pyth-crosschain/express_relay/examples/easy_lend/contracts/EasyLend.sol

359 lines
12 KiB
Solidity

// Copyright (C) 2024 Lavra Holdings Limited - All Rights Reserved
pragma solidity ^0.8.13;
import "./EasyLendStructs.sol";
import "./EasyLendErrors.sol";
import "forge-std/StdMath.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@pythnetwork/pyth-sdk-solidity/PythStructs.sol";
import "@pythnetwork/pyth-sdk-solidity/IPyth.sol";
import "@pythnetwork/express-relay-sdk-solidity/IExpressRelayFeeReceiver.sol";
import "@pythnetwork/express-relay-sdk-solidity/IExpressRelay.sol";
contract EasyLend is IExpressRelayFeeReceiver {
using SafeERC20 for IERC20;
event VaultReceivedETH(address sender, uint256 amount, bytes permissionKey);
uint256 _nVaults;
address public immutable expressRelay;
mapping(uint256 => Vault) _vaults;
address _oracle;
bool _allowUndercollateralized;
/**
* @notice EasyLend constructor - Initializes a new token vault contract with given parameters
*
* @param expressRelayAddress: address of the express relay
* @param oracleAddress: address of the oracle contract
* @param allowUndercollateralized: boolean to allow undercollateralized vaults to be created and updated. Can be set to true for testing.
*/
constructor(
address expressRelayAddress,
address oracleAddress,
bool allowUndercollateralized
) {
_nVaults = 0;
expressRelay = expressRelayAddress;
_oracle = oracleAddress;
_allowUndercollateralized = allowUndercollateralized;
}
/**
* @notice getLastVaultId function - getter function to get the id of the next vault to be created
* Ids are sequential and start from 0
*/
function getLastVaultId() public view returns (uint256) {
return _nVaults;
}
/**
* @notice convertToUint function - converts a Pyth price struct to a uint256 representing the price of an asset
*
* @param price: Pyth price struct to be converted
* @param targetDecimals: target number of decimals for the output
*/
function convertToUint(
PythStructs.Price memory price,
uint8 targetDecimals
) private pure returns (uint256) {
if (price.price < 0 || price.expo > 0 || price.expo < -255) {
revert InvalidPriceExponent();
}
uint8 priceDecimals = uint8(uint32(-1 * price.expo));
if (targetDecimals >= priceDecimals) {
return
uint(uint64(price.price)) *
10 ** uint32(targetDecimals - priceDecimals);
} else {
return
uint(uint64(price.price)) /
10 ** uint32(priceDecimals - targetDecimals);
}
}
/**
* @notice getPrice function - retrieves price of a given token from the oracle
*
* @param id: price feed Id of the token
*/
function _getPrice(bytes32 id) internal view returns (uint256) {
IPyth oracle = IPyth(payable(_oracle));
return convertToUint(oracle.getPrice(id), 18);
}
function getAllowUndercollateralized() public view returns (bool) {
return _allowUndercollateralized;
}
function getOracle() public view returns (address) {
return _oracle;
}
/**
* @notice getVaultHealth function - calculates vault collateral/debt ratio
*
* @param vaultId: Id of the vault for which to calculate health
*/
function getVaultHealth(uint256 vaultId) public view returns (uint256) {
Vault memory vault = _vaults[vaultId];
return _getVaultHealth(vault);
}
/**
* @notice _getVaultHealth function - calculates vault collateral/debt ratio using the on-chain price feeds.
* In a real world scenario, caller should ensure that the price feeds are up to date before calling this function.
*
* @param vault: vault struct containing vault parameters
*/
function _getVaultHealth(
Vault memory vault
) internal view returns (uint256) {
uint256 priceCollateral = _getPrice(vault.tokenIdCollateral);
uint256 priceDebt = _getPrice(vault.tokenIdDebt);
if (priceCollateral < 0) {
revert NegativePrice();
}
if (priceDebt < 0) {
revert NegativePrice();
}
uint256 valueCollateral = priceCollateral * vault.amountCollateral;
uint256 valueDebt = priceDebt * vault.amountDebt;
return (valueCollateral * 1_000_000_000_000_000_000) / valueDebt;
}
/**
* @notice createVault function - creates a vault
*
* @param tokenCollateral: address of the collateral token of the vault
* @param tokenDebt: address of the debt token of the vault
* @param amountCollateral: amount of collateral tokens in the vault
* @param amountDebt: amount of debt tokens in the vault
* @param minHealthRatio: minimum health ratio of the vault, 10**18 is 100%
* @param minPermissionlessHealthRatio: minimum health ratio of the vault before permissionless liquidations are allowed. This should be less than minHealthRatio
* @param tokenIdCollateral: price feed Id of the collateral token
* @param tokenIdDebt: price feed Id of the debt token
* @param updateData: data to update price feeds with
*/
function createVault(
address tokenCollateral,
address tokenDebt,
uint256 amountCollateral,
uint256 amountDebt,
uint256 minHealthRatio,
uint256 minPermissionlessHealthRatio,
bytes32 tokenIdCollateral,
bytes32 tokenIdDebt,
bytes[] calldata updateData
) public payable returns (uint256) {
_updatePriceFeeds(updateData);
Vault memory vault = Vault(
tokenCollateral,
tokenDebt,
amountCollateral,
amountDebt,
minHealthRatio,
minPermissionlessHealthRatio,
tokenIdCollateral,
tokenIdDebt
);
if (minPermissionlessHealthRatio > minHealthRatio) {
revert InvalidHealthRatios();
