1
// SPDX-License-Identifier: UNLICENSED
2
pragma solidity ^0.8.20;
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4
import "@openzeppelin/contracts/proxy/Clones.sol";
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import "@openzeppelin/contracts/access/Ownable.sol";
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import "@openzeppelin-upgradeable/contracts/token/ERC20/ERC20Upgradeable.sol";
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import "@openzeppelin-upgradeable/contracts/access/OwnableUpgradeable.sol";
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import "../lib/curta/src/interfaces/IPuzzle.sol";
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contract FailedLendingMarket is IPuzzle {
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    ChallFactory public challFactory;
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14
    mapping(uint256 => Challenge) public instances;
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    address public owner;
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    constructor() {
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        owner = msg.sender;
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        challFactory = new ChallFactory(address(this));
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    }
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    function name() external pure returns (string memory) {
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        return "CurtaLending";
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    }
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26
    function generate(address solver) public pure returns (uint256) {
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        return uint256(keccak256(abi.encode(solver)));
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    }
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    function verify(uint256 seed, uint256) external view returns (bool) {
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        return instances[seed].isSolved();
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    }
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    function deploy() external returns (address) {
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        uint256 seed = generate(msg.sender);
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        instances[seed] = Challenge(challFactory.createChallenge(seed, msg.sender));
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        return address(instances[seed]);
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    }
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}
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contract ChallFactory is Ownable {
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    address immutable tokenImplementation;
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    address immutable rebasingTokenImplementation;
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    address immutable oracleImplementation;
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    address immutable curtaLendingImplementation;
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    address immutable challengeImplementation;
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    constructor(address _curta) Ownable(_curta) {
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        tokenImplementation = address(new CurtaToken());
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        rebasingTokenImplementation = address(new CurtaRebasingToken());
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        oracleImplementation = address(new Oracle());
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        curtaLendingImplementation = address(new CurtaLending());
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        challengeImplementation = address(new Challenge());
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    }
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    function createChallenge(uint256 seed, address player) external onlyOwner returns (address) {
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        address usdClone = Clones.clone(tokenImplementation);
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        address wethClone = Clones.clone(tokenImplementation);
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        address rebasingWETHClone = Clones.clone(rebasingTokenImplementation);
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        address oracleClone = Clones.clone(oracleImplementation);
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        address curtaLendingClone = Clones.clone(curtaLendingImplementation);
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        address challClone = Clones.clone(challengeImplementation);
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        CurtaToken(usdClone).initialize("CurtaUSD", "USD", address(this));
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        CurtaToken(wethClone).initialize("CurtaWETH", "WETH", address(this));
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        CurtaRebasingToken(rebasingWETHClone).initialize("CurtaRebasingWETH", "RebasingWETH", wethClone, address(this));
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        Oracle(oracleClone).initialize(address(this));
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        CurtaLending(curtaLendingClone).initialize(address(this), oracleClone);
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        Challenge(challClone).initialize(address(this), usdClone, wethClone, rebasingWETHClone, curtaLendingClone, seed);
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        Oracle(oracleClone).setPrice(usdClone, 1e18);
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        Oracle(oracleClone).setPrice(wethClone, 3000e18);
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        Oracle(oracleClone).setPrice(rebasingWETHClone, 3100e18);
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        CurtaLending(curtaLendingClone).setAsset(usdClone, true, 500, 0.8 ether, 0.9 ether, 0.05 ether);
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        CurtaLending(curtaLendingClone).setAsset(wethClone, true, 300, 0.7 ether, 0.8 ether, 0.05 ether);
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        CurtaLending(curtaLendingClone).setAsset(rebasingWETHClone, true, 300, 0.7 ether, 0.8 ether, 0.05 ether);
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        CurtaToken(usdClone).mint(address(this), 10000 ether);
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        CurtaToken(wethClone).mint(address(this), 20000 ether);
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        CurtaToken(wethClone).approve(rebasingWETHClone, 10000 ether);
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        CurtaRebasingToken(rebasingWETHClone).deposit(10000 ether);
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        CurtaToken(usdClone).mint(player, 10000 ether);
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        CurtaToken(wethClone).mint(player, 10000 ether);
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        CurtaToken(usdClone).approve(curtaLendingClone, 10000 ether);
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        CurtaLending(curtaLendingClone).depositLiquidity(usdClone, 10000 ether);
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        CurtaToken(wethClone).approve(curtaLendingClone, 10000 ether);
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        CurtaLending(curtaLendingClone).depositLiquidity(wethClone, 10000 ether);
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        CurtaRebasingToken(rebasingWETHClone).approve(curtaLendingClone, 10000 ether);
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        CurtaLending(curtaLendingClone).depositLiquidity(rebasingWETHClone, 10000 ether);
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95
        return challClone;
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    }
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}
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99
contract CurtaToken is ERC20Upgradeable, OwnableUpgradeable {
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    constructor() {
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        _disableInitializers();
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    }
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    function initialize(string memory _name, string memory _symbol, address _initialOwner) external initializer {
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        __ERC20_init(_name, _symbol);
