Private Credit Token

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/AccessControl.sol)

pragma solidity ^0.8.20;

import {IAccessControl} from "./IAccessControl.sol";
import {Context} from "../utils/Context.sol";
import {ERC165} from "../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:
 *
 * ```solidity
 * 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}:
 *
 * ```solidity
 * 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. We recommend using {AccessControlDefaultAdminRules}
 * to enforce additional security measures for this role.
 */
abstract contract AccessControl is Context, IAccessControl, ERC165 {
    struct RoleData {
        mapping(address account => bool) hasRole;
        bytes32 adminRole;
    }

    mapping(bytes32 role => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with an {AccessControlUnauthorizedAccount} error including the required role.
     */
    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 returns (bool) {
        return _roles[role].hasRole[account];
    }

    /**
     * @dev Reverts with an {AccessControlUnauthorizedAccount} error if `_msgSender()`
     * is missing `role`. Overriding this function changes the behavior of the {onlyRole} modifier.
     */
    function _checkRole(bytes32 role) internal view virtual {
        _checkRole(role, _msgSender());
    }

    /**
     * @dev Reverts with an {AccessControlUnauthorizedAccount} error if `account`
     * is missing `role`.
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert AccessControlUnauthorizedAccount(account, role);
        }
    }

    /**
     * @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 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 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 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 `callerConfirmation`.
     *
     * May emit a {RoleRevoked} event.
     */
    function renounceRole(bytes32 role, address callerConfirmation) public virtual {
        if (callerConfirmation != _msgSender()) {
            revert AccessControlBadConfirmation();
        }

        _revokeRole(role, callerConfirmation);
    }

    /**
     * @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 Attempts to grant `role` to `account` and returns a boolean indicating if `role` was granted.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleGranted} event.
     */
    function _grantRole(bytes32 role, address account) internal virtual returns (bool) {
        if (!hasRole(role, account)) {
            _roles[role].hasRole[account] = true;
            emit RoleGranted(role, account, _msgSender());
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Attempts to revoke `role` to `account` and returns a boolean indicating if `role` was revoked.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleRevoked} event.
     */
    function _revokeRole(bytes32 role, address account) internal virtual returns (bool) {
        if (hasRole(role, account)) {
            _roles[role].hasRole[account] = false;
            emit RoleRevoked(role, account, _msgSender());
            return true;
        } else {
            return false;
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/Address.sol)

pragma solidity ^0.8.20;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev The ETH balance of the account is not enough to perform the operation.
     */
    error AddressInsufficientBalance(address account);

    /**
     * @dev There's no code at `target` (it is not a contract).
     */
    error AddressEmptyCode(address target);

    /**
     * @dev A call to an address target failed. The target may have reverted.
     */
    error FailedInnerCall();

    /**
     * @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://consensys.net/diligence/blog/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/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        if (address(this).balance < amount) {
            revert AddressInsufficientBalance(address(this));
        }

        (bool success, ) = recipient.call{value: amount}("");
        if (!success) {
            revert FailedInnerCall();
        }
    }

    /**
     * @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 or custom error, it is bubbled
     * up by this function (like regular Solidity function calls). However, if
     * the call reverted with no returned reason, this function reverts with a
     * {FailedInnerCall} error.
     *
     * 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.
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0);
    }

    /**
     * @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`.
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        if (address(this).balance < value) {
            revert AddressInsufficientBalance(address(this));
        }
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
     * was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
     * unsuccessful call.
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata
    ) internal view returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            // only check if target is a contract if the call was successful and the return data is empty
            // otherwise we already know that it was a contract
            if (returndata.length == 0 && target.code.length == 0) {
                revert AddressEmptyCode(target);
            }
            return returndata;
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
     * revert reason or with a default {FailedInnerCall} error.
     */
    function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            return returndata;
        }
    }

    /**
     * @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
     */
    function _revert(bytes memory returndata) 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 FailedInnerCall();
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/Context.sol)

pragma solidity ^0.8.20;

