// File: contracts/DegenDistributor.sol



// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.10;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
import {IDegenDistributor} from "./IDegenDistributor.sol";
import {IDegenNFT} from "@gearbox-protocol/core-v2/contracts/interfaces/IDegenNFT.sol";
import {DegenNFT} from "@gearbox-protocol/core-v2/contracts/tokens/DegenNFT.sol";

contract DegenDistributor is IDegenDistributor {
    IDegenNFT public immutable override token;
    bytes32 public immutable override merkleRoot;

    // This is a packed array of booleans.
    mapping(uint256 => uint256) private claimedBitMap;

    constructor(address token_, bytes32 merkleRoot_) {
        token = IDegenNFT(token_);
        merkleRoot = merkleRoot_;
    }

    function isClaimed(uint256 index) public view override returns (bool) {
        uint256 claimedWordIndex = index / 256;
        uint256 claimedBitIndex = index % 256;
        uint256 claimedWord = claimedBitMap[claimedWordIndex];
        uint256 mask = (1 << claimedBitIndex);
        return claimedWord & mask == mask;
    }

    function _setClaimed(uint256 index) private {
        uint256 claimedWordIndex = index / 256;
        uint256 claimedBitIndex = index % 256;
        claimedBitMap[claimedWordIndex] =
            claimedBitMap[claimedWordIndex] |
            (1 << claimedBitIndex);
    }

    function claim(
        uint256 index,
        address account,
        uint256 amount,
        bytes32[] calldata merkleProof
    ) external override {
        require(!isClaimed(index), "MerkleDistributor: Drop already claimed.");

        // Verify the merkle proof.
        bytes32 node = keccak256(abi.encodePacked(index, account, amount));
        require(
            MerkleProof.verify(merkleProof, merkleRoot, node),
            "MerkleDistributor: Invalid proof."
        );

        // Mark it claimed and send the token.
        _setClaimed(index);
        token.mint(account, amount);

        emit Claimed(index, account, amount);
    }
}

// File: contracts/IDegenDistributor.sol



// SPDX-License-Identifier: UNLICENSED
pragma solidity >=0.5.0;

import { IDegenNFT } from "@gearbox-protocol/core-v2/contracts/interfaces/IDegenNFT.sol";

// Allows anyone to claim a token if they exist in a merkle root.
interface IDegenDistributor {
    // Returns the address of the token distributed by this contract.
    function token() external view returns (IDegenNFT);

    // Returns the merkle root of the merkle tree containing account balances available to claim.
    function merkleRoot() external view returns (bytes32);

    // Returns true if the index has been marked claimed.
    function isClaimed(uint256 index) external view returns (bool);

    // Claim the given amount of the token to the given address. Reverts if the inputs are invalid.
    function claim(
        uint256 index,
        address account,
        uint256 amount,
        bytes32[] calldata merkleProof
    ) external;

    // This event is triggered whenever a call to #claim succeeds.
    event Claimed(uint256 index, address account, uint256 amount);
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// File: @openzeppelin/contracts/utils/cryptography/MerkleProof.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/cryptography/MerkleProof.sol)

pragma solidity ^0.8.0;

/**
 * @dev These functions deal with verification of Merkle Tree proofs.
 *
 * The proofs can be generated using the JavaScript library
 * https://github.com/miguelmota/merkletreejs[merkletreejs].
 * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
 *
 * See `test/utils/cryptography/MerkleProof.test.js` for some examples.
 *
 * WARNING: You should avoid using leaf values that are 64 bytes long prior to
 * hashing, or use a hash function other than keccak256 for hashing leaves.
 * This is because the concatenation of a sorted pair of internal nodes in
 * the merkle tree could be reinterpreted as a leaf value.
 */
library MerkleProof {
    /**
     * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
     * defined by `root`. For this, a `proof` must be provided, containing
     * sibling hashes on the branch from the leaf to the root of the tree. Each
     * pair of leaves and each pair of pre-images are assumed to be sorted.
     */
    function verify(
        bytes32[] memory proof,
        bytes32 root,
        bytes32 leaf
    ) internal pure returns (bool) {
        return processProof(proof, leaf) == root;
    }

    /**
     * @dev Calldata version of {verify}
     *
     * _Available since v4.7._
     */
    function verifyCalldata(
        bytes32[] calldata proof,
        bytes32 root,
        bytes32 leaf
    ) internal pure returns (bool) {
        return processProofCalldata(proof, leaf) == root;
    }

    /**
     * @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
     * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
     * hash matches the root of the tree. When processing the proof, the pairs
     * of leafs & pre-images are assumed to be sorted.
     *
     * _Available since v4.4._
     */
    function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            computedHash = _hashPair(computedHash, proof[i]);
        }
        return computedHash;
    }

    /**
     * @dev Calldata version of {processProof}
     *
     * _Available since v4.7._
     */
    function processProofCalldata(bytes32[] calldata proof, bytes32 leaf) internal pure returns (bytes32) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            computedHash = _hashPair(computedHash, proof[i]);
        }
        return computedHash;
    }

    /**
     * @dev Returns true if the `leaves` can be proved to be a part of a Merkle tree defined by
     * `root`, according to `proof` and `proofFlags` as described in {processMultiProof}.
     *
     * _Available since v4.7._
     */
    function multiProofVerify(
        bytes32[] memory proof,
        bool[] memory proofFlags,
        bytes32 root,
        bytes32[] memory leaves
    ) internal pure returns (bool) {
        return processMultiProof(proof, proofFlags, leaves) == root;
    }

    /**
     * @dev Calldata version of {multiProofVerify}
     *
     * _Available since v4.7._
     */
    function multiProofVerifyCalldata(
        bytes32[] calldata proof,
        bool[] calldata proofFlags,
        bytes32 root,
        bytes32[] memory leaves
    ) internal pure returns (bool) {
        return processMultiProofCalldata(proof, proofFlags, leaves) == root;
    }

    /**
     * @dev Returns the root of a tree reconstructed from `leaves` and the sibling nodes in `proof`,
     * consuming from one or the other at each step according to the instructions given by
     * `proofFlags`.
     *
     * _Available since v4.7._
     */
    function processMultiProof(
        bytes32[] memory proof,
        bool[] memory proofFlags,
        bytes32[] memory leaves
    ) internal pure returns (bytes32 merkleRoot) {
        // This function rebuild the root hash by traversing the tree up from the leaves. The root is rebuilt by
        // consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
        // `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
        // the merkle tree.
        uint256 leavesLen = leaves.length;
        uint256 totalHashes = proofFlags.length;

        // Check proof validity.
        require(leavesLen + proof.length - 1 == totalHashes, "MerkleProof: invalid multiproof");

        // The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
        // `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
        bytes32[] memory hashes = new bytes32[](totalHashes);
        uint256 leafPos = 0;
        uint256 hashPos = 0;
        uint256 proofPos = 0;
        // At each step, we compute the next hash using two values:
        // - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
        //   get the next hash.
        // - depending on the flag, either another value for the "main queue" (merging branches) or an element from the
        //   `proof` array.
        for (uint256 i = 0; i < totalHashes; i++) {
            bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
            bytes32 b = proofFlags[i] ? leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++] : proof[proofPos++];
            hashes[i] = _hashPair(a, b);
        }

        if (totalHashes > 0) {
            return hashes[totalHashes - 1];
        } else if (leavesLen > 0) {
            return leaves[0];
        } else {
            return proof[0];
        }
    }

    /**
     * @dev Calldata version of {processMultiProof}
     *
     * _Available since v4.7._
     */
    function processMultiProofCalldata(
        bytes32[] calldata proof,
        bool[] calldata proofFlags,
        bytes32[] memory leaves
    ) internal pure returns (bytes32 merkleRoot) {
        // This function rebuild the root hash by traversing the tree up from the leaves. The root is rebuilt by
        // consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
        // `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
        // the merkle tree.
        uint256 leavesLen = leaves.length;
        uint256 totalHashes = proofFlags.length;

        // Check proof validity.
        require(leavesLen + proof.length - 1 == totalHashes, "MerkleProof: invalid multiproof");

        // The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
        // `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
        bytes32[] memory hashes = new bytes32[](totalHashes);
        uint256 leafPos = 0;
        uint256 hashPos = 0;
        uint256 proofPos = 0;
        // At each step, we compute the next hash using two values:
        // - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
        //   get the next hash.
        // - depending on the flag, either another value for the "main queue" (merging branches) or an element from the
        //   `proof` array.
        for (uint256 i = 0; i < totalHashes; i++) {
            bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
            bytes32 b = proofFlags[i] ? leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++] : proof[proofPos++];
            hashes[i] = _hashPair(a, b);
        }

        if (totalHashes > 0) {
            return hashes[totalHashes - 1];
        } else if (leavesLen > 0) {
            return leaves[0];
        } else {
            return proof[0];
        }
    }

    function _hashPair(bytes32 a, bytes32 b) private pure returns (bytes32) {
        return a < b ? _efficientHash(a, b) : _efficientHash(b, a);
    }

    function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, a)
            mstore(0x20, b)
            value := keccak256(0x00, 0x40)
        }
    }
}

// File: @gearbox-protocol/core-v2/contracts/tokens/DegenNFT.sol



// SPDX-License-Identifier: GPL-2.0
pragma solidity ^0.8.10;

import { ERC721 } from "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import { IERC721 } from "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import { IERC721Metadata } from "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
import { Address } from "@openzeppelin/contracts/utils/Address.sol";

import { AddressProvider } from "../core/AddressProvider.sol";
import { ContractsRegister } from "../core/ContractsRegister.sol";

import { ACLTrait } from "../core/ACLTrait.sol";
import { NotImplementedException } from "../interfaces/IErrors.sol";

import { ICreditManagerV2 } from "../interfaces/ICreditManagerV2.sol";
import { ICreditFacade } from "../interfaces/ICreditFacade.sol";
import { IDegenNFT } from "../interfaces/IDegenNFT.sol";

contract DegenNFT is ERC721, ACLTrait, IDegenNFT {
    using Address for address;

    /// @dev Stores the total number of tokens on holder accounts
    uint256 public override totalSupply;

    /// @dev address of Contracts register
    ContractsRegister internal immutable contractsRegister;

    /// @dev address of the current minter
    address public minter;

    /// @dev mapping from address to supported Credit Facade status
    mapping(address => bool) public isSupportedCreditFacade;

    /// @dev Stores the base URI for NFT metadata
    string public override baseURI;

    /// @dev contract version
    uint256 public constant override version = 1;

    /// @dev Restricts calls to this contract's minter
    modifier onlyMinter() {
        if (msg.sender != minter) {
            revert MinterOnlyException();
        }
        _;
    }