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        __Ownable_init(_initialOwner);
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    }
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    function mint(address to, uint256 amount) external onlyOwner {
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        _mint(to, amount);
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    }
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}
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contract CurtaRebasingToken is ERC20Upgradeable, OwnableUpgradeable {
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    IERC20 public underlyingToken;
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    uint256 public unavaliableLiquidity;
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118
    constructor() {
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        _disableInitializers();
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    }
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122
    function initialize(string memory _name, string memory _symbol, address _underlyingToken, address _initialOwner)
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        external
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        initializer
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    {
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        __ERC20_init(_name, _symbol);
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        __Ownable_init(_initialOwner);
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129
        underlyingToken = IERC20(_underlyingToken);
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    }
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132
    function deposit(uint256 amount) external {
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        _mint(msg.sender, amount * 1e18 / getExchangeRate());
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        require(IERC20(underlyingToken).transferFrom(msg.sender, address(this), amount));
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    }
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137
    function withdraw(uint256 amount) external {
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        require(super.balanceOf(msg.sender) >= amount);
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        require(IERC20(underlyingToken).transfer(msg.sender, amount * getExchangeRate() / 1e18));
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        _burn(msg.sender, amount);
141
    }
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143
    function addYield(uint256 amount) external onlyOwner {
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        require(IERC20(underlyingToken).transferFrom(msg.sender, address(this), amount));
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    }
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147
    function invest(uint256 amount) external onlyOwner {
148
        require(IERC20(underlyingToken).transfer(msg.sender, amount));
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        unavaliableLiquidity += amount;
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    }
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152
    function payback(uint256 amount) external onlyOwner {
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        require(IERC20(underlyingToken).transferFrom(msg.sender, address(this), amount));
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        unavaliableLiquidity -= amount;
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    }
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157
    function balanceOf(address account) public view override returns (uint256) {
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        return super.balanceOf(account) * getExchangeRate() / 1e18;
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    }
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    function shareBalanceOf(address account) public view returns (uint256) {
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        return super.balanceOf(account);
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    }
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165
    function getExchangeRate() public view returns (uint256) {
166
        if (super.totalSupply() == 0) {
167
            return 1e18;
168
        }
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        return (underlyingToken.balanceOf(address(this)) + unavaliableLiquidity) * 1e18 / super.totalSupply();
170
    }
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172
    function totalSupply() public view override returns (uint256) {
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        return super.totalSupply() * getExchangeRate() / 1e18;
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    }
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}
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struct UserInfo {
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    address borrowAsset;
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    uint256 liquidityAmount;
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    uint256 collateralAmount;
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    uint256 liquidityIndex;
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    uint256 borrowIndex;
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    uint256 claimableReward;
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    uint256 totalDebt;
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    uint256 principal;
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}
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struct AssetInfo {
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    bool isAsset;
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    uint256 totalLiquidity;
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    uint256 avaliableLiquidity;
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    uint256 totalDebt;
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    uint256 totalPrincipal;
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    uint256 interestRate;
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    uint256 avaliableClaimableReward;
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    uint256 borrowLTV;
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    uint256 liquidationLTV;
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    uint256 liquidationBonus;
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    uint256 globalIndex;
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    uint256 lastUpdateBlock;
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}
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contract CurtaLending is OwnableUpgradeable {
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    mapping(address => mapping(address => UserInfo)) public userInfo;
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    mapping(address => AssetInfo) public assetInfo;
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    Oracle public oracle;
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209
    constructor() {
210
        _disableInitializers();
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    }
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    function initialize(address _initialOwner, address _oracle) external initializer {
214
        oracle = Oracle(_oracle);
215
        __Ownable_init(_initialOwner);
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    }
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218
    function setAsset(
219
        address _asset,
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        bool _isAsset,
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        uint256 _interestRate,
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        uint256 _borrowLTV,
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        uint256 _liquidationLTV,
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        uint256 _liquidationBonus
225
    ) external onlyOwner {
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        assetInfo[_asset].isAsset = _isAsset;
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        assetInfo[_asset].interestRate = _interestRate;
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        assetInfo[_asset].borrowLTV = _borrowLTV;
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        assetInfo[_asset].liquidationLTV = _liquidationLTV;
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        assetInfo[_asset].liquidationBonus = _liquidationBonus;
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        assetInfo[_asset].lastUpdateBlock = block.number;
232
    }
233

