// File: contracts/earn/LoanPoolRouter.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/utils/cryptography/draft-EIP712.sol";
import "@openzeppelin/contracts/utils/structs/BitMaps.sol";

import "../interfaces/ILoanPoolRouter.sol";

/// @title LoanPoolRouter
/// @author Bluejay Core Team
/// @notice LoanPoolRouter routes user funds into different loan pool. It serves as a
/// single point for funding loan pool and keeps a record of all pools funded by a user.
/// @dev Users' loan pool are not held in custody of this contract.
contract LoanPoolRouter is ILoanPoolRouter, EIP712 {
  using SafeERC20 for IERC20;
  using BitMaps for BitMaps.BitMap;

  string private constant EIP712_NAME = "Loan Pool Router";
  string private constant EIP712_REVISION = "1";
  bytes32 private constant PERMIT_TYPEHASH =
    keccak256(
      "Permit(address loanPool,address recipient,uint256 amount,uint256 nonce,uint256 deadline,uint256 salt)"
    );

  /// @notice Nonce for fundLoanPoolWithPermit to allow users to cancel permits
  mapping(address => uint256) public override permitNonce;

  /// @notice Mapping of a permit nullifier to a boolean to check if the permit has been used
  BitMaps.BitMap private permitNullifier;

  /// @dev Initializes the {EIP712} domain separator and cache the DOMAIN_SEPARATOR
  constructor() EIP712(EIP712_NAME, EIP712_REVISION) {}

  // =============================== PUBLIC FUNCTIONS =================================

  /// @notice Funds a loan pool
  /// @dev The function assumes the loan pool to be valid to reduce gas costs
  /// Applications executing this function should perform additional checks.
  /// @param loanPool Address of the loan pool to be funded
  /// @param amount Amount of funds to be deposited, in funding asset decimal
  /// @param recipient Address where loan token is credited to
  function fundLoanPool(
    ILoanPool loanPool,
    uint256 amount,
    address recipient
  ) external override {
    _fundLoanPool(msg.sender, loanPool, amount, recipient);
  }

  /// @notice Funds a loan pool with permit to allow for sponsored transactions
  /// @dev The function assumes the loan pool to be valid to reduce gas costs
  /// Applications executing this function should perform additional checks.
  /// The lender will still have to approve tokens to the router which can be
  /// sponsored using EIP2612 as well.
  /// @param lender Address of the lender where funds are pulled from
  /// @param loanPool Address of the loan pool to be funded
  /// @param amount Amount of funds to be deposited, in funding asset decimal
  /// @param recipient Address where loan token is credited to
  /// @param deadline Deadline where the permit expires
  /// @param salt Random number to make the permit unique
  /// @param v Signature parameter
  /// @param r Signature parameter
  /// @param s Signature parameter
  function fundLoanPoolWithPermit(
    address lender,
    ILoanPool loanPool,
    uint256 amount,
    address recipient,
    uint256 deadline,
    uint256 salt,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) external override {
    if (deadline < block.timestamp) revert PermitExpired();

    bytes32 structHash = keccak256(
      abi.encode(
        PERMIT_TYPEHASH,
        loanPool,
        recipient,
        amount,
        permitNonce[lender],
        deadline,
        salt
      )
    );
    bytes32 hash = _hashTypedDataV4(structHash);

    if (permitNullifier.get(uint256(structHash))) revert PermitUsed();
    permitNullifier.set(uint256(structHash));

    address signer = ecrecover(hash, v, r, s);
    if (signer != lender) revert InvalidSignature();

    _fundLoanPool(lender, loanPool, amount, recipient);
  }

  /// @notice Cancels all previously signed permits of previous nonce
  function cancelPermit() external override {
    permitNonce[msg.sender] = permitNonce[msg.sender] + 1;
  }

  // =============================== VIEW FUNCTIONS =================================

  /// @notice Returns the DOMAIN_SEPARATOR used for EIP712 signatures
  /// @return separator The domain separator value
  function domainSeparator()
    external
    view
    override
    returns (bytes32 separator)
  {
    return _domainSeparatorV4();
  }

  // =============================== INTERNAL FUNCTIONS =================================

  /// @notice Internal function for funding a loan pool
  /// @param lender Address of the lender where funds are pulled from
  /// @param loanPool Address of the loan pool to be funded
  /// @param amount Amount of funds to be deposited, in funding asset decimal
  /// @param recipient Address where loan token is credited to
  function _fundLoanPool(
    address lender,
    ILoanPool loanPool,
    uint256 amount,
    address recipient
  ) internal {
    IERC20 fundingAsset = loanPool.fundingAsset();
    fundingAsset.safeTransferFrom(lender, address(loanPool), amount);
    loanPool.fundDangerous(recipient);
    emit LoanPoolFunded(address(loanPool), lender, recipient, amount);
  }
}