    /// @dev Restricts calls to the configurator or Credit Facades
    modifier creditFacadeOrConfiguratorOnly() {
        if (
            !isSupportedCreditFacade[msg.sender] &&
            !_acl.isConfigurator(msg.sender)
        ) {
            revert CreditFacadeOrConfiguratorOnlyException();
        }
        _;
    }

    constructor(
        address _addressProvider,
        string memory _name,
        string memory _symbol
    )
        ACLTrait(_addressProvider)
        ERC721(_name, _symbol) // F:[DNFT-1]
    {
        contractsRegister = ContractsRegister(
            AddressProvider(_addressProvider).getContractsRegister()
        );
    }

    function setMinter(address minter_)
        external
        configuratorOnly // F:[DNFT-2B]
    {
        minter = minter_; // F: [DNFT-5A]
        emit NewMinterSet(minter);
    }

    function addCreditFacade(address creditFacade_)
        external
        configuratorOnly // F: [DNFT-2C]
    {
        if (!isSupportedCreditFacade[creditFacade_]) {
            if (!creditFacade_.isContract()) {
                revert InvalidCreditFacadeException(); // F:[DNFT-6]
            }

            address creditManager;
            try ICreditFacade(creditFacade_).creditManager() returns (
                ICreditManagerV2 cm
            ) {
                creditManager = address(cm);
            } catch {
                revert InvalidCreditFacadeException(); // F:[DNFT-6]
            }

            if (
                !contractsRegister.isCreditManager(creditManager) ||
                ICreditFacade(creditFacade_).degenNFT() != address(this) ||
                ICreditManagerV2(creditManager).creditFacade() != creditFacade_
            ) revert InvalidCreditFacadeException(); // F:[DNFT-6]

            isSupportedCreditFacade[creditFacade_] = true; // F: [DNFT-10]
            emit NewCreditFacadeAdded(creditFacade_);
        }
    }

    function removeCreditFacade(address creditFacade_)
        external
        configuratorOnly // F: [DNFT-2D]
    {
        if (isSupportedCreditFacade[creditFacade_]) {
            isSupportedCreditFacade[creditFacade_] = false; // F: [DNFT-9]
            emit NewCreditFacadeRemoved(creditFacade_);
        }
    }

    function setBaseUri(string calldata baseURI_)
        external
        configuratorOnly // F:[DNFT-2A]
    {
        baseURI = baseURI_; // F:[DNFT-5]
    }

    function _baseURI() internal view override returns (string memory) {
        return baseURI; // F:[DNFT-5]
    }

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId)
        public
        view
        override(IERC721Metadata, ERC721)
        returns (string memory)
    {
        require(
            _exists(tokenId),
            "ERC721Metadata: URI query for nonexistent token"
        );

        return _baseURI();
    }

    /// @dev Mints a specified amount of tokens to the address
    /// @param to Address the tokens are minted to
    /// @param amount The number of tokens to mint
    function mint(address to, uint256 amount)
        external
        override
        onlyMinter // F:[DNFT-3]
    {
        uint256 balanceBefore = balanceOf(to); // F:[DNFT-7]

        for (uint256 i; i < amount; ) {
            uint256 tokenId = (uint256(uint160(to)) << 40) + balanceBefore + i; // F:[DNFT-7]
            _mint(to, tokenId); // F:[DNFT-7]

            unchecked {
                ++i; // F:[DNFT-7]
            }
        }

        totalSupply += amount; // F:[DNFT-7]
    }

    /// @dev Burns a number of tokens from a specified address
    /// @param from The address a token will be burnt from
    /// @param amount The number of tokens to burn
    function burn(address from, uint256 amount)
        external
        override
        creditFacadeOrConfiguratorOnly // F:[DNFT-4]
    {
        uint256 balance = balanceOf(from); // F:[DNFT-8,8A]

        if (balance < amount) {
            revert InsufficientBalanceException(); // F:[DNFT-8A]
        }

        for (uint256 i; i < amount; ) {
            uint256 tokenId = (uint256(uint160(from)) << 40) + balance - i - 1; // F:[DNFT-8]
            _burn(tokenId); // F:[DNFT-8]

            unchecked {
                ++i; // F:[DNFT-8]
            }
        }

        totalSupply -= amount; // F:[DNFT-8]
    }

    /// @dev Not implemented as the token is not transferrable
    function approve(address, uint256)
        public
        pure
        virtual
        override(IERC721, ERC721)
    {
        revert NotImplementedException(); // F:[DNFT-11]
    }

    /// @dev Not implemented as the token is not transferrable
    function setApprovalForAll(address, bool)
        public
        pure
        virtual
        override(IERC721, ERC721)
    {
        revert NotImplementedException(); // F:[DNFT-11]
    }

    /// @dev Not implemented as the token is not transferrable
    function transferFrom(
        address,
        address,
        uint256
    ) public pure virtual override(IERC721, ERC721) {
        revert NotImplementedException(); // F:[DNFT-11]
    }

    /// @dev Not implemented as the token is not transferrable
    function safeTransferFrom(
        address,
        address,
        uint256
    ) public pure virtual override(IERC721, ERC721) {
        revert NotImplementedException(); // F:[DNFT-11]
    }

    /// @dev Not implemented as the token is not transferrable
    function safeTransferFrom(
        address,
        address,
        uint256,
        bytes memory
    ) public pure virtual override(IERC721, ERC721) {
        revert NotImplementedException(); // F:[DNFT-11]
    }
}

// File: @gearbox-protocol/core-v2/contracts/interfaces/IDegenNFT.sol



// SPDX-License-Identifier: MIT
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;
import { IVersion } from "./IVersion.sol";
import { IERC721Metadata } from "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";

interface IDegenNFTExceptions {
    /// @dev Thrown if an access-restricted function was called by non-CreditFacade
    error CreditFacadeOrConfiguratorOnlyException();

    /// @dev Thrown if an access-restricted function was called by non-minter
    error MinterOnlyException();

    /// @dev Thrown if trying to add a burner address that is not a correct Credit Facade
    error InvalidCreditFacadeException();

    /// @dev Thrown if the account's balance is not sufficient for an action (usually a burn)
    error InsufficientBalanceException();
}

interface IDegenNFTEvents {
    /// @dev Minted when new minter set
    event NewMinterSet(address indexed);

    /// @dev Minted each time when new credit facade added
    event NewCreditFacadeAdded(address indexed);

    /// @dev Minted each time when new credit facade added
    event NewCreditFacadeRemoved(address indexed);
}

interface IDegenNFT is
    IDegenNFTExceptions,
    IDegenNFTEvents,
    IVersion,
    IERC721Metadata
{
    /// @dev address of the current minter
    function minter() external view returns (address);

    /// @dev Stores the total number of tokens on holder accounts
    function totalSupply() external view returns (uint256);

    /// @dev Stores the base URI for NFT metadata
    function baseURI() external view returns (string memory);

    /// @dev Mints a specified amount of tokens to the address
    /// @param to Address the tokens are minted to
    /// @param amount The number of tokens to mint
    function mint(address to, uint256 amount) external;

    /// @dev Burns a number of tokens from a specified address
    /// @param from The address a token will be burnt from
    /// @param amount The number of tokens to burn
    function burn(address from, uint256 amount) external;
}

// File: @gearbox-protocol/core-v2/contracts/interfaces/IVersion.sol



// SPDX-License-Identifier: MIT
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;

/// @title IVersion
/// @dev Declares a version function which returns the contract's version
interface IVersion {
    /// @dev Returns contract version
    function version() external view returns (uint256);
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Metadata is IERC721 {
    /**
     * @dev Returns the token collection name.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the token collection symbol.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    function tokenURI(uint256 tokenId) external view returns (string memory);
}

// File: @openzeppelin/contracts/token/ERC721/IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @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`.
     *
     * 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;

    /**
     * @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 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 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 the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @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);
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT
// 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/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (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
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC721/ERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to owner address
    mapping(uint256 => address) private _owners;

    // Mapping owner address to token count
    mapping(address => uint256) private _balances;

    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return
            interfaceId == type(IERC721).interfaceId ||
            interfaceId == type(IERC721Metadata).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: address zero is not a valid owner");
        return _balances[owner];
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _owners[tokenId];
        require(owner != address(0), "ERC721: invalid token ID");
        return owner;
    }

    /**
     * @dev See {IERC721Metadata-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev See {IERC721Metadata-symbol}.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        _requireMinted(tokenId);

        string memory baseURI = _baseURI();
        return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
    }

    /**
     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
     * by default, can be overridden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return "";
    }

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            "ERC721: approve caller is not token owner nor approved for all"
        );

        _approve(to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        _requireMinted(tokenId);

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        _setApprovalForAll(_msgSender(), operator, approved);
    }

    /**
     * @dev See {IERC721-isApprovedForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner nor approved");

        _transfer(from, to, tokenId);
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, "");
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) public virtual override {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner nor approved");
        _safeTransfer(from, to, tokenId, data);
    }

    /**
     * @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.
     *
     * `data` is additional data, it has no specified format and it is sent in call to `to`.
     *
     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
     * implement alternative mechanisms to perform token transfer, such as signature-based.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeTransfer(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, data), "ERC721: transfer to non ERC721Receiver implementer");
    }

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     * and stop existing when they are burned (`_burn`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _owners[tokenId] != address(0);
    }

    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
    }

    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, "");
    }

    /**
     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
     */
    function _safeMint(
        address to,
        uint256 tokenId,
        bytes memory data
    ) internal virtual {
        _mint(to, tokenId);
        require(
            _checkOnERC721Received(address(0), to, tokenId, data),
            "ERC721: transfer to non ERC721Receiver implementer"
        );
    }

    /**
     * @dev Mints `tokenId` and transfers it to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - `to` cannot be the zero address.
     *
     * Emits a {Transfer} event.
     */
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "ERC721: mint to the zero address");
        require(!_exists(tokenId), "ERC721: token already minted");

        _beforeTokenTransfer(address(0), to, tokenId);

        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(address(0), to, tokenId);

        _afterTokenTransfer(address(0), to, tokenId);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);

        _beforeTokenTransfer(owner, address(0), tokenId);

        // Clear approvals
        _approve(address(0), tokenId);

        _balances[owner] -= 1;
        delete _owners[tokenId];

        emit Transfer(owner, address(0), tokenId);

        _afterTokenTransfer(owner, address(0), tokenId);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
        require(to != address(0), "ERC721: transfer to the zero address");

        _beforeTokenTransfer(from, to, tokenId);

        // Clear approvals from the previous owner
        _approve(address(0), tokenId);

        _balances[from] -= 1;
        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(from, to, tokenId);

