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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (access/AccessControl.sol)

pragma solidity ^0.8.0;

import "./IAccessControl.sol";
import "../utils/Context.sol";
import "../utils/Strings.sol";
import "../utils/introspection/ERC165.sol";

/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControl is Context, IAccessControl, ERC165 {
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }

    mapping(bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role);
        _;
    }

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

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }

    /**
     * @dev Revert with a standard message if `_msgSender()` is missing `role`.
     * Overriding this function changes the behavior of the {onlyRole} modifier.
     *
     * Format of the revert message is described in {_checkRole}.
     *
     * _Available since v4.6._
     */
    function _checkRole(bytes32 role) internal view virtual {
        _checkRole(role, _msgSender());
    }

    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        Strings.toHexString(account),
                        " is missing role ",
                        Strings.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     *
     * May emit a {RoleGranted} event.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     *
     * May emit a {RoleRevoked} event.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     *
     * May emit a {RoleRevoked} event.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * May emit a {RoleGranted} event.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleGranted} event.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleRevoked} event.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)

pragma solidity ^0.8.0;

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControl {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}

// File: @openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}

// 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/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.sol";
import "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or 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 {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // 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/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/Counters.sol



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

pragma solidity ^0.8.0;

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 */
library Counters {
    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }

    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }

    function increment(Counter storage counter) internal {
        unchecked {
            counter._value += 1;
        }
    }

    function decrement(Counter storage counter) internal {
        uint256 value = counter._value;
        require(value > 0, "Counter: decrement overflow");
        unchecked {
            counter._value = value - 1;
        }
    }

    function reset(Counter storage counter) internal {
        counter._value = 0;
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/cryptography/draft-EIP712.sol)

pragma solidity ^0.8.0;

// EIP-712 is Final as of 2022-08-11. This file is deprecated.

import "./EIP712.sol";

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/cryptography/ECDSA.sol)

pragma solidity ^0.8.0;

import "../Strings.sol";

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    enum RecoverError {
        NoError,
        InvalidSignature,
        InvalidSignatureLength,
        InvalidSignatureS,
        InvalidSignatureV // Deprecated in v4.8
    }

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

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

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

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
     *
     * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
     *
     * _Available since v4.3._
     */
    function tryRecover(
        bytes32 hash,
        bytes32 r,
        bytes32 vs
    ) internal pure returns (address, RecoverError) {
        bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
        uint8 v = uint8((uint256(vs) >> 255) + 27);
        return tryRecover(hash, v, r, s);
    }

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

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

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

        return (signer, RecoverError.NoError);
    }

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

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

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

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

// File: @openzeppelin/contracts/utils/cryptography/EIP712.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/cryptography/EIP712.sol)

pragma solidity ^0.8.0;

import "./ECDSA.sol";

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

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

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

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

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

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

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

// File: @openzeppelin/contracts/utils/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: @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/math/Math.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/Math.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }

    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }

    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
     * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
     * with further edits by Uniswap Labs also under MIT license.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1);

            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////

            // Make division exact by subtracting the remainder from [prod1 prod0].
            uint256 remainder;
            assembly {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)

                // Subtract 256 bit number from 512 bit number.
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }

            // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
            // See https://cs.stackexchange.com/q/138556/92363.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;

            // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            uint256 inverse = (3 * denominator) ^ 2;

            // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
            // in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256

            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }

    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator,
        Rounding rounding
    ) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        //
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
        //
        // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
        // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
        // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
        //
        // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1 << (log2(a) >> 1);

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = sqrt(a);
            return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 2, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 10, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10**64) {
                value /= 10**64;
                result += 64;
            }
            if (value >= 10**32) {
                value /= 10**32;
                result += 32;
            }
            if (value >= 10**16) {
                value /= 10**16;
                result += 16;
            }
            if (value >= 10**8) {
                value /= 10**8;
                result += 8;
            }
            if (value >= 10**4) {
                value /= 10**4;
                result += 4;
            }
            if (value >= 10**2) {
                value /= 10**2;
                result += 2;
            }
            if (value >= 10**1) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + (rounding == Rounding.Up && 10**result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 256, rounded down, of a positive value.
     * Returns 0 if given 0.
     *
     * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
     */
    function log256(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + (rounding == Rounding.Up && 1 << (result * 8) < value ? 1 : 0);
        }
    }
}

// File: @openzeppelin/contracts/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

import "./math/Math.sol";

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _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) {
        unchecked {
            uint256 length = Math.log10(value) + 1;
            string memory buffer = new string(length);
            uint256 ptr;
            /// @solidity memory-safe-assembly
            assembly {
                ptr := add(buffer, add(32, length))
            }
            while (true) {
                ptr--;
                /// @solidity memory-safe-assembly
                assembly {
                    mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                }
                value /= 10;
                if (value == 0) break;
            }
            return buffer;
        }
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        unchecked {
            return toHexString(value, Math.log256(value) + 1);
        }
    }

    /**
     * @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] = _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: contracts/dex/PaymentGateway.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "@openzeppelin/contracts/access/AccessControl.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";

import "../libraries/Errors.sol";
import "../interfaces/dex/IUniswapRouter.sol";