234
    function depositCollateral(address asset, uint256 amount) external {
235
        require(assetInfo[asset].isAsset);
236
        accrueInterest(msg.sender, asset);
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238
        UserInfo storage _userInfo = userInfo[msg.sender][asset];
239
        AssetInfo storage _assetInfo = assetInfo[asset];
240

241
        uint256 liquidityAmount = _userInfo.liquidityAmount;
242

243
        if (_userInfo.liquidityAmount < amount) {
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            _userInfo.collateralAmount += amount;
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            _userInfo.liquidityAmount = 0;
246
            _assetInfo.totalLiquidity -= liquidityAmount;
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            _assetInfo.avaliableLiquidity -= liquidityAmount;
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            require(IERC20(asset).transferFrom(msg.sender, address(this), amount - liquidityAmount));
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        } else {
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            _userInfo.collateralAmount += amount;
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            _userInfo.liquidityAmount -= amount;
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            _assetInfo.totalLiquidity -= amount;
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            _assetInfo.avaliableLiquidity -= amount;
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        }
255
    }
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257
    function withdrawCollateral(address asset, uint256 amount) external {
258
        accrueInterest(msg.sender, asset);
259

260
        UserInfo storage _userInfo = userInfo[msg.sender][asset];
261
        AssetInfo storage _assetInfo = assetInfo[asset];
262

263
        uint256 collateralValue = (_userInfo.collateralAmount - amount) * oracle.getPrice(asset);
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        uint256 borrowValue = _userInfo.totalDebt * oracle.getPrice(_userInfo.borrowAsset);
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        require(collateralValue * _assetInfo.borrowLTV >= borrowValue * 1e18);
266

267
        if (amount == 0) {
268
            _userInfo.liquidityAmount += _userInfo.collateralAmount;
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            _assetInfo.totalLiquidity += _userInfo.collateralAmount;
270
            _assetInfo.avaliableLiquidity += _userInfo.collateralAmount;
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            _userInfo.collateralAmount = 0;
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        } else {
273
            require(_userInfo.collateralAmount >= amount);
274
            _userInfo.liquidityAmount += amount;
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            _userInfo.collateralAmount -= amount;
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            _assetInfo.totalLiquidity += amount;
277
            _assetInfo.avaliableLiquidity += amount;
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        }
279
    }
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281
    function depositLiquidity(address asset, uint256 amount) external {
282
        require(assetInfo[asset].isAsset);
283
        accrueInterest(msg.sender, asset);
284

285
        UserInfo storage _userInfo = userInfo[msg.sender][asset];
286
        AssetInfo storage _assetInfo = assetInfo[asset];
287

288
        if (_userInfo.liquidityIndex == 0) {
289
            _userInfo.liquidityIndex = _assetInfo.globalIndex;
290
        }
291

292
        uint256 beforeBalance = IERC20(asset).balanceOf(address(this));
293
        require(IERC20(asset).transferFrom(msg.sender, address(this), amount));
294
        uint256 afterBalance = IERC20(asset).balanceOf(address(this)) - beforeBalance;
295

296
        _userInfo.liquidityAmount += afterBalance;
297
        _assetInfo.totalLiquidity += afterBalance;
298
        _assetInfo.avaliableLiquidity += afterBalance;
299
    }
300

301
    function withdrawLiquidity(address asset, uint256 amount) external {
302
        accrueInterest(msg.sender, asset);
303

304
        UserInfo storage _userInfo = userInfo[msg.sender][asset];
305
        AssetInfo storage _assetInfo = assetInfo[asset];
306

307
        require(_assetInfo.avaliableLiquidity >= amount);
308

309
        _userInfo.liquidityAmount -= amount;
310
        _assetInfo.totalLiquidity -= amount;
311
        _assetInfo.avaliableLiquidity -= amount;
312

313
        require(IERC20(asset).transfer(msg.sender, amount));
314
    }
315

316
    function borrow(address collateral, address borrowAsset, uint256 amount) external {
317
        require(assetInfo[borrowAsset].isAsset);
318
        UserInfo storage _userInfo = userInfo[msg.sender][collateral];
319
        require(_userInfo.borrowAsset == address(0) || _userInfo.borrowAsset == borrowAsset);
320

321
        if (_userInfo.borrowAsset == address(0)) {
322
            _userInfo.borrowAsset = borrowAsset;
323
        }
324

325
        accrueInterest(msg.sender, collateral);
326

327
        AssetInfo storage _assetInfo = assetInfo[borrowAsset];
328
        require(_assetInfo.avaliableLiquidity >= amount);
329

330
        if (_userInfo.borrowIndex == 0) {
331
            _userInfo.borrowIndex = _assetInfo.globalIndex;
332
        }
333

334
        uint256 collateralValue = _userInfo.collateralAmount * oracle.getPrice(collateral);
335
        uint256 borrowValue = amount * oracle.getPrice(borrowAsset);
336
        require(collateralValue * assetInfo[collateral].borrowLTV >= borrowValue * 1e18);
337

338
        _userInfo.totalDebt += amount;
339
        _userInfo.principal += amount;
340
        _assetInfo.totalDebt += amount;
341
        _assetInfo.totalPrincipal += amount;
342
        _assetInfo.avaliableLiquidity -= amount;
343

344
        require(IERC20(borrowAsset).transfer(msg.sender, amount));
345
    }
346