        _afterTokenTransfer(from, to, tokenId);
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits an {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
    }

    /**
     * @dev Approve `operator` to operate on all of `owner` tokens
     *
     * Emits an {ApprovalForAll} event.
     */
    function _setApprovalForAll(
        address owner,
        address operator,
        bool approved
    ) internal virtual {
        require(owner != operator, "ERC721: approve to caller");
        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

    /**
     * @dev Reverts if the `tokenId` has not been minted yet.
     */
    function _requireMinted(uint256 tokenId) internal view virtual {
        require(_exists(tokenId), "ERC721: invalid token ID");
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) private returns (bool) {
        if (to.isContract()) {
            try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, data) returns (bytes4 retval) {
                return retval == IERC721Receiver.onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert("ERC721: transfer to non ERC721Receiver implementer");
                } else {
                    /// @solidity memory-safe-assembly
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, ``from``'s `tokenId` 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 tokenId
    ) 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.
     * - `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 tokenId
    ) internal virtual {}
}

// File: @gearbox-protocol/core-v2/contracts/core/AddressProvider.sol



// SPDX-License-Identifier: BUSL-1.1
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;

import { IAddressProvider } from "../interfaces/IAddressProvider.sol";
import { Claimable } from "./access/Claimable.sol";
import { Errors } from "../libraries/Errors.sol";

// Repositories & services
bytes32 constant CONTRACTS_REGISTER = "CONTRACTS_REGISTER";
bytes32 constant ACL = "ACL";
bytes32 constant PRICE_ORACLE = "PRICE_ORACLE";
bytes32 constant ACCOUNT_FACTORY = "ACCOUNT_FACTORY";
bytes32 constant DATA_COMPRESSOR = "DATA_COMPRESSOR";
bytes32 constant TREASURY_CONTRACT = "TREASURY_CONTRACT";
bytes32 constant GEAR_TOKEN = "GEAR_TOKEN";
bytes32 constant WETH_TOKEN = "WETH_TOKEN";
bytes32 constant WETH_GATEWAY = "WETH_GATEWAY";
bytes32 constant LEVERAGED_ACTIONS = "LEVERAGED_ACTIONS";

/// @title AddressRepository
/// @notice Stores addresses of deployed contracts
contract AddressProvider is Claimable, IAddressProvider {
    // Mapping from contract keys to respective addresses
    mapping(bytes32 => address) public addresses;

    // Contract version
    uint256 public constant version = 2;

    constructor() {
        // @dev Emits first event for contract discovery
        emit AddressSet("ADDRESS_PROVIDER", address(this));
    }

    /// @return Address of ACL contract
    function getACL() external view returns (address) {
        return _getAddress(ACL); // F:[AP-3]
    }

    /// @dev Sets address of ACL contract
    /// @param _address Address of ACL contract
    function setACL(address _address)
        external
        onlyOwner // F:[AP-12]
    {
        _setAddress(ACL, _address); // F:[AP-3]
    }

    /// @return Address of ContractsRegister
    function getContractsRegister() external view returns (address) {
        return _getAddress(CONTRACTS_REGISTER); // F:[AP-4]
    }

    /// @dev Sets address of ContractsRegister
    /// @param _address Address of ContractsRegister
    function setContractsRegister(address _address)
        external
        onlyOwner // F:[AP-12]
    {
        _setAddress(CONTRACTS_REGISTER, _address); // F:[AP-4]
    }

    /// @return Address of PriceOracle
    function getPriceOracle() external view override returns (address) {
        return _getAddress(PRICE_ORACLE); // F:[AP-5]
    }

    /// @dev Sets address of PriceOracle
    /// @param _address Address of PriceOracle
    function setPriceOracle(address _address)
        external
        onlyOwner // F:[AP-12]
    {
        _setAddress(PRICE_ORACLE, _address); // F:[AP-5]
    }

    /// @return Address of AccountFactory
    function getAccountFactory() external view returns (address) {
        return _getAddress(ACCOUNT_FACTORY); // F:[AP-6]
    }

    /// @dev Sets address of AccountFactory
    /// @param _address Address of AccountFactory
    function setAccountFactory(address _address)
        external
        onlyOwner // F:[AP-12]
    {
        _setAddress(ACCOUNT_FACTORY, _address); // F:[AP-6]
    }

    /// @return Address of DataCompressor
    function getDataCompressor() external view override returns (address) {
        return _getAddress(DATA_COMPRESSOR); // F:[AP-7]
    }

    /// @dev Sets address of AccountFactory
    /// @param _address Address of AccountFactory
    function setDataCompressor(address _address)
        external
        onlyOwner // F:[AP-12]
    {
        _setAddress(DATA_COMPRESSOR, _address); // F:[AP-7]
    }

    /// @return Address of Treasury contract
    function getTreasuryContract() external view returns (address) {
        return _getAddress(TREASURY_CONTRACT); // F:[AP-8]
    }

    /// @dev Sets address of Treasury Contract
    /// @param _address Address of Treasury Contract
    function setTreasuryContract(address _address)
        external
        onlyOwner // F:[AP-12]
    {
        _setAddress(TREASURY_CONTRACT, _address); // F:[AP-8]
    }

    /// @return Address of GEAR token
    function getGearToken() external view override returns (address) {
        return _getAddress(GEAR_TOKEN); // F:[AP-9]
    }

    /// @dev Sets address of GEAR token
    /// @param _address Address of GEAR token
    function setGearToken(address _address)
        external
        onlyOwner // F:[AP-12]
    {
        _setAddress(GEAR_TOKEN, _address); // F:[AP-9]
    }

    /// @return Address of WETH token
    function getWethToken() external view override returns (address) {
        return _getAddress(WETH_TOKEN); // F:[AP-10]
    }

    /// @dev Sets address of WETH token
    /// @param _address Address of WETH token
    function setWethToken(address _address)
        external
        onlyOwner // F:[AP-12]
    {
        _setAddress(WETH_TOKEN, _address); // F:[AP-10]
    }

    /// @return Address of WETH token
    function getWETHGateway() external view override returns (address) {
        return _getAddress(WETH_GATEWAY); // F:[AP-11]
    }

    /// @dev Sets address of WETH token
    /// @param _address Address of WETH token
    function setWETHGateway(address _address)
        external
        onlyOwner // F:[AP-12]
    {
        _setAddress(WETH_GATEWAY, _address); // F:[AP-11]
    }

    /// @return Address of PathFinder
    function getLeveragedActions() external view returns (address) {
        return _getAddress(LEVERAGED_ACTIONS); // T:[AP-7]
    }

    /// @dev Sets address of  PathFinder
    /// @param _address Address of  PathFinder
    function setLeveragedActions(address _address)
        external
        onlyOwner // T:[AP-15]
    {
        _setAddress(LEVERAGED_ACTIONS, _address); // T:[AP-7]
    }

    /// @return Address of key, reverts if the key doesn't exist
    function _getAddress(bytes32 key) internal view returns (address) {
        address result = addresses[key];
        require(result != address(0), Errors.AS_ADDRESS_NOT_FOUND); // F:[AP-1]
        return result; // F:[AP-3, 4, 5, 6, 7, 8, 9, 10, 11]
    }

    /// @dev Sets address to map by its key
    /// @param key Key in string format
    /// @param value Address
    function _setAddress(bytes32 key, address value) internal {
        addresses[key] = value; // F:[AP-3, 4, 5, 6, 7, 8, 9, 10, 11]
        emit AddressSet(key, value); // F:[AP-2]
    }
}

// File: @gearbox-protocol/core-v2/contracts/interfaces/ICreditManagerV2.sol



// SPDX-License-Identifier: MIT
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;

import { IPriceOracleV2 } from "./IPriceOracle.sol";
import { IVersion } from "./IVersion.sol";

enum ClosureAction {
    CLOSE_ACCOUNT,
    LIQUIDATE_ACCOUNT,
    LIQUIDATE_EXPIRED_ACCOUNT,
    LIQUIDATE_PAUSED
}

interface ICreditManagerV2Events {
    /// @dev Emits when a call to an external contract is made through the Credit Manager
    event ExecuteOrder(address indexed borrower, address indexed target);

    /// @dev Emits when a configurator is upgraded
    event NewConfigurator(address indexed newConfigurator);
}

interface ICreditManagerV2Exceptions {
    /// @dev Thrown if an access-restricted function is called by an address that is not
    ///      the connected Credit Facade, or an allowed adapter
    error AdaptersOrCreditFacadeOnlyException();

    /// @dev Thrown if an access-restricted function is called by an address that is not
    ///      the connected Credit Facade
    error CreditFacadeOnlyException();

    /// @dev Thrown if an access-restricted function is called by an address that is not
    ///      the connected Credit Configurator
    error CreditConfiguratorOnlyException();

    /// @dev Thrown on attempting to open a Credit Account for or transfer a Credit Account
    ///      to the zero address or an address that already owns a Credit Account
    error ZeroAddressOrUserAlreadyHasAccountException();

    /// @dev Thrown on attempting to execute an order to an address that is not an allowed
    ///      target contract
    error TargetContractNotAllowedException();

    /// @dev Thrown on failing a full collateral check after an operation
    error NotEnoughCollateralException();

    /// @dev Thrown on attempting to receive a token that is not a collateral token
    ///      or was forbidden
    error TokenNotAllowedException();

    /// @dev Thrown if an attempt to approve a collateral token to a target contract failed
    error AllowanceFailedException();

    /// @dev Thrown on attempting to perform an action for an address that owns no Credit Account
    error HasNoOpenedAccountException();

    /// @dev Thrown on attempting to add a token that is already in a collateral list
    error TokenAlreadyAddedException();

    /// @dev Thrown on configurator attempting to add more than 256 collateral tokens
    error TooManyTokensException();

    /// @dev Thrown if more than the maximal number of tokens were enabled on a Credit Account,
    ///      and there are not enough unused token to disable
    error TooManyEnabledTokensException();

    /// @dev Thrown when a reentrancy into the contract is attempted
    error ReentrancyLockException();
}

/// @notice All Credit Manager functions are access-restricted and can only be called
///         by the Credit Facade or allowed adapters. Users are not allowed to
///         interact with the Credit Manager directly
interface ICreditManagerV2 is
    ICreditManagerV2Events,
    ICreditManagerV2Exceptions,
    IVersion
{
    //
    // CREDIT ACCOUNT MANAGEMENT
    //

    ///  @dev Opens credit account and borrows funds from the pool.
    /// - Takes Credit Account from the factory;
    /// - Requests the pool to lend underlying to the Credit Account
    ///
    /// @param borrowedAmount Amount to be borrowed by the Credit Account
    /// @param onBehalfOf The owner of the newly opened Credit Account
    function openCreditAccount(uint256 borrowedAmount, address onBehalfOf)
        external
        returns (address);