/// @title Pay using a Decentralized automated market maker (AMM) when needed
/// @author Masa Finance
/// @notice Smart contract to call a Dex AMM smart contract to pay to a reserve wallet recipient
/// @dev This smart contract will call the Uniswap Router interface, based on
/// https://github.com/Uniswap/v2-periphery/blob/master/contracts/interfaces/IUniswapV2Router01.sol
abstract contract PaymentGateway is AccessControl {
    using SafeERC20 for IERC20;
    using SafeMath for uint256;

    struct PaymentParams {
        address swapRouter; // Swap router address
        address wrappedNativeToken; // Wrapped native token address
        address stableCoin; // Stable coin to pay the fee in (USDC)
        address masaToken; // Utility token to pay the fee in (MASA)
        address reserveWallet; // Wallet that will receive the fee
    }

    /* ========== STATE VARIABLES =========================================== */

    address public swapRouter;
    address public wrappedNativeToken;

    address public stableCoin; // USDC. It also needs to be enabled as payment method, if we want to pay in USDC
    address public masaToken; // MASA. It also needs to be enabled as payment method, if we want to pay in MASA

    // enabled payment methods: ETH and ERC20 tokens
    mapping(address => bool) public enabledPaymentMethod;
    address[] public enabledPaymentMethods;

    address public reserveWallet;

    /* ========== INITIALIZE ================================================ */

    /// @notice Creates a new Dex AMM
    /// @dev Creates a new Decentralized automated market maker (AMM) smart contract,
    // that will call the Uniswap Router interface
    /// @param admin Administrator of the smart contract
    /// @param paymentParams Payment params
    constructor(address admin, PaymentParams memory paymentParams) {
        if (paymentParams.swapRouter == address(0)) revert ZeroAddress();
        if (paymentParams.wrappedNativeToken == address(0))
            revert ZeroAddress();
        if (paymentParams.stableCoin == address(0)) revert ZeroAddress();
        if (paymentParams.reserveWallet == address(0)) revert ZeroAddress();

        _grantRole(DEFAULT_ADMIN_ROLE, admin);

        swapRouter = paymentParams.swapRouter;
        wrappedNativeToken = paymentParams.wrappedNativeToken;
        stableCoin = paymentParams.stableCoin;
        masaToken = paymentParams.masaToken;
        reserveWallet = paymentParams.reserveWallet;
    }

    /* ========== RESTRICTED FUNCTIONS ====================================== */

    /// @notice Sets the swap router address
    /// @dev The caller must have the admin role to call this function
    /// @param _swapRouter New swap router address
    function setSwapRouter(
        address _swapRouter
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (_swapRouter == address(0)) revert ZeroAddress();
        if (swapRouter == _swapRouter) revert SameValue();
        swapRouter = _swapRouter;
    }

    /// @notice Sets the wrapped native token address
    /// @dev The caller must have the admin role to call this function
    /// @param _wrappedNativeToken New wrapped native token address
    function setWrappedNativeToken(
        address _wrappedNativeToken
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (_wrappedNativeToken == address(0)) revert ZeroAddress();
        if (wrappedNativeToken == _wrappedNativeToken) revert SameValue();
        wrappedNativeToken = _wrappedNativeToken;
    }

    /// @notice Sets the stable coin to pay the fee in (USDC)
    /// @dev The caller must have the admin role to call this function
    /// @param _stableCoin New stable coin to pay the fee in
    function setStableCoin(
        address _stableCoin
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (_stableCoin == address(0)) revert ZeroAddress();
        if (stableCoin == _stableCoin) revert SameValue();
        stableCoin = _stableCoin;
    }

    /// @notice Sets the utility token to pay the fee in (MASA)
    /// @dev The caller must have the admin role to call this function
    /// It can be set to address(0) to disable paying in MASA
    /// @param _masaToken New utility token to pay the fee in
    function setMasaToken(
        address _masaToken
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (masaToken == _masaToken) revert SameValue();
        masaToken = _masaToken;
    }

    /// @notice Adds a new token as a valid payment method
    /// @dev The caller must have the admin role to call this function
    /// @param _paymentMethod New token to add
    function enablePaymentMethod(
        address _paymentMethod
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (enabledPaymentMethod[_paymentMethod]) revert AlreadyAdded();

        enabledPaymentMethod[_paymentMethod] = true;
        enabledPaymentMethods.push(_paymentMethod);
    }

    /// @notice Removes a token as a valid payment method
    /// @dev The caller must have the admin role to call this function
    /// @param _paymentMethod Token to remove
    function disablePaymentMethod(
        address _paymentMethod
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (!enabledPaymentMethod[_paymentMethod])
            revert NonExistingErc20Token(_paymentMethod);

        enabledPaymentMethod[_paymentMethod] = false;
        for (uint256 i = 0; i < enabledPaymentMethods.length; i++) {
            if (enabledPaymentMethods[i] == _paymentMethod) {
                enabledPaymentMethods[i] = enabledPaymentMethods[
                    enabledPaymentMethods.length - 1
                ];
                enabledPaymentMethods.pop();
                break;
            }
        }
    }

    /// @notice Set the reserve wallet
    /// @dev The caller must have the admin role to call this function
    /// @param _reserveWallet New reserve wallet
    function setReserveWallet(
        address _reserveWallet
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (_reserveWallet == address(0)) revert ZeroAddress();
        if (_reserveWallet == reserveWallet) revert SameValue();
        reserveWallet = _reserveWallet;
    }

    /* ========== MUTATIVE FUNCTIONS ======================================== */

    /* ========== VIEWS ===================================================== */

    /// @notice Returns all available payment methods
    /// @dev Returns the address of all available payment methods
    /// @return Array of all enabled payment methods
    function getEnabledPaymentMethods()
        external
        view
        returns (address[] memory)
    {
        return enabledPaymentMethods;
    }

