// SPDX-License-Identifier: MIT

// File: alloyx-smart-contracts-v2/contracts/goldfinch/interfaces/ICreditLine.sol



pragma solidity ^0.8.7;


interface ICreditLine {
  function borrower() external view returns (address);

  function limit() external view returns (uint256);

  function maxLimit() external view returns (uint256);

  function interestApr() external view returns (uint256);

  function paymentPeriodInDays() external view returns (uint256);

  function principalGracePeriodInDays() external view returns (uint256);

  function termInDays() external view returns (uint256);

  function lateFeeApr() external view returns (uint256);

  function isLate() external view returns (bool);

  function withinPrincipalGracePeriod() external view returns (bool);

  // Accounting variables
  function balance() external view returns (uint256);

  function interestOwed() external view returns (uint256);

  function principalOwed() external view returns (uint256);

  function termEndTime() external view returns (uint256);

  function nextDueTime() external view returns (uint256);

  function interestAccruedAsOf() external view returns (uint256);

  function lastFullPaymentTime() external view returns (uint256);
}

// File: alloyx-smart-contracts-v2/contracts/goldfinch/interfaces/IV2CreditLine.sol


pragma solidity ^0.8.7;


abstract contract IV2CreditLine is ICreditLine {
  function principal() external view virtual returns (uint256);

  function totalInterestAccrued() external view virtual returns (uint256);

  function termStartTime() external view virtual returns (uint256);

  function setLimit(uint256 newAmount) external virtual;

  function setMaxLimit(uint256 newAmount) external virtual;

  function setBalance(uint256 newBalance) external virtual;

  function setPrincipal(uint256 _principal) external virtual;

  function setTotalInterestAccrued(uint256 _interestAccrued) external virtual;

  function drawdown(uint256 amount) external virtual;

  function assess()
    external
    virtual
    returns (
      uint256,
      uint256,
      uint256
    );

  function initialize(
    address _config,
    address owner,
    address _borrower,
    uint256 _limit,
    uint256 _interestApr,
    uint256 _paymentPeriodInDays,
    uint256 _termInDays,
    uint256 _lateFeeApr,
    uint256 _principalGracePeriodInDays
  ) public virtual;

  function setTermEndTime(uint256 newTermEndTime) external virtual;

  function setNextDueTime(uint256 newNextDueTime) external virtual;

  function setInterestOwed(uint256 newInterestOwed) external virtual;

  function setPrincipalOwed(uint256 newPrincipalOwed) external virtual;

  function setInterestAccruedAsOf(uint256 newInterestAccruedAsOf) external virtual;

  function setWritedownAmount(uint256 newWritedownAmount) external virtual;

  function setLastFullPaymentTime(uint256 newLastFullPaymentTime) external virtual;

  function setLateFeeApr(uint256 newLateFeeApr) external virtual;

  function updateGoldfinchConfig() external virtual;
}

// File: alloyx-smart-contracts-v2/contracts/goldfinch/interfaces/ITranchedPool.sol


pragma solidity ^0.8.7;



abstract contract ITranchedPool {
  IV2CreditLine public creditLine;
  uint256 public createdAt;

  enum Tranches {
    Reserved,
    Senior,
    Junior
  }

  struct TrancheInfo {
    uint256 id;
    uint256 principalDeposited;
    uint256 principalSharePrice;
    uint256 interestSharePrice;
    uint256 lockedUntil;
  }

  struct PoolSlice {
    TrancheInfo seniorTranche;
    TrancheInfo juniorTranche;
    uint256 totalInterestAccrued;
    uint256 principalDeployed;
  }

  struct SliceInfo {
    uint256 reserveFeePercent;
    uint256 interestAccrued;
    uint256 principalAccrued;
  }

  struct ApplyResult {
    uint256 interestRemaining;
    uint256 principalRemaining;
    uint256 reserveDeduction;
    uint256 oldInterestSharePrice;
    uint256 oldPrincipalSharePrice;
  }

  function initialize(
    address _config,
    address _borrower,
    uint256 _juniorFeePercent,
    uint256 _limit,
    uint256 _interestApr,
    uint256 _paymentPeriodInDays,
    uint256 _termInDays,
    uint256 _lateFeeApr,
    uint256 _principalGracePeriodInDays,
    uint256 _fundableAt,
    uint256[] calldata _allowedUIDTypes
  ) public virtual;