    ///  @dev Closes a Credit Account - covers both normal closure and liquidation
    /// - Checks whether the contract is paused, and, if so, if the payer is an emergency liquidator.
    ///   Only emergency liquidators are able to liquidate account while the CM is paused.
    ///   Emergency liquidations do not pay a liquidator premium or liquidation fees.
    /// - Calculates payments to various recipients on closure:
    ///    + Computes amountToPool, which is the amount to be sent back to the pool.
    ///      This includes the principal, interest and fees, but can't be more than
    ///      total position value
    ///    + Computes remainingFunds during liquidations - these are leftover funds
    ///      after paying the pool and the liquidator, and are sent to the borrower
    ///    + Computes protocol profit, which includes interest and liquidation fees
    ///    + Computes loss if the totalValue is less than borrow amount + interest
    /// - Checks the underlying token balance:
    ///    + if it is larger than amountToPool, then the pool is paid fully from funds on the Credit Account
    ///    + else tries to transfer the shortfall from the payer - either the borrower during closure, or liquidator during liquidation
    /// - Send assets to the "to" address, as long as they are not included into skipTokenMask
    /// - If convertWETH is true, the function converts WETH into ETH before sending
    /// - Returns the Credit Account back to factory
    ///
    /// @param borrower Borrower address
    /// @param closureActionType Whether the account is closed, liquidated or liquidated due to expiry
    /// @param totalValue Portfolio value for liqution, 0 for ordinary closure
    /// @param payer Address which would be charged if credit account has not enough funds to cover amountToPool
    /// @param to Address to which the leftover funds will be sent
    /// @param skipTokenMask Tokenmask contains 1 for tokens which needed to be skipped for sending
    /// @param convertWETH If true converts WETH to ETH
    function closeCreditAccount(
        address borrower,
        ClosureAction closureActionType,
        uint256 totalValue,
        address payer,
        address to,
        uint256 skipTokenMask,
        bool convertWETH
    ) external returns (uint256 remainingFunds);

    /// @dev Manages debt size for borrower:
    ///
    /// - Increase debt:
    ///   + Increases debt by transferring funds from the pool to the credit account
    ///   + Updates the cumulative index to keep interest the same. Since interest
    ///     is always computed dynamically as borrowedAmount * (cumulativeIndexNew / cumulativeIndexOpen - 1),
    ///     cumulativeIndexOpen needs to be updated, as the borrow amount has changed
    ///
    /// - Decrease debt:
    ///   + Repays debt partially + all interest and fees accrued thus far
    ///   + Updates cunulativeIndex to cumulativeIndex now
    ///
    /// @param creditAccount Address of the Credit Account to change debt for
    /// @param amount Amount to increase / decrease the principal by
    /// @param increase True to increase principal, false to decrease
    /// @return newBorrowedAmount The new debt principal
    function manageDebt(
        address creditAccount,
        uint256 amount,
        bool increase
    ) external returns (uint256 newBorrowedAmount);

    /// @dev Adds collateral to borrower's credit account
    /// @param payer Address of the account which will be charged to provide additional collateral
    /// @param creditAccount Address of the Credit Account
    /// @param token Collateral token to add
    /// @param amount Amount to add
    function addCollateral(
        address payer,
        address creditAccount,
        address token,
        uint256 amount
    ) external;

    /// @dev Transfers Credit Account ownership to another address
    /// @param from Address of previous owner
    /// @param to Address of new owner
    function transferAccountOwnership(address from, address to) external;

    /// @dev Requests the Credit Account to approve a collateral token to another contract.
    /// @param borrower Borrower's address
    /// @param targetContract Spender to change allowance for
    /// @param token Collateral token to approve
    /// @param amount New allowance amount
    function approveCreditAccount(
        address borrower,
        address targetContract,
        address token,
        uint256 amount
    ) external;

    /// @dev Requests a Credit Account to make a low-level call with provided data
    /// This is the intended pathway for state-changing interactions with 3rd-party protocols
    /// @param borrower Borrower's address
    /// @param targetContract Contract to be called
    /// @param data Data to pass with the call
    function executeOrder(
        address borrower,
        address targetContract,
        bytes memory data
    ) external returns (bytes memory);

    //
    // COLLATERAL VALIDITY AND ACCOUNT HEALTH CHECKS
    //

    /// @dev Enables a token on a Credit Account, including it
    /// into account health and total value calculations
    /// @param creditAccount Address of a Credit Account to enable the token for
    /// @param token Address of the token to be enabled
    function checkAndEnableToken(address creditAccount, address token) external;

    /// @dev Optimized health check for individual swap-like operations.
    /// @notice Fast health check assumes that only two tokens (input and output)
    ///         participate in the operation and computes a % change in weighted value between
    ///         inbound and outbound collateral. The cumulative negative change across several
    ///         swaps in sequence cannot be larger than feeLiquidation (a fee that the
    ///         protocol is ready to waive if needed). Since this records a % change
    ///         between just two tokens, the corresponding % change in TWV will always be smaller,
    ///         which makes this check safe.
    ///         More details at https://dev.gearbox.fi/docs/documentation/risk/fast-collateral-check#fast-check-protection
    /// @param creditAccount Address of the Credit Account
    /// @param tokenIn Address of the token spent by the swap
    /// @param tokenOut Address of the token received from the swap
    /// @param balanceInBefore Balance of tokenIn before the operation
    /// @param balanceOutBefore Balance of tokenOut before the operation
    function fastCollateralCheck(
        address creditAccount,
        address tokenIn,
        address tokenOut,
        uint256 balanceInBefore,
        uint256 balanceOutBefore
    ) external;

    /// @dev Performs a full health check on an account, summing up
    /// value of all enabled collateral tokens
    /// @param creditAccount Address of the Credit Account to check
    function fullCollateralCheck(address creditAccount) external;

    /// @dev Checks that the number of enabled tokens on a Credit Account
    ///      does not violate the maximal enabled token limit and tries
    ///      to disable unused tokens if it does
    /// @param creditAccount Account to check enabled tokens for
    function checkAndOptimizeEnabledTokens(address creditAccount) external;

    /// @dev Disables a token on a credit account
    /// @notice Usually called by adapters to disable spent tokens during a multicall,
    ///         but can also be called separately from the Credit Facade to remove
    ///         unwanted tokens
    /// @return True if token mask was change otherwise False
    function disableToken(address creditAccount, address token)
        external
        returns (bool);

    //
    // GETTERS
    //

    /// @dev Returns the address of a borrower's Credit Account, or reverts if there is none.
    /// @param borrower Borrower's address
    function getCreditAccountOrRevert(address borrower)
        external
        view
        returns (address);

    /// @dev Computes amounts that must be sent to various addresses before closing an account
    /// @param totalValue Credit Accounts total value in underlying
    /// @param closureActionType Type of account closure
    ///        * CLOSE_ACCOUNT: The account is healthy and is closed normally
    ///        * LIQUIDATE_ACCOUNT: The account is unhealthy and is being liquidated to avoid bad debt
    ///        * LIQUIDATE_EXPIRED_ACCOUNT: The account has expired and is being liquidated (lowered liquidation premium)
    ///        * LIQUIDATE_PAUSED: The account is liquidated while the system is paused due to emergency (no liquidation premium)
    /// @param borrowedAmount Credit Account's debt principal
    /// @param borrowedAmountWithInterest Credit Account's debt principal + interest
    /// @return amountToPool Amount of underlying to be sent to the pool
    /// @return remainingFunds Amount of underlying to be sent to the borrower (only applicable to liquidations)
    /// @return profit Protocol's profit from fees (if any)
    /// @return loss Protocol's loss from bad debt (if any)
    function calcClosePayments(
        uint256 totalValue,
        ClosureAction closureActionType,
        uint256 borrowedAmount,
        uint256 borrowedAmountWithInterest
    )
        external
        view
        returns (
            uint256 amountToPool,
            uint256 remainingFunds,
            uint256 profit,
            uint256 loss
        );

    /// @dev Calculates the debt accrued by a Credit Account
    /// @param creditAccount Address of the Credit Account
    /// @return borrowedAmount The debt principal
    /// @return borrowedAmountWithInterest The debt principal + accrued interest
    /// @return borrowedAmountWithInterestAndFees The debt principal + accrued interest and protocol fees
    function calcCreditAccountAccruedInterest(address creditAccount)
        external
        view
        returns (
            uint256 borrowedAmount,
            uint256 borrowedAmountWithInterest,
            uint256 borrowedAmountWithInterestAndFees
        );

    /// @dev Maps Credit Accounts to bit masks encoding their enabled token sets
    /// Only enabled tokens are counted as collateral for the Credit Account
    /// @notice An enabled token mask encodes an enabled token by setting
    ///         the bit at the position equal to token's index to 1
    function enabledTokensMap(address creditAccount)
        external
        view
        returns (uint256);

    /// @dev Maps the Credit Account to its current percentage drop across all swaps since
    ///      the last full check, in RAY format
    function cumulativeDropAtFastCheckRAY(address creditAccount)
        external
        view
        returns (uint256);

    /// @dev Returns the collateral token at requested index and its liquidation threshold
    /// @param id The index of token to return
    function collateralTokens(uint256 id)
        external
        view
        returns (address token, uint16 liquidationThreshold);

    /// @dev Returns the collateral token with requested mask and its liquidationThreshold
    /// @param tokenMask Token mask corresponding to the token
    function collateralTokensByMask(uint256 tokenMask)
        external
        view
        returns (address token, uint16 liquidationThreshold);

    /// @dev Total number of known collateral tokens.
    function collateralTokensCount() external view returns (uint256);

    /// @dev Returns the mask for the provided token
    /// @param token Token to returns the mask for
    function tokenMasksMap(address token) external view returns (uint256);

    /// @dev Bit mask encoding a set of forbidden tokens
    function forbiddenTokenMask() external view returns (uint256);

    /// @dev Maps allowed adapters to their respective target contracts.
    function adapterToContract(address adapter) external view returns (address);

    /// @dev Maps 3rd party contracts to their respective adapters
    function contractToAdapter(address targetContract)
        external
        view
        returns (address);

    /// @dev Address of the underlying asset
    function underlying() external view returns (address);

    /// @dev Address of the connected pool
    function pool() external view returns (address);

    /// @dev Address of the connected pool
    /// @notice [DEPRECATED]: use pool() instead.
    function poolService() external view returns (address);

    /// @dev A map from borrower addresses to Credit Account addresses
    function creditAccounts(address borrower) external view returns (address);

    /// @dev Address of the connected Credit Configurator
    function creditConfigurator() external view returns (address);