347
    function repay(address collateral, uint256 amount) external {
348
        accrueInterest(msg.sender, collateral);
349
        UserInfo storage _userInfo = userInfo[msg.sender][collateral];
350
        AssetInfo storage _assetInfo = assetInfo[_userInfo.borrowAsset];
351

352
        require(_userInfo.borrowAsset != address(0));
353

354
        uint256 borrowInterest = _userInfo.totalDebt - _userInfo.principal;
355

356
        if (_userInfo.totalDebt < amount) {
357
            amount = _userInfo.totalDebt;
358
        }
359

360
        _userInfo.totalDebt -= amount;
361
        _assetInfo.totalDebt -= amount;
362

363
        if (borrowInterest < amount) {
364
            _userInfo.principal -= amount - borrowInterest;
365
            _assetInfo.totalPrincipal -= amount - borrowInterest;
366
            _assetInfo.avaliableClaimableReward += borrowInterest;
367
            _assetInfo.avaliableLiquidity += amount - borrowInterest;
368
        } else {
369
            _assetInfo.avaliableClaimableReward += amount;
370
        }
371

372
        require(IERC20(_userInfo.borrowAsset).transferFrom(msg.sender, address(this), amount));
373
    }
374

375
    function liquidate(address user, address collateral, uint256 amount) external {
376
        accrueInterest(user, collateral);
377

378
        UserInfo storage _userInfo = userInfo[msg.sender][collateral];
379

380
        address asset = _userInfo.borrowAsset;
381

382
        if (_userInfo.totalDebt * 5 < amount * 10) {
383
            amount = _userInfo.totalDebt / 2;
384
        }
385

386
        uint256 collateralValue = _userInfo.collateralAmount * oracle.getPrice(collateral);
387
        uint256 borrowValue = _userInfo.totalDebt * oracle.getPrice(asset);
388
        require(collateralValue * assetInfo[collateral].liquidationLTV <= borrowValue * 1e18);
389

390
        AssetInfo storage _assetInfo = assetInfo[_userInfo.borrowAsset];
391

392
        uint256 refundCollateral = amount * oracle.getPrice(asset) / oracle.getPrice(collateral)
393
            + amount * oracle.getPrice(asset) / oracle.getPrice(collateral) * _assetInfo.liquidationBonus / 1e18;
394

395
        if (refundCollateral > _userInfo.collateralAmount) {
396
            refundCollateral = _userInfo.collateralAmount;
397
        }
398

399
        _userInfo.collateralAmount -= refundCollateral;
400

401
        uint256 borrowInterest = _userInfo.totalDebt - _userInfo.principal;
402

403
        _userInfo.totalDebt -= amount;
404
        _assetInfo.totalDebt -= amount;
405

406
        if (borrowInterest < amount) {
407
            _userInfo.principal -= amount - borrowInterest;
408
            _assetInfo.totalPrincipal -= amount - borrowInterest;
409
            _assetInfo.avaliableClaimableReward += borrowInterest;
410
            _assetInfo.avaliableLiquidity += amount - borrowInterest;
411
        } else {
412
            _assetInfo.avaliableClaimableReward += amount;
413
        }
414

415
        require(IERC20(asset).transferFrom(msg.sender, address(this), amount));
416
        require(IERC20(collateral).transfer(msg.sender, refundCollateral));
417
    }
418

419
    function resetBorrowAsset(address collateral) external {
420
        accrueInterest(msg.sender, collateral);
421

422
        UserInfo storage _userInfo = userInfo[msg.sender][collateral];
423
        require(_userInfo.borrowAsset != address(0));
424
        require(_userInfo.principal == 0 && _userInfo.totalDebt == 0);
425

426
        _userInfo.borrowAsset = address(0);
427
        _userInfo.borrowIndex = 0;
428
    }
429

430
    function burnBadDebt(address user, address collateral) external {
431
        accrueInterest(user, collateral);
432

433
        UserInfo storage _userInfo = userInfo[user][collateral];
434
        require(_userInfo.collateralAmount == 0 && _userInfo.totalDebt != 0);
435

436
        AssetInfo storage _assetInfo = assetInfo[_userInfo.borrowAsset];
437

438
        require(IERC20(_userInfo.borrowAsset).transferFrom(msg.sender, address(this), _userInfo.totalDebt));
439

440
        _assetInfo.totalDebt -= _userInfo.totalDebt;
441
        _assetInfo.totalPrincipal -= _userInfo.principal;
442
        _assetInfo.avaliableClaimableReward += _userInfo.totalDebt - _userInfo.principal;
443
        _assetInfo.avaliableLiquidity += _userInfo.principal;
444
        _userInfo.totalDebt = 0;
445
        _userInfo.principal = 0;
446
    }
447

448
    function claimReward(address asset, uint256 amount) external {
449
        require(assetInfo[asset].avaliableClaimableReward >= amount);
450
        accrueInterest(msg.sender, asset);
451