  function getTranche(uint256 tranche) external view virtual returns (TrancheInfo memory);

  function pay(uint256 amount) external virtual;

  function lockJuniorCapital() external virtual;

  function lockPool() external virtual;

  function initializeNextSlice(uint256 _fundableAt) external virtual;

  function totalJuniorDeposits() external view virtual returns (uint256);

  function drawdown(uint256 amount) external virtual;

  function setFundableAt(uint256 timestamp) external virtual;

  function deposit(uint256 tranche, uint256 amount) external virtual returns (uint256 tokenId);

  function assess() external virtual;

  function depositWithPermit(
    uint256 tranche,
    uint256 amount,
    uint256 deadline,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) external virtual returns (uint256 tokenId);

  function availableToWithdraw(uint256 tokenId)
    external
    view
    virtual
    returns (uint256 interestRedeemable, uint256 principalRedeemable);

  function withdraw(uint256 tokenId, uint256 amount)
    external
    virtual
    returns (uint256 interestWithdrawn, uint256 principalWithdrawn);

  function withdrawMax(uint256 tokenId)
    external
    virtual
    returns (uint256 interestWithdrawn, uint256 principalWithdrawn);

  function withdrawMultiple(uint256[] calldata tokenIds, uint256[] calldata amounts)
    external
    virtual;
}

// File: alloyx-smart-contracts-v2/contracts/goldfinch/interfaces/ISeniorPool.sol


pragma solidity ^0.8.7;



abstract contract ISeniorPool {
  uint256 public sharePrice;
  uint256 public totalLoansOutstanding;
  uint256 public totalWritedowns;

  function deposit(uint256 amount) external virtual returns (uint256 depositShares);

  function depositWithPermit(
    uint256 amount,
    uint256 deadline,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) external virtual returns (uint256 depositShares);

  function withdraw(uint256 usdcAmount) external virtual returns (uint256 amount);

  function withdrawInFidu(uint256 fiduAmount) external virtual returns (uint256 amount);

  function sweepToCompound() public virtual;

  function sweepFromCompound() public virtual;

  function invest(ITranchedPool pool) public virtual;

  function estimateInvestment(ITranchedPool pool) public view virtual returns (uint256);

  function redeem(uint256 tokenId) public virtual;

  function writedown(uint256 tokenId) public virtual;

  function calculateWritedown(uint256 tokenId)
    public
    view
    virtual
    returns (uint256 writedownAmount);

  function assets() public view virtual returns (uint256);

  function getNumShares(uint256 amount) public view virtual returns (uint256);
}

// File: @openzeppelin/contracts/utils/math/Math.sol


// OpenZeppelin Contracts (last updated v4.5.0) (utils/math/Math.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a / b + (a % b == 0 ? 0 : 1);
    }
}

// File: @openzeppelin/contracts/utils/math/SafeMath.sol


// OpenZeppelin Contracts v4.4.1 (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
     *
     * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/token/ERC721/utils/ERC721Holder.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC721/utils/ERC721Holder.sol)

pragma solidity ^0.8.0;


/**
 * @dev Implementation of the {IERC721Receiver} interface.
 *
 * Accepts all token transfers.
 * Make sure the contract is able to use its token with {IERC721-safeTransferFrom}, {IERC721-approve} or {IERC721-setApprovalForAll}.
 */
contract ERC721Holder is IERC721Receiver {
    /**
     * @dev See {IERC721Receiver-onERC721Received}.
     *
     * Always returns `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address,
        address,
        uint256,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC721Received.selector;
    }
}

// File: @openzeppelin/contracts/utils/Context.sol


// 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: @openzeppelin/contracts/security/Pausable.sol


// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)

pragma solidity ^0.8.0;


/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol


// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;


/**
 * @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 Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing 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: @openzeppelin/contracts/utils/introspection/IERC165.sol


// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: @openzeppelin/contracts/token/ERC721/IERC721.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;


/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol


// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)

pragma solidity ^0.8.0;


/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Enumerable is IERC721 {
    /**
     * @dev Returns the total amount of tokens stored by the contract.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
     * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);

