %d transactions, found %d", expectedCount, len(txs))
	}
	for i, txi := range txs {
		fromi, _ := Sender(signer, txi)

		// Make sure the nonce order is valid
		for j, txj := range txs[i+1:] {
			fromj, _ := Sender(signer, txj)
			if fromi == fromj && txi.Nonce() > txj.Nonce() {
				t.Errorf("invalid nonce ordering: tx #%d (A=%x N=%v) < tx #%d (A=%x N=%v)", i, fromi[:4], txi.Nonce(), i+j, fromj[:4], txj.Nonce())
			}
		}
		// If the next tx has different from account, the price must be lower than the current one
		if i+1 < len(txs) {
			next := txs[i+1]
			fromNext, _ := Sender(signer, next)
			tip, err := txi.EffectiveGasTip(baseFee)
			nextTip, nextErr := next.EffectiveGasTip(baseFee)
			if err != nil || nextErr != nil {
				t.Errorf("error calculating effective tip")
			}
			if fromi != fromNext && tip.Cmp(nextTip) < 0 {
				t.Errorf("invalid gasprice ordering: tx #%d (A=%x P=%v) < tx #%d (A=%x P=%v)", i, fromi[:4], txi.GasPrice(), i+1, fromNext[:4], next.GasPrice())
			}
		}
	}
}

// Tests that if multiple transactions have the same price, the ones seen earlier
// are prioritized to avoid network spam attacks aiming for a specific ordering.
func TestTransactionTimeSort(t *testing.T) {
	// Generate a batch of accounts to start with
	keys := make([]*ecdsa.PrivateKey, 5)
	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
	}
	signer := HomesteadSigner{}

	// Generate a batch of transactions with overlapping prices, but different creation times
	groups := map[common.Address]Transactions{}
	for start, key := range keys {
		addr := crypto.PubkeyToAddress(key.PublicKey)

		tx, _ := SignTx(NewTransaction(0, common.Address{}, big.NewInt(100), 100, big.NewInt(1), nil), signer, key)
		tx.time = time.Unix(0, int64(len(keys)-start))

		groups[addr] = append(groups[addr], tx)
	}
	// Sort the transactions and cross check the nonce ordering
	txset := NewTransactionsByPriceAndNonce(signer, groups, nil)

	txs := Transactions{}
	for tx := txset.Peek(); tx != nil; tx = txset.Peek() {
		txs = append(txs, tx)
		txset.Shift()
	}
	if len(txs) != len(keys) {
		t.Errorf("expected %d transactions, found %d", len(keys), len(txs))
	}
	for i, txi := range txs {
		fromi, _ := Sender(signer, txi)
		if i+1 < len(txs) {
			next := txs[i+1]
			fromNext, _ := Sender(signer, next)

			if txi.GasPrice().Cmp(next.GasPrice()) < 0 {
				t.Errorf("invalid gasprice ordering: tx #%d (A=%x P=%v) < tx #%d (A=%x P=%v)", i, fromi[:4], txi.GasPrice(), i+1, fromNext[:4], next.GasPrice())
			}
			// Make sure time order is ascending if the txs have the same gas price
			if txi.GasPrice().Cmp(next.GasPrice()) == 0 && txi.time.After(next.time) {
				t.Errorf("invalid received time ordering: tx #%d (A=%x T=%v) > tx #%d (A=%x T=%v)", i, fromi[:4], txi.time, i+1, fromNext[:4], next.time)
			}
		}
	}
}

// TestTransactionCoding tests serializing/de-serializing to/from rlp and JSON.
func TestTransactionCoding(t *testing.T) {
	key, err := crypto.GenerateKey()
	if err != nil {
		t.Fatalf("could not generate key: %v", err)
	}
	var (
		signer    = NewEIP2930Signer(common.Big1)
		addr      = common.HexToAddress("0x0000000000000000000000000000000000000001")
		recipient = common.HexToAddress("095e7baea6a6c7c4c2dfeb977efac326af552d87")
		accesses  = AccessList{{Address: addr, StorageKeys: []common.Hash{{0}}}}
	)
	for i := uint64(0); i < 500; i++ {
		var txdata TxData
		switch i % 5 {
		case 0:
			// Legacy tx.
			txdata = &LegacyTx{
				Nonce:    i,
				To:       &recipient,
				Gas:      1,
				GasPrice: big.NewInt(2),
				Data:     []byte("abcdef"),
			}
		case 1:
			// Legacy tx contract creation.
			txdata = &LegacyTx{
				Nonce:    i,
				Gas:      1,
				GasPrice: big.NewInt(2),
				Data:     []byte("abcdef"),
			}
		case 2:
			// Tx with non-zero access list.
			txdata = &AccessListTx{
				ChainID:    big.NewInt(1),
				Nonce:      i,
				To:         &recipient,
				Gas:        123457,
				GasPrice:   big.NewInt(10),
				AccessList: accesses,
				Data:       []byte("abcdef"),
			}
		case 3:
			// Tx with empty access list.
			txdata = &AccessListTx{
				ChainID:  big.NewInt(1),
				Nonce:    i,
				To:       &recipient,
				Gas:      123457,
				GasPrice: big.NewInt(10),
				Data:     []byte("abcdef"),
			}
		case 4:
			// Contract creation with access list.
			txdata = &AccessListTx{
				ChainID:    big.NewInt(1),
				Nonce:      i,
				Gas:        123457,
				GasPrice:   big.NewInt(10),
				AccessList: accesses,
			}
		}
		tx, err := SignNewTx(key, signer, txdata)
		if err != nil {
			t.Fatalf("could not sign transaction: %v", err)
		}
		// RLP
		parsedTx, err := encodeDecodeBinary(tx)
		if err != nil {
			t.Fatal(err)
		}
		if err := assertEqual(parsedTx, tx); err != nil {
			t.Fatal(err)
		}

		// JSON
		parsedTx, err = encodeDecodeJSON(tx)
		if err != nil {
			t.Fatal(err)
		}
		if err := assertEqual(parsedTx, tx); err != nil {
			t.Fatal(err)
		}
	}
}

func encodeDecodeJSON(tx *Transaction) (*Transaction, error) {
	data, err := json.Marshal(tx)
	if err != nil {
		return nil, fmt.Errorf("json encoding failed: %v", err)
	}
	var parsedTx = &Transaction{}
	if err := json.Unmarshal(data, &parsedTx); err != nil {
		return nil, fmt.Errorf("json decoding failed: %v", err)
	}
	return parsedTx, nil
}

func encodeDecodeBinary(tx *Transaction) (*Transaction, error) {
	data, err := tx.MarshalBinary()
	if err != nil {
		return nil, fmt.Errorf("rlp encoding failed: %v", err)
	}
	var parsedTx = &Transaction{}
	if err := parsedTx.UnmarshalBinary(data); err != nil {
		return nil, fmt.Errorf("rlp decoding failed: %v", err)
	}
	return parsedTx, nil
}

func assertEqual(orig *Transaction, cpy *Transaction) error {
	// compare nonce, price, gaslimit, recipient, amount, payload, V, R, S
	if want, got := orig.Hash(), cpy.Hash(); want != got {
		return fmt.Errorf("parsed tx differs from original tx, want %v, got %v", want, got)
	}
	if want, got := orig.ChainId(), cpy.ChainId(); want.Cmp(got) != 0 {
		return fmt.Errorf("invalid chain id, want %d, got %d", want, got)
	}
	if orig.AccessList() != nil {
		if !reflect.DeepEqual(orig.AccessList(), cpy.AccessList()) {
			return fmt.Errorf("access list wrong!")
		}
	}
	return nil
}