    /// @dev Address of WETH
    function wethAddress() external view returns (address);

    /// @dev Returns the liquidation threshold for the provided token
    /// @param token Token to retrieve the LT for
    function liquidationThresholds(address token)
        external
        view
        returns (uint16);

    /// @dev The maximal number of enabled tokens on a single Credit Account
    function maxAllowedEnabledTokenLength() external view returns (uint8);

    /// @dev Maps addresses to their status as emergency liquidator.
    /// @notice Emergency liquidators are trusted addresses
    /// that are able to liquidate positions while the contracts are paused,
    /// e.g. when there is a risk of bad debt while an exploit is being patched.
    /// In the interest of fairness, emergency liquidators do not receive a premium
    /// And are compensated by the Gearbox DAO separately.
    function canLiquidateWhilePaused(address) external view returns (bool);

    /// @dev Returns the fee parameters of the Credit Manager
    /// @return feeInterest Percentage of interest taken by the protocol as profit
    /// @return feeLiquidation Percentage of account value taken by the protocol as profit
    ///         during unhealthy account liquidations
    /// @return liquidationDiscount Multiplier that reduces the effective totalValue during unhealthy account liquidations,
    ///         allowing the liquidator to take the unaccounted for remainder as premium. Equal to (1 - liquidationPremium)
    /// @return feeLiquidationExpired Percentage of account value taken by the protocol as profit
    ///         during expired account liquidations
    /// @return liquidationDiscountExpired Multiplier that reduces the effective totalValue during expired account liquidations,
    ///         allowing the liquidator to take the unaccounted for remainder as premium. Equal to (1 - liquidationPremiumExpired)
    function fees()
        external
        view
        returns (
            uint16 feeInterest,
            uint16 feeLiquidation,
            uint16 liquidationDiscount,
            uint16 feeLiquidationExpired,
            uint16 liquidationDiscountExpired
        );

    /// @dev Address of the connected Credit Facade
    function creditFacade() external view returns (address);

    /// @dev Address of the connected Price Oracle
    function priceOracle() external view returns (IPriceOracleV2);

    /// @dev Address of the universal adapter
    function universalAdapter() external view returns (address);

    /// @dev Contract's version
    function version() external view returns (uint256);

    /// @dev Paused() state
    function checkEmergencyPausable(address caller, bool state)
        external
        returns (bool);
}

// File: @gearbox-protocol/core-v2/contracts/core/ContractsRegister.sol



// SPDX-License-Identifier: BUSL-1.1
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;

import { IContractsRegister } from "../interfaces/IContractsRegister.sol";
import { Errors } from "../libraries/Errors.sol";
import { ACLTrait } from "./ACLTrait.sol";

/// @title Pool & Credit Manager registry
/// @notice Stores addresses of Pools and Credit Managers
contract ContractsRegister is IContractsRegister, ACLTrait {
    /// @dev List of all registered pools
    address[] public override pools;

    /// @dev Mapping storing whether an address is a pool
    mapping(address => bool) public override isPool;

    /// @dev List of all registered Credit Managers
    address[] public override creditManagers;

    /// @dev Mapping storing whether an address is a Credit Manager
    mapping(address => bool) public override isCreditManager;

    /// @dev Contract version
    uint256 public constant version = 1;

    constructor(address addressProvider) ACLTrait(addressProvider) {}

    /// @dev Adds a pool to the list
    /// @param newPoolAddress Address of the new pool
    function addPool(address newPoolAddress)
        external
        configuratorOnly // T:[CR-1]
    {
        require(
            newPoolAddress != address(0),
            Errors.ZERO_ADDRESS_IS_NOT_ALLOWED
        );
        require(!isPool[newPoolAddress], Errors.CR_POOL_ALREADY_ADDED); // T:[CR-2]
        pools.push(newPoolAddress); // T:[CR-3]
        isPool[newPoolAddress] = true; // T:[CR-3]

        emit NewPoolAdded(newPoolAddress); // T:[CR-4]
    }

    /// @dev Returns the array of registered pool addresses
    function getPools() external view override returns (address[] memory) {
        return pools;
    }

    /// @return Returns the number of registered pools
    function getPoolsCount() external view override returns (uint256) {
        return pools.length; // T:[CR-3]
    }

    /// @dev Adds credit accounts manager address to the registry
    /// @param newCreditManager Address of the new Credit Manager
    function addCreditManager(address newCreditManager)
        external
        configuratorOnly // T:[CR-1]
    {
        require(
            newCreditManager != address(0),
            Errors.ZERO_ADDRESS_IS_NOT_ALLOWED
        );

        require(
            !isCreditManager[newCreditManager],
            Errors.CR_CREDIT_MANAGER_ALREADY_ADDED
        ); // T:[CR-5]
        creditManagers.push(newCreditManager); // T:[CR-6]
        isCreditManager[newCreditManager] = true; // T:[CR-6]

        emit NewCreditManagerAdded(newCreditManager); // T:[CR-7]
    }

    /// @dev Returns the array of registered credit manager addresses
    function getCreditManagers()
        external
        view
        override
        returns (address[] memory)
    {
        return creditManagers;
    }

    /// @return Returns the number of registered credit managers
    function getCreditManagersCount() external view override returns (uint256) {
        return creditManagers.length; // T:[CR-6]
    }
}

// File: @gearbox-protocol/core-v2/contracts/core/ACLTrait.sol



// SPDX-License-Identifier: BUSL-1.1
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;

import { Pausable } from "@openzeppelin/contracts/security/Pausable.sol";
import { AddressProvider } from "./AddressProvider.sol";
import { IACL } from "../interfaces/IACL.sol";
import { ZeroAddressException, CallerNotConfiguratorException, CallerNotPausableAdminException, CallerNotUnPausableAdminException } from "../interfaces/IErrors.sol";

/// @title ACL Trait
/// @notice Utility class for ACL consumers
abstract contract ACLTrait is Pausable {
    // ACL contract to check rights
    IACL public immutable _acl;

    /// @dev constructor
    /// @param addressProvider Address of address repository
    constructor(address addressProvider) {
        if (addressProvider == address(0)) revert ZeroAddressException(); // F:[AA-2]

        _acl = IACL(AddressProvider(addressProvider).getACL());
    }

    /// @dev  Reverts if msg.sender is not configurator
    modifier configuratorOnly() {
        if (!_acl.isConfigurator(msg.sender))
            revert CallerNotConfiguratorException();
        _;
    }

    ///@dev Pause contract
    function pause() external {
        if (!_acl.isPausableAdmin(msg.sender))
            revert CallerNotPausableAdminException();
        _pause();
    }

    /// @dev Unpause contract
    function unpause() external {
        if (!_acl.isUnpausableAdmin(msg.sender))
            revert CallerNotUnPausableAdminException();

        _unpause();
    }
}

// File: @gearbox-protocol/core-v2/contracts/interfaces/IErrors.sol



// SPDX-License-Identifier: MIT
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;

/// @dev Common contract exceptions

/// @dev Thrown on attempting to set an important address to zero address
error ZeroAddressException();

/// @dev Thrown on attempting to call a non-implemented function
error NotImplementedException();

/// @dev Thrown on attempting to set an EOA as an important contract in the system
error AddressIsNotContractException(address);

/// @dev Thrown on attempting to use a non-ERC20 contract or an EOA as a token
error IncorrectTokenContractException();

/// @dev Thrown on attempting to set a token price feed to an address that is not a
///      correct price feed
error IncorrectPriceFeedException();

/// @dev Thrown on attempting to call an access restricted function as a non-Configurator
error CallerNotConfiguratorException();

/// @dev Thrown on attempting to pause a contract as a non-Pausable admin
error CallerNotPausableAdminException();

/// @dev Thrown on attempting to pause a contract as a non-Unpausable admin
error CallerNotUnPausableAdminException();

error TokenIsNotAddedToCreditManagerException(address token);

// File: @gearbox-protocol/core-v2/contracts/interfaces/ICreditFacade.sol



// SPDX-License-Identifier: MIT
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;

import { Balance } from "../libraries/Balances.sol";
import { MultiCall } from "../libraries/MultiCall.sol";
import { ICreditManagerV2, ICreditManagerV2Exceptions } from "./ICreditManagerV2.sol";
import { IVersion } from "./IVersion.sol";

interface ICreditFacadeExtended {
    /// @dev Stores expected balances (computed as current balance + passed delta)
    ///      and compare with actual balances at the end of a multicall, reverts
    ///      if at least one is less than expected
    /// @param expected Array of expected balance changes
    /// @notice This is an extenstion function that does not exist in the Credit Facade
    ///         itself and can only be used within a multicall
    function revertIfReceivedLessThan(Balance[] memory expected) external;

    /// @dev Enables token in enabledTokenMask for the Credit Account of msg.sender
    /// @param token Address of token to enable
    function enableToken(address token) external;

    /// @dev Disables a token on the caller's Credit Account
    /// @param token Token to disable
    /// @notice This is an extenstion function that does not exist in the Credit Facade
    ///         itself and can only be used within a multicall
    function disableToken(address token) external;

    /// @dev Adds collateral to borrower's credit account
    /// @param onBehalfOf Address of the borrower whose account is funded
    /// @param token Address of a collateral token
    /// @param amount Amount to add
    function addCollateral(
        address onBehalfOf,
        address token,
        uint256 amount
    ) external payable;

    /// @dev Increases debt for msg.sender's Credit Account
    /// - Borrows the requested amount from the pool
    /// - Updates the CA's borrowAmount / cumulativeIndexOpen
    ///   to correctly compute interest going forward
    /// - Performs a full collateral check
    ///
    /// @param amount Amount to borrow
    function increaseDebt(uint256 amount) external;

    /// @dev Decrease debt
    /// - Decreases the debt by paying the requested amount + accrued interest + fees back to the pool
    /// - It's also include to this payment interest accrued at the moment and fees
    /// - Updates cunulativeIndex to cumulativeIndex now
    ///
    /// @param amount Amount to increase borrowed amount
    function decreaseDebt(uint256 amount) external;
}

interface ICreditFacadeEvents {
    /// @dev Emits when a new Credit Account is opened through the
    ///      Credit Facade
    event OpenCreditAccount(
        address indexed onBehalfOf,
        address indexed creditAccount,
        uint256 borrowAmount,
        uint16 referralCode
    );

    /// @dev Emits when the account owner closes their CA normally
    event CloseCreditAccount(address indexed borrower, address indexed to);

    /// @dev Emits when a Credit Account is liquidated due to low health factor
    event LiquidateCreditAccount(
        address indexed borrower,
        address indexed liquidator,
        address indexed to,
        uint256 remainingFunds
    );

