CompoundLens.sol

pragma solidity >=0.5.16;
pragma experimental ABIEncoderV2;

import "./CErc20.sol";
import "./CToken.sol";
import "./PriceOracle.sol";
import "./Comp.sol";
import "./GovernorAlpha.sol";

interface ComptrollerLensInterface {
    function markets(address) external view returns (bool, uint256);

    function oracle() external view returns (PriceOracle);

    function getAccountLiquidity(address)
        external
        view
        returns (
            uint256,
            uint256,
            uint256
        );

    function getAssetsIn(address) external view returns (CToken[] memory);

    function claimComp(address) external;
    function compAccrued(address) external view returns (uint);
}

interface GovernorBravoInterface {
    struct Receipt {
        bool hasVoted;
        uint8 support;
        uint96 votes;
    }
    struct Proposal {
        uint id;
        address proposer;
        uint eta;
        uint startBlock;
        uint endBlock;
        uint forVotes;
        uint againstVotes;
        uint abstainVotes;
        bool canceled;
        bool executed;
    }
    function getActions(uint proposalId) external view returns (address[] memory targets, uint[] memory values, string[] memory signatures, bytes[] memory calldatas);
    function proposals(uint proposalId) external view returns (Proposal memory);
    function getReceipt(uint proposalId, address voter) external view returns (Receipt memory);
}

contract CompoundLens {
    struct CTokenMetadata {
        address cToken;
        uint256 exchangeRateCurrent;
        uint256 supplyRatePerBlock;
        uint256 borrowRatePerBlock;
        uint256 reserveFactorMantissa;
        uint256 totalBorrows;
        uint256 totalReserves;
        uint256 totalSupply;
        uint256 totalCash;
        bool isListed;
        uint256 collateralFactorMantissa;
        address underlyingAssetAddress;
        uint256 cTokenDecimals;
        uint256 underlyingDecimals;
    }

    function cTokenMetadata(CToken cToken)
        public
        returns (CTokenMetadata memory)
    {
        uint256 exchangeRateCurrent = cToken.exchangeRateCurrent();
        ComptrollerLensInterface comptroller =
            ComptrollerLensInterface(address(cToken.comptroller()));
        (bool isListed, uint256 collateralFactorMantissa) =
            comptroller.markets(address(cToken));
        address underlyingAssetAddress;
        uint256 underlyingDecimals;

        if (compareStrings(cToken.symbol(), "aMATIC")) {
            underlyingAssetAddress = address(0);
            underlyingDecimals = 18;
        } else {
            CErc20 cErc20 = CErc20(address(cToken));
            underlyingAssetAddress = cErc20.underlying();
            underlyingDecimals = EIP20Interface(cErc20.underlying()).decimals();
        }

        return
            CTokenMetadata({
                cToken: address(cToken),
                exchangeRateCurrent: exchangeRateCurrent,
                supplyRatePerBlock: cToken.supplyRatePerBlock(),
                borrowRatePerBlock: cToken.borrowRatePerBlock(),
                reserveFactorMantissa: cToken.reserveFactorMantissa(),
                totalBorrows: cToken.totalBorrows(),
                totalReserves: cToken.totalReserves(),
                totalSupply: cToken.totalSupply(),
                totalCash: cToken.getCash(),
                isListed: isListed,
                collateralFactorMantissa: collateralFactorMantissa,
                underlyingAssetAddress: underlyingAssetAddress,
                cTokenDecimals: cToken.decimals(),
                underlyingDecimals: underlyingDecimals
            });
    }

    function cTokenMetadataAll(CToken[] calldata cTokens)
        external
        returns (CTokenMetadata[] memory)
    {
        uint256 cTokenCount = cTokens.length;
        CTokenMetadata[] memory res = new CTokenMetadata[](cTokenCount);
        for (uint256 i = 0; i < cTokenCount; i++) {
            res[i] = cTokenMetadata(cTokens[i]);
        }
        return res;
    }

    struct CTokenBalances {
        address cToken;
        uint256 balanceOf;
        uint256 borrowBalanceCurrent;
        uint256 balanceOfUnderlying;
        uint256 tokenBalance;
        uint256 tokenAllowance;
    }

    function cTokenBalances(CToken cToken, address payable account)
        public
        returns (CTokenBalances memory)
    {
        uint256 balanceOf = cToken.balanceOf(account);
        uint256 borrowBalanceCurrent = cToken.borrowBalanceCurrent(account);
        uint256 balanceOfUnderlying = cToken.balanceOfUnderlying(account);
        uint256 tokenBalance;
        uint256 tokenAllowance;

        if (compareStrings(cToken.symbol(), "aMATIC")) {
            tokenBalance = account.balance;
            tokenAllowance = account.balance;
        } else {
            CErc20 cErc20 = CErc20(address(cToken));
            EIP20Interface underlying = EIP20Interface(cErc20.underlying());
            tokenBalance = underlying.balanceOf(account);
            tokenAllowance = underlying.allowance(account, address(cToken));
        }

