2022-11-23 19:46:29 -03:00

456 lines
12 KiB
Solidity

// SPDX-License-Identifier: MIT
pragma solidity 0.8.9;
/// ______ __
/// .-----.|__ |.-----.|__|.--.--.
/// | _ || __|| _ || ||_ _|
/// | __||______|| __||__||__.__|
/// |__| |__|
///
import { Owned } from "./lib/auth/Owned.sol";
import { Counters } from "./lib/utils/Counters.sol";
import { ERC20, SafeTransferLib } from "./lib/utils/SafeTransferLib.sol";
import { ReentrancyGuard } from "./lib/utils/ReentrancyGuard.sol";
import { EventAndErrors } from "./EventAndErrors.sol";
import { DataTypes as DT } from "./DataTypes.sol";
contract P2PIX is
EventAndErrors,
Owned(msg.sender),
ReentrancyGuard
{
// solhint-disable use-forbidden-name
// solhint-disable no-inline-assembly
using Counters for Counters.Counter;
using DT for DT.Deposit;
using DT for DT.Lock;
/// ███ Storage ████████████████████████████████████████████████████████████
Counters.Counter public depositCount;
/// @dev Default blocks that lock will hold tokens.
uint256 public defaultLockBlocks;
/// @dev List of valid Bacen signature addresses
mapping(uint256 => bool) public validBacenSigners;
/// @dev Seller list of deposits
mapping(uint256 => DT.Deposit) public mapDeposits;
/// @dev List of Locks.
mapping(bytes32 => DT.Lock) public mapLocks;
/// @dev List of Pix transactions already signed.
mapping(bytes32 => bool) private usedTransactions;
/// ███ Constructor ████████████████████████████████████████████████████████
constructor(
uint256 defaultBlocks,
address[] memory validSigners
) payable {
assembly {
sstore(defaultLockBlocks.slot, defaultBlocks)
}
unchecked {
uint256 i;
uint256 len = validSigners.length;
for (i; i < len; ) {
uint256 key = _castAddrToKey(validSigners[i]);
validBacenSigners[key] = true;
++i;
}
}
}
/// ███ Public FX ██████████████████████████████████████████████████████████
// Vendedor precisa mandar token para o smart contract + chave PIX destino. Retorna um DepositID.
function deposit(
address token,
uint256 amount,
string calldata pixTarget
)
public
payable
returns (uint256 depositID)
{
(depositID) = _encodeDepositID();
ERC20 t = ERC20(token);
DT.Deposit memory d =
DT.Deposit({
remaining: amount,
premium: msg.value,
pixTarget: pixTarget,
seller: msg.sender,
token: token,
valid: true
});
setReentrancyGuard();
mapDeposits[depositID] = d;
depositCount.increment();
SafeTransferLib.safeTransferFrom(
t,
msg.sender,
address(this),
amount
);
clearReentrancyGuard();
emit DepositAdded(
msg.sender,
depositID,
token,
msg.value,
amount
);
}
// Vendedor pode invalidar da ordem de venda impedindo novos
// locks na mesma (isso não afeta nenhum lock que esteja ativo).
function cancelDeposit(
uint256 depositID
) public {
_onlySeller(depositID);
mapDeposits[depositID].valid = false;
emit DepositClosed(
mapDeposits[depositID].seller,
depositID
);
}
// Relayer interaje adicionando um “lock” na ordem de venda.
// O lock precisa incluir address do comprador + address do relayer + reembolso/premio relayer + valor.
// **Só poder ter um lock em aberto para cada (ordem de venda, valor)**.
// Só pode fazer lock de ordens que não estão invalidadas(Passo 5).
// Essa etapa pode ser feita pelo vendedor conjuntamente com a parte 1.
// Retorna um LockID.
function lock(
uint256 _depositID,
address _targetAddress,
address _relayerAddress,
uint256 _relayerPremium,
uint256 _amount,
bytes32[] calldata expiredLocks
)
public
nonReentrant
returns (bytes32 lockID)
{
unlockExpired(expiredLocks);
DT.Deposit storage d =
mapDeposits[_depositID];
if(!d.valid)
revert InvalidDeposit();
if(d.remaining < _amount)
revert NotEnoughTokens();
(lockID) =
_encodeLockID(
_depositID,
_amount,
_targetAddress
);
DT.Lock memory l =
DT.Lock
({
depositID: _depositID,
relayerPremium: _relayerPremium,
amount: _amount,
expirationBlock: (block.number + defaultLockBlocks),
targetAddress: _targetAddress,
relayerAddress: _relayerAddress
});
mapLocks[lockID] = l;
d.remaining -= _amount;
emit LockAdded(
_targetAddress,
lockID,
_depositID,
_amount
);
}
// Relayer interage com o smart contract, colocando no calldata o comprovante do PIX realizado.