// File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../../../utils/Address.sol";

/**
 * @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: @openzeppelin/contracts/utils/cryptography/draft-EIP712.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/cryptography/draft-EIP712.sol)

pragma solidity ^0.8.0;

import "./ECDSA.sol";

/**
 * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
 *
 * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
 * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
 * they need in their contracts using a combination of `abi.encode` and `keccak256`.
 *
 * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
 * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
 * ({_hashTypedDataV4}).
 *
 * The implementation of the domain separator was designed to be as efficient as possible while still properly updating
 * the chain id to protect against replay attacks on an eventual fork of the chain.
 *
 * NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
 * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
 *
 * _Available since v3.4._
 */
abstract contract EIP712 {
    /* solhint-disable var-name-mixedcase */
    // Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to
    // invalidate the cached domain separator if the chain id changes.
    bytes32 private immutable _CACHED_DOMAIN_SEPARATOR;
    uint256 private immutable _CACHED_CHAIN_ID;
    address private immutable _CACHED_THIS;

    bytes32 private immutable _HASHED_NAME;
    bytes32 private immutable _HASHED_VERSION;
    bytes32 private immutable _TYPE_HASH;

    /* solhint-enable var-name-mixedcase */

    /**
     * @dev Initializes the domain separator and parameter caches.
     *
     * The meaning of `name` and `version` is specified in
     * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
     *
     * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
     * - `version`: the current major version of the signing domain.
     *
     * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
     * contract upgrade].
     */
    constructor(string memory name, string memory version) {
        bytes32 hashedName = keccak256(bytes(name));
        bytes32 hashedVersion = keccak256(bytes(version));
        bytes32 typeHash = keccak256(
            "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
        );
        _HASHED_NAME = hashedName;
        _HASHED_VERSION = hashedVersion;
        _CACHED_CHAIN_ID = block.chainid;
        _CACHED_DOMAIN_SEPARATOR = _buildDomainSeparator(typeHash, hashedName, hashedVersion);
        _CACHED_THIS = address(this);
        _TYPE_HASH = typeHash;
    }

    /**
     * @dev Returns the domain separator for the current chain.
     */
    function _domainSeparatorV4() internal view returns (bytes32) {
        if (address(this) == _CACHED_THIS && block.chainid == _CACHED_CHAIN_ID) {
            return _CACHED_DOMAIN_SEPARATOR;
        } else {
            return _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION);
        }
    }

    function _buildDomainSeparator(
        bytes32 typeHash,
        bytes32 nameHash,
        bytes32 versionHash
    ) private view returns (bytes32) {
        return keccak256(abi.encode(typeHash, nameHash, versionHash, block.chainid, address(this)));
    }

    /**
     * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
     * function returns the hash of the fully encoded EIP712 message for this domain.
     *
     * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
     *
     * ```solidity
     * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
     *     keccak256("Mail(address to,string contents)"),
     *     mailTo,
     *     keccak256(bytes(mailContents))
     * )));
     * address signer = ECDSA.recover(digest, signature);
     * ```
     */
    function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
        return ECDSA.toTypedDataHash(_domainSeparatorV4(), structHash);
    }
}

// File: @openzeppelin/contracts/utils/structs/BitMaps.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/structs/BitMaps.sol)
pragma solidity ^0.8.0;

/**
 * @dev Library for managing uint256 to bool mapping in a compact and efficient way, providing the keys are sequential.
 * Largelly inspired by Uniswap's https://github.com/Uniswap/merkle-distributor/blob/master/contracts/MerkleDistributor.sol[merkle-distributor].
 */
library BitMaps {
    struct BitMap {
        mapping(uint256 => uint256) _data;
    }

    /**
     * @dev Returns whether the bit at `index` is set.
     */
    function get(BitMap storage bitmap, uint256 index) internal view returns (bool) {
        uint256 bucket = index >> 8;
        uint256 mask = 1 << (index & 0xff);
        return bitmap._data[bucket] & mask != 0;
    }

    /**
     * @dev Sets the bit at `index` to the boolean `value`.
     */
    function setTo(
        BitMap storage bitmap,
        uint256 index,
        bool value
    ) internal {
        if (value) {
            set(bitmap, index);
        } else {
            unset(bitmap, index);
        }
    }