/**
 * @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;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/ERC165.sol)

pragma solidity ^0.8.20;

import {IERC165} from "./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);
 * }
 * ```
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "./IERC20.sol";
import {IERC20Metadata} from "./extensions/IERC20Metadata.sol";
import {Context} from "../../utils/Context.sol";
import {IERC20Errors} from "../../interfaces/draft-IERC6093.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 */
abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
    mapping(address account => uint256) private _balances;

    mapping(address account => mapping(address spender => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the default value returned by this function, unless
     * it's overridden.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `value`.
     */
    function transfer(address to, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, value);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `value` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, value);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `value`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `value`.
     */
    function transferFrom(address from, address to, uint256 value) public virtual returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, value);
        _transfer(from, to, value);
        return true;
    }

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _transfer(address from, address to, uint256 value) internal virtual {
        if (from == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        if (to == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(from, to, value);
    }

    /**
     * @dev Transfers a `value` amount of tokens from `from` to `to`, or alternatively mints (or burns) if `from`
     * (or `to`) is the zero address. All customizations to transfers, mints, and burns should be done by overriding
     * this function.
     *
     * Emits a {Transfer} event.
     */
    function _update(address from, address to, uint256 value) internal virtual {
        if (from == address(0)) {
            // Overflow check required: The rest of the code assumes that totalSupply never overflows
            _totalSupply += value;
        } else {
            uint256 fromBalance = _balances[from];
            if (fromBalance < value) {
                revert ERC20InsufficientBalance(from, fromBalance, value);
            }
            unchecked {
                // Overflow not possible: value <= fromBalance <= totalSupply.
                _balances[from] = fromBalance - value;
            }
        }

        if (to == address(0)) {
            unchecked {
                // Overflow not possible: value <= totalSupply or value <= fromBalance <= totalSupply.
                _totalSupply -= value;
            }
        } else {
            unchecked {
                // Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
                _balances[to] += value;
            }
        }

        emit Transfer(from, to, value);
    }

    /**
     * @dev Creates a `value` amount of tokens and assigns them to `account`, by transferring it from address(0).
     * Relies on the `_update` mechanism
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _mint(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(address(0), account, value);
    }

    /**
     * @dev Destroys a `value` amount of tokens from `account`, lowering the total supply.
     * Relies on the `_update` mechanism.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead
     */
    function _burn(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        _update(account, address(0), value);
    }

    /**
     * @dev Sets `value` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     *
     * Overrides to this logic should be done to the variant with an additional `bool emitEvent` argument.
     */
    function _approve(address owner, address spender, uint256 value) internal {
        _approve(owner, spender, value, true);
    }

    /**
     * @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
     *
     * By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made by
     * `_spendAllowance` during the `transferFrom` operation set the flag to false. This saves gas by not emitting any
     * `Approval` event during `transferFrom` operations.
     *
     * Anyone who wishes to continue emitting `Approval` events on the`transferFrom` operation can force the flag to
     * true using the following override:
     * ```
     * function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
     *     super._approve(owner, spender, value, true);
     * }
     * ```
     *
     * Requirements are the same as {_approve}.
     */
    function _approve(address owner, address spender, uint256 value, bool emitEvent) internal virtual {
        if (owner == address(0)) {
            revert ERC20InvalidApprover(address(0));
        }
