// File: contracts/fund/ShareV2.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity >=0.6.10 <0.8.0;

import "../interfaces/IFundV3.sol";
import "../interfaces/IShareV2.sol";

contract ShareV2 is IShareV2 {
    uint8 public constant decimals = 18;
    IFundV3 public immutable fund;
    uint256 public immutable tranche;

    string public name;
    string public symbol;

    constructor(
        string memory name_,
        string memory symbol_,
        address fund_,
        uint256 tranche_
    ) public {
        name = name_;
        symbol = symbol_;
        fund = IFundV3(fund_);
        tranche = tranche_;
    }

    function totalSupply() external view override returns (uint256) {
        return fund.trancheTotalSupply(tranche);
    }

    function balanceOf(address account) external view override returns (uint256) {
        return fund.trancheBalanceOf(tranche, account);
    }

    function transfer(address recipient, uint256 amount) external override returns (bool) {
        fund.shareTransfer(msg.sender, recipient, amount);
        return true;
    }

    function allowance(address owner, address spender) external view override returns (uint256) {
        return fund.trancheAllowance(tranche, owner, spender);
    }

    function approve(address spender, uint256 amount) external override returns (bool) {
        fund.shareApprove(msg.sender, spender, amount);
        return true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external override returns (bool) {
        fund.shareTransferFrom(msg.sender, sender, recipient, amount);
        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) external returns (bool) {
        fund.shareIncreaseAllowance(msg.sender, spender, addedValue);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool) {
        fund.shareDecreaseAllowance(msg.sender, spender, subtractedValue);
        return true;
    }

    modifier onlyFund() {
        require(msg.sender == address(fund), "Only fund");
        _;
    }

    function fundEmitTransfer(
        address sender,
        address recipient,
        uint256 amount
    ) external override onlyFund {
        emit Transfer(sender, recipient, amount);
    }

    function fundEmitApproval(
        address owner,
        address spender,
        uint256 amount
    ) external override onlyFund {
        emit Approval(owner, spender, amount);
    }
}

// File: contracts/interfaces/IFundV3.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity >=0.6.10 <0.8.0;
pragma experimental ABIEncoderV2;

import "./ITwapOracleV2.sol";

interface IFundV3 {
    /// @notice A linear transformation matrix that represents a rebalance.
    ///
    ///         ```
    ///             [        1        0        0 ]
    ///         R = [ ratioB2Q  ratioBR        0 ]
    ///             [ ratioR2Q        0  ratioBR ]
    ///         ```
    ///
    ///         Amounts of the three tranches `q`, `b` and `r` can be rebalanced by multiplying the matrix:
    ///
    ///         ```
    ///         [ q', b', r' ] = [ q, b, r ] * R
    ///         ```
    struct Rebalance {
        uint256 ratioB2Q;
        uint256 ratioR2Q;
        uint256 ratioBR;
        uint256 timestamp;
    }

    function tokenUnderlying() external view returns (address);

    function tokenQ() external view returns (address);

    function tokenB() external view returns (address);

    function tokenR() external view returns (address);

    function tokenShare(uint256 tranche) external view returns (address);

    function primaryMarket() external view returns (address);

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

    function strategy() external view returns (address);

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

    function underlyingDecimalMultiplier() external view returns (uint256);

    function twapOracle() external view returns (ITwapOracleV2);

    function feeCollector() external view returns (address);

    function endOfDay(uint256 timestamp) external pure returns (uint256);

    function trancheTotalSupply(uint256 tranche) external view returns (uint256);

    function trancheBalanceOf(uint256 tranche, address account) external view returns (uint256);

