// File: contracts/lybraFund.sol



// SPDX-License-Identifier: GPL-3.0

pragma solidity 0.8.17;
/**
 * @title LybraFund is a derivative version of Synthetix StakingRewards.sol, distributing Protocol revenue to esLBR stakers.
 * Converting esLBR to LBR.
 * Differences from the original contract,
 * - Get `totalStaked` from totalSupply() in contract esLBR.
 * - Get `stakedOf(user)` from balanceOf(user) in contract esLBR.
 * - When an address esLBR balance changes, call the refreshReward method to update rewards to be claimed.
 */
 import "./Ownable.sol";
import "./ERC20.sol";
import "./ILybra.sol";
import "./IesLBR.sol";
contract LybraFund is  Ownable {
    ILybra public lybra;
    IesLBR public esLBR;
    IesLBR public LBR;

    // Sum of (reward rate * dt * 1e18 / total supply)
    uint public rewardPerTokenStored;
    // User address => rewardPerTokenStored
    mapping(address => uint) public userRewardPerTokenPaid;
    // User address => rewards to be claimed
    mapping(address => uint) public rewards;
    mapping(address => uint) public time2fullRedemption;
    mapping(address => uint) public unstakeRate;
    mapping(address => uint) public lastWithdrawTime;
    uint256 immutable exitCycle = 30 days;
    uint256 public claimAbleTime;

    constructor(address _lybra) {
        lybra = ILybra(_lybra);
    }

    function setLybra(address _lybra) external onlyOwner {
        lybra = ILybra(_lybra);
    }

    function setTokenAddress(address _eslbr, address _lbr) external onlyOwner {
        esLBR = IesLBR(_eslbr);
        LBR = IesLBR(_lbr);
    }

    function setClaimAbleTime(uint256 _time) external onlyOwner {
        claimAbleTime = _time;
    }

    // Total staked
    function totalStaked() internal view returns (uint256) {
        return esLBR.totalSupply();
    }

    // User address => esLBR balance
    function stakedOf(address staker) internal view returns (uint256) {
        return esLBR.balanceOf(staker);
    }

    function stake(uint256 amount) external updateReward(msg.sender) {
        LBR.burn(msg.sender, amount);
        esLBR.mint(msg.sender, amount);
    }

    function unstake(uint256 amount) external updateReward(msg.sender) {
        require(block.timestamp >= claimAbleTime, "It is not yet time to claim.");
        esLBR.burn(msg.sender, amount);
        withdraw(msg.sender);
        uint256 total = amount;
        if(time2fullRedemption[msg.sender] > block.timestamp) {
            total += unstakeRate[msg.sender] * (time2fullRedemption[msg.sender] - block.timestamp);
        }
        unstakeRate[msg.sender] = total / exitCycle;
        time2fullRedemption[msg.sender] = block.timestamp + exitCycle;
    }

    function withdraw(address user) public {
        uint256 amount = getClaimAbleLBR(user);
        if(amount > 0) {
            LBR.mint(user, amount);
        }
        lastWithdrawTime[user] = block.timestamp;
    }

    function reStake() external updateReward(msg.sender) {
        esLBR.mint(msg.sender, getReservedLBRForVesting(msg.sender) + getClaimAbleLBR(msg.sender));
        unstakeRate[msg.sender] = 0;
        time2fullRedemption[msg.sender] = 0;
    }

    function getClaimAbleLBR(address user) public view returns (uint256 amount) {
        if(time2fullRedemption[user] > lastWithdrawTime[user]) {
            amount = block.timestamp > time2fullRedemption[user] ? unstakeRate[user] * (time2fullRedemption[user] - lastWithdrawTime[user]) : unstakeRate[user] * (block.timestamp - lastWithdrawTime[user]);
        }
    }

    function getReservedLBRForVesting(address user) public  view returns (uint256 amount) {
        if(time2fullRedemption[user] > block.timestamp) {
            amount = unstakeRate[user] * (time2fullRedemption[user] - block.timestamp);
        }
    }

    function earned(address _account) public view returns (uint) {
        return
            ((stakedOf(_account) *
                (rewardPerTokenStored - userRewardPerTokenPaid[_account])) /
                1e18) + rewards[_account];
    }

    function getClaimAbleUSD(address user) external view returns (uint256 amount) {
        amount = lybra.getMintedEUSDByShares(earned(user));
    }

    /**
     * @dev Call this function when deposit or withdraw ETH on Lybra and update the status of corresponding user.
     */
    modifier updateReward(address account) {
        rewards[account] = earned(account);
        userRewardPerTokenPaid[account] = rewardPerTokenStored;
        _;
    }

    function refreshReward(address _account) external updateReward(_account) {}

    function getReward() external updateReward(msg.sender) {
        uint reward = rewards[msg.sender];
        if (reward > 0) {
            rewards[msg.sender] = 0;
            lybra.transferShares(msg.sender, reward);
        }
    }

    /**
     * @dev The amount of EUSD acquiered from the sender is euitably distributed to LBR stakers.
     * Calculate share by amount, and calculate the shares could claim by per unit of staked ETH.
     * Add into rewardPerTokenStored.
     */
    function notifyRewardAmount(uint amount) external {
        require(msg.sender == address(lybra));
        if (totalStaked() == 0) return;
        require(amount > 0, "amount = 0");
        uint256 share = lybra.getSharesByMintedEUSD(amount);
        rewardPerTokenStored =
            rewardPerTokenStored +
            (share * 1e18) /
            totalStaked();
    }
}
// File: contracts/IesLBR.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.17;

interface IesLBR {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function mint(address user, uint256 amount) external returns(bool);
    function burn(address user, uint256 amount) external returns(bool);
}
// File: contracts/ILybra.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.17;

interface ILybra {
    function totalSupply() external view returns (uint256);

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

    function totalDepositedEther() external view returns (uint256);

    function safeCollateralRate() external view returns (uint256);

    function redemptionFee() external view returns (uint256);

    function keeperRate() external view returns (uint256);

    function depositedEther(address user) external view returns (uint256);

    function getBorrowedOf(address user) external view returns (uint256);

    function isRedemptionProvider(address user) external view returns (bool);

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

    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);

    function transferShares(
        address _recipient,
        uint256 _sharesAmount
    ) external returns (uint256);

    function getSharesByMintedEUSD(
        uint256 _EUSDAmount
    ) external view returns (uint256);

    function getMintedEUSDByShares(
        uint256 _sharesAmount
    ) external view returns (uint256);
}

// File: contracts/ERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";

import "./Context.sol";

contract ERC20 is Context, IERC20 {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the default value returned by this function, unless
     * it's overridden.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(address from, address to, uint256 amount) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _balances[to] += amount;
        }

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}
// File: contracts/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "./Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
// File: contracts/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
// File: contracts/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 amount) external returns (bool);
}