    /* ========== PRIVATE FUNCTIONS ========================================= */

    /// @notice Converts an amount from a stable coin to a payment method amount
    /// @dev This method will perform the swap between the stable coin and the
    /// payment method, and return the amount of the payment method,
    /// performing the swap if necessary
    /// @param paymentMethod Address of token that user want to pay
    /// @param amount Price to be converted in the specified payment method
    function _convertFromStableCoin(
        address paymentMethod,
        uint256 amount
    ) internal view returns (uint256) {
        if (!enabledPaymentMethod[paymentMethod] || paymentMethod == stableCoin)
            revert InvalidToken(paymentMethod);

        if (paymentMethod == address(0)) {
            return _estimateSwapAmount(wrappedNativeToken, stableCoin, amount);
        } else {
            return _estimateSwapAmount(paymentMethod, stableCoin, amount);
        }
    }

    /// @notice Performs the payment in any payment method
    /// @dev This method will transfer the funds to the reserve wallet, performing
    /// the swap if necessary
    /// @param paymentMethod Address of token that user want to pay
    /// @param amount Price to be paid in the specified payment method
    function _pay(address paymentMethod, uint256 amount) internal {
        if (amount == 0) return;
        if (!enabledPaymentMethod[paymentMethod])
            revert InvalidPaymentMethod(paymentMethod);
        if (paymentMethod == address(0)) {
            // ETH
            if (msg.value < amount) revert InsufficientEthAmount(amount);
            (bool success, ) = payable(reserveWallet).call{value: amount}("");
            if (!success) revert TransferFailed();
            if (msg.value > amount) {
                // return diff
                uint256 refund = msg.value.sub(amount);
                (success, ) = payable(msg.sender).call{value: refund}("");
                if (!success) revert RefundFailed();
            }
        } else {
            // ERC20 token, including MASA and USDC
            IERC20(paymentMethod).safeTransferFrom(
                msg.sender,
                reserveWallet,
                amount
            );
        }
    }

    function _estimateSwapAmount(
        address _fromToken,
        address _toToken,
        uint256 _amountOut
    ) private view returns (uint256) {
        uint256[] memory amounts;
        address[] memory path;
        path = _getPathFromTokenToToken(_fromToken, _toToken);
        amounts = IUniswapRouter(swapRouter).getAmountsIn(_amountOut, path);
        return amounts[0];
    }

    function _getPathFromTokenToToken(
        address fromToken,
        address toToken
    ) private view returns (address[] memory) {
        if (fromToken == wrappedNativeToken || toToken == wrappedNativeToken) {
            address[] memory path = new address[](2);
            path[0] = fromToken == wrappedNativeToken
                ? wrappedNativeToken
                : fromToken;
            path[1] = toToken == wrappedNativeToken
                ? wrappedNativeToken
                : toToken;
            return path;
        } else {
            address[] memory path = new address[](3);
            path[0] = fromToken;
            path[1] = wrappedNativeToken;
            path[2] = toToken;
            return path;
        }
    }

    /* ========== MODIFIERS ================================================= */

    /* ========== EVENTS ==================================================== */
}

// File: contracts/interfaces/dex/IUniswapRouter.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

/// @title Uniswap Router interface
/// @author Masa Finance
/// @notice Interface of the Uniswap Router contract
/// @dev This interface is used to interact with the Uniswap Router contract,
/// and gets the most important functions of the contract. It's based on
/// https://github.com/Uniswap/v2-periphery/blob/master/contracts/interfaces/IUniswapV2Router01.sol
interface IUniswapRouter {
    function swapExactTokensForTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactETHForTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function swapExactTokensForETH(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function getAmountsOut(
        uint256 amountIn,
        address[] calldata path
    ) external view returns (uint256[] memory amounts);

    function getAmountsIn(
        uint256 amountOut,
        address[] calldata path
    ) external view returns (uint256[] memory amounts);
}

// File: contracts/interfaces/ILinkableSBT.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "../tokens/SBT/ISBT.sol";

interface ILinkableSBT is ISBT {
    function addLinkPrice() external view returns (uint256);

    function addLinkPriceMASA() external view returns (uint256);

    function queryLinkPrice() external view returns (uint256);

    function queryLinkPriceMASA() external view returns (uint256);
}

// File: contracts/interfaces/ISoulboundIdentity.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "../tokens/SBT/ISBT.sol";

import "./ISoulName.sol";

interface ISoulboundIdentity is ISBT {
    function mint(address to) external returns (uint256);

    function mintIdentityWithName(
        address to,
        string memory name,
        uint256 yearsPeriod,
        string memory _tokenURI
    ) external returns (uint256);

    function getSoulName() external view returns (ISoulName);

    function tokenOfOwner(address owner) external view returns (uint256);
}

// File: contracts/interfaces/ISoulName.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

interface ISoulName {
    function mint(
        address to,
        string memory name,
        uint256 yearsPeriod,
        string memory _tokenURI
    ) external returns (uint256);

    function getExtension() external view returns (string memory);

    function isAvailable(
        string memory name
    ) external view returns (bool available);

    function getTokenData(
        string memory name
    )
        external
        view
        returns (
            string memory sbtName,
            bool linked,
            uint256 identityId,
            uint256 tokenId,
            uint256 expirationDate,
            bool active
        );

    function getTokenId(string memory name) external view returns (uint256);

    function getSoulNames(
        address owner
    ) external view returns (string[] memory sbtNames);

    function getSoulNames(
        uint256 identityId
    ) external view returns (string[] memory sbtNames);
}

