all files / plugins/assets/compoundv2/ CTokenFiatCollateral.sol

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// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.17;
 
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "../../../libraries/Fixed.sol";
import "../AppreciatingFiatCollateral.sol";
import "./ICToken.sol";
 
/**
 * @title CTokenFiatCollateral
 * @notice Collateral plugin for a cToken of fiat collateral, like cUSDC or cUSDP
 * Expected: {tok} != {ref}, {ref} is pegged to {target} unless defaulting, {target} == {UoA}
 * Also used for FluxFinance
 */
contract CTokenFiatCollateral is AppreciatingFiatCollateral {
    using OracleLib for AggregatorV3Interface;
    using FixLib for uint192;
 
    // All v2 cTokens have 8 decimals, but their underlying may have 18 or 6 or something else.
 
    uint8 public immutable referenceERC20Decimals;
 
    IComptroller public immutable comptroller;
 
    /// @param revenueHiding {1} A value like 1e-6 that represents the maximum refPerTok to hide
    /// @param comptroller_ The CompoundFinance Comptroller
    constructor(
        CollateralConfig memory config,
        uint192 revenueHiding,
        IComptroller comptroller_
    ) AppreciatingFiatCollateral(config, revenueHiding) {
        require(address(comptroller_) != address(0), "comptroller missing");
        ICToken erc20 = ICToken(address(config.erc20));
        referenceERC20Decimals = IERC20Metadata(erc20.underlying()).decimals();
        comptroller = comptroller_;
    }
 
    /// Refresh exchange rates and update default status.
    /// @custom:interaction RCEI
    function refresh() public virtual override {
        // == Refresh ==
        // Update the Compound Protocol
        ICToken(address(erc20)).exchangeRateCurrent();
 
        // Intentional and correct for the super call to be last!
        super.refresh(); // already handles all necessary default checks
    }
 
    /// @return {ref/tok} Actual quantity of whole reference units per whole collateral tokens
    function _underlyingRefPerTok() internal view override returns (uint192) {
        uint256 rate = ICToken(address(erc20)).exchangeRateStored();
        int8 shiftLeft = 8 - int8(referenceERC20Decimals) - 18;
        return shiftl_toFix(rate, shiftLeft);
    }
 
    /// Claim rewards earned by holding a balance of the ERC20 token
    /// @dev delegatecall
    function claimRewards() external virtual override(Asset, IRewardable) {
        IERC20 comp = IERC20(comptroller.getCompAddress());
        uint256 oldBal = comp.balanceOf(address(this));
        comptroller.claimComp(address(this));
        emit RewardsClaimed(comp, comp.balanceOf(address(this)) - oldBal);
    }
}