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

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

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

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

    function trancheTransfer(
        uint256 tranche,
        address recipient,
        uint256 amount,
        uint256 version
    ) external;

    function trancheTransferFrom(
        uint256 tranche,
        address sender,
        address recipient,
        uint256 amount,
        uint256 version
    ) external;

    function trancheApprove(
        uint256 tranche,
        address spender,
        uint256 amount,
        uint256 version
    ) external;

    function getRebalanceSize() external view returns (uint256);

    function getRebalance(uint256 index) external view returns (Rebalance memory);

    function getRebalanceTimestamp(uint256 index) external view returns (uint256);

    function currentDay() external view returns (uint256);

    function splitRatio() external view returns (uint256);

    function historicalSplitRatio(uint256 version) external view returns (uint256);

    function fundActivityStartTime() external view returns (uint256);

    function isFundActive(uint256 timestamp) external view returns (bool);

    function getEquivalentTotalB() external view returns (uint256);

    function getEquivalentTotalQ() external view returns (uint256);

    function historicalEquivalentTotalB(uint256 timestamp) external view returns (uint256);

    function historicalNavs(uint256 timestamp) external view returns (uint256 navB, uint256 navR);

    function extrapolateNav(uint256 price)
        external
        view
        returns (
            uint256,
            uint256,
            uint256
        );

    function doRebalance(
        uint256 amountQ,
        uint256 amountB,
        uint256 amountR,
        uint256 index
    )
        external
        view
        returns (
            uint256 newAmountQ,
            uint256 newAmountB,
            uint256 newAmountR
        );

    function batchRebalance(
        uint256 amountQ,
        uint256 amountB,
        uint256 amountR,
        uint256 fromIndex,
        uint256 toIndex
    )
        external
        view
        returns (
            uint256 newAmountQ,
            uint256 newAmountB,
            uint256 newAmountR
        );

    function refreshBalance(address account, uint256 targetVersion) external;

    function refreshAllowance(
        address owner,
        address spender,
        uint256 targetVersion
    ) external;

    function shareTransfer(
        address sender,
        address recipient,
        uint256 amount
    ) external;

    function shareTransferFrom(
        address spender,
        address sender,
        address recipient,
        uint256 amount
    ) external returns (uint256 newAllowance);

    function shareIncreaseAllowance(
        address sender,
        address spender,
        uint256 addedValue
    ) external returns (uint256 newAllowance);

    function shareDecreaseAllowance(
        address sender,
        address spender,
        uint256 subtractedValue
    ) external returns (uint256 newAllowance);

    function shareApprove(
        address owner,
        address spender,
        uint256 amount
    ) external;

    function historicalUnderlying(uint256 timestamp) external view returns (uint256);

    function getTotalUnderlying() external view returns (uint256);

    function getStrategyUnderlying() external view returns (uint256);

    function getTotalDebt() external view returns (uint256);

    event RebalanceTriggered(
        uint256 indexed index,
        uint256 indexed day,
        uint256 navSum,
        uint256 navB,
        uint256 navROrZero,
        uint256 ratioB2Q,
        uint256 ratioR2Q,
        uint256 ratioBR
    );
    event Settled(uint256 indexed day, uint256 navB, uint256 navR, uint256 interestRate);
    event InterestRateUpdated(uint256 baseInterestRate, uint256 floatingInterestRate);
    event BalancesRebalanced(
        address indexed account,
        uint256 version,
        uint256 balanceQ,
        uint256 balanceB,
        uint256 balanceR
    );
    event AllowancesRebalanced(
        address indexed owner,
        address indexed spender,
        uint256 version,
        uint256 allowanceQ,
        uint256 allowanceB,
        uint256 allowanceR
    );
}

// File: contracts/interfaces/IShareV2.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity >=0.6.10 <0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

interface IShareV2 is IERC20 {
    function fundEmitTransfer(
        address sender,
        address recipient,
        uint256 amount
    ) external;

    function fundEmitApproval(
        address owner,
        address spender,
        uint256 amount
    ) external;
}

// File: contracts/interfaces/ITwapOracleV2.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity >=0.6.10 <0.8.0;

import "./ITwapOracle.sol";

interface ITwapOracleV2 is ITwapOracle {
    function getLatest() external view returns (uint256);
}

// File: contracts/interfaces/ITwapOracle.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity >=0.6.10 <0.8.0;

interface ITwapOracle {
    enum UpdateType {PRIMARY, SECONDARY, OWNER, CHAINLINK, UNISWAP_V2}

    function getTwap(uint256 timestamp) external view returns (uint256);
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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 `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @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);
}