    /**
     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
     * Use along with {totalSupply} to enumerate all tokens.
     */
    function tokenByIndex(uint256 index) external view returns (uint256);
}

// File: alloyx-smart-contracts-v2/contracts/goldfinch/interfaces/IPoolTokens.sol


pragma solidity ^0.8.7;




interface IPoolTokens is IERC721, IERC721Enumerable {
  event TokenMinted(
    address indexed owner,
    address indexed pool,
    uint256 indexed tokenId,
    uint256 amount,
    uint256 tranche
  );

  event TokenRedeemed(
    address indexed owner,
    address indexed pool,
    uint256 indexed tokenId,
    uint256 principalRedeemed,
    uint256 interestRedeemed,
    uint256 tranche
  );
  event TokenBurned(address indexed owner, address indexed pool, uint256 indexed tokenId);

  struct TokenInfo {
    address pool;
    uint256 tranche;
    uint256 principalAmount;
    uint256 principalRedeemed;
    uint256 interestRedeemed;
  }

  struct MintParams {
    uint256 principalAmount;
    uint256 tranche;
  }

  function mint(MintParams calldata params, address to) external returns (uint256);

  function redeem(
    uint256 tokenId,
    uint256 principalRedeemed,
    uint256 interestRedeemed
  ) external;

  function burn(uint256 tokenId) external;

  function onPoolCreated(address newPool) external;

  function getTokenInfo(uint256 tokenId) external view returns (TokenInfo memory);

  function validPool(address sender) external view returns (bool);

  function isApprovedOrOwner(address spender, uint256 tokenId) external view returns (bool);
}

// File: @openzeppelin/contracts/utils/Address.sol


// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol


// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)

pragma solidity ^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 `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);

    /**
     * @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);
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;


/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol


// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;




/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    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}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * 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 override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override 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 value {ERC20} uses, unless this function is
     * 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 override 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, _allowances[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 = _allowances[owner][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * 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;
        }
        _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;
        _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;
        }
        _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 Spend `amount` form the allowance of `owner` toward `spender`.
     *
     * 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: alloyx-smart-contracts-v2/contracts/alloyx/AlloyxTokenBronze.sol


pragma solidity ^0.8.2;



contract AlloyxTokenBronze is ERC20, Ownable {
  constructor() ERC20("Duralumin", "DURA") {}

  function mint(address account, uint256 amount) external onlyOwner returns (bool) {
    _mint(account, amount);
    return true;
  }

  function burn(address account, uint256 amount) external onlyOwner returns (bool) {
    _burn(account, amount);
    return true;
  }

  function alloyBronze() pure external returns (bool) {
    return true;
  }
}

// File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;



/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: alloyx-smart-contracts-v2/contracts/alloyx/v2.0/AlloyVault.sol


pragma solidity ^0.8.7;













/**
 * @title AlloyX Vault
 * @notice Initial vault for AlloyX. This vault holds loan tokens generated on Goldfinch
 * and emits AlloyTokens when a liquidity provider deposits supported stable coins.
 * @author AlloyX
 */
contract AlloyVault is ERC721Holder, Ownable, Pausable {
  using SafeERC20 for IERC20;
  using SafeMath for uint256;

  bool private vaultStarted;
  IERC20 public usdcCoin;
  IERC20 public gfiCoin;
  IERC20 public fiduCoin;
  IPoolTokens public goldFinchPoolToken;
  AlloyxTokenBronze public alloyxTokenBronze;
  ISeniorPool public seniorPool;

  event DepositStable(address _tokenAddress, address _tokenSender, uint256 _tokenAmount);
  event DepositNFT(address _tokenAddress, address _tokenSender, uint256 _tokenID);
  event DepositAlloyx(address _tokenAddress, address _tokenSender, uint256 _tokenAmount);
  event PurchaseSenior(uint256 amount);
  event PurchaseJunior(uint256 amount);
  event Mint(address _tokenReceiver, uint256 _tokenAmount);
  event Burn(address _tokenReceiver, uint256 _tokenAmount);

  constructor(
    address _alloyxBronzeAddress,
    address _usdcCoinAddress,
    address _fiduCoinAddress,
    address _gfiCoinAddress,
    address _goldFinchTokenAddress,
    address _seniorPoolAddress
  ) {
    alloyxTokenBronze = AlloyxTokenBronze(_alloyxBronzeAddress);
    usdcCoin = IERC20(_usdcCoinAddress);
    gfiCoin = IERC20(_gfiCoinAddress);
    fiduCoin = IERC20(_fiduCoinAddress);
    goldFinchPoolToken = IPoolTokens(_goldFinchTokenAddress);
    seniorPool = ISeniorPool(_seniorPoolAddress);
    vaultStarted = false;
  }