    /// @dev Emits when a Credit Account is liquidated due to expiry
    event LiquidateExpiredCreditAccount(
        address indexed borrower,
        address indexed liquidator,
        address indexed to,
        uint256 remainingFunds
    );

    /// @dev Emits when the account owner increases CA's debt
    event IncreaseBorrowedAmount(address indexed borrower, uint256 amount);

    /// @dev Emits when the account owner reduces CA's debt
    event DecreaseBorrowedAmount(address indexed borrower, uint256 amount);

    /// @dev Emits when the account owner add new collateral to a CA
    event AddCollateral(
        address indexed onBehalfOf,
        address indexed token,
        uint256 value
    );

    /// @dev Emits when a multicall is started
    event MultiCallStarted(address indexed borrower);

    /// @dev Emits when a multicall is finished
    event MultiCallFinished();

    /// @dev Emits when Credit Account ownership is transferred
    event TransferAccount(address indexed oldOwner, address indexed newOwner);

    /// @dev Emits when the user changes approval for account transfers to itself from another address
    event TransferAccountAllowed(
        address indexed from,
        address indexed to,
        bool state
    );

    /// @dev Emits when the account owner enables a token on their CA
    event TokenEnabled(address indexed borrower, address indexed token);

    /// @dev Emits when the account owner disables a token on their CA
    event TokenDisabled(address indexed borrower, address indexed token);
}

interface ICreditFacadeExceptions is ICreditManagerV2Exceptions {
    /// @dev Thrown if the CreditFacade is not expirable, and an aciton is attempted that
    ///      requires expirability
    error NotAllowedWhenNotExpirableException();

    /// @dev Thrown if whitelisted mode is enabled, and an action is attempted that is
    ///      not allowed in whitelisted mode
    error NotAllowedInWhitelistedMode();

    /// @dev Thrown if a user attempts to transfer a CA to an address that didn't allow it
    error AccountTransferNotAllowedException();

    /// @dev Thrown if a liquidator tries to liquidate an account with a health factor above 1
    error CantLiquidateWithSuchHealthFactorException();

    /// @dev Thrown if a liquidator tries to liquidate an account by expiry while a Credit Facade is not expired
    error CantLiquidateNonExpiredException();

    /// @dev Thrown if call data passed to a multicall is too short
    error IncorrectCallDataException();

    /// @dev Thrown inside account closure multicall if the borrower attempts an action that is forbidden on closing
    ///      an account
    error ForbiddenDuringClosureException();

    /// @dev Thrown if debt increase and decrease are subsequently attempted in one multicall
    error IncreaseAndDecreaseForbiddenInOneCallException();

    /// @dev Thrown if a selector that doesn't match any allowed function is passed to the Credit Facade
    ///      during a multicall
    error UnknownMethodException();

    /// @dev Thrown if a user tries to open an account or increase debt with increaseDebtForbidden mode on
    error IncreaseDebtForbiddenException();

    /// @dev Thrown if the account owner tries to transfer an unhealthy account
    error CantTransferLiquidatableAccountException();

    /// @dev Thrown if too much new debt was taken within a single block
    error BorrowedBlockLimitException();

    /// @dev Thrown if the new debt principal for a CA falls outside of borrowing limits
    error BorrowAmountOutOfLimitsException();

    /// @dev Thrown if one of the balances on a Credit Account is less than expected
    ///      at the end of a multicall, if revertIfReceivedLessThan was called
    error BalanceLessThanMinimumDesiredException(address);

    /// @dev Thrown if a user attempts to open an account on a Credit Facade that has expired
    error OpenAccountNotAllowedAfterExpirationException();

    /// @dev Thrown if expected balances are attempted to be set through revertIfReceivedLessThan twice
    error ExpectedBalancesAlreadySetException();

    /// @dev Thrown if a Credit Account has enabled forbidden tokens and the owner attempts to perform an action
    ///      that is not allowed with any forbidden tokens enabled
    error ActionProhibitedWithForbiddenTokensException();
}

interface ICreditFacade is
    ICreditFacadeEvents,
    ICreditFacadeExceptions,
    IVersion
{
    //
    // CREDIT ACCOUNT MANAGEMENT
    //

    /// @dev Opens credit account, borrows funds from the pool and pulls collateral
    /// without any additional action.
    /// @param amount The amount of collateral provided by the borrower
    /// @param onBehalfOf The address to open an account for. Transfers to it have to be allowed if
    /// msg.sender != obBehalfOf
    /// @param leverageFactor Percentage of the user's own funds to borrow. 100 is equal to 100% - borrows the same amount
    /// as the user's own collateral, equivalent to 2x leverage.
    /// @param referralCode Referral code that is used for potential rewards. 0 if no referral code provided.
    function openCreditAccount(
        uint256 amount,
        address onBehalfOf,
        uint16 leverageFactor,
        uint16 referralCode
    ) external payable;

    /// @dev Opens a Credit Account and runs a batch of operations in a multicall
    /// @param borrowedAmount Debt size
    /// @param onBehalfOf The address to open an account for. Transfers to it have to be allowed if
    /// msg.sender != obBehalfOf
    /// @param calls The array of MultiCall structs encoding the required operations. Generally must have
    /// at least a call to addCollateral, as otherwise the health check at the end will fail.
    /// @param referralCode Referral code which is used for potential rewards. 0 if no referral code provided
    function openCreditAccountMulticall(
        uint256 borrowedAmount,
        address onBehalfOf,
        MultiCall[] calldata calls,
        uint16 referralCode
    ) external payable;

    /// @dev Runs a batch of transactions within a multicall and closes the account
    /// - Wraps ETH to WETH and sends it msg.sender if value > 0
    /// - Executes the multicall - the main purpose of a multicall when closing is to convert all assets to underlying
    /// in order to pay the debt.
    /// - Closes credit account:
    ///    + Checks the underlying balance: if it is greater than the amount paid to the pool, transfers the underlying
    ///      from the Credit Account and proceeds. If not, tries to transfer the shortfall from msg.sender.
    ///    + Transfers all enabled assets with non-zero balances to the "to" address, unless they are marked
    ///      to be skipped in skipTokenMask
    ///    + If convertWETH is true, converts WETH into ETH before sending to the recipient
    /// - Emits a CloseCreditAccount event
    ///
    /// @param to Address to send funds to during account closing
    /// @param skipTokenMask Uint-encoded bit mask where 1's mark tokens that shouldn't be transferred
    /// @param convertWETH If true, converts WETH into ETH before sending to "to"
    /// @param calls The array of MultiCall structs encoding the operations to execute before closing the account.
    function closeCreditAccount(
        address to,
        uint256 skipTokenMask,
        bool convertWETH,
        MultiCall[] calldata calls
    ) external payable;

    /// @dev Runs a batch of transactions within a multicall and liquidates the account
    /// - Computes the total value and checks that hf < 1. An account can't be liquidated when hf >= 1.
    ///   Total value has to be computed before the multicall, otherwise the liquidator would be able
    ///   to manipulate it.
    /// - Wraps ETH to WETH and sends it to msg.sender (liquidator) if value > 0
    /// - Executes the multicall - the main purpose of a multicall when liquidating is to convert all assets to underlying
    ///   in order to pay the debt.
    /// - Liquidate credit account:
    ///    + Computes the amount that needs to be paid to the pool. If totalValue * liquidationDiscount < borrow + interest + fees,
    ///      only totalValue * liquidationDiscount has to be paid. Since liquidationDiscount < 1, the liquidator can take
    ///      totalValue * (1 - liquidationDiscount) as premium. Also computes the remaining funds to be sent to borrower
    ///      as totalValue * liquidationDiscount - amountToPool.
    ///    + Checks the underlying balance: if it is greater than amountToPool + remainingFunds, transfers the underlying
    ///      from the Credit Account and proceeds. If not, tries to transfer the shortfall from the liquidator.
    ///    + Transfers all enabled assets with non-zero balances to the "to" address, unless they are marked
    ///      to be skipped in skipTokenMask. If the liquidator is confident that all assets were converted
    ///      during the multicall, they can set the mask to uint256.max - 1, to only transfer the underlying
    ///    + If convertWETH is true, converts WETH into ETH before sending
    /// - Emits LiquidateCreditAccount event
    ///
    /// @param to Address to send funds to after liquidation
    /// @param skipTokenMask Uint-encoded bit mask where 1's mark tokens that shouldn't be transferred
    /// @param convertWETH If true, converts WETH into ETH before sending to "to"
    /// @param calls The array of MultiCall structs encoding the operations to execute before liquidating the account.
    function liquidateCreditAccount(
        address borrower,
        address to,
        uint256 skipTokenMask,
        bool convertWETH,
        MultiCall[] calldata calls
    ) external payable;

    /// @dev Runs a batch of transactions within a multicall and liquidates the account when
    /// this Credit Facade is expired
    /// The general flow of liquidation is nearly the same as normal liquidations, with two main differences:
    ///     - An account can be liquidated on an expired Credit Facade even with hf > 1. However,
    ///       no accounts can be liquidated through this function if the Credit Facade is not expired.
    ///     - Liquidation premiums and fees for liquidating expired accounts are reduced.
    /// It is still possible to normally liquidate an underwater Credit Account, even when the Credit Facade
    /// is expired.
    /// @param to Address to send funds to after liquidation
    /// @param skipTokenMask Uint-encoded bit mask where 1's mark tokens that shouldn't be transferred
    /// @param convertWETH If true, converts WETH into ETH before sending to "to"
    /// @param calls The array of MultiCall structs encoding the operations to execute before liquidating the account.
    /// @notice See more at https://dev.gearbox.fi/docs/documentation/credit/liquidation#liquidating-accounts-by-expiration
    function liquidateExpiredCreditAccount(
        address borrower,
        address to,
        uint256 skipTokenMask,
        bool convertWETH,
        MultiCall[] calldata calls
    ) external payable;

    /// @dev Increases debt for msg.sender's Credit Account
    /// - Borrows the requested amount from the pool
    /// - Updates the CA's borrowAmount / cumulativeIndexOpen
    ///   to correctly compute interest going forward
    /// - Performs a full collateral check
    ///
    /// @param amount Amount to borrow
    function increaseDebt(uint256 amount) external;

    /// @dev Decrease debt
    /// - Decreases the debt by paying the requested amount + accrued interest + fees back to the pool
    /// - It's also include to this payment interest accrued at the moment and fees
    /// - Updates cunulativeIndex to cumulativeIndex now
    ///
    /// @param amount Amount to increase borrowed amount
    function decreaseDebt(uint256 amount) external;