// File: contracts/libraries/Errors.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

error AddressDoesNotHaveIdentity(address to);
error AlreadyAdded();
error AuthorityNotExists(address authority);
error CallerNotOwner(address caller);
error CallerNotReader(address caller);
error CreditScoreAlreadyCreated(address to);
error IdentityAlreadyCreated(address to);
error IdentityOwnerIsReader(uint256 readerIdentityId);
error InsufficientEthAmount(uint256 amount);
error IdentityOwnerNotTokenOwner(uint256 tokenId, uint256 ownerIdentityId);
error InvalidPaymentMethod(address paymentMethod);
error InvalidSignature();
error InvalidSignatureDate(uint256 signatureDate);
error InvalidToken(address token);
error InvalidTokenURI(string tokenURI);
error LinkAlreadyExists(
    address token,
    uint256 tokenId,
    uint256 readerIdentityId,
    uint256 signatureDate
);
error LinkAlreadyRevoked();
error LinkDoesNotExist();
error NameAlreadyExists(string name);
error NameNotFound(string name);
error NameRegisteredByOtherAccount(string name, uint256 tokenId);
error NotAuthorized(address signer);
error NonExistingErc20Token(address erc20token);
error NotLinkedToAnIdentitySBT();
error RefundFailed();
error SameValue();
error SBTAlreadyLinked(address token);
error SoulNameContractNotSet();
error TokenNotFound(uint256 tokenId);
error TransferFailed();
error URIAlreadyExists(string tokenURI);
error ValidPeriodExpired(uint256 expirationDate);
error ZeroAddress();
error ZeroLengthName(string name);
error ZeroYearsPeriod(uint256 yearsPeriod);

// File: contracts/SoulboundGreen.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "@openzeppelin/contracts/security/ReentrancyGuard.sol";

import "./libraries/Errors.sol";
import "./tokens/MasaSBTSelfSovereign.sol";

/// @title Soulbound Two-factor authentication (Green - 2FA)
/// @author Masa Finance
/// @notice Soulbound token that represents a Two-factor authentication (2FA)
/// @dev Soulbound Green, that inherits from the SBT contract.
contract SoulboundGreen is MasaSBTSelfSovereign, ReentrancyGuard {
    /* ========== STATE VARIABLES =========================================== */

    /* ========== INITIALIZE ================================================ */

    /// @notice Creates a new soulbound Two-factor authentication (Green - 2FA)
    /// @dev Creates a new soulbound Green, inheriting from the SBT contract.
    /// @param admin Administrator of the smart contract
    /// @param baseTokenURI Base URI of the token
    /// @param soulboundIdentity Address of the SoulboundIdentity contract
    /// @param paymentParams Payment gateway params
    constructor(
        address admin,
        string memory baseTokenURI,
        ISoulboundIdentity soulboundIdentity,
        PaymentParams memory paymentParams
    )
        MasaSBTSelfSovereign(
            admin,
            "Masa Green",
            "MG-2FA",
            baseTokenURI,
            soulboundIdentity,
            paymentParams
        )
        EIP712("SoulboundGreen", "1.0.0")
    {}

    /* ========== RESTRICTED FUNCTIONS ====================================== */

    /* ========== MUTATIVE FUNCTIONS ======================================== */

    /// @notice Mints a new SBT
    /// @dev The caller must have the MINTER role
    /// @param paymentMethod Address of token that user want to pay
    /// @param identityId TokenId of the identity to mint the NFT to
    /// @param authorityAddress Address of the authority that signed the message
    /// @param signatureDate Date of the signature
    /// @param signature Signature of the message
    /// @return The NFT ID of the newly minted SBT
    function mint(
        address paymentMethod,
        uint256 identityId,
        address authorityAddress,
        uint256 signatureDate,
        bytes calldata signature
    ) public payable virtual nonReentrant returns (uint256) {
        address to = soulboundIdentity.ownerOf(identityId);
        if (to != _msgSender()) revert CallerNotOwner(_msgSender());

        _verify(
            _hash(identityId, authorityAddress, signatureDate),
            signature,
            authorityAddress
        );

        _pay(paymentMethod, getMintPrice(paymentMethod));

        uint256 tokenId = _mintWithCounter(to);

        emit SoulboundGreenMintedToIdentity(
            tokenId,
            identityId,
            authorityAddress,
            signatureDate,
            paymentMethod,
            mintPrice
        );

        return tokenId;
    }

    /// @notice Mints a new SBT
    /// @dev The caller must have the MINTER role
    /// @param paymentMethod Address of token that user want to pay
    /// @param to The address to mint the SBT to
    /// @param authorityAddress Address of the authority that signed the message
    /// @param signatureDate Date of the signature
    /// @param signature Signature of the message
    /// @return The SBT ID of the newly minted SBT
    function mint(
        address paymentMethod,
        address to,
        address authorityAddress,
        uint256 signatureDate,
        bytes calldata signature
    ) external payable virtual returns (uint256) {
        if (to != _msgSender()) revert CallerNotOwner(_msgSender());

        _verify(
            _hash(to, authorityAddress, signatureDate),
            signature,
            authorityAddress
        );