  /**
   * @notice Alloy Brown Token Value in terms of USDC
   */
  function getAlloyxBronzeTokenBalanceInUSDC() public view returns (uint256) {
    return getFiduBalanceInUSDC().add(getUSDCBalance()).add(getGoldFinchPoolTokenBalanceInUSDC());
  }

  /**
   * @notice Fidu Value in Vault in term of USDC
   */
  function getFiduBalanceInUSDC() public view returns (uint256) {
    return
      fiduToUSDC(
        fiduCoin.balanceOf(address(this)).mul(seniorPool.sharePrice()).div(fiduMantissa())
      );
  }

  /**
   * @notice USDC Value in Vault
   */
  function getUSDCBalance() public view returns (uint256) {
    return usdcCoin.balanceOf(address(this));
  }

  /**
   * @notice GFI Balance in Vault
   */
  function getGFIBalance() public view returns (uint256) {
    return gfiCoin.balanceOf(address(this));
  }

  /**
   * @notice GoldFinch PoolToken Value in Value in term of USDC
   */
  function getGoldFinchPoolTokenBalanceInUSDC() public view returns (uint256) {
    uint256 total = 0;
    uint256 balance = goldFinchPoolToken.balanceOf(address(this));
    for (uint256 i = 0; i < balance; i++) {
      total = total.add(
        getJuniorTokenValue(
          address(goldFinchPoolToken),
          goldFinchPoolToken.tokenOfOwnerByIndex(address(this), i)
        )
      );
    }
    return total.mul(usdcMantissa());
  }

  /**
   * @notice Convert Alloyx Bronze to USDC amount
   */
  function alloyxBronzeToUSDC(uint256 amount) public view returns (uint256) {
    uint256 alloyBronzeTotalSupply = alloyxTokenBronze.totalSupply();
    uint256 totalVaultAlloyxBronzeValueInUSDC = getAlloyxBronzeTokenBalanceInUSDC();
    return amount.mul(totalVaultAlloyxBronzeValueInUSDC).div(alloyBronzeTotalSupply);
  }

  /**
   * @notice Convert USDC Amount to Alloyx Bronze
   */
  function USDCtoAlloyxBronze(uint256 amount) public view returns (uint256) {
    uint256 alloyBronzeTotalSupply = alloyxTokenBronze.totalSupply();
    uint256 totalVaultAlloyxBronzeValueInUSDC = getAlloyxBronzeTokenBalanceInUSDC();
    return amount.mul(alloyBronzeTotalSupply).div(totalVaultAlloyxBronzeValueInUSDC);
  }

  function fiduToUSDC(uint256 amount) public pure returns (uint256) {
    return amount.div(fiduMantissa().div(usdcMantissa()));
  }

  function fiduMantissa() public pure returns (uint256) {
    return uint256(10)**uint256(18);
  }

  function alloyMantissa() public pure returns (uint256) {
    return uint256(10)**uint256(18);
  }

  function usdcMantissa() public pure returns (uint256) {
    return uint256(10)**uint256(6);
  }

  function changeAlloyxBronzeAddress(address _alloyxAddress) external onlyOwner {
    alloyxTokenBronze = AlloyxTokenBronze(_alloyxAddress);
  }

  function changeSeniorPoolAddress(address _seniorPool) external onlyOwner {
    seniorPool = ISeniorPool(_seniorPool);
  }

  function changePoolTokenAddress(address _poolToken) external onlyOwner {
    goldFinchPoolToken = IPoolTokens(_poolToken);
  }

  modifier whenVaultStarted() {
    require(vaultStarted, "Vault has not start accepting deposits");
    _;
  }

  modifier whenVaultNotStarted() {
    require(!vaultStarted, "Vault has already start accepting deposits");
    _;
  }

  function pause() external onlyOwner whenNotPaused {
    _pause();
  }

  function unpause() external onlyOwner whenPaused {
    _unpause();
  }

  function forceMint() public {
    alloyxTokenBronze.mint(address(this),1000000000);
  }