452
        UserInfo storage _userInfo = userInfo[msg.sender][asset];
453
        require(_userInfo.claimableReward >= amount * 1e18);
454

455
        _userInfo.claimableReward -= amount * 1e18;
456
        assetInfo[asset].avaliableClaimableReward -= amount;
457

458
        require(IERC20(asset).transfer(msg.sender, amount));
459
    }
460

461
    function accrueInterest(address user, address asset) public {
462
        UserInfo storage _userInfo = userInfo[user][asset];
463

464
        if (_userInfo.liquidityIndex == 0 && _userInfo.borrowIndex == 0) {
465
            return;
466
        }
467

468
        address borrowAsset = _userInfo.borrowAsset;
469

470
        updateAsset(asset);
471
        updateAsset(borrowAsset);
472

473
        AssetInfo memory _assetInfo = assetInfo[asset];
474
        AssetInfo memory _borrowAssetInfo = assetInfo[borrowAsset];
475

476
        if (_userInfo.liquidityIndex != 0) {
477
            uint256 pending = _assetInfo.globalIndex - _userInfo.liquidityIndex;
478
            _userInfo.claimableReward += pending * 1e18 * _userInfo.liquidityAmount / _assetInfo.totalLiquidity;
479
            _userInfo.liquidityIndex = _assetInfo.globalIndex;
480
        }
481

482
        if (_userInfo.borrowIndex != 0) {
483
            uint256 pending = _borrowAssetInfo.globalIndex - _userInfo.borrowIndex;
484
            _userInfo.totalDebt += pending * _userInfo.principal / _borrowAssetInfo.totalPrincipal;
485
            _userInfo.borrowIndex = _borrowAssetInfo.globalIndex;
486

487
            if ((pending * _userInfo.principal) % _borrowAssetInfo.totalPrincipal != 0) {
488
                _userInfo.totalDebt += 1;
489
                _borrowAssetInfo.totalDebt += 1;
490
            }
491
        }
492
    }
493

494
    function updateAsset(address asset) public {
495
        AssetInfo storage _assetInfo = assetInfo[asset];
496

497
        if (block.number == _assetInfo.lastUpdateBlock) {
498
            return;
499
        }
500

501
        _assetInfo.globalIndex +=
502
            (block.number - _assetInfo.lastUpdateBlock) * _assetInfo.totalPrincipal * _assetInfo.interestRate / 10000;
503
        _assetInfo.totalDebt +=
504
            (block.number - _assetInfo.lastUpdateBlock) * _assetInfo.totalPrincipal * _assetInfo.interestRate / 10000;
505
        _assetInfo.lastUpdateBlock = block.number;
506
    }
507
}
508

509
contract Oracle is OwnableUpgradeable {
510
    mapping(address => uint256) private prices;
511

512
    constructor() {
513
        _disableInitializers();
514
    }
515

516
    function initialize(address _initialOwner) external initializer {
517
        __Ownable_init(_initialOwner);
518
    }
519

520
    function setPrice(address asset, uint256 price) external onlyOwner {
521
        prices[asset] = price;
522
    }
523

524
    function getPrice(address asset) external view returns (uint256) {
525
        return prices[asset];
526
    }
527
}
528

529
// SPDX-License-Identifier: UNLICENSED
530
pragma solidity ^0.8.13;
531

532
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
533
import "@openzeppelin-upgradeable/contracts/access/OwnableUpgradeable.sol";
534

535
import "./Oracle.sol";
536

537
struct UserInfo {
538
    address borrowAsset;
539
    uint256 liquidityAmount;
540
    uint256 collateralAmount;
541
    uint256 liquidityIndex;
542
    uint256 borrowIndex;
543
    uint256 claimableReward;
544
    uint256 totalDebt;
545
    uint256 principal;
546
}
547

548
struct AssetInfo {
549
    bool isAsset;
550
    uint256 totalLiquidity;
551
    uint256 avaliableLiquidity;
552
    uint256 totalDebt;
553
    uint256 totalPrincipal;
554
    uint256 interestRate;
555
    uint256 avaliableClaimableReward;
556
    uint256 borrowLTV;
557
    uint256 liquidationLTV;
558
    uint256 liquidationBonus;
559
    uint256 globalIndex;
560
    uint256 lastUpdateBlock;
561
}
562

563
contract CurtaLending is OwnableUpgradeable {
564
    mapping(address => mapping(address => UserInfo)) public userInfo;
565
    mapping(address => AssetInfo) public assetInfo;
566

567
    Oracle public oracle;
568

569
    constructor() {
570
        _disableInitializers();
571
    }
572

573
    function initialize(address _initialOwner, address _oracle) external initializer {
574
        oracle = Oracle(_oracle);
575
        __Ownable_init(_initialOwner);
576
    }
577