        if (spender == address(0)) {
            revert ERC20InvalidSpender(address(0));
        }
        _allowances[owner][spender] = value;
        if (emitEvent) {
            emit Approval(owner, spender, value);
        }
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `value`.
     *
     * Does not update the allowance value in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Does not emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 value) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            if (currentAllowance < value) {
                revert ERC20InsufficientAllowance(spender, currentAllowance, value);
            }
            unchecked {
                _approve(owner, spender, currentAllowance - value, false);
            }
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/IAccessControl.sol)

pragma solidity ^0.8.20;

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControl {
    /**
     * @dev The `account` is missing a role.
     */
    error AccessControlUnauthorizedAccount(address account, bytes32 neededRole);

    /**
     * @dev The caller of a function is not the expected one.
     *
     * NOTE: Don't confuse with {AccessControlUnauthorizedAccount}.
     */
    error AccessControlBadConfirmation();

    /**
     * @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.
     */
    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 `callerConfirmation`.
     */
    function renounceRole(bytes32 role, address callerConfirmation) external;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/IERC165.sol)

pragma solidity ^0.8.20;

/**
 * @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);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

/**
 * @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 value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

    /**
     * @dev Moves a `value` amount of 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 value) 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 a `value` amount of tokens 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 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` 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 value) external returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.20;

import {IERC20} from "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

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

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.20;

/**
 * @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.
 *
 * ==== Security Considerations
 *
 * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
 * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
 * considered as an intention to spend the allowance in any specific way. The second is that because permits have
 * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
 * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
 * generally recommended is:
 *
 * ```solidity
 * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
 *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
 *     doThing(..., value);
 * }
 *
 * function doThing(..., uint256 value) public {
 *     token.safeTransferFrom(msg.sender, address(this), value);
 *     ...
 * }
 * ```
 *
 * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
 * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
 * {SafeERC20-safeTransferFrom}).
 *
 * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
 * contracts should have entry points that don't rely on permit.
 */
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].
     *
     * CAUTION: See Security Considerations above.
     */
    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);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

interface ISPCT {
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Burn(address indexed user, uint256 amount, uint256 timestamp);
    event Deposit(address indexed user, uint256 amount, uint256 timestamp);
    event Execute(uint256 amount, uint256 timestamp);
    event InterestsDistribute(uint256 amount, uint256 fromTime, uint256 toTime);
    event Mint(address indexed user, uint256 amount, uint256 timestamp);
    event Paused(address account);
    event Redeem(address indexed user, uint256 amount, uint256 timestamp);
    event Repay(uint256 amount, uint256 timestamp);
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
    event SharesBurnt(
        address indexed account, uint256 preRebaseTokenAmount, uint256 postRebaseTokenAmount, uint256 sharesAmount
    );
    event Transfer(address indexed from, address indexed to, uint256 value);
    event TransferShares(address indexed from, address indexed to, uint256 sharesValue);
    event Unpaused(address account);
    event mintFeeRateChanged(uint256 newFeeRate, uint256 timestamp);
    event redeemFeeRateChanged(uint256 newFeeRate, uint256 timestamp);
    event treasuryChanged(address newTreasury, uint256 timestamp);

    function DEFAULT_ADMIN_ROLE() external view returns (bytes32);