        _pay(paymentMethod, getMintPrice(paymentMethod));

        uint256 tokenId = _mintWithCounter(to);

        emit SoulboundGreenMintedToAddress(
            tokenId,
            to,
            authorityAddress,
            signatureDate,
            paymentMethod,
            mintPrice
        );

        return tokenId;
    }

    /* ========== VIEWS ===================================================== */

    /* ========== PRIVATE FUNCTIONS ========================================= */

    function _hash(
        uint256 identityId,
        address authorityAddress,
        uint256 signatureDate
    ) internal view returns (bytes32) {
        return
            _hashTypedDataV4(
                keccak256(
                    abi.encode(
                        keccak256(
                            "MintGreen(uint256 identityId,address authorityAddress,uint256 signatureDate)"
                        ),
                        identityId,
                        authorityAddress,
                        signatureDate
                    )
                )
            );
    }

    function _hash(
        address to,
        address authorityAddress,
        uint256 signatureDate
    ) internal view returns (bytes32) {
        return
            _hashTypedDataV4(
                keccak256(
                    abi.encode(
                        keccak256(
                            "MintGreen(address to,address authorityAddress,uint256 signatureDate)"
                        ),
                        to,
                        authorityAddress,
                        signatureDate
                    )
                )
            );
    }

    /* ========== MODIFIERS ================================================= */

    /* ========== EVENTS ==================================================== */

    event SoulboundGreenMintedToIdentity(
        uint256 tokenId,
        uint256 identityId,
        address authorityAddress,
        uint256 signatureDate,
        address paymentMethod,
        uint256 mintPrice
    );

    event SoulboundGreenMintedToAddress(
        uint256 tokenId,
        address to,
        address authorityAddress,
        uint256 signatureDate,
        address paymentMethod,
        uint256 mintPrice
    );
}

// File: contracts/tokens/MasaSBT.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "@openzeppelin/contracts/access/AccessControl.sol";
import "@openzeppelin/contracts/utils/Strings.sol";

import "../libraries/Errors.sol";
import "../interfaces/ILinkableSBT.sol";
import "./SBT/SBT.sol";
import "./SBT/extensions/SBTEnumerable.sol";
import "./SBT/extensions/SBTBurnable.sol";

/// @title MasaSBT
/// @author Masa Finance
/// @notice Soulbound token. Non-fungible token that is not transferable.
/// @dev Implementation of https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4105763 Soulbound token.
abstract contract MasaSBT is
    SBT,
    SBTEnumerable,
    AccessControl,
    SBTBurnable,
    ILinkableSBT
{
    /* ========== STATE VARIABLES =========================================== */

    using Strings for uint256;

    string private _baseTokenURI;

    uint256 public override addLinkPrice; // price in stable coin
    uint256 public override addLinkPriceMASA; // price in MASA
    uint256 public override queryLinkPrice; // price in stable coin
    uint256 public override queryLinkPriceMASA; // price in MASA

    /* ========== INITIALIZE ================================================ */

    /// @notice Creates a new soulbound token
    /// @dev Creates a new soulbound token
    /// @param admin Administrator of the smart contract
    /// @param name Name of the token
    /// @param symbol Symbol of the token
    /// @param baseTokenURI Base URI of the token
    constructor(
        address admin,
        string memory name,
        string memory symbol,
        string memory baseTokenURI
    ) SBT(name, symbol) {
        _grantRole(DEFAULT_ADMIN_ROLE, admin);

        _baseTokenURI = baseTokenURI;
    }

    /* ========== RESTRICTED FUNCTIONS ====================================== */

    /// @notice Sets the price for adding the link in SoulLinker in stable coin
    /// @dev The caller must have the admin role to call this function
    /// @param _addLinkPrice New price for adding the link in SoulLinker in stable coin
    function setAddLinkPrice(
        uint256 _addLinkPrice
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (addLinkPrice == _addLinkPrice) revert SameValue();
        addLinkPrice = _addLinkPrice;
    }

    /// @notice Sets the price for adding the link in SoulLinker in MASA
    /// @dev The caller must have the admin role to call this function
    /// @param _addLinkPriceMASA New price for adding the link in SoulLinker in MASA
    function setAddLinkPriceMASA(
        uint256 _addLinkPriceMASA
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (addLinkPriceMASA == _addLinkPriceMASA) revert SameValue();
        addLinkPriceMASA = _addLinkPriceMASA;
    }

    /// @notice Sets the price for reading data in SoulLinker in stable coin
    /// @dev The caller must have the admin role to call this function
    /// @param _queryLinkPrice New price for reading data in SoulLinker in stable coin
    function setQueryLinkPrice(
        uint256 _queryLinkPrice
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (queryLinkPrice == _queryLinkPrice) revert SameValue();
        queryLinkPrice = _queryLinkPrice;
    }

    /// @notice Sets the price for reading data in SoulLinker in MASA
    /// @dev The caller must have the admin role to call this function
    /// @param _queryLinkPriceMASA New price for reading data in SoulLinker in MASA
    function setQueryLinkPriceMASA(
        uint256 _queryLinkPriceMASA
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (queryLinkPriceMASA == _queryLinkPriceMASA) revert SameValue();
        queryLinkPriceMASA = _queryLinkPriceMASA;
    }

