package types_test

import (
	"fmt"
	"math/big"
	"reflect"
	"testing"

	"github.com/stretchr/testify/suite"

	"github.com/cosmos/cosmos-sdk/client"
	"github.com/cosmos/cosmos-sdk/crypto/keyring"
	sdk "github.com/cosmos/cosmos-sdk/types"
	"github.com/tharsis/ethermint/crypto/ethsecp256k1"
	"github.com/tharsis/ethermint/tests"

	"github.com/ethereum/go-ethereum/common"
	ethtypes "github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/crypto"

	"github.com/tharsis/ethermint/app"
	"github.com/tharsis/ethermint/encoding"
	"github.com/tharsis/ethermint/x/evm/types"
)

const invalidFromAddress = "0x0000"

type MsgsTestSuite struct {
	suite.Suite

	signer  keyring.Signer
	from    common.Address
	to      common.Address
	chainID *big.Int

	clientCtx client.Context
}

func TestMsgsTestSuite(t *testing.T) {
	suite.Run(t, new(MsgsTestSuite))
}

func (suite *MsgsTestSuite) SetupTest() {
	from, privFrom := tests.NewAddrKey()

	suite.signer = tests.NewSigner(privFrom)
	suite.from = from
	suite.to = tests.GenerateAddress()
	suite.chainID = big.NewInt(1)

	encodingConfig := encoding.MakeConfig(app.ModuleBasics)
	suite.clientCtx = client.Context{}.WithTxConfig(encodingConfig.TxConfig)
}

func (suite *MsgsTestSuite) TestMsgEthereumTx_Constructor() {
	msg := types.NewTx(nil, 0, &suite.to, nil, 100000, nil, nil, nil, []byte("test"), nil)

	// suite.Require().Equal(msg.Data.To, suite.to.Hex())
	suite.Require().Equal(msg.Route(), types.RouterKey)
	suite.Require().Equal(msg.Type(), types.TypeMsgEthereumTx)
	// suite.Require().NotNil(msg.To())
	suite.Require().Equal(msg.GetMsgs(), []sdk.Msg{msg})
	suite.Require().Panics(func() { msg.GetSigners() })
	suite.Require().Panics(func() { msg.GetSignBytes() })

	msg = types.NewTxContract(nil, 0, nil, 100000, nil, nil, nil, []byte("test"), nil)
	suite.Require().NotNil(msg)
	// suite.Require().Empty(msg.Data.To)
	// suite.Require().Nil(msg.To())
}

func (suite *MsgsTestSuite) TestMsgEthereumTx_BuildTx() {
	msg := types.NewTx(nil, 0, &suite.to, nil, 100000, big.NewInt(1), big.NewInt(1), big.NewInt(0), []byte("test"), nil)

	err := msg.ValidateBasic()
	suite.Require().NoError(err)

	tx, err := msg.BuildTx(suite.clientCtx.TxConfig.NewTxBuilder(), "aphoton")
	suite.Require().NoError(err)

	suite.Require().Empty(tx.GetMemo())
	suite.Require().Empty(tx.GetTimeoutHeight())
	suite.Require().Equal(uint64(100000), tx.GetGas())
	suite.Require().Equal(sdk.NewCoins(sdk.NewCoin("aphoton", sdk.NewInt(100000))), tx.GetFee())
}

func (suite *MsgsTestSuite) TestMsgEthereumTx_ValidateBasic() {
	hundredInt := sdk.NewInt(100)
	zeroInt := sdk.ZeroInt()
	minusOneInt := sdk.NewInt(-1)
	exp_2_255 := sdk.NewIntFromBigInt(new(big.Int).Exp(big.NewInt(2), big.NewInt(255), nil))