    /// @dev Adds collateral to borrower's credit account
    /// @param onBehalfOf Address of the borrower whose account is funded
    /// @param token Address of a collateral token
    /// @param amount Amount to add
    function addCollateral(
        address onBehalfOf,
        address token,
        uint256 amount
    ) external payable;

    /// @dev Executes a batch of transactions within a Multicall, to manage an existing account
    ///  - Wraps ETH and sends it back to msg.sender, if value > 0
    ///  - Executes the Multicall
    ///  - Performs a fullCollateralCheck to verify that hf > 1 after all actions
    /// @param calls The array of MultiCall structs encoding the operations to execute.
    function multicall(MultiCall[] calldata calls) external payable;

    /// @dev Returns true if the borrower has an open Credit Account
    /// @param borrower Borrower address
    function hasOpenedCreditAccount(address borrower)
        external
        view
        returns (bool);

    /// @dev Sets token allowance from msg.sender's Credit Account to a connected target contract
    /// @param targetContract Contract to set allowance to. Cannot be in the list of upgradeable contracts
    /// @param token Token address
    /// @param amount Allowance amount
    function approve(
        address targetContract,
        address token,
        uint256 amount
    ) external;

    /// @dev Approves account transfer from another user to msg.sender
    /// @param from Address for which account transfers are allowed/forbidden
    /// @param state True is transfer is allowed, false if forbidden
    function approveAccountTransfer(address from, bool state) external;

    /// @dev Enables token in enabledTokenMask for the Credit Account of msg.sender
    /// @param token Address of token to enable
    function enableToken(address token) external;

    /// @dev Transfers credit account to another user
    /// By default, this action is forbidden, and the user has to approve transfers from sender to itself
    /// by calling approveAccountTransfer.
    /// This is done to prevent malicious actors from transferring compromised accounts to other users.
    /// @param to Address to transfer the account to
    function transferAccountOwnership(address to) external;

    //
    // GETTERS
    //

    /// @dev Calculates total value for provided Credit Account in underlying
    ///
    /// @param creditAccount Credit Account address
    /// @return total Total value in underlying
    /// @return twv Total weighted (discounted by liquidation thresholds) value in underlying
    function calcTotalValue(address creditAccount)
        external
        view
        returns (uint256 total, uint256 twv);

    /**
     * @dev Calculates health factor for the credit account
     *
     *          sum(asset[i] * liquidation threshold[i])
     *   Hf = --------------------------------------------
     *         borrowed amount + interest accrued + fees
     *
     *
     * More info: https://dev.gearbox.fi/developers/credit/economy#health-factor
     *
     * @param creditAccount Credit account address
     * @return hf = Health factor in bp (see PERCENTAGE FACTOR in PercentageMath.sol)
     */
    function calcCreditAccountHealthFactor(address creditAccount)
        external
        view
        returns (uint256 hf);

    /// @dev Returns true if token is a collateral token and is not forbidden,
    /// otherwise returns false
    /// @param token Token to check
    function isTokenAllowed(address token) external view returns (bool);

    /// @dev Returns the CreditManager connected to this Credit Facade
    function creditManager() external view returns (ICreditManagerV2);

    /// @dev Returns true if 'from' is allowed to transfer Credit Accounts to 'to'
    /// @param from Sender address to check allowance for
    /// @param to Receiver address to check allowance for
    function transfersAllowed(address from, address to)
        external
        view
        returns (bool);

    /// @return maxBorrowedAmountPerBlock Maximal amount of new debt that can be taken per block
    /// @return isIncreaseDebtForbidden True if increasing debt is forbidden
    /// @return expirationDate Timestamp of the next expiration (for expirable Credit Facades only)
    function params()
        external
        view
        returns (
            uint128 maxBorrowedAmountPerBlock,
            bool isIncreaseDebtForbidden,
            uint40 expirationDate
        );

    /// @return minBorrowedAmount Minimal borrowed amount per credit account
    /// @return maxBorrowedAmount Maximal borrowed amount per credit account
    function limits()
        external
        view
        returns (uint128 minBorrowedAmount, uint128 maxBorrowedAmount);

    /// @dev Address of the DegenNFT that gatekeeps account openings in whitelisted mode
    function degenNFT() external view returns (address);

    /// @dev Address of the underlying asset
    function underlying() external view returns (address);
}

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



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

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @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);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (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 `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/utils/introspection/ERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// File: @gearbox-protocol/core-v2/contracts/interfaces/IAddressProvider.sol



// SPDX-License-Identifier: MIT
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;
import { IVersion } from "./IVersion.sol";

interface IAddressProviderEvents {
    /// @dev Emits when an address is set for a contract role
    event AddressSet(bytes32 indexed service, address indexed newAddress);
}

/// @title Optimised for front-end Address Provider interface
interface IAddressProvider is IAddressProviderEvents, IVersion {
    /// @return Address of ACL contract
    function getACL() external view returns (address);

    /// @return Address of ContractsRegister
    function getContractsRegister() external view returns (address);

    /// @return Address of AccountFactory
    function getAccountFactory() external view returns (address);

    /// @return Address of DataCompressor
    function getDataCompressor() external view returns (address);

    /// @return Address of GEAR token
    function getGearToken() external view returns (address);

    /// @return Address of WETH token
    function getWethToken() external view returns (address);

    /// @return Address of WETH Gateway
    function getWETHGateway() external view returns (address);

    /// @return Address of PriceOracle
    function getPriceOracle() external view returns (address);

    /// @return Address of DAO Treasury Multisig
    function getTreasuryContract() external view returns (address);

    /// @return Address of PathFinder
    function getLeveragedActions() external view returns (address);
}

// File: @gearbox-protocol/core-v2/contracts/libraries/Errors.sol



// SPDX-License-Identifier: GPL-2.0-or-later
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;

/// @title Errors library
library Errors {
    //
    // COMMON
    //
    string public constant ZERO_ADDRESS_IS_NOT_ALLOWED = "Z0";
    string public constant NOT_IMPLEMENTED = "NI";
    string public constant INCORRECT_PATH_LENGTH = "PL";
    string public constant INCORRECT_ARRAY_LENGTH = "CR";
    string public constant REGISTERED_CREDIT_ACCOUNT_MANAGERS_ONLY = "CP";
    string public constant REGISTERED_POOLS_ONLY = "RP";
    string public constant INCORRECT_PARAMETER = "IP";

    //
    // MATH
    //
    string public constant MATH_MULTIPLICATION_OVERFLOW = "M1";
    string public constant MATH_ADDITION_OVERFLOW = "M2";
    string public constant MATH_DIVISION_BY_ZERO = "M3";

    //
    // POOL
    //
    string public constant POOL_CONNECTED_CREDIT_MANAGERS_ONLY = "PS0";
    string public constant POOL_INCOMPATIBLE_CREDIT_ACCOUNT_MANAGER = "PS1";
    string public constant POOL_MORE_THAN_EXPECTED_LIQUIDITY_LIMIT = "PS2";
    string public constant POOL_INCORRECT_WITHDRAW_FEE = "PS3";
    string public constant POOL_CANT_ADD_CREDIT_MANAGER_TWICE = "PS4";

    //
    // ACCOUNT FACTORY
    //
    string public constant AF_CANT_CLOSE_CREDIT_ACCOUNT_IN_THE_SAME_BLOCK =
        "AF1";
    string public constant AF_MINING_IS_FINISHED = "AF2";
    string public constant AF_CREDIT_ACCOUNT_NOT_IN_STOCK = "AF3";
    string public constant AF_EXTERNAL_ACCOUNTS_ARE_FORBIDDEN = "AF4";

    //
    // ADDRESS PROVIDER
    //
    string public constant AS_ADDRESS_NOT_FOUND = "AP1";

    //
    // CONTRACTS REGISTER
    //
    string public constant CR_POOL_ALREADY_ADDED = "CR1";
    string public constant CR_CREDIT_MANAGER_ALREADY_ADDED = "CR2";

    //
    // CREDIT ACCOUNT
    //
    string public constant CA_CONNECTED_CREDIT_MANAGER_ONLY = "CA1";
    string public constant CA_FACTORY_ONLY = "CA2";

    //
    // ACL
    //
    string public constant ACL_CALLER_NOT_PAUSABLE_ADMIN = "ACL1";
    string public constant ACL_CALLER_NOT_CONFIGURATOR = "ACL2";

    //
    // WETH GATEWAY
    //
    string public constant WG_DESTINATION_IS_NOT_WETH_COMPATIBLE = "WG1";
    string public constant WG_RECEIVE_IS_NOT_ALLOWED = "WG2";
    string public constant WG_NOT_ENOUGH_FUNDS = "WG3";

    //
    // TOKEN DISTRIBUTOR
    //
    string public constant TD_WALLET_IS_ALREADY_CONNECTED_TO_VC = "TD1";
    string public constant TD_INCORRECT_WEIGHTS = "TD2";
    string public constant TD_NON_ZERO_BALANCE_AFTER_DISTRIBUTION = "TD3";
    string public constant TD_CONTRIBUTOR_IS_NOT_REGISTERED = "TD4";
}

// File: @gearbox-protocol/core-v2/contracts/core/access/Claimable.sol



// SPDX-License-Identifier: BUSL-1.1
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;

import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";

/// @title Claimable
/// @dev Implements logic for a two-step ownership transfer on top of Ownable
contract Claimable is Ownable {
    /// @dev The new owner that has not claimed ownership yet
    address public pendingOwner;

    /// @dev A modifier that restricts the function to the pending owner only
    modifier onlyPendingOwner() {
        if (msg.sender != pendingOwner) {
            revert("Claimable: Sender is not pending owner");
        }
        _;
    }

    /// @dev Sets pending owner to the new owner, but does not
    /// transfer ownership yet
    /// @param newOwner The address to become the future owner
    function transferOwnership(address newOwner) public override onlyOwner {
        require(
            newOwner != address(0),
            "Claimable: new owner is the zero address"
        );
        pendingOwner = newOwner;
    }

    /// @dev Used by the pending owner to claim ownership after transferOwnership
    function claimOwnership() external onlyPendingOwner {
        _transferOwnership(pendingOwner);
        pendingOwner = address(0);
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions 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: @gearbox-protocol/core-v2/contracts/interfaces/IPriceOracle.sol



// SPDX-License-Identifier: MIT
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;
import { IVersion } from "./IVersion.sol";

interface IPriceOracleV2Events {
    /// @dev Emits when a new price feed is added
    event NewPriceFeed(address indexed token, address indexed priceFeed);
}

interface IPriceOracleV2Exceptions {
    /// @dev Thrown if a price feed returns 0
    error ZeroPriceException();

    /// @dev Thrown if the last recorded result was not updated in the last round
    error ChainPriceStaleException();