}
if (
!_allowUndercollateralized &&
_getVaultHealth(vault) < vault.minHealthRatio
) {
revert UncollateralizedVaultCreation();
}
IERC20(vault.tokenCollateral).safeTransferFrom(
msg.sender,
address(this),
vault.amountCollateral
);
IERC20(vault.tokenDebt).safeTransfer(msg.sender, vault.amountDebt);
_vaults[_nVaults] = vault;
_nVaults += 1;
return _nVaults;
}
/**
* @notice updateVault function - updates a vault's collateral and debt amounts
*
* @param vaultId: Id of the vault to be updated
* @param deltaCollateral: delta change to collateral amount (+ means adding collateral tokens, - means removing collateral tokens)
* @param deltaDebt: delta change to debt amount (+ means withdrawing debt tokens from protocol, - means resending debt tokens to protocol)
*/
function updateVault(
uint256 vaultId,
int256 deltaCollateral,
int256 deltaDebt
) public {
Vault memory vault = _vaults[vaultId];
uint256 qCollateral = stdMath.abs(deltaCollateral);
uint256 qDebt = stdMath.abs(deltaDebt);
bool withdrawExcessiveCollateral = (deltaCollateral < 0) &&
(qCollateral > vault.amountCollateral);
if (withdrawExcessiveCollateral) {
revert InvalidVaultUpdate();
}
uint256 futureCollateral = (deltaCollateral >= 0)
? (vault.amountCollateral + qCollateral)
: (vault.amountCollateral - qCollateral);
uint256 futureDebt = (deltaDebt >= 0)
? (vault.amountDebt + qDebt)
: (vault.amountDebt - qDebt);
vault.amountCollateral = futureCollateral;
vault.amountDebt = futureDebt;
if (
!_allowUndercollateralized &&
_getVaultHealth(vault) < vault.minHealthRatio
) {
revert InvalidVaultUpdate();
}
// update collateral position
if (deltaCollateral >= 0) {
// sender adds more collateral to their vault
IERC20(vault.tokenCollateral).safeTransferFrom(
msg.sender,
address(this),
qCollateral
);
_vaults[vaultId].amountCollateral += qCollateral;
} else {
// sender takes back collateral from their vault
IERC20(vault.tokenCollateral).safeTransfer(msg.sender, qCollateral);
_vaults[vaultId].amountCollateral -= qCollateral;
}
// update debt position
if (deltaDebt >= 0) {
// sender takes out more debt position
IERC20(vault.tokenDebt).safeTransfer(msg.sender, qDebt);
_vaults[vaultId].amountDebt += qDebt;
} else {
// sender sends back debt tokens
IERC20(vault.tokenDebt).safeTransferFrom(
msg.sender,
address(this),
qDebt
);
_vaults[vaultId].amountDebt -= qDebt;
}
}
/**
* @notice getVault function - getter function to get a vault's parameters
*
* @param vaultId: Id of the vault
*/
function getVault(uint256 vaultId) public view returns (Vault memory) {
return _vaults[vaultId];
}
/**
* @notice _updatePriceFeeds function - updates the specified price feeds with given data
*
* @param updateData: data to update price feeds with
*/
function _updatePriceFeeds(bytes[] calldata updateData) internal {
if (updateData.length == 0) {
return;
}
IPyth oracle = IPyth(payable(_oracle));
oracle.updatePriceFeeds{value: msg.value}(updateData);
}
/**
* @notice liquidate function - liquidates a vault
* This function calculates the health of the vault and based on the vault parameters one of the following actions is taken:
* 1. If health >= minHealthRatio, don't liquidate
* 2. If minHealthRatio > health >= minPermissionlessHealthRatio, only liquidate if the vault is permissioned via express relay
* 3. If minPermissionlessHealthRatio > health, liquidate no matter what
*
* @param vaultId: Id of the vault to be liquidated
*/
function liquidate(uint256 vaultId) public {
Vault memory vault = _vaults[vaultId];
uint256 vaultHealth = _getVaultHealth(vault);
// if vault health is above the minimum health ratio, don't liquidate
if (vaultHealth >= vault.minHealthRatio) {
revert InvalidLiquidation();
}
if (vaultHealth >= vault.minPermissionlessHealthRatio) {
// if vault health is below the minimum health ratio but above the minimum permissionless health ratio,
// only liquidate if permissioned
if (
!IExpressRelay(expressRelay).isPermissioned(
address(this), // protocol fee receiver
abi.encode(vaultId) // vault id uniquely represents the opportunity and can be used as permission id
)
) {
revert InvalidLiquidation();
}
}
IERC20(vault.tokenDebt).transferFrom(
msg.sender,
address(this),
vault.amountDebt
);
IERC20(vault.tokenCollateral).transfer(
msg.sender,
vault.amountCollateral
);
_vaults[vaultId].amountCollateral = 0;
_vaults[vaultId].amountDebt = 0;
}
/**
* @notice liquidateWithPriceUpdate function - liquidates a vault after updating the specified price feeds with given data
*
* @param vaultId: Id of the vault to be liquidated
* @param updateData: data to update price feeds with
*/
function liquidateWithPriceUpdate(
uint256 vaultId,
bytes[] calldata updateData
) external payable {
_updatePriceFeeds(updateData);
liquidate(vaultId);
}
/**
* @notice receiveAuctionProceedings function - receives native token from the express relay
* You can use permission key to distribute the received funds to users who got liquidated, LPs, etc...
*
* @param permissionKey: permission key that was used for the auction
*/
function receiveAuctionProceedings(
bytes calldata permissionKey
) external payable {
emit VaultReceivedETH(msg.sender, msg.value, permissionKey);
}
receive() external payable {}
}