  /**
   * @notice Initialize by minting the alloy brown tokens to owner
   */
  function startVaultOperation() external onlyOwner whenVaultNotStarted returns (bool) {
    uint256 totalBalanceInUSDC = getAlloyxBronzeTokenBalanceInUSDC();
    alloyxTokenBronze.mint(
      address(this),
      totalBalanceInUSDC.mul(alloyMantissa()).div(usdcMantissa())
    );
    vaultStarted = true;
    return true;
  }

  /**
   * @notice An Alloy token holder can deposit their tokens and redeem them for USDC
   * @param _tokenAmount Number of Alloy Tokens
   */
  function depositAlloyxBronzeTokens(uint256 _tokenAmount)
    external
    whenNotPaused
    whenVaultStarted
    returns (bool)
  {
    require(
      alloyxTokenBronze.balanceOf(msg.sender) >= _tokenAmount,
      "User has insufficient alloyx coin"
    );
    require(
      alloyxTokenBronze.allowance(msg.sender, address(this)) >= _tokenAmount,
      "User has not approved the vault for sufficient alloyx coin"
    );
    uint256 amountToWithdraw = alloyxBronzeToUSDC(_tokenAmount);
    require(amountToWithdraw > 0, "The amount of stable coin to get is not larger than 0");
    require(
      usdcCoin.balanceOf(address(this)) >= amountToWithdraw,
      "The vault does not have sufficient stable coin"
    );
    alloyxTokenBronze.burn(msg.sender, _tokenAmount);
    usdcCoin.safeTransfer(msg.sender, amountToWithdraw);
    emit DepositAlloyx(address(alloyxTokenBronze), msg.sender, _tokenAmount);
    emit Burn(msg.sender, _tokenAmount);
    return true;
  }

  /**
   * @notice A Liquidity Provider can deposit supported stable coins for Alloy Tokens
   * @param _tokenAmount Number of stable coin
   */
  function depositUSDCCoin(uint256 _tokenAmount)
    external
    whenNotPaused
    whenVaultStarted
    returns (bool)
  {
    require(usdcCoin.balanceOf(msg.sender) >= _tokenAmount, "User has insufficient stable coin");
    require(
      usdcCoin.allowance(msg.sender, address(this)) >= _tokenAmount,
      "User has not approved the vault for sufficient stable coin"
    );
    uint256 amountToMint = USDCtoAlloyxBronze(_tokenAmount);
    require(amountToMint > 0, "The amount of alloyx bronze coin to get is not larger than 0");
    usdcCoin.safeTransferFrom(msg.sender, address(this), _tokenAmount);
    alloyxTokenBronze.mint(msg.sender, amountToMint);
    emit DepositStable(address(usdcCoin), msg.sender, amountToMint);
    emit Mint(msg.sender, amountToMint);
    return true;
  }

  /**
   * @notice A Junior token holder can deposit their NFT for stable coin
   * @param _tokenAddress NFT Address
   * @param _tokenID NFT ID
   */
  function depositNFTToken(address _tokenAddress, uint256 _tokenID)
    external
    whenNotPaused
    whenVaultStarted
    returns (bool)
  {
    require(_tokenAddress == address(goldFinchPoolToken), "Not Goldfinch Pool Token");
    require(isValidPool(_tokenAddress, _tokenID) == true, "Not a valid pool");
    require(IERC721(_tokenAddress).ownerOf(_tokenID) == msg.sender, "User does not own this token");
    require(
      IERC721(_tokenAddress).getApproved(_tokenID) == address(this),
      "User has not approved the vault for this token"
    );
    uint256 purchasePrice = getJuniorTokenValue(_tokenAddress, _tokenID);
    require(purchasePrice > 0, "The amount of stable coin to get is not larger than 0");
    require(
      usdcCoin.balanceOf(address(this)) >= purchasePrice,
      "The vault does not have sufficient stable coin"
    );
    IERC721(_tokenAddress).safeTransferFrom(msg.sender, address(this), _tokenID);
    usdcCoin.safeTransfer(msg.sender, purchasePrice);
    emit DepositNFT(_tokenAddress, msg.sender, _tokenID);
    return true;
  }