// Smart contract valida o comprovante, manda os tokens para o endereço do pagador,
// e reembolsa o custo do gás para o endereço do relayer especificado na parte (2).
function release(
bytes32 lockID,
uint256 pixTimestamp,
bytes32 r,
bytes32 s,
uint8 v
)
public
nonReentrant
{
// TODO **Prevenir que um Pix não relacionado ao APP seja usado pois tem o mesmo destino
DT.Lock storage l = mapLocks[lockID];
if(
l.expirationBlock <= block.number
&& l.amount <= 0
) revert
AlreadyReleased();
DT.Deposit storage d = mapDeposits[l.depositID];
bytes32 message = keccak256(
abi.encodePacked(
d.pixTarget,
l.amount,
pixTimestamp
)
);
bytes32 messageDigest = keccak256(
abi.encodePacked(
"\x19Ethereum Signed Message:\n32",
message
)
);
if(
usedTransactions[message]
== true
) revert
TxAlreadyUsed();
uint256 signer = _castAddrToKey(
ecrecover(
messageDigest,
v,
r,
s
));
if(!validBacenSigners[signer])
revert InvalidSigner();
ERC20 t = ERC20(d.token);
// We cache values before zeroing them out.
uint256 totalAmount = (l.amount - l.relayerPremium);
l.amount = 0;
l.expirationBlock = 0;
usedTransactions[message] = true;
SafeTransferLib.safeTransfer(
t,
l.targetAddress,
totalAmount
);
if (l.relayerPremium != 0) {
SafeTransferLib.safeTransfer(
t,
l.relayerAddress,
l.relayerPremium
);
}
emit LockReleased(
l.targetAddress,
lockID
);
}
// Unlock expired locks
function unlockExpired(
bytes32[] calldata lockIDs
) public {
uint256 i;
uint256 locksSize =
lockIDs.length;
for (i; i < locksSize;)
{
DT.Lock storage l = mapLocks[lockIDs[i]];
_notExpired(l);
mapDeposits[l.depositID].remaining
+= l.amount;
l.amount = 0;
emit LockReturned(
l.targetAddress,
lockIDs[i]
);
unchecked {
++i;
}
}
assembly {
if lt(i, locksSize) {
// LoopOverflow()
mstore(
0x00,
0xdfb035c9
)
revert(
0x1c,
0x04
)
}
}
}
// Após os locks expirarem, vendedor pode interagir c/ o contrato e recuperar os tokens de um depósito específico.
function withdraw(
uint256 depositID,
bytes32[] calldata expiredLocks
)
public
nonReentrant
{
_onlySeller(depositID);
unlockExpired(expiredLocks);
DT.Deposit storage d =
mapDeposits[depositID];
if (d.valid == true) {
cancelDeposit(depositID);
}
ERC20 token = ERC20(d.token);
// Withdraw remaining tokens from mapDeposit[depositID]
uint256 amount = d.remaining;
d.remaining = 0;
// safeTransfer tokens to seller
SafeTransferLib.safeTransfer(
token,
d.seller,
amount
);
emit DepositWithdrawn(
msg.sender,
depositID,
amount
);
}
/// ███ Owner Only █████████████████████████████████████████████████████████
// O dono do contrato pode sacar os premiums pagos
function withdrawPremiums() external onlyOwner {
uint256 balance =
address(this).balance;
SafeTransferLib.safeTransferETH(
msg.sender,
balance
);
emit PremiumsWithdrawn(
msg.sender,
balance
);
}
/// ███ Helper FX ██████████████████████████████████████████████████████████
function _onlySeller(uint256 _depositID)
private
view
{
if (
mapDeposits[_depositID].seller
!= msg.sender
) revert
OnlySeller();
}
function _notExpired(DT.Lock storage _l)
private
view
{
// Custom Error Solidity Impl
if
(
_l.expirationBlock >= block.number ||
_l.amount <= 0
) revert
NotExpired();
// Custom Error Yul Impl
// assembly {
// if iszero(iszero(
// or(
// or(
// lt(number(), sload(add(_l.slot, 3))),
// eq(sload(add(_l.slot, 3)), number())
// ),
// iszero(sload(add(_l.slot, 2)))
// )))
// {
// mstore(0x00, 0xd0404f85)
// revert(0x1c, 0x04)
// }
// }
// Require Error Solidity Impl
// require(
// _l.expirationBlock < block.number &&
// _l.amount > 0,
// "P2PIX: Lock not expired or already released"
// );
}
function _encodeDepositID()
internal
view
returns (uint256 _depositID)
{
(_depositID) = depositCount.current();
if (
mapDeposits[_depositID].valid
== true
) revert
DepositAlreadyExists();
}
function _encodeLockID(
uint256 _depositID,
uint256 _amount,
address _targetAddress)
private
view
returns (bytes32 _lockID)
{
_lockID = keccak256(
abi.encodePacked(_depositID, _amount, _targetAddress)
);
if (
mapLocks[_lockID].expirationBlock
>= block.number
) revert
NotExpired();
}
function _castAddrToKey(address _addr)
public
pure
returns (uint256 _key)
{
_key = uint256(
uint160(
address(
_addr
))) << 12;
}
}