	testCases := []struct {
		msg        string
		to         string
		amount     *sdk.Int
		gasPrice   *sdk.Int
		from       string
		accessList *ethtypes.AccessList
		chainID    *sdk.Int
		expectPass bool
	}{
		{msg: "pass with recipient - Legacy Tx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: &hundredInt, expectPass: true},
		{msg: "pass with recipient - AccessList Tx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: &zeroInt, accessList: &ethtypes.AccessList{}, chainID: &hundredInt, expectPass: true},
		{msg: "pass contract - Legacy Tx", to: "", amount: &hundredInt, gasPrice: &hundredInt, expectPass: true},
		// {msg: "invalid recipient", to: invalidFromAddress, amount: &minusOneInt, gasPrice: &hundredInt, expectPass: false},
		{msg: "nil amount - Legacy Tx", to: suite.to.Hex(), amount: nil, gasPrice: &hundredInt, expectPass: true},
		{msg: "negative amount - Legacy Tx", to: suite.to.Hex(), amount: &minusOneInt, gasPrice: &hundredInt, expectPass: false},
		{msg: "nil gas price - Legacy Tx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: nil, expectPass: false},
		{msg: "negative gas price - Legacy Tx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: &minusOneInt, expectPass: false},
		{msg: "zero gas price - Legacy Tx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: &zeroInt, expectPass: true},
		{msg: "invalid from address - Legacy Tx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: &zeroInt, from: invalidFromAddress, expectPass: false},
		{msg: "out of bound gas fee - Legacy Tx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: &exp_2_255, expectPass: false},
		{msg: "nil amount - AccessListTx", to: suite.to.Hex(), amount: nil, gasPrice: &hundredInt, accessList: &ethtypes.AccessList{}, chainID: &hundredInt, expectPass: true},
		{msg: "negative amount - AccessListTx", to: suite.to.Hex(), amount: &minusOneInt, gasPrice: &hundredInt, accessList: &ethtypes.AccessList{}, chainID: nil, expectPass: false},
		{msg: "nil gas price - AccessListTx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: nil, accessList: &ethtypes.AccessList{}, chainID: &hundredInt, expectPass: false},
		{msg: "negative gas price - AccessListTx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: &minusOneInt, accessList: &ethtypes.AccessList{}, chainID: nil, expectPass: false},
		{msg: "zero gas price - AccessListTx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: &zeroInt, accessList: &ethtypes.AccessList{}, chainID: &hundredInt, expectPass: true},
		{msg: "invalid from address - AccessListTx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: &zeroInt, from: invalidFromAddress, accessList: &ethtypes.AccessList{}, chainID: &hundredInt, expectPass: false},
		{msg: "chain ID not set on AccessListTx", to: suite.to.Hex(), amount: &hundredInt, gasPrice: &zeroInt, accessList: &ethtypes.AccessList{}, chainID: nil, expectPass: false},
	}

	for i, tc := range testCases {
		to := common.HexToAddress(tc.from)

		var chainID, amount, gasPrice *big.Int
		if tc.chainID != nil {
			chainID = tc.chainID.BigInt()
		}
		if tc.amount != nil {
			amount = tc.amount.BigInt()
		}
		if tc.gasPrice != nil {
			gasPrice = tc.gasPrice.BigInt()
		}

		tx := types.NewTx(chainID, 1, &to, amount, 1000, gasPrice, nil, nil, nil, tc.accessList)
		tx.From = tc.from

		err := tx.ValidateBasic()

		if tc.expectPass {
			suite.Require().NoError(err, "valid test %d failed: %s, %v", i, tc.msg)
		} else {
			suite.Require().Error(err, "invalid test %d passed: %s, %v", i, tc.msg)
		}
	}
}