    /**
     * @dev Sets the bit at `index`.
     */
    function set(BitMap storage bitmap, uint256 index) internal {
        uint256 bucket = index >> 8;
        uint256 mask = 1 << (index & 0xff);
        bitmap._data[bucket] |= mask;
    }

    /**
     * @dev Unsets the bit at `index`.
     */
    function unset(BitMap storage bitmap, uint256 index) internal {
        uint256 bucket = index >> 8;
        uint256 mask = 1 << (index & 0xff);
        bitmap._data[bucket] &= ~mask;
    }
}

// File: contracts/interfaces/ILoanPoolRouter.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "./ILoanPool.sol";

interface ILoanPoolRouter {
  function fundLoanPool(
    ILoanPool loanPool,
    uint256 amount,
    address recipient
  ) external;

  function domainSeparator() external view returns (bytes32 separator);

  function fundLoanPoolWithPermit(
    address lender,
    ILoanPool loanPool,
    uint256 amount,
    address recipient,
    uint256 deadline,
    uint256 salt,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) external;

  function cancelPermit() external;

  function permitNonce(address lender) external view returns (uint256 nonce);

  event LoanPoolFunded(
    address indexed loanPool,
    address indexed lender,
    address indexed recipient,
    uint256 amount
  );

  error PermitUsed();
  error PermitExpired();
  error InvalidSignature();
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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 `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);
}

// File: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)

pragma solidity ^0.8.0;

/**
 * @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
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 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/utils/cryptography/ECDSA.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/cryptography/ECDSA.sol)

pragma solidity ^0.8.0;

import "../Strings.sol";

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    enum RecoverError {
        NoError,
        InvalidSignature,
        InvalidSignatureLength,
        InvalidSignatureS,
        InvalidSignatureV
    }

    function _throwError(RecoverError error) private pure {
        if (error == RecoverError.NoError) {
            return; // no error: do nothing
        } else if (error == RecoverError.InvalidSignature) {
            revert("ECDSA: invalid signature");
        } else if (error == RecoverError.InvalidSignatureLength) {
            revert("ECDSA: invalid signature length");
        } else if (error == RecoverError.InvalidSignatureS) {
            revert("ECDSA: invalid signature 's' value");
        } else if (error == RecoverError.InvalidSignatureV) {
            revert("ECDSA: invalid signature 'v' value");
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature` or error string. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     *
     * Documentation for signature generation:
     * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
     * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
        // Check the signature length
        // - case 65: r,s,v signature (standard)
        // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
        if (signature.length == 65) {
            bytes32 r;
            bytes32 s;
            uint8 v;
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            assembly {
                r := mload(add(signature, 0x20))
                s := mload(add(signature, 0x40))
                v := byte(0, mload(add(signature, 0x60)))
            }
            return tryRecover(hash, v, r, s);
        } else if (signature.length == 64) {
            bytes32 r;
            bytes32 vs;
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            assembly {
                r := mload(add(signature, 0x20))
                vs := mload(add(signature, 0x40))
            }
            return tryRecover(hash, r, vs);
        } else {
            return (address(0), RecoverError.InvalidSignatureLength);
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, signature);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
     *
     * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
     *
     * _Available since v4.3._
     */
    function tryRecover(
        bytes32 hash,
        bytes32 r,
        bytes32 vs
    ) internal pure returns (address, RecoverError) {
        bytes32 s;
        uint8 v;
        assembly {
            s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
            v := add(shr(255, vs), 27)
        }
        return tryRecover(hash, v, r, s);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
     *
     * _Available since v4.2._
     */
    function recover(
        bytes32 hash,
        bytes32 r,
        bytes32 vs
    ) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, r, vs);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
     * `r` and `s` signature fields separately.
     *
     * _Available since v4.3._
     */
    function tryRecover(
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address, RecoverError) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
            return (address(0), RecoverError.InvalidSignatureS);
        }
        if (v != 27 && v != 28) {
            return (address(0), RecoverError.InvalidSignatureV);
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(hash, v, r, s);
        if (signer == address(0)) {
            return (address(0), RecoverError.InvalidSignature);
        }

        return (signer, RecoverError.NoError);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function recover(
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from a `hash`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
        // 32 is the length in bytes of hash,
        // enforced by the type signature above
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from `s`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
    }

    /**
     * @dev Returns an Ethereum Signed Typed Data, created from a
     * `domainSeparator` and a `structHash`. This produces hash corresponding
     * to the one signed with the
     * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
     * JSON-RPC method as part of EIP-712.
     *
     * See {recover}.
     */
    function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
    }
}