    function FEE_COEFFICIENT() external view returns (uint256);
    function POOL_MANAGER_ROLE() external view returns (bytes32);
    function addToWhitelist(address _user) external;
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 value) external returns (bool);
    function balanceOf(address _account) external view returns (uint256);
    function decimals() external pure returns (uint8);
    function deposit(uint256 _amount) external;
    function depositByFiat(address _user, uint256 _amount) external;
    function distributeInterests(uint256 _amount, uint256 _fromTime, uint256 _toTime) external;
    function execute(uint256 _amount) external;
    function executedShares() external view returns (uint256);
    function getPooledUSDByShares(uint256 _sharesAmount) external view returns (uint256);
    function getRoleAdmin(bytes32 role) external view returns (bytes32);
    function getSharesByPooledUSD(uint256 _usdAmount) external view returns (uint256);
    function getTotalPooledUSD() external view returns (uint256);
    function getTotalShares() external view returns (uint256);
    function grantRole(bytes32 role, address account) external;
    function hasRole(bytes32 role, address account) external view returns (bool);
    function isWhitelist(address _user) external view returns (bool);
    function lastDistribution() external view returns (uint256);
    function maxMintFeeRate() external view returns (uint256);
    function maxRedeemFeeRate() external view returns (uint256);
    function mintFeeRate() external view returns (uint256);
    function name() external view returns (string memory);
    function pause() external;
    function paused() external view returns (bool);
    function redeem(uint256 _amount) external;
    function redeemByFiat(address _user, uint256 _amount) external;
    function redeemFeeRate() external view returns (uint256);
    function removeFromWhitelist(address _user) external;
    function renounceRole(bytes32 role, address callerConfirmation) external;
    function repay(uint256 _amount) external;
    function rescueERC20(address token, address to, uint256 amount) external;
    function reserveUSD() external view returns (uint256);
    function revokeRole(bytes32 role, address account) external;
    function setMintFeeRate(uint256 newMintFeeRate) external;
    function setRedeemFeeRate(uint256 newRedeemFeeRate) external;
    function setTreasury(address newTreasury) external;
    function sharesOf(address _account) external view returns (uint256);
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
    function symbol() external view returns (string memory);
    function totalPooledUSD() external view returns (uint256);
    function totalSupply() external view returns (uint256);
    function transfer(address to, uint256 value) external returns (bool);
    function transferFrom(address from, address to, uint256 value) external returns (bool);
    function transferShares(address _recipient, uint256 _sharesAmount) external returns (uint256);
    function treasury() external view returns (address);
    function unpause() external;
    function usdc() external view returns (address);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

interface ISPCTPriceOracle {
    function getPrice() external view returns (uint256);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

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

import "./utils/SafeMath.sol";

/**
 * @title Interest-bearing ERC20-like token for Anzen protocol.
 *
 * This contract is abstract. To make the contract deployable override the
 * `_getTotalPooledSPCT` function. `PCTPool.sol` contract inherits PCT and defines
 * the `_getTotalPooledSPCT` function.
 *
 * PCT balances are dynamic and represent the holder's share in the total amount
 * of SPCT controlled by the protocol. Account shares aren't normalized, so the
 * contract also stores the sum of all shares to calculate each account's token balance
 * which equals to:
 *
 *   shares[account] * _getTotalPooledSPCT() / _getTotalShares()
 *
 * For example, assume that we have:
 *
 *   _getTotalPooledSPCT() -> 10 SPCT
 *   sharesOf(user1) -> 100
 *   sharesOf(user2) -> 400
 *
 * Therefore:
 *
 *   balanceOf(user1) -> 2 tokens which corresponds 2 SPCT
 *   balanceOf(user2) -> 8 tokens which corresponds 8 SPCT
 *
 * Since balances of all token holders change when the amount of total pooled SPCT
 * changes, this token cannot fully implement ERC20 standard: it only emits `Transfer`
 * events upon explicit transfer between holders. In contrast, when total amount of
 * pooled SPCT increases, no `Transfer` events are generated: doing so would require
 * emitting an event for each token holder and thus running an unbounded loop.
 *
 * The token inherits from `Pausable` and uses `whenNotStopped` modifier for methods
 * which change `shares` or `allowances`. This is useful for emergency scenarios,
 * e.g. a protocol bug, where one might want to freeze all token transfers and
 * approvals until the emergency is resolved.
