// SPDX-License-Identifier: UNLICENSED

pragma solidity ^0.5.16;

import "./JoetrollerInterface.sol";
import "./InterestRateModel.sol";
import "./ERC3156FlashBorrowerInterface.sol";

contract JTokenStorage {
    /**
     * @dev Guard variable for re-entrancy checks
     */
    bool internal _notEntered;

    /**
     * @notice EIP-20 token name for this token
     */
    string public name;

    /**
     * @notice EIP-20 token symbol for this token
     */
    string public symbol;

    /**
     * @notice EIP-20 token decimals for this token
     */
    uint8 public decimals;

    /**
     * @notice Maximum borrow rate that can ever be applied (.0005% / sec)
     */

    uint256 internal constant borrowRateMaxMantissa = 0.0005e16;

    /**
     * @notice Maximum fraction of interest that can be set aside for reserves
     */
    uint256 internal constant reserveFactorMaxMantissa = 1e18;

    /**
     * @notice Administrator for this contract
     */
    address payable public admin;

    /**
     * @notice Pending administrator for this contract
     */
    address payable public pendingAdmin;

    /**
     * @notice Contract which oversees inter-jToken operations
     */
    JoetrollerInterface public joetroller;

    /**
     * @notice Model which tells what the current interest rate should be
     */
    InterestRateModel public interestRateModel;

    /**
     * @notice Initial exchange rate used when minting the first JTokens (used when totalSupply = 0)
     */
    uint256 internal initialExchangeRateMantissa;

    /**
     * @notice Fraction of interest currently set aside for reserves
     */
    uint256 public reserveFactorMantissa;

    /**
     * @notice Block timestamp that interest was last accrued at
     */
    uint256 public accrualBlockTimestamp;

    /**
     * @notice Accumulator of the total earned interest rate since the opening of the market
     */
    uint256 public borrowIndex;

    /**
     * @notice Total amount of outstanding borrows of the underlying in this market
     */
    uint256 public totalBorrows;

    /**
     * @notice Total amount of reserves of the underlying held in this market
     */
    uint256 public totalReserves;

    /**
     * @notice Total number of tokens in circulation
     */
    uint256 public totalSupply;

    /**
     * @notice Official record of token balances for each account
     */
    mapping(address => uint256) internal accountTokens;

    /**
     * @notice Approved token transfer amounts on behalf of others
     */
    mapping(address => mapping(address => uint256)) internal transferAllowances;

    /**
     * @notice Container for borrow balance information
     * @member principal Total balance (with accrued interest), after applying the most recent balance-changing action
     * @member interestIndex Global borrowIndex as of the most recent balance-changing action
     */
    struct BorrowSnapshot {
        uint256 principal;
        uint256 interestIndex;
    }

    /**
     * @notice Mapping of account addresses to outstanding borrow balances
     */
    mapping(address => BorrowSnapshot) internal accountBorrows;
}

contract JErc20Storage {
    /**
     * @notice Underlying asset for this JToken
     */
    address public underlying;

    /**
     * @notice Implementation address for this contract
     */
    address public implementation;
}

contract JSupplyCapStorage {
    /**
     * @notice Internal cash counter for this JToken. Should equal underlying.balanceOf(address(this)) for CERC20.
     */
    uint256 public internalCash;
}

contract JCollateralCapStorage {
    /**
     * @notice Total number of tokens used as collateral in circulation.
     */
    uint256 public totalCollateralTokens;

    /**
     * @notice Record of token balances which could be treated as collateral for each account.
     *         If collateral cap is not set, the value should be equal to accountTokens.
     */
    mapping(address => uint256) public accountCollateralTokens;

    /**
     * @notice Check if accountCollateralTokens have been initialized.
     */
    mapping(address => bool) public isCollateralTokenInit;

    /**
     * @notice Collateral cap for this JToken, zero for no cap.
     */
    uint256 public collateralCap;
}

/*** Interface ***/

contract JTokenInterface is JTokenStorage {
    /**
     * @notice Indicator that this is a JToken contract (for inspection)
     */
    bool public constant isJToken = true;

    /*** Market Events ***/

    /**
     * @notice Event emitted when interest is accrued
     */
    event AccrueInterest(uint256 cashPrior, uint256 interestAccumulated, uint256 borrowIndex, uint256 totalBorrows);

    /**
     * @notice Event emitted when tokens are minted
     */
    event Mint(address minter, uint256 mintAmount, uint256 mintTokens);