        return
            CTokenBalances({
                cToken: address(cToken),
                balanceOf: balanceOf,
                borrowBalanceCurrent: borrowBalanceCurrent,
                balanceOfUnderlying: balanceOfUnderlying,
                tokenBalance: tokenBalance,
                tokenAllowance: tokenAllowance
            });
    }

    function cTokenBalancesAll(
        CToken[] calldata cTokens,
        address payable account
    ) external returns (CTokenBalances[] memory) {
        uint256 cTokenCount = cTokens.length;
        CTokenBalances[] memory res = new CTokenBalances[](cTokenCount);
        for (uint256 i = 0; i < cTokenCount; i++) {
            res[i] = cTokenBalances(cTokens[i], account);
        }
        return res;
    }

    struct CTokenUnderlyingPrice {
        address cToken;
        uint256 underlyingPrice;
    }

    function cTokenUnderlyingPrice(CToken cToken)
        public
        returns (CTokenUnderlyingPrice memory)
    {
        ComptrollerLensInterface comptroller =
            ComptrollerLensInterface(address(cToken.comptroller()));
        PriceOracle priceOracle = comptroller.oracle();

        return
            CTokenUnderlyingPrice({
                cToken: address(cToken),
                underlyingPrice: priceOracle.getUnderlyingPrice(cToken)
            });
    }

    function cTokenUnderlyingPriceAll(CToken[] calldata cTokens)
        external
        returns (CTokenUnderlyingPrice[] memory)
    {
        uint256 cTokenCount = cTokens.length;
        CTokenUnderlyingPrice[] memory res =
            new CTokenUnderlyingPrice[](cTokenCount);
        for (uint256 i = 0; i < cTokenCount; i++) {
            res[i] = cTokenUnderlyingPrice(cTokens[i]);
        }
        return res;
    }

    struct AccountLimits {
        CToken[] markets;
        uint256 liquidity;
        uint256 shortfall;
    }

    function getAccountLimits(
        ComptrollerLensInterface comptroller,
        address account
    ) public returns (AccountLimits memory) {
        (uint256 errorCode, uint256 liquidity, uint256 shortfall) =
            comptroller.getAccountLiquidity(account);
        require(errorCode == 0);

        return
            AccountLimits({
                markets: comptroller.getAssetsIn(account),
                liquidity: liquidity,
                shortfall: shortfall
            });
    }
    
    struct GovReceipt {
        uint proposalId;
        bool hasVoted;
        bool support;
        uint96 votes;
    }

    function getGovReceipts(GovernorAlpha governor, address voter, uint[] memory proposalIds) public view returns (GovReceipt[] memory) {
        uint proposalCount = proposalIds.length;
        GovReceipt[] memory res = new GovReceipt[](proposalCount);
        for (uint i = 0; i < proposalCount; i++) {
            GovernorAlpha.Receipt memory receipt = governor.getReceipt(proposalIds[i], voter);
            res[i] = GovReceipt({
                proposalId: proposalIds[i],
                hasVoted: receipt.hasVoted,
                support: receipt.support,
                votes: receipt.votes
            });
        }
        return res;
    }

    struct GovBravoReceipt {
        uint proposalId;
        bool hasVoted;
        uint8 support;
        uint96 votes;
    }

    function getGovBravoReceipts(GovernorBravoInterface governor, address voter, uint[] memory proposalIds) public view returns (GovBravoReceipt[] memory) {
        uint proposalCount = proposalIds.length;
        GovBravoReceipt[] memory res = new GovBravoReceipt[](proposalCount);
        for (uint i = 0; i < proposalCount; i++) {
            GovernorBravoInterface.Receipt memory receipt = governor.getReceipt(proposalIds[i], voter);
            res[i] = GovBravoReceipt({
                proposalId: proposalIds[i],
                hasVoted: receipt.hasVoted,
                support: receipt.support,
                votes: receipt.votes
            });
        }
        return res;
    }

    struct GovProposal {
        uint proposalId;
        address proposer;
        uint eta;
        address[] targets;
        uint[] values;
        string[] signatures;
        bytes[] calldatas;
        uint startBlock;
        uint endBlock;
        uint forVotes;
        uint againstVotes;
        bool canceled;
        bool executed;
    }

    function setProposal(GovProposal memory res, GovernorAlpha governor, uint proposalId) internal view {
        (
            ,
            address proposer,
            uint eta,
            uint startBlock,
            uint endBlock,
            uint forVotes,
            uint againstVotes,
            bool canceled,
            bool executed
        ) = governor.proposals(proposalId);
        res.proposalId = proposalId;
        res.proposer = proposer;
        res.eta = eta;
        res.startBlock = startBlock;
        res.endBlock = endBlock;
        res.forVotes = forVotes;
        res.againstVotes = againstVotes;
        res.canceled = canceled;
        res.executed = executed;
    }