 */

abstract contract PCT is ERC20 {
    using SafeMath for uint256;

    uint256 private _totalShares;

    /**
     * @dev PCT balances are dynamic and are calculated based on the accounts' shares
     * and the total amount of SPCT controlled by the protocol. Account shares aren't
     * normalized, so the contract also stores the sum of all shares to calculate
     * each account's token balance which equals to:
     *
     *   shares[account] * _getTotalPooledSPCT() / _getTotalShares()
     */
    mapping(address => uint256) private _shares;

    /**
     * @dev Allowances are nominated in tokens, not token shares.
     */
    mapping(address => mapping(address => uint256)) private _allowances;

    /**
     * @notice An executed shares transfer from `sender` to `recipient`.
     *
     * @dev emitted in pair with an ERC20-defined `Transfer` event.
     */
    event TransferShares(address indexed from, address indexed to, uint256 sharesValue);

    /**
     * @notice An executed `burnShares` request
     *
     * @dev Reports simultaneously burnt shares amount
     * and corresponding PCT amount.
     * The PCT amount is calculated twice: before and after the burning incurred rebase.
     *
     * @param account holder of the burnt shares
     * @param preRebaseTokenAmount amount of PCT the burnt shares corresponded to before the burn
     * @param postRebaseTokenAmount amount of PCT the burnt shares corresponded to after the burn
     * @param sharesAmount amount of burnt shares
     */
    event SharesBurnt(
        address indexed account, uint256 preRebaseTokenAmount, uint256 postRebaseTokenAmount, uint256 sharesAmount
    );

    /**
     * @return the number of decimals for getting user representation of a token amount.
     */
    function decimals() public pure override returns (uint8) {
        return 18;
    }

    /**
     * @return the amount of tokens in existence.
     *
     * @dev Always equals to `_getTotalPooledSPCT()` since token amount
     * is pegged to the total amount of SPCT controlled by the protocol.
     */
    function totalSupply() public view override returns (uint256) {
        return _getTotalPooledSPCT();
    }

    /**
     * @return the entire amount of SPCT controlled by the protocol.
     *
     * @dev The sum of all SPCT balances in the protocol, equals to the total supply of PCT.
     */
    function getTotalPooledSPCT() public view returns (uint256) {
        return _getTotalPooledSPCT();
    }

    /**
     * @return the amount of tokens owned by the `_account`.
     *
     * @dev Balances are dynamic and equal the `_account`'s share in the amount of the
     * total SPCT controlled by the protocol. See `sharesOf`.
     */
    function balanceOf(address _account) public view override returns (uint256) {
        return getPooledSPCTByShares(_sharesOf(_account));
    }

    /**
     * @return the total amount of shares in existence.
     *
     * @dev The sum of all accounts' shares can be an arbitrary number, therefore
     * it is necessary to store it in order to calculate each account's relative share.
     */
    function getTotalShares() public view returns (uint256) {
        return _getTotalShares();
    }

    /**
     * @return the amount of shares owned by `_account`.
     */
    function sharesOf(address _account) external view returns (uint256) {
        return _sharesOf(_account);
    }

    /**
     * @return the amount of shares that corresponds to `_spctAmount` protocol-supplied SPCT.
     */
    function getSharesByPooledSPCT(uint256 _spctAmount) public view returns (uint256) {
        uint256 totalPooledSPCT = _getTotalPooledSPCT();
        return totalPooledSPCT == 0 ? 0 : _spctAmount.mul(_getTotalShares()).div(totalPooledSPCT);
    }

    /**
     * @return the amount of SPCT that corresponds to `_sharesAmount` token shares.
     */
    function getPooledSPCTByShares(uint256 _sharesAmount) public view returns (uint256) {
        uint256 totalSharesAmount = _getTotalShares();
        return totalSharesAmount == 0 ? 0 : _sharesAmount.mul(_getTotalPooledSPCT()).div(totalSharesAmount);
    }

    /**
     * @notice Moves `_sharesAmount` token shares from the caller's account to the `_recipient` account.
     *
     * @return amount of transferred tokens.
     * Emits a `TransferShares` event.
     * Emits a `Transfer` event.
     *
     * Requirements:
     *
     * - `_recipient` cannot be the zero address.
     * - the caller must have at least `_sharesAmount` shares.
     * - the contract must not be paused.
     *
     * @dev The `_sharesAmount` argument is the amount of shares, not tokens.
     */
    function transferShares(address _recipient, uint256 _sharesAmount) external returns (uint256) {
        _transferShares(msg.sender, _recipient, _sharesAmount);
        uint256 tokensAmount = getPooledSPCTByShares(_sharesAmount);
        _emitTransferEvents(msg.sender, _recipient, tokensAmount, _sharesAmount);
        return tokensAmount;
    }

    /**