// File: @openzeppelin/contracts/utils/Strings.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}

// File: contracts/interfaces/ILoanPool.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

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

import "./ICreditLineBase.sol";

interface ILoanPool {
  /// @notice Amount is zero
  error ZeroAmount();

  /// @notice Funding period has not started
  error FundingPeriodNotStarted();

  /// @notice Funding period has ended
  error FundingPeriodEnded();

  /// @notice Funding period has not ended
  error FundingPeriodNotEnded();

  /// @notice Minimum amount of funds has been raised
  error MinimumFundingReached();

  /// @notice Minimum amount of funds has not been raised
  error MinimumFundingNotReached();

  /// @notice Drawdown period has not ended
  error DrawdownPeriodNotEnded();

  /// @notice Drawdown period has ended
  error DrawdownPeriodEnded();

  /// @notice Loan is not in funding state
  error NotFundingState();

  /// @notice Loan is not in repayment or repaid state
  error NotRepaymentOrRepaidState();

  /// @notice Insufficient balance for withdraw
  error InsufficientBalance();

  /// @notice Tokens cannot be transferred
  error TransferDisabled();

  /// @notice Attempt to transfer token which has claimed repayments
  error EncumberedTokenTransfer();

  /// @notice Attempt to unwithdraw more than what was withdrawn
  error ExcessiveUnwithdraw();

  /// @notice Loan is not in refund state
  error NotRefundState();

  /// @notice Caller is not the borrower
  error NotBorrower();

  /// @notice Funds have been deposited into the loan pool
  /// @param lender Address of the lender
  /// @param recipient Address where loan token is credited to
  /// @param amount Amount of funds deposited
  event Fund(address indexed lender, address indexed recipient, uint256 amount);

  /// @notice Lenders are allowed to withdraw their funds from the loan pool
  event Refunded();

  /// @notice Borrower has drawndown on the loan
  event Drawndown(address indexed borrower, uint256 amount);

  /// @notice Fees are collected from the loan pool
  /// @param borrower Address of borrower
  /// @param recipient Address where fees are credited to
  /// @param amount Amount of fees collected
  event FeesCollected(
    address indexed borrower,
    address indexed recipient,
    uint256 amount
  );

  /// @notice Funds are beind refunded to lender
  /// @param lender Address of the lender
  /// @param recipient Address where refunds are being sent
  /// @param amount Amount of funds refunded
  event Refund(
    address indexed lender,
    address indexed recipient,
    uint256 amount
  );

  /// @notice Borrower repays funds to the loan pool
  /// @param payer Address of the payer
  /// @param amount Amount of funds repaid
  event Repay(address indexed payer, uint256 amount);

  /// @notice Additional payments was refunded to the borrower
  /// @param payer Address of the payer
  /// @param amount Amount of funds refunded
  event RefundAdditionalPayment(address indexed payer, uint256 amount);

  /// @notice Funds are being withdrawn from the loan pool as lender
  /// after funds are repaid by the borrower
  /// @param lender Address of the lender
  /// @param recipient Address where funds are being sent
  /// @param amount Amount of funds withdrawn
  event Withdraw(
    address indexed lender,
    address indexed recipient,
    uint256 amount
  );

  /// @notice Funds are being returned to the loan pool by lender
  /// usually to free up more tokens for transfer
  /// @param sender Address of the sender
  /// @param lender Address where refunds are processed
  /// @param amount Amount of funds withdrawn
  event Unwithdraw(
    address indexed sender,
    address indexed lender,
    uint256 amount
  );

  function initialize(
    ICreditLineBase _creditLine,
    IERC20 _fundingAsset,
    address _borrower,
    address _feeRecipient,
    uint256[12] calldata _uints // collapsing because of stack too deep
  ) external;

  function creditLine() external view returns (ICreditLineBase);

  function fundingAsset() external view returns (IERC20);

  function borrower() external view returns (address);

  function deployer() external view returns (address);

  function feeRecipient() external view returns (address);

  function fundingStart() external view returns (uint256);

  function fundingEnd() external view returns (uint256);

  function minFundingRequired() external view returns (uint256);

  function drawdownPeriod() external view returns (uint256);

  function fees() external view returns (uint256);

  function repayments(address) external view returns (uint256);

  function fund(uint256 amount, address recipient) external;

  function fundDangerous(address recipient) external;

  function refundMinimumNotMet() external;