    function getGovProposals(GovernorAlpha governor, uint[] calldata proposalIds) external view returns (GovProposal[] memory) {
        GovProposal[] memory res = new GovProposal[](proposalIds.length);
        for (uint i = 0; i < proposalIds.length; i++) {
            (
                address[] memory targets,
                uint[] memory values,
                string[] memory signatures,
                bytes[] memory calldatas
            ) = governor.getActions(proposalIds[i]);
            res[i] = GovProposal({
                proposalId: 0,
                proposer: address(0),
                eta: 0,
                targets: targets,
                values: values,
                signatures: signatures,
                calldatas: calldatas,
                startBlock: 0,
                endBlock: 0,
                forVotes: 0,
                againstVotes: 0,
                canceled: false,
                executed: false
            });
            setProposal(res[i], governor, proposalIds[i]);
        }
        return res;
    }

    struct GovBravoProposal {
        uint proposalId;
        address proposer;
        uint eta;
        address[] targets;
        uint[] values;
        string[] signatures;
        bytes[] calldatas;
        uint startBlock;
        uint endBlock;
        uint forVotes;
        uint againstVotes;
        uint abstainVotes;
        bool canceled;
        bool executed;
    }

    function setBravoProposal(GovBravoProposal memory res, GovernorBravoInterface governor, uint proposalId) internal view {
        GovernorBravoInterface.Proposal memory p = governor.proposals(proposalId);

        res.proposalId = proposalId;
        res.proposer = p.proposer;
        res.eta = p.eta;
        res.startBlock = p.startBlock;
        res.endBlock = p.endBlock;
        res.forVotes = p.forVotes;
        res.againstVotes = p.againstVotes;
        res.abstainVotes = p.abstainVotes;
        res.canceled = p.canceled;
        res.executed = p.executed;
    }

    function getGovBravoProposals(GovernorBravoInterface governor, uint[] calldata proposalIds) external view returns (GovBravoProposal[] memory) {
        GovBravoProposal[] memory res = new GovBravoProposal[](proposalIds.length);
        for (uint i = 0; i < proposalIds.length; i++) {
            (
                address[] memory targets,
                uint[] memory values,
                string[] memory signatures,
                bytes[] memory calldatas
            ) = governor.getActions(proposalIds[i]);
            res[i] = GovBravoProposal({
                proposalId: 0,
                proposer: address(0),
                eta: 0,
                targets: targets,
                values: values,
                signatures: signatures,
                calldatas: calldatas,
                startBlock: 0,
                endBlock: 0,
                forVotes: 0,
                againstVotes: 0,
                abstainVotes: 0,
                canceled: false,
                executed: false
            });
            setBravoProposal(res[i], governor, proposalIds[i]);
        }
        return res;
    }

    struct CompBalanceMetadata {
        uint256 balance;
        uint256 votes;
        address delegate;
    }

    function getCompBalanceMetadata(Comp lhb, address account)
        external
        view
        returns (CompBalanceMetadata memory)
    {
        return
            CompBalanceMetadata({
                balance: lhb.balanceOf(account),
                votes: uint256(lhb.getCurrentVotes(account)),
                delegate: lhb.delegates(account)
            });
    }

    struct CompBalanceMetadataExt {
        uint256 balance;
        uint256 votes;
        address delegate;
        uint256 allocated;
    }

    function getCompBalanceMetadataExt(
        Comp lhb,
        ComptrollerLensInterface comptroller,
        address account
    ) external returns (CompBalanceMetadataExt memory) {
        uint256 balance = lhb.balanceOf(account);
        comptroller.claimComp(account);
        uint256 newBalance = lhb.balanceOf(account);
        uint256 accrued = comptroller.compAccrued(account);
        uint256 total = add(accrued, newBalance, "sum LHB total");
        uint256 allocated = sub(total, balance, "sub allocated");

        return
            CompBalanceMetadataExt({
                balance: balance,
                votes: uint256(lhb.getCurrentVotes(account)),
                delegate: lhb.delegates(account),
                allocated: allocated
            });
    }

    struct CompVotes {
        uint256 blockNumber;
        uint256 votes;
    }

    function getCompVotes(
        Comp lhb,
        address account,
        uint32[] calldata blockNumbers
    ) external view returns (CompVotes[] memory) {
        CompVotes[] memory res = new CompVotes[](blockNumbers.length);
        for (uint256 i = 0; i < blockNumbers.length; i++) {
            res[i] = CompVotes({
                blockNumber: uint256(blockNumbers[i]),
                votes: uint256(lhb.getPriorVotes(account, blockNumbers[i]))
            });
        }
        return res;
    }

    function compareStrings(string memory a, string memory b)
        internal
        pure
        returns (bool)
    {
        return (keccak256(abi.encodePacked((a))) ==
            keccak256(abi.encodePacked((b))));
    }

    function add(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, errorMessage);
        return c;
    }

    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;
        return c;
    }
}