     * @return the total amount of SPCT.
     * @dev This is used for calculating tokens from shares and vice versa.
     * @dev This function is required to be implemented in a derived contract.
     */
    function _getTotalPooledSPCT() internal view virtual returns (uint256);

    /**
     * @notice Moves `_amount` tokens from `_sender` to `_recipient`.
     * Emits a `Transfer` event.
     * Emits a `TransferShares` event.
     */
    function _transfer(address _sender, address _recipient, uint256 _amount) internal override {
        uint256 _sharesToTransfer = getSharesByPooledSPCT(_amount);
        _transferShares(_sender, _recipient, _sharesToTransfer);
        _emitTransferEvents(_sender, _recipient, _amount, _sharesToTransfer);
    }

    /**
     * @return the total amount of shares in existence.
     */
    function _getTotalShares() internal view returns (uint256) {
        return _totalShares;
    }

    /**
     * @return the amount of shares owned by `_account`.
     */
    function _sharesOf(address _account) internal view returns (uint256) {
        return _shares[_account];
    }

    /**
     * @notice Moves `_sharesAmount` shares from `_sender` to `_recipient`.
     *
     * Requirements:
     *
     * - `_sender` cannot be the zero address.
     * - `_recipient` cannot be the zero address.
     * - `_sender` must hold at least `_sharesAmount` shares.
     * - the contract must not be paused.
     */
    function _transferShares(address _sender, address _recipient, uint256 _sharesAmount) internal {
        require(_sender != address(0), "TRANSFER_FROM_THE_ZERO_ADDRESS");
        require(_recipient != address(0), "TRANSFER_TO_THE_ZERO_ADDRESS");

        uint256 currentSenderShares = _shares[_sender];
        require(_sharesAmount <= currentSenderShares, "TRANSFER_AMOUNT_EXCEEDS_BALANCE");

        _shares[_sender] = currentSenderShares.sub(_sharesAmount);
        _shares[_recipient] = _shares[_recipient].add(_sharesAmount);
    }

    /**
     * @notice Creates `_sharesAmount` shares and assigns them to `_recipient`, increasing the total amount of shares.
     * @dev This doesn't increase the token total supply.
     *
     * NB: The method doesn't check protocol pause relying on the external enforcement.
     *
     * Requirements:
     *
     * - `_recipient` cannot be the zero address.
     * - the contract must not be paused.
     * - _recipient is verified.
     */
    function _mintShares(address _recipient, uint256 _sharesAmount) internal returns (uint256 newTotalShares) {
        require(_recipient != address(0), "MINT_TO_ZERO_ADDR");

        newTotalShares = _getTotalShares().add(_sharesAmount);
        _totalShares = newTotalShares;

        _shares[_recipient] = _shares[_recipient].add(_sharesAmount);

        // Notice: we're not emitting a Transfer event from the zero address here since shares mint
        // works by taking the amount of tokens corresponding to the minted shares from all other
        // token holders, proportionally to their share. The total supply of the token doesn't change
        // as the result. This is equivalent to performing a send from each other token holder's
        // address to `address`, but we cannot reflect this as it would require sending an unbounded
        // number of events.
    }

    /**
     * @notice Destroys `_sharesAmount` shares from `_account`'s holdings, decreasing the total amount of shares.
     * @dev This doesn't decrease the token total supply.
     *
     * Requirements:
     *
     * - `_account` cannot be the zero address.
     * - `_account` must hold at least `_sharesAmount` shares.
     * - the contract must not be paused.
     */
    function _burnShares(address _account, uint256 _sharesAmount) internal returns (uint256 newTotalShares) {
        require(_account != address(0), "BURN_FROM_ZERO_ADDR");

        uint256 accountShares = _shares[_account];
        require(_sharesAmount <= accountShares, "BALANCE_EXCEEDED");

        uint256 preRebaseTokenAmount = getPooledSPCTByShares(_sharesAmount);

        newTotalShares = _getTotalShares().sub(_sharesAmount);
        _totalShares = newTotalShares;

        _shares[_account] = accountShares.sub(_sharesAmount);

        uint256 postRebaseTokenAmount = getPooledSPCTByShares(_sharesAmount);

        emit SharesBurnt(_account, preRebaseTokenAmount, postRebaseTokenAmount, _sharesAmount);

        // Notice: we're not emitting a Transfer event to the zero address here since shares burn
        // works by redistributing the amount of tokens corresponding to the burned shares between
        // all other token holders. The total supply of the token doesn't change as the result.
        // This is equivalent to performing a send from `address` to each other token holder address,
        // but we cannot reflect this as it would require sending an unbounded number of events.

        // We're emitting `SharesBurnt` event to provide an explicit rebase log record nonetheless.
    }

    /**
     * @dev Emits {Transfer} and