    /* ========== MUTATIVE FUNCTIONS ======================================== */

    /* ========== VIEWS ===================================================== */

    /// @notice Returns true if the token exists
    /// @dev Returns true if the token has been minted
    /// @param tokenId Token to check
    /// @return True if the token exists
    function exists(uint256 tokenId) external view returns (bool) {
        return _exists(tokenId);
    }

    /// @notice A distinct Uniform Resource Identifier (URI) for a given asset.
    /// @dev Throws if `_tokenId` is not a valid SBT. URIs are defined in RFC
    ///  3986. The URI may point to a JSON file that conforms to the "ERC721
    ///  Metadata JSON Schema".
    /// @param tokenId SBT to get the URI of
    /// @return URI of the SBT
    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(), ".json"))
                : "";
    }

    /// @notice Query if a contract implements an interface
    /// @dev Interface identification is specified in ERC-165.
    /// @param interfaceId The interface identifier, as specified in ERC-165
    /// @return `true` if the contract implements `interfaceId` and
    ///  `interfaceId` is not 0xffffffff, `false` otherwise
    function supportsInterface(
        bytes4 interfaceId
    )
        public
        view
        virtual
        override(SBT, SBTEnumerable, AccessControl, IERC165)
        returns (bool)
    {
        return super.supportsInterface(interfaceId);
    }

    /* ========== PRIVATE FUNCTIONS ========================================= */

    function _baseURI() internal view virtual override returns (string memory) {
        return _baseTokenURI;
    }

    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual override(SBT, SBTEnumerable) {
        super._beforeTokenTransfer(from, to, tokenId);
    }

    /* ========== MODIFIERS ================================================= */

    /* ========== EVENTS ==================================================== */
}

// File: contracts/tokens/MasaSBTSelfSovereign.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "@openzeppelin/contracts/utils/cryptography/draft-EIP712.sol";
import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
import "@openzeppelin/contracts/utils/Counters.sol";

import "../libraries/Errors.sol";
import "../interfaces/ISoulboundIdentity.sol";
import "../dex/PaymentGateway.sol";
import "./MasaSBT.sol";

/// @title MasaSBTSelfSovereign
/// @author Masa Finance
/// @notice Soulbound token. Non-fungible token that is not transferable.
/// Adds a link to a SoulboundIdentity SC to let minting using the identityId
/// Adds a payment gateway to let minting paying a fee
/// Adds a self-sovereign protocol to let minting using an authority signature
/// @dev Implementation of https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4105763 Soulbound token.
abstract contract MasaSBTSelfSovereign is PaymentGateway, MasaSBT, EIP712 {
    /* ========== STATE VARIABLES =========================================== */

    using Counters for Counters.Counter;

    Counters.Counter private _tokenIdCounter;

    ISoulboundIdentity public soulboundIdentity;

    uint256 public mintPrice; // price in stable coin
    uint256 public mintPriceMASA; // price in MASA

    mapping(address => bool) public authorities;

    /* ========== INITIALIZE ================================================ */

    /// @notice Creates a new soulbound token
    /// @dev Creates a new soulbound token
    /// @param admin Administrator of the smart contract
    /// @param name Name of the token
    /// @param symbol Symbol of the token
    /// @param baseTokenURI Base URI of the token
    /// @param _soulboundIdentity Address of the SoulboundIdentity contract
    /// @param paymentParams Payment gateway params
    constructor(
        address admin,
        string memory name,
        string memory symbol,
        string memory baseTokenURI,
        ISoulboundIdentity _soulboundIdentity,
        PaymentParams memory paymentParams
    )
        PaymentGateway(admin, paymentParams)
        MasaSBT(admin, name, symbol, baseTokenURI)
    {
        soulboundIdentity = _soulboundIdentity;
    }

    /* ========== RESTRICTED FUNCTIONS ====================================== */

    /// @notice Sets the SoulboundIdentity contract address linked to this SBT
    /// @dev The caller must be the admin to call this function
    /// @param _soulboundIdentity Address of the SoulboundIdentity contract
    function setSoulboundIdentity(
        ISoulboundIdentity _soulboundIdentity
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (soulboundIdentity == _soulboundIdentity) revert SameValue();
        soulboundIdentity = _soulboundIdentity;
    }

    /// @notice Sets the price of minting in stable coin
    /// @dev The caller must have the admin role to call this function
    /// @param _mintPrice New price of minting in stable coin
    function setMintPrice(
        uint256 _mintPrice
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (mintPrice == _mintPrice) revert SameValue();
        mintPrice = _mintPrice;
    }

    /// @notice Sets the price of minting in MASA
    /// @dev The caller must have the admin role to call this function
    /// @param _mintPriceMASA New price of minting in MASA
    function setMintPriceMASA(
        uint256 _mintPriceMASA
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (mintPriceMASA == _mintPriceMASA) revert SameValue();
        mintPriceMASA = _mintPriceMASA;
    }

    /// @notice Adds a new authority to the list of authorities
    /// @dev The caller must have the admin role to call this function
    /// @param _authority New authority to add
    function addAuthority(
        address _authority
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (_authority == address(0)) revert ZeroAddress();
        if (authorities[_authority]) revert AlreadyAdded();

        authorities[_authority] = true;
    }

    /// @notice Removes an authority from the list of authorities
    /// @dev The caller must have the admin role to call this function
    /// @param _authority Authority to remove
    function removeAuthority(
        address _authority
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        if (_authority == address(0)) revert ZeroAddress();
        if (!authorities[_authority]) revert AuthorityNotExists(_authority);

        authorities[_authority] = false;
    }

    /* ========== MUTATIVE FUNCTIONS ======================================== */

    /* ========== VIEWS ===================================================== */

    /// @notice Returns the identityId owned by the given token
    /// @param tokenId Id of the token
    /// @return Id of the identity
    function getIdentityId(uint256 tokenId) external view returns (uint256) {
        if (soulboundIdentity == ISoulboundIdentity(address(0)))
            revert NotLinkedToAnIdentitySBT();

        address owner = super.ownerOf(tokenId);
        return soulboundIdentity.tokenOfOwner(owner);
    }