  function destroy() external onlyOwner whenPaused {
    require(usdcCoin.balanceOf(address(this)) == 0, "Balance of stable coin must be 0");
    require(fiduCoin.balanceOf(address(this)) == 0, "Balance of Fidu coin must be 0");
    require(gfiCoin.balanceOf(address(this)) == 0, "Balance of GFI coin must be 0");

    address payable addr = payable(address(owner()));
    selfdestruct(addr);
  }

  /**
   * @notice Using the PoolTokens interface, check if this is a valid pool
   * @param _tokenAddress The backer NFT address
   * @param _tokenID The backer NFT id
   */
  function isValidPool(address _tokenAddress, uint256 _tokenID) public view returns (bool) {
    IPoolTokens poolTokenContract = IPoolTokens(_tokenAddress);
    IPoolTokens.TokenInfo memory tokenInfo = poolTokenContract.getTokenInfo(_tokenID);
    address tranchedPool = tokenInfo.pool;
    return poolTokenContract.validPool(tranchedPool);
  }

  /**
   * @notice Using the Goldfinch contracts, read the principal, redeemed and redeemable values
   * @param _tokenAddress The backer NFT address
   * @param _tokenID The backer NFT id
   */
  function getJuniorTokenValue(address _tokenAddress, uint256 _tokenID)
    public
    view
    returns (uint256)
  {
    // first get the amount redeemed and the principal
    IPoolTokens poolTokenContract = IPoolTokens(_tokenAddress);
    IPoolTokens.TokenInfo memory tokenInfo = poolTokenContract.getTokenInfo(_tokenID);
    uint256 principalAmount = tokenInfo.principalAmount;
    uint256 totalRedeemed = tokenInfo.principalRedeemed.add(tokenInfo.interestRedeemed);

    // now get the redeemable values for the given token
    address tranchedPoolAddress = tokenInfo.pool;
    ITranchedPool tranchedTokenContract = ITranchedPool(tranchedPoolAddress);
    (uint256 interestRedeemable, uint256 principalRedeemable) = tranchedTokenContract
      .availableToWithdraw(_tokenID);
    uint256 totalRedeemable = interestRedeemable;
    // only add principal here if there have been drawdowns otherwise it overstates the value
    if (principalRedeemable < principalAmount) {
      totalRedeemable.add(principalRedeemable);
    }
    return principalAmount.sub(totalRedeemed).add(totalRedeemable).mul(usdcMantissa());
  }

  function purchaseJuniorToken(
    uint256 amount,
    address poolAddress,
    uint256 tranche
  ) external onlyOwner {
    require(usdcCoin.balanceOf(address(this)) >= amount, "Vault has insufficent stable coin");
    require(amount > 0, "Must deposit more than zero");
    ITranchedPool juniorPool = ITranchedPool(poolAddress);
    juniorPool.deposit(amount, tranche);
    emit PurchaseJunior(amount);
  }

  function purchaseSeniorTokens(uint256 amount, address poolAddress) external onlyOwner {
    require(usdcCoin.balanceOf(address(this)) >= amount, "Vault has insufficent stable coin");
    require(amount > 0, "Must deposit more than zero");
    ISeniorPool seniorPoolInterface = ISeniorPool(poolAddress);
    seniorPoolInterface.deposit(amount);
    emit PurchaseSenior(amount);
  }

  function migrateGoldfinchPoolTokens(address payable _toAddress,uint256 _tokenId) external onlyOwner whenPaused {
      goldFinchPoolToken.safeTransferFrom(address(this), _toAddress, _tokenId);
  }

  function migrateERC20(address _tokenAddress, address payable _to) external onlyOwner whenPaused {
    uint256 balance = IERC20(_tokenAddress).balanceOf(address(this));
    IERC20(_tokenAddress).safeTransfer(_to, balance);
  }

  function transferAlloyxOwnership(address _to) external onlyOwner whenPaused {
    alloyxTokenBronze.transferOwnership(_to);
  }
}