  function refundInactiveBorrower() external;

  function refund(address recipient) external;

  function drawdown() external;

  function repay(uint256 amount) external;

  function withdraw(uint256 amount, address recipient) external;

  function unwithdraw(uint256 amount, address recipient) external;

  function maxRepaymentAmount(
    address account
  ) external view returns (uint256 repaymentCeiling);

  function balanceAvailable(
    address account
  ) external view returns (uint256 balance);

  function shareOfPool(address account) external view returns (uint256 share);
}

// File: contracts/interfaces/ICreditLineBase.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

interface ICreditLineBase {
  /// @notice State of the loan
  /// @param Funding loan is currently fundraising from lenders
  /// @param Refund funding failed, funds to be returned to lenders, terminal state
  /// @param Repayment loan has been drawndown and borrower is repaying the loan
  /// @param Repaid loan has been fully repaid by borrower, terminal state
  enum State {
    Funding,
    Refund,
    Repayment,
    Repaid
  }

  /// @notice When a function is executed under the wrong loan state
  /// @param expectedState State that the loan should be in for the function to execute
  /// @param currentState State that the loan is currently in
  error IncorrectState(State expectedState, State currentState);

  /// @notice Funding exceeds the max limit
  error MaxLimitExceeded();

  /// @notice Loan state of the credit line has been updated
  /// @param newState State of the loan after the update
  event LoanStateUpdate(State indexed newState);

  /// @notice Repayment has been made towards loan
  /// @param timestamp Timestamp of repayment
  /// @param amount Amount of repayment
  /// @param interestRepaid Payment towards interest
  /// @param principalRepaid Payment towards principal
  /// @param additionalRepayment Excess payments
  event Repayment(
    uint256 timestamp,
    uint256 amount,
    uint256 interestRepaid,
    uint256 principalRepaid,
    uint256 additionalRepayment
  );

  function maxLimit() external view returns (uint256);

  function interestApr() external view returns (uint256);

  function paymentPeriod() external view returns (uint256);

  function gracePeriod() external view returns (uint256);

  function lateFeeApr() external view returns (uint256);

  function earlyRepaymentFee() external view returns (uint256);

  function principalBalance() external view returns (uint256);

  function interestBalance() external view returns (uint256);

  function totalPrincipalRepaid() external view returns (uint256);

  function totalInterestRepaid() external view returns (uint256);

  function totalEarlyFeePaid() external view returns (uint256);

  function additionalRepayment() external view returns (uint256);

  function lateInterestAccrued() external view returns (uint256);

  function interestAccruedAsOf() external view returns (uint256);

  function lastFullPaymentTime() external view returns (uint256);

  function minPaymentPerPeriod() external view returns (uint256);

  function loanStartTime() external view returns (uint256);

  function loanTenureInPeriods() external view returns (uint256);

  function loanState() external view returns (State);

  function initialize(
    uint256 _maxLimit,
    uint256 _interestApr,
    uint256 _paymentPeriod,
    uint256 _gracePeriod,
    uint256 _lateFeeApr,
    uint256 _loanTenureInPeriods,
    uint256 _earlyRepaymentFee
  ) external;

  function fund(uint256 amount) external;

  function drawdown() external returns (uint256 amount);

  function refund() external;

  function repay(
    uint256 amount
  )
    external
    returns (
      uint256 interestPayment,
      uint256 principalPayment,
      uint256 earlyFeePayment,
      uint256 additionalBalancePayment
    );

  function allocatePayment(
    uint256 amount,
    uint256 interestOutstanding,
    uint256 principalOutstanding,
    uint256 paymentExpected
  )
    external
    view
    returns (
      uint256 interestPayment,
      uint256 principalPayment,
      uint256 earlyFeePayment,
      uint256 additionalBalancePayment
    );

  function paymentDue() external view returns (uint256 amount);

  function interestAccruedSinceLastAssessed()
    external
    view
    returns (
      uint256 interestOwed,
      uint256 lateInterestOwed,
      uint256 fullPeriodsElapsed
    );

  function interestAccruedAtTimestamp(
    uint256 timestamp
  )
    external
    view
    returns (
      uint256 interestOwed,
      uint256 lateInterestOwed,
      uint256 fullPeriodsElapsed
    );

  function interestOnBalance(
    uint256 timePeriod
  ) external view returns (uint256 interestOwed);

  function lateInterestOnBalance(
    uint256 timePeriod
  ) external view returns (uint256 interestOwed);

  function totalRepayments() external view returns (uint256 amount);
}