    /// @notice Returns the price for minting
    /// @dev Returns current pricing for minting
    /// @param paymentMethod Address of token that user want to pay
    /// @return Current price for minting in the given payment method
    function getMintPrice(address paymentMethod) public view returns (uint256) {
        if (mintPrice == 0 && mintPriceMASA == 0) {
            return 0;
        } else if (
            paymentMethod == masaToken &&
            enabledPaymentMethod[paymentMethod] &&
            mintPriceMASA > 0
        ) {
            // price in MASA without conversion rate
            return mintPriceMASA;
        } else if (
            paymentMethod == stableCoin && enabledPaymentMethod[paymentMethod]
        ) {
            // stable coin
            return mintPrice;
        } else if (enabledPaymentMethod[paymentMethod]) {
            // ETH and ERC 20 token
            return _convertFromStableCoin(paymentMethod, mintPrice);
        } else {
            revert InvalidPaymentMethod(paymentMethod);
        }
    }

    /// @notice Query if a contract implements an interface
    /// @dev Interface identification is specified in ERC-165.
    /// @param interfaceId The interface identifier, as specified in ERC-165
    /// @return `true` if the contract implements `interfaceId` and
    ///  `interfaceId` is not 0xffffffff, `false` otherwise
    function supportsInterface(
        bytes4 interfaceId
    ) public view virtual override(AccessControl, MasaSBT) returns (bool) {
        return super.supportsInterface(interfaceId);
    }

    /* ========== PRIVATE FUNCTIONS ========================================= */

    function _verify(
        bytes32 digest,
        bytes memory signature,
        address signer
    ) internal view {
        address _signer = ECDSA.recover(digest, signature);
        if (_signer != signer) revert InvalidSignature();
        if (!authorities[_signer]) revert NotAuthorized(_signer);
    }

    function _mintWithCounter(address to) internal virtual returns (uint256) {
        uint256 tokenId = _tokenIdCounter.current();
        _tokenIdCounter.increment();
        _mint(to, tokenId);

        return tokenId;
    }

    /* ========== MODIFIERS ================================================= */

    /* ========== EVENTS ==================================================== */
}

// File: contracts/tokens/SBT/extensions/ISBTEnumerable.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "../ISBT.sol";

/**
 * @title SBT Soulbound Token Standard, optional enumeration extension
 */
interface ISBTEnumerable is ISBT {
    /**
     * @dev Returns the total amount of tokens stored by the contract.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
     * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
     */
    function tokenOfOwnerByIndex(
        address owner,
        uint256 index
    ) external view returns (uint256);

    /**
     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
     * Use along with {totalSupply} to enumerate all tokens.
     */
    function tokenByIndex(uint256 index) external view returns (uint256);
}

// File: contracts/tokens/SBT/extensions/ISBTMetadata.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "../ISBT.sol";

/**
 * @title SBT Soulbound Token Standard, optional metadata extension
 */
interface ISBTMetadata is ISBT {
    /**
     * @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: contracts/tokens/SBT/extensions/SBTBurnable.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "@openzeppelin/contracts/utils/Context.sol";

import "../SBT.sol";

/**
 * @title SBT Burnable Token
 * @dev SBT Token that can be burned (destroyed).
 */
abstract contract SBTBurnable is Context, SBT {
    /**
     * @dev Burns `tokenId`. See {SBT-_burn}.
     *
     * Requirements:
     *
     * - The caller must own `tokenId` or be an approved operator.
     */
    function burn(uint256 tokenId) public virtual {
        //solhint-disable-next-line max-line-length
        require(
            _isOwner(_msgSender(), tokenId),
            "SBT: caller is not token owner"
        );
        _burn(tokenId);
    }
}

// File: contracts/tokens/SBT/extensions/SBTEnumerable.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "../SBT.sol";
import "./ISBTEnumerable.sol";

/**
 * @dev This implements an optional extension of {SBT} defined in the EIP that adds
 * enumerability of all the token ids in the contract as well as all token ids owned by each
 * account.
 */
abstract contract SBTEnumerable is SBT, ISBTEnumerable {
    // Mapping from owner to list of owned token IDs
    mapping(address => mapping(uint256 => uint256)) private _ownedTokens;

    // Mapping from token ID to index of the owner tokens list
    mapping(uint256 => uint256) private _ownedTokensIndex;

    // Array with all token ids, used for enumeration
    uint256[] private _allTokens;

    // Mapping from token id to position in the allTokens array
    mapping(uint256 => uint256) private _allTokensIndex;

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

    /**
     * @dev See {ISBTEnumerable-tokenOfOwnerByIndex}.
     */
    function tokenOfOwnerByIndex(
        address owner,
        uint256 index
    ) public view virtual override returns (uint256) {
        require(
            index < SBT.balanceOf(owner),
            "SBTEnumerable: owner index out of bounds"
        );
        return _ownedTokens[owner][index];
    }