    /**
     * @notice Event emitted when tokens are redeemed
     */
    event Redeem(address redeemer, uint256 redeemAmount, uint256 redeemTokens);

    /**
     * @notice Event emitted when underlying is borrowed
     */
    event Borrow(address borrower, uint256 borrowAmount, uint256 accountBorrows, uint256 totalBorrows);

    /**
     * @notice Event emitted when a borrow is repaid
     */
    event RepayBorrow(
        address payer,
        address borrower,
        uint256 repayAmount,
        uint256 accountBorrows,
        uint256 totalBorrows
    );

    /**
     * @notice Event emitted when a borrow is liquidated
     */
    event LiquidateBorrow(
        address liquidator,
        address borrower,
        uint256 repayAmount,
        address jTokenCollateral,
        uint256 seizeTokens
    );

    /*** Admin Events ***/

    /**
     * @notice Event emitted when pendingAdmin is changed
     */
    event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin);

    /**
     * @notice Event emitted when pendingAdmin is accepted, which means admin is updated
     */
    event NewAdmin(address oldAdmin, address newAdmin);

    /**
     * @notice Event emitted when joetroller is changed
     */
    event NewJoetroller(JoetrollerInterface oldJoetroller, JoetrollerInterface newJoetroller);

    /**
     * @notice Event emitted when interestRateModel is changed
     */
    event NewMarketInterestRateModel(InterestRateModel oldInterestRateModel, InterestRateModel newInterestRateModel);

    /**
     * @notice Event emitted when the reserve factor is changed
     */
    event NewReserveFactor(uint256 oldReserveFactorMantissa, uint256 newReserveFactorMantissa);

    /**
     * @notice Event emitted when the reserves are added
     */
    event ReservesAdded(address benefactor, uint256 addAmount, uint256 newTotalReserves);

    /**
     * @notice Event emitted when the reserves are reduced
     */
    event ReservesReduced(address admin, uint256 reduceAmount, uint256 newTotalReserves);

    /**
     * @notice EIP20 Transfer event
     */
    event Transfer(address indexed from, address indexed to, uint256 amount);

    /**
     * @notice EIP20 Approval event
     */
    event Approval(address indexed owner, address indexed spender, uint256 amount);

    /**
     * @notice Failure event
     */
    event Failure(uint256 error, uint256 info, uint256 detail);

    /*** User Interface ***/

    function transfer(address dst, uint256 amount) external returns (bool);

    function transferFrom(
        address src,
        address dst,
        uint256 amount
    ) external returns (bool);

    function approve(address spender, uint256 amount) external returns (bool);

    function allowance(address owner, address spender) external view returns (uint256);

    function balanceOf(address owner) external view returns (uint256);

    function balanceOfUnderlying(address owner) external returns (uint256);

    function getAccountSnapshot(address account)
        external
        view
        returns (
            uint256,
            uint256,
            uint256,
            uint256
        );

    function borrowRatePerSecond() external view returns (uint256);

    function supplyRatePerSecond() external view returns (uint256);

    function totalBorrowsCurrent() external returns (uint256);

    function borrowBalanceCurrent(address account) external returns (uint256);

    function borrowBalanceStored(address account) public view returns (uint256);

    function exchangeRateCurrent() public returns (uint256);

    function exchangeRateStored() public view returns (uint256);

    function getCash() external view returns (uint256);

    function accrueInterest() public returns (uint256);

    function seize(
        address liquidator,
        address borrower,
        uint256 seizeTokens
    ) external returns (uint256);

    /*** Admin Functions ***/

    function _setPendingAdmin(address payable newPendingAdmin) external returns (uint256);

    function _acceptAdmin() external returns (uint256);

    function _setJoetroller(JoetrollerInterface newJoetroller) public returns (uint256);

    function _setReserveFactor(uint256 newReserveFactorMantissa) external returns (uint256);

    function _reduceReserves(uint256 reduceAmount) external returns (uint256);

    function _setInterestRateModel(InterestRateModel newInterestRateModel) public returns (uint256);
}

contract JErc20Interface is JErc20Storage {
    /*** User Interface ***/

    function mint(uint256 mintAmount) external returns (uint256);

    function redeem(uint256 redeemTokens) external returns (uint256);

    function redeemUnderlying(uint256 redeemAmount) external returns (uint256);

    function borrow(uint256 borrowAmount) external returns (uint256);

    function repayBorrow(uint256 repayAmount) external returns (uint256);

    function repayBorrowBehalf(address borrower, uint256 repayAmount) external returns (uint256);

    function liquidateBorrow(
        address borrower,
        uint256 repayAmount,
        JTokenInterface jTokenCollateral
    ) external returns (uint256);

    function _addReserves(uint256 addAmount) external returns (uint256);
}

contract JWrappedNativeInterface is JErc20Interface {
    /**
     * @notice Flash loan fee ratio
     */
    uint256 public constant flashFeeBips = 8;