    /// @dev Thrown on attempting to get a result for a token that does not have a price feed
    error PriceOracleNotExistsException();
}

/// @title Price oracle interface
interface IPriceOracleV2 is
    IPriceOracleV2Events,
    IPriceOracleV2Exceptions,
    IVersion
{
    /// @dev Converts a quantity of an asset to USD (decimals = 8).
    /// @param amount Amount to convert
    /// @param token Address of the token to be converted
    function convertToUSD(uint256 amount, address token)
        external
        view
        returns (uint256);

    /// @dev Converts a quantity of USD (decimals = 8) to an equivalent amount of an asset
    /// @param amount Amount to convert
    /// @param token Address of the token converted to
    function convertFromUSD(uint256 amount, address token)
        external
        view
        returns (uint256);

    /// @dev Converts one asset into another
    ///
    /// @param amount Amount to convert
    /// @param tokenFrom Address of the token to convert from
    /// @param tokenTo Address of the token to convert to
    function convert(
        uint256 amount,
        address tokenFrom,
        address tokenTo
    ) external view returns (uint256);

    /// @dev Returns collateral values for two tokens, required for a fast check
    /// @param amountFrom Amount of the outbound token
    /// @param tokenFrom Address of the outbound token
    /// @param amountTo Amount of the inbound token
    /// @param tokenTo Address of the inbound token
    /// @return collateralFrom Value of the outbound token amount in USD
    /// @return collateralTo Value of the inbound token amount in USD
    function fastCheck(
        uint256 amountFrom,
        address tokenFrom,
        uint256 amountTo,
        address tokenTo
    ) external view returns (uint256 collateralFrom, uint256 collateralTo);

    /// @dev Returns token's price in USD (8 decimals)
    /// @param token The token to compute the price for
    function getPrice(address token) external view returns (uint256);

    /// @dev Returns the price feed address for the passed token
    /// @param token Token to get the price feed for
    function priceFeeds(address token)
        external
        view
        returns (address priceFeed);

    /// @dev Returns the price feed for the passed token,
    ///      with additional parameters
    /// @param token Token to get the price feed for
    function priceFeedsWithFlags(address token)
        external
        view
        returns (
            address priceFeed,
            bool skipCheck,
            uint256 decimals
        );
}

interface IPriceOracleV2Ext is IPriceOracleV2 {
    /// @dev Sets a price feed if it doesn't exist, or updates an existing one
    /// @param token Address of the token to set the price feed for
    /// @param priceFeed Address of a USD price feed adhering to Chainlink's interface
    function addPriceFeed(address token, address priceFeed) external;
}

// File: @gearbox-protocol/core-v2/contracts/interfaces/IContractsRegister.sol



// SPDX-License-Identifier: MIT
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;
import { IVersion } from "./IVersion.sol";

interface IContractsRegisterEvents {
    /// @dev Emits when a new pool is registered in the system
    event NewPoolAdded(address indexed pool);

    /// @dev Emits when a new Credit Manager is registered in the system
    event NewCreditManagerAdded(address indexed creditManager);
}

interface IContractsRegister is IContractsRegisterEvents, IVersion {
    //
    // POOLS
    //

    /// @dev Returns the array of registered pools
    function getPools() external view returns (address[] memory);

    /// @dev Returns a pool address from the list under the passed index
    /// @param i Index of the pool to retrieve
    function pools(uint256 i) external returns (address);

    /// @return Returns the number of registered pools
    function getPoolsCount() external view returns (uint256);

    /// @dev Returns true if the passed address is a pool
    function isPool(address) external view returns (bool);

    //
    // CREDIT MANAGERS
    //

    /// @dev Returns the array of registered Credit Managers
    function getCreditManagers() external view returns (address[] memory);

    /// @dev Returns a Credit Manager's address from the list under the passed index
    /// @param i Index of the Credit Manager to retrieve
    function creditManagers(uint256 i) external returns (address);

    /// @return Returns the number of registered Credit Managers
    function getCreditManagersCount() external view returns (uint256);

    /// @dev Returns true if the passed address is a Credit Manager
    function isCreditManager(address) external view returns (bool);
}

// File: @openzeppelin/contracts/security/Pausable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @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 Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        _requireNotPaused();
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        _requirePaused();
        _;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        require(!paused(), "Pausable: paused");
    }

    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        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: @gearbox-protocol/core-v2/contracts/interfaces/IACL.sol



// SPDX-License-Identifier: MIT
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;
import { IVersion } from "./IVersion.sol";

interface IACLExceptions {
    /// @dev Thrown when attempting to delete an address from a set that is not a pausable admin
    error AddressNotPausableAdminException(address addr);

    /// @dev Thrown when attempting to delete an address from a set that is not a unpausable admin
    error AddressNotUnpausableAdminException(address addr);
}

interface IACLEvents {
    /// @dev Emits when a new admin is added that can pause contracts
    event PausableAdminAdded(address indexed newAdmin);

    /// @dev Emits when a Pausable admin is removed
    event PausableAdminRemoved(address indexed admin);

    /// @dev Emits when a new admin is added that can unpause contracts
    event UnpausableAdminAdded(address indexed newAdmin);

    /// @dev Emits when an Unpausable admin is removed
    event UnpausableAdminRemoved(address indexed admin);
}

/// @title ACL interface
interface IACL is IACLEvents, IACLExceptions, IVersion {
    /// @dev Returns true if the address is a pausable admin and false if not
    /// @param addr Address to check
    function isPausableAdmin(address addr) external view returns (bool);

    /// @dev Returns true if the address is unpausable admin and false if not
    /// @param addr Address to check
    function isUnpausableAdmin(address addr) external view returns (bool);

    /// @dev Returns true if an address has configurator rights
    /// @param account Address to check
    function isConfigurator(address account) external view returns (bool);

    /// @dev Returns address of configurator
    function owner() external view returns (address);
}

// File: @gearbox-protocol/core-v2/contracts/libraries/Balances.sol



// SPDX-License-Identifier: GPL-2.0-or-later
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;

struct Balance {
    address token;
    uint256 balance;
}

library BalanceOps {
    error UnknownToken(address);

    function copyBalance(Balance memory b)
        internal
        pure
        returns (Balance memory)
    {
        return Balance({ token: b.token, balance: b.balance });
    }

    function addBalance(
        Balance[] memory b,
        address token,
        uint256 amount
    ) internal pure {
        b[getIndex(b, token)].balance += amount;
    }

    function subBalance(
        Balance[] memory b,
        address token,
        uint256 amount
    ) internal pure {
        b[getIndex(b, token)].balance -= amount;
    }

    function getBalance(Balance[] memory b, address token)
        internal
        pure
        returns (uint256 amount)
    {
        return b[getIndex(b, token)].balance;
    }

    function setBalance(
        Balance[] memory b,
        address token,
        uint256 amount
    ) internal pure {
        b[getIndex(b, token)].balance = amount;
    }

    function getIndex(Balance[] memory b, address token)
        internal
        pure
        returns (uint256 index)
    {
        for (uint256 i; i < b.length; ) {
            if (b[i].token == token) {
                return i;
            }

            unchecked {
                ++i;
            }
        }
        revert UnknownToken(token);
    }

    function copy(Balance[] memory b, uint256 len)
        internal
        pure
        returns (Balance[] memory res)
    {
        res = new Balance[](len);
        for (uint256 i; i < len; ) {
            res[i] = copyBalance(b[i]);
            unchecked {
                ++i;
            }
        }
    }

    function clone(Balance[] memory b)
        internal
        pure
        returns (Balance[] memory)
    {
        return copy(b, b.length);
    }

    function getModifiedAfterSwap(
        Balance[] memory b,
        address tokenFrom,
        uint256 amountFrom,
        address tokenTo,
        uint256 amountTo
    ) internal pure returns (Balance[] memory res) {
        res = copy(b, b.length);
        setBalance(res, tokenFrom, getBalance(b, tokenFrom) - amountFrom);
        setBalance(res, tokenTo, getBalance(b, tokenTo) + amountTo);
    }
}

// File: @gearbox-protocol/core-v2/contracts/libraries/MultiCall.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity ^0.8.10;

struct MultiCall {
    address target;
    bytes callData;
}

library MultiCallOps {
    function copyMulticall(MultiCall memory call)
        internal
        pure
        returns (MultiCall memory)
    {
        return MultiCall({ target: call.target, callData: call.callData });
    }

    function trim(MultiCall[] memory calls)
        internal
        pure
        returns (MultiCall[] memory trimmed)
    {
        uint256 len = calls.length;

        if (len == 0) return calls;

        uint256 foundLen;
        while (calls[foundLen].target != address(0)) {
            unchecked {
                ++foundLen;
                if (foundLen == len) return calls;
            }
        }

        if (foundLen > 0) return copy(calls, foundLen);
    }

    function copy(MultiCall[] memory calls, uint256 len)
        internal
        pure
        returns (MultiCall[] memory res)
    {
        res = new MultiCall[](len);
        for (uint256 i; i < len; ) {
            res[i] = copyMulticall(calls[i]);
            unchecked {
                ++i;
            }
        }
    }

    function clone(MultiCall[] memory calls)
        internal
        pure
        returns (MultiCall[] memory res)
    {
        return copy(calls, calls.length);
    }

    function append(MultiCall[] memory calls, MultiCall memory newCall)
        internal
        pure
        returns (MultiCall[] memory res)
    {
        uint256 len = calls.length;
        res = new MultiCall[](len + 1);
        for (uint256 i; i < len; ) {
            res[i] = copyMulticall(calls[i]);
            unchecked {
                ++i;
            }
        }
        res[len] = copyMulticall(newCall);
    }

    function prepend(MultiCall[] memory calls, MultiCall memory newCall)
        internal
        pure
        returns (MultiCall[] memory res)
    {
        uint256 len = calls.length;
        res = new MultiCall[](len + 1);
        res[0] = copyMulticall(newCall);

        for (uint256 i = 1; i < len + 1; ) {
            res[i] = copyMulticall(calls[i]);
            unchecked {
                ++i;
            }
        }
    }

    function concat(MultiCall[] memory calls1, MultiCall[] memory calls2)
        internal
        pure
        returns (MultiCall[] memory res)
    {
        uint256 len1 = calls1.length;
        uint256 lenTotal = len1 + calls2.length;

        if (lenTotal == calls1.length) return clone(calls1);
        if (lenTotal == calls2.length) return clone(calls2);

        res = new MultiCall[](lenTotal);

        for (uint256 i; i < lenTotal; ) {
            res[i] = (i < len1)
                ? copyMulticall(calls1[i])
                : copyMulticall(calls2[i - len1]);
            unchecked {
                ++i;
            }
        }
    }
}