    /**
     * @dev See {ISBTEnumerable-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _allTokens.length;
    }

    /**
     * @dev See {ISBTEnumerable-tokenByIndex}.
     */
    function tokenByIndex(
        uint256 index
    ) public view virtual override returns (uint256) {
        require(
            index < SBTEnumerable.totalSupply(),
            "SBTEnumerable: global index out of bounds"
        );
        return _allTokens[index];
    }

    /**
     * @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` cannot be the zero address.
     * - `to` cannot be the zero address.
     *
     * 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 override {
        super._beforeTokenTransfer(from, to, tokenId);

        if (from == address(0)) {
            _addTokenToAllTokensEnumeration(tokenId);
        } else if (from != to) {
            _removeTokenFromOwnerEnumeration(from, tokenId);
        }
        if (to == address(0)) {
            _removeTokenFromAllTokensEnumeration(tokenId);
        } else if (to != from) {
            _addTokenToOwnerEnumeration(to, tokenId);
        }
    }

    /**
     * @dev Private function to add a token to this extension's ownership-tracking data structures.
     * @param to address representing the new owner of the given token ID
     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
     */
    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
        uint256 length = SBT.balanceOf(to);
        _ownedTokens[to][length] = tokenId;
        _ownedTokensIndex[tokenId] = length;
    }

    /**
     * @dev Private function to add a token to this extension's token tracking data structures.
     * @param tokenId uint256 ID of the token to be added to the tokens list
     */
    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
        _allTokensIndex[tokenId] = _allTokens.length;
        _allTokens.push(tokenId);
    }

    /**
     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
     * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
     * This has O(1) time complexity, but alters the order of the _ownedTokens array.
     * @param from address representing the previous owner of the given token ID
     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
     */
    function _removeTokenFromOwnerEnumeration(
        address from,
        uint256 tokenId
    ) private {
        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
        // then delete the last slot (swap and pop).

        uint256 lastTokenIndex = SBT.balanceOf(from) - 1;
        uint256 tokenIndex = _ownedTokensIndex[tokenId];

        // When the token to delete is the last token, the swap operation is unnecessary
        if (tokenIndex != lastTokenIndex) {
            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];

            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
        }

        // This also deletes the contents at the last position of the array
        delete _ownedTokensIndex[tokenId];
        delete _ownedTokens[from][lastTokenIndex];
    }

    /**
     * @dev Private function to remove a token from this extension's token tracking data structures.
     * This has O(1) time complexity, but alters the order of the _allTokens array.
     * @param tokenId uint256 ID of the token to be removed from the tokens list
     */
    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
        // then delete the last slot (swap and pop).

        uint256 lastTokenIndex = _allTokens.length - 1;
        uint256 tokenIndex = _allTokensIndex[tokenId];

        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
        uint256 lastTokenId = _allTokens[lastTokenIndex];

        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index

        // This also deletes the contents at the last position of the array
        delete _allTokensIndex[tokenId];
        _allTokens.pop();
    }
}

// File: contracts/tokens/SBT/ISBT.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "@openzeppelin/contracts/utils/introspection/IERC165.sol";

interface ISBT is IERC165 {
    /// @dev This emits when an SBT is newly minted.
    ///  This event emits when SBTs are created
    event Mint(address indexed _owner, uint256 indexed _tokenId);

    /// @dev This emits when an SBT is burned
    ///  This event emits when SBTs are destroyed
    event Burn(address indexed _owner, uint256 indexed _tokenId);

    /// @notice Count all SBTs assigned to an owner
    /// @dev SBTs assigned to the zero address are considered invalid, and this
    ///  function throws for queries about the zero address.
    /// @param _owner An address for whom to query the balance
    /// @return The number of SBTs owned by `_owner`, possibly zero
    function balanceOf(address _owner) external view returns (uint256);

    /// @notice Find the owner of an SBT
    /// @dev SBTs assigned to zero address are considered invalid, and queries
    ///  about them do throw.
    /// @param _tokenId The identifier for an SBT
    /// @return The address of the owner of the SBT
    function ownerOf(uint256 _tokenId) external view returns (address);
}

// File: contracts/tokens/SBT/SBT.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "@openzeppelin/contracts/utils/introspection/ERC165.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@openzeppelin/contracts/utils/Strings.sol";

import "./ISBT.sol";
import "./extensions/ISBTMetadata.sol";

/// @title SBT
/// @author Masa Finance
/// @notice Soulbound token is an NFT token that is not transferable.
contract SBT is Context, ERC165, ISBT, ISBTMetadata {
    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;

    /**
     * @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(ISBT).interfaceId ||
            interfaceId == type(ISBTMetadata).interfaceId ||
            super.supportsInterface(interfaceId);
    }

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

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

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

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

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

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner.
     *
     * 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 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 {Mint} event.
     */
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "SBT: mint to the zero address");
        require(!_exists(tokenId), "SBT: token already minted");

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

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

        emit Mint(to, tokenId);

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

    /**
     * @dev Destroys `tokenId`.
     *
     * Requirements:
     * - `tokenId` must exist.
     *
     * Emits a {Burn} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = SBT.ownerOf(tokenId);

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

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

        emit Burn(owner, tokenId);

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

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

    /**
     * @dev Hook that is called before any token minting/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, address, uint256) internal virtual {}

    /**
     * @dev Hook that is called after any minting/burning of tokens
     *
     * 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, address, uint256) internal virtual {}
}