578
    function setAsset(
579
        address _asset,
580
        bool _isAsset,
581
        uint256 _interestRate,
582
        uint256 _borrowLTV,
583
        uint256 _liquidationLTV,
584
        uint256 _liquidationBonus
585
    ) external onlyOwner {
586
        assetInfo[_asset].isAsset = _isAsset;
587
        assetInfo[_asset].interestRate = _interestRate;
588
        assetInfo[_asset].borrowLTV = _borrowLTV;
589
        assetInfo[_asset].liquidationLTV = _liquidationLTV;
590
        assetInfo[_asset].liquidationBonus = _liquidationBonus;
591
        assetInfo[_asset].lastUpdateBlock = block.number;
592
    }
593

594
    function depositCollateral(address asset, uint256 amount) external {
595
        require(assetInfo[asset].isAsset);
596
        accrueInterest(msg.sender, asset);
597

598
        UserInfo storage _userInfo = userInfo[msg.sender][asset];
599
        AssetInfo storage _assetInfo = assetInfo[asset];
600

601
        uint256 liquidityAmount = _userInfo.liquidityAmount;
602

603
        if (_userInfo.liquidityAmount < amount) {
604
            _userInfo.collateralAmount += amount;
605
            _userInfo.liquidityAmount = 0;
606
            _assetInfo.totalLiquidity -= liquidityAmount;
607
            _assetInfo.avaliableLiquidity -= liquidityAmount;
608
            require(IERC20(asset).transferFrom(msg.sender, address(this), amount - liquidityAmount));
609
        } else {
610
            _userInfo.collateralAmount += amount;
611
            _userInfo.liquidityAmount -= amount;
612
            _assetInfo.totalLiquidity -= amount;
613
            _assetInfo.avaliableLiquidity -= amount;
614
        }
615
    }
616

617
    function withdrawCollateral(address asset, uint256 amount) external {
618
        accrueInterest(msg.sender, asset);
619

620
        UserInfo storage _userInfo = userInfo[msg.sender][asset];
621
        AssetInfo storage _assetInfo = assetInfo[asset];
622

623
        uint256 collateralValue = (_userInfo.collateralAmount - amount) * oracle.getPrice(asset);
624
        uint256 borrowValue = _userInfo.totalDebt * oracle.getPrice(_userInfo.borrowAsset);
625
        require(collateralValue * _assetInfo.borrowLTV >= borrowValue * 1e18);
626

627
        if (amount == 0) {
628
            _userInfo.liquidityAmount += _userInfo.collateralAmount;
629
            _assetInfo.totalLiquidity += _userInfo.collateralAmount;
630
            _assetInfo.avaliableLiquidity += _userInfo.collateralAmount;
631
            _userInfo.collateralAmount = 0;
632
        } else {
633
            require(_userInfo.collateralAmount >= amount);
634
            _userInfo.liquidityAmount += amount;
635
            _userInfo.collateralAmount -= amount;
636
            _assetInfo.totalLiquidity += amount;
637
            _assetInfo.avaliableLiquidity += amount;
638
        }
639
    }
640

641
    function depositLiquidity(address asset, uint256 amount) external {
642
        require(assetInfo[asset].isAsset);
643
        accrueInterest(msg.sender, asset);
644

645
        UserInfo storage _userInfo = userInfo[msg.sender][asset];
646
        AssetInfo storage _assetInfo = assetInfo[asset];
647

648
        if (_userInfo.liquidityIndex == 0) {
649
            _userInfo.liquidityIndex = _assetInfo.globalIndex;
650
        }
651

652
        uint256 beforeBalance = IERC20(asset).balanceOf(address(this));
653
        require(IERC20(asset).transferFrom(msg.sender, address(this), amount));
654
        uint256 afterBalance = IERC20(asset).balanceOf(address(this)) - beforeBalance;
655

656
        _userInfo.liquidityAmount += afterBalance;
657
        _assetInfo.totalLiquidity += afterBalance;
658
        _assetInfo.avaliableLiquidity += afterBalance;
659
    }
660

661
    function withdrawLiquidity(address asset, uint256 amount) external {
662
        accrueInterest(msg.sender, asset);
663

664
        UserInfo storage _userInfo = userInfo[msg.sender][asset];
665
        AssetInfo storage _assetInfo = assetInfo[asset];
666

667
        require(_assetInfo.avaliableLiquidity >= amount);
668

669
        _userInfo.liquidityAmount -= amount;
670
        _assetInfo.totalLiquidity -= amount;
671
        _assetInfo.avaliableLiquidity -= amount;
672

673
        require(IERC20(asset).transfer(msg.sender, amount));
674
    }
675

676
    function borrow(address collateral, address borrowAsset, uint256 amount) external {
677
        require(assetInfo[borrowAsset].isAsset);
678
        UserInfo storage _userInfo = userInfo[msg.sender][collateral];
679
        require(_userInfo.borrowAsset == address(0) || _userInfo.borrowAsset == borrowAsset);
680

681
        if (_userInfo.borrowAsset == address(0)) {
682
            _userInfo.borrowAsset = borrowAsset;
683
        }
684