func (suite *MsgsTestSuite) TestMsgEthereumTx_Sign() {
	testCases := []struct {
		msg        string
		tx         *types.MsgEthereumTx
		ethSigner  ethtypes.Signer
		malleate   func(tx *types.MsgEthereumTx)
		expectPass bool
	}{
		{
			"pass - EIP2930 signer",
			types.NewTx(suite.chainID, 0, &suite.to, nil, 100000, nil, nil, nil, []byte("test"), &ethtypes.AccessList{}),
			ethtypes.NewEIP2930Signer(suite.chainID),
			func(tx *types.MsgEthereumTx) { tx.From = suite.from.Hex() },
			true,
		},
		{
			"pass - EIP155 signer",
			types.NewTx(suite.chainID, 0, &suite.to, nil, 100000, nil, nil, nil, []byte("test"), nil),
			ethtypes.NewEIP155Signer(suite.chainID),
			func(tx *types.MsgEthereumTx) { tx.From = suite.from.Hex() },
			true,
		},
		{
			"pass - Homestead signer",
			types.NewTx(suite.chainID, 0, &suite.to, nil, 100000, nil, nil, nil, []byte("test"), nil),
			ethtypes.HomesteadSigner{},
			func(tx *types.MsgEthereumTx) { tx.From = suite.from.Hex() },
			true,
		},
		{
			"pass - Frontier signer",
			types.NewTx(suite.chainID, 0, &suite.to, nil, 100000, nil, nil, nil, []byte("test"), nil),
			ethtypes.FrontierSigner{},
			func(tx *types.MsgEthereumTx) { tx.From = suite.from.Hex() },
			true,
		},
		{
			"no from address ",
			types.NewTx(suite.chainID, 0, &suite.to, nil, 100000, nil, nil, nil, []byte("test"), &ethtypes.AccessList{}),
			ethtypes.NewEIP2930Signer(suite.chainID),
			func(tx *types.MsgEthereumTx) { tx.From = "" },
			false,
		},
		{
			"from address ≠ signer address",
			types.NewTx(suite.chainID, 0, &suite.to, nil, 100000, nil, nil, nil, []byte("test"), &ethtypes.AccessList{}),
			ethtypes.NewEIP2930Signer(suite.chainID),
			func(tx *types.MsgEthereumTx) { tx.From = suite.to.Hex() },
			false,
		},
	}

	for i, tc := range testCases {
		tc.malleate(tc.tx)

		err := tc.tx.Sign(tc.ethSigner, suite.signer)
		if tc.expectPass {
			suite.Require().NoError(err, "valid test %d failed: %s", i, tc.msg)

			sender, err := tc.tx.GetSender(suite.chainID)
			suite.Require().NoError(err, tc.msg)
			suite.Require().Equal(tc.tx.From, sender.Hex(), tc.msg)
		} else {
			suite.Require().Error(err, "invalid test %d passed: %s", i, tc.msg)
		}
	}
}

func (suite *MsgsTestSuite) TestFromEthereumTx() {
	privkey, _ := ethsecp256k1.GenerateKey()
	ethPriv, err := privkey.ToECDSA()
	suite.Require().NoError(err)

	// 10^80 is more than 256 bits
	exp_10_80 := new(big.Int).Mul(big.NewInt(1), new(big.Int).Exp(big.NewInt(10), big.NewInt(80), nil))

	testCases := []struct {
		msg        string
		expectPass bool
		buildTx    func() *ethtypes.Transaction
	}{
		{"success, normal tx", true, func() *ethtypes.Transaction {
			tx := ethtypes.NewTransaction(
				0,
				common.BigToAddress(big.NewInt(1)),
				big.NewInt(10),
				21000, big.NewInt(0),
				nil,
			)
			tx, err := ethtypes.SignTx(tx, ethtypes.NewEIP2930Signer(suite.chainID), ethPriv)
			suite.Require().NoError(err)
			return tx
		}},
		{"fail, value bigger than 256bits", false, func() *ethtypes.Transaction {
			tx := ethtypes.NewTransaction(
				0,
				common.BigToAddress(big.NewInt(1)),
				exp_10_80,
				21000, big.NewInt(0),
				nil,
			)
			tx, err := ethtypes.SignTx(tx, ethtypes.NewEIP2930Signer(suite.chainID), ethPriv)
			suite.Require().NoError(err)
			return tx
		}},
		{"fail, gas price bigger than 256bits", false, func() *ethtypes.Transaction {
			tx := ethtypes.NewTransaction(
				0,
				common.BigToAddress(big.NewInt(1)),
				big.NewInt(10),
				21000, exp_10_80,
				nil,
			)
			tx, err := ethtypes.SignTx(tx, ethtypes.NewEIP2930Signer(suite.chainID), ethPriv)
			suite.Require().NoError(err)
			return tx
		}},
	}

	for _, tc := range testCases {
		ethTx := tc.buildTx()
		tx := &types.MsgEthereumTx{}
		err := tx.FromEthereumTx(ethTx)
		if tc.expectPass {
			suite.Require().NoError(err)

			// round-trip test
			suite.Require().NoError(assertEqual(tx.AsTransaction(), ethTx))
		} else {
			suite.Require().Error(err)
		}
	}
}

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

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

func assertEqual(orig *ethtypes.Transaction, cpy *ethtypes.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
}