    /*** Market Events ***/

    /**
     * @notice Event emitted when a flashloan occured
     */
    event Flashloan(address indexed receiver, uint256 amount, uint256 totalFee, uint256 reservesFee);

    /*** User Interface ***/

    function mintNative() external payable returns (uint256);

    function redeemNative(uint256 redeemTokens) external returns (uint256);

    function redeemUnderlyingNative(uint256 redeemAmount) external returns (uint256);

    function borrowNative(uint256 borrowAmount) external returns (uint256);

    function repayBorrowNative() external payable returns (uint256);

    function repayBorrowBehalfNative(address borrower) external payable returns (uint256);

    function liquidateBorrowNative(address borrower, JTokenInterface jTokenCollateral)
        external
        payable
        returns (uint256);

    function flashLoan(
        ERC3156FlashBorrowerInterface receiver,
        address initiator,
        uint256 amount,
        bytes calldata data
    ) external returns (bool);

    function _addReservesNative() external payable returns (uint256);
}

contract JCapableErc20Interface is JErc20Interface, JSupplyCapStorage {
    /**
     * @notice Flash loan fee ratio
     */
    uint256 public constant flashFeeBips = 8;

    /*** Market Events ***/

    /**
     * @notice Event emitted when a flashloan occured
     */
    event Flashloan(address indexed receiver, uint256 amount, uint256 totalFee, uint256 reservesFee);

    /*** User Interface ***/

    function gulp() external;
}

contract JCollateralCapErc20Interface is JCapableErc20Interface, JCollateralCapStorage {
    /*** Admin Events ***/

    /**
     * @notice Event emitted when collateral cap is set
     */
    event NewCollateralCap(address token, uint256 newCap);

    /**
     * @notice Event emitted when user collateral is changed
     */
    event UserCollateralChanged(address account, uint256 newCollateralTokens);

    /*** User Interface ***/

    function registerCollateral(address account) external returns (uint256);

    function unregisterCollateral(address account) external;

    function flashLoan(
        ERC3156FlashBorrowerInterface receiver,
        address initiator,
        uint256 amount,
        bytes calldata data
    ) external returns (bool);

    /*** Admin Functions ***/

    function _setCollateralCap(uint256 newCollateralCap) external;
}

contract JDelegatorInterface {
    /**
     * @notice Emitted when implementation is changed
     */
    event NewImplementation(address oldImplementation, address newImplementation);

    /**
     * @notice Called by the admin to update the implementation of the delegator
     * @param implementation_ The address of the new implementation for delegation
     * @param allowResign Flag to indicate whether to call _resignImplementation on the old implementation
     * @param becomeImplementationData The encoded bytes data to be passed to _becomeImplementation
     */
    function _setImplementation(
        address implementation_,
        bool allowResign,
        bytes memory becomeImplementationData
    ) public;
}

contract JDelegateInterface {
    /**
     * @notice Called by the delegator on a delegate to initialize it for duty
     * @dev Should revert if any issues arise which make it unfit for delegation
     * @param data The encoded bytes data for any initialization
     */
    function _becomeImplementation(bytes memory data) public;

    /**
     * @notice Called by the delegator on a delegate to forfeit its responsibility
     */
    function _resignImplementation() public;
}

/*** External interface ***/

/**
 * @title Flash loan receiver interface
 */
interface IFlashloanReceiver {
    function executeOperation(
        address sender,
        address underlying,
        uint256 amount,
        uint256 fee,
        bytes calldata params
    ) external;
}

contract JProtocolSeizeShareStorage {
    /**
     * @notice Event emitted when the protocol share of seized collateral is changed
     */
    event NewProtocolSeizeShare(uint256 oldProtocolSeizeShareMantissa, uint256 newProtocolSeizeShareMantissa);

    /**
     * @notice Share of seized collateral that is added to reserves
     */
    uint256 public protocolSeizeShareMantissa;

    /**
     * @notice Maximum fraction of seized collateral that can be set aside for reserves
     */
    uint256 internal constant protocolSeizeShareMaxMantissa = 1e18;
}