685
        accrueInterest(msg.sender, collateral);
686

687
        AssetInfo storage _assetInfo = assetInfo[borrowAsset];
688
        require(_assetInfo.avaliableLiquidity >= amount);
689

690
        if (_userInfo.borrowIndex == 0) {
691
            _userInfo.borrowIndex = _assetInfo.globalIndex;
692
        }
693

694
        uint256 collateralValue = _userInfo.collateralAmount * oracle.getPrice(collateral);
695
        uint256 borrowValue = amount * oracle.getPrice(borrowAsset);
696
        require(collateralValue * assetInfo[collateral].borrowLTV >= borrowValue * 1e18);
697

698
        _userInfo.totalDebt += amount;
699
        _userInfo.principal += amount;
700
        _assetInfo.totalDebt += amount;
701
        _assetInfo.totalPrincipal += amount;
702
        _assetInfo.avaliableLiquidity -= amount;
703

704
        require(IERC20(borrowAsset).transfer(msg.sender, amount));
705
    }
706

707
    function repay(address collateral, uint256 amount) external {
708
        accrueInterest(msg.sender, collateral);
709
        UserInfo storage _userInfo = userInfo[msg.sender][collateral];
710
        AssetInfo storage _assetInfo = assetInfo[_userInfo.borrowAsset];
711

712
        require(_userInfo.borrowAsset != address(0));
713

714
        uint256 borrowInterest = _userInfo.totalDebt - _userInfo.principal;
715

716
        if (_userInfo.totalDebt < amount) {
717
            amount = _userInfo.totalDebt;
718
        }
719

720
        _userInfo.totalDebt -= amount;
721
        _assetInfo.totalDebt -= amount;
722

723
        if (borrowInterest < amount) {
724
            _userInfo.principal -= amount - borrowInterest;
725
            _assetInfo.totalPrincipal -= amount - borrowInterest;
726
            _assetInfo.avaliableClaimableReward += borrowInterest;
727
            _assetInfo.avaliableLiquidity += amount - borrowInterest;
728
        } else {
729
            _assetInfo.avaliableClaimableReward += amount;
730
        }
731

732
        require(IERC20(_userInfo.borrowAsset).transferFrom(msg.sender, address(this), amount));
733
    }
734

735
    function liquidate(address user, address collateral, uint256 amount) external {
736
        accrueInterest(user, collateral);
737

738
        UserInfo storage _userInfo = userInfo[msg.sender][collateral];
739

740
        address asset = _userInfo.borrowAsset;
741

742
        if (_userInfo.totalDebt * 5 < amount * 10) {
743
            amount = _userInfo.totalDebt / 2;
744
        }
745

746
        uint256 collateralValue = _userInfo.collateralAmount * oracle.getPrice(collateral);
747
        uint256 borrowValue = _userInfo.totalDebt * oracle.getPrice(asset);
748
        require(collateralValue * assetInfo[collateral].liquidationLTV <= borrowValue * 1e18);
749

750
        AssetInfo storage _assetInfo = assetInfo[_userInfo.borrowAsset];
751

752
        uint256 refundCollateral = amount * oracle.getPrice(asset) / oracle.getPrice(collateral)
753
            + amount * oracle.getPrice(asset) / oracle.getPrice(collateral) * _assetInfo.liquidationBonus / 1e18;
754

755
        if (refundCollateral > _userInfo.collateralAmount) {
756
            refundCollateral = _userInfo.collateralAmount;
757
        }
758

759
        _userInfo.collateralAmount -= refundCollateral;
760

761
        uint256 borrowInterest = _userInfo.totalDebt - _userInfo.principal;
762

763
        _userInfo.totalDebt -= amount;
764
        _assetInfo.totalDebt -= amount;
765

766
        if (borrowInterest < amount) {
767
            _userInfo.principal -= amount - borrowInterest;
768
            _assetInfo.totalPrincipal -= amount - borrowInterest;
769
            _assetInfo.avaliableClaimableReward += borrowInterest;
770
            _assetInfo.avaliableLiquidity += amount - borrowInterest;
771
        } else {
772
            _assetInfo.avaliableClaimableReward += amount;
773
        }
774

775
        require(IERC20(asset).transferFrom(msg.sender, address(this), amount));
776
        require(IERC20(collateral).transfer(msg.sender, refundCollateral));
777
    }
778

779
    function resetBorrowAsset(address collateral) external {
780
        accrueInterest(msg.sender, collateral);
781

782
        UserInfo storage _userInfo = userInfo[msg.sender][collateral];
783
        require(_userInfo.borrowAsset != address(0));
784
        require(_userInfo.principal == 0 && _userInfo.totalDebt == 0);
785

786
        _userInfo.borrowAsset = address(0);
787
        _userInfo.borrowIndex = 0;
788
    }
789

790
    function burnBadDebt(address user, address collateral) external {
791
        accrueInterest(user, collateral);
792

793
        UserInfo storage _userInfo = userInfo[user][collateral];
794
        require(_userInfo.collateralAmount == 0 && _userInfo.totalDebt != 0);
795

796
        AssetInfo storage _assetInfo = assetInfo[_userInfo.borrowAsset];
797

798
        require(IERC20(_userInfo.borrowAsset).transferFrom(msg.sender, address(this), _userInfo.totalDebt));
799

800
        _assetInfo.totalDebt -= _userInfo.totalDebt;
801
        _assetInfo.totalPrincipal -= _userInfo.principal;
802
        _assetInfo.avaliableClaimableReward += _userInfo.totalDebt - _userInfo.principal;
803
        _assetInfo.avaliableLiquidity += _userInfo.principal;
804
        _userInfo.totalDebt = 0;
805
        _userInfo.principal = 0;
806
    }
807

808
    function claimReward(address asset, uint256 amount) external {
809
        require(assetInfo[asset].avaliableClaimableReward >= amount);
810
        accrueInterest(msg.sender, asset);
811

812
        UserInfo storage _userInfo = userInfo[msg.sender][asset];
813
        require(_userInfo.claimableReward >= amount * 1e18);
814

815
        _userInfo.claimableReward -= amount * 1e18;
816
        assetInfo[asset].avaliableClaimableReward -= amount;
817

818
        require(IERC20(asset).transfer(msg.sender, amount));
819
    }
820

821
    function accrueInterest(address user, address asset) public {
822
        UserInfo storage _userInfo = userInfo[user][asset];
823

824
        if (_userInfo.liquidityIndex == 0 && _userInfo.borrowIndex == 0) {
825
            return;
826
        }
827

828
        address borrowAsset = _userInfo.borrowAsset;
829

830
        updateAsset(asset);
831
        updateAsset(borrowAsset);
832

833
        AssetInfo memory _assetInfo = assetInfo[asset];
834
        AssetInfo memory _borrowAssetInfo = assetInfo[borrowAsset];
835

836
        if (_userInfo.liquidityIndex != 0) {
837
            uint256 pending = _assetInfo.globalIndex - _userInfo.liquidityIndex;
838
            _userInfo.claimableReward += pending * 1e18 * _userInfo.liquidityAmount / _assetInfo.totalLiquidity;
839
            _userInfo.liquidityIndex = _assetInfo.globalIndex;
840
        }
841

842
        if (_userInfo.borrowIndex != 0) {
843
            uint256 pending = _borrowAssetInfo.globalIndex - _userInfo.borrowIndex;
844
            _userInfo.totalDebt += pending * _userInfo.principal / _borrowAssetInfo.totalPrincipal;
845
            _userInfo.borrowIndex = _borrowAssetInfo.globalIndex;
846

847
            if ((pending * _userInfo.principal) % _borrowAssetInfo.totalPrincipal != 0) {
848
                _userInfo.totalDebt += 1;
849
                _borrowAssetInfo.totalDebt += 1;
850
            }
851
        }
852
    }
853

854
    function updateAsset(address asset) public {
855
        AssetInfo storage _assetInfo = assetInfo[asset];
856

857
        if (block.number == _assetInfo.lastUpdateBlock) {
858
            return;
859
        }
860

861
        _assetInfo.globalIndex +=
862
            (block.number - _assetInfo.lastUpdateBlock) * _assetInfo.totalPrincipal * _assetInfo.interestRate / 10000;
863
        _assetInfo.totalDebt +=
864
            (block.number - _assetInfo.lastUpdateBlock) * _assetInfo.totalPrincipal * _assetInfo.interestRate / 10000;
865
        _assetInfo.lastUpdateBlock = block.number;
866
    }
867
}
868

869
contract Challenge is OwnableUpgradeable {
870
    CurtaToken public curtaUSD;
871
    CurtaToken public curtaWETH;
872
    CurtaRebasingToken public curtaRebasingETH;
873
    CurtaLending public curtaLending;
874

875
    uint256 public seed;
876

877
    constructor() {
878
        _disableInitializers();
879
    }
880

881
    function initialize(
882
        address _initialOwner,
883
        address _curtaUSD,
884
        address _curtaWETH,
885
        address _curtaRebasingETH,
886
        address _curtaLending,
887
        uint256 _seed
888
    ) external initializer {
889
        __Ownable_init(_initialOwner);
890

891
        curtaUSD = CurtaToken(_curtaUSD);
892
        curtaWETH = CurtaToken(_curtaWETH);
893
        curtaRebasingETH = CurtaRebasingToken(_curtaRebasingETH);
894
        curtaLending = CurtaLending(_curtaLending);
895

896
        seed = _seed;
897
    }
898

899
    function isSolved() external view returns (bool) {
900
        require(
901
            curtaUSD.balanceOf(address(uint160(seed))) == 20000 ether
902
                && curtaWETH.balanceOf(address(uint160(seed))) == 30000 ether
903
        );
904
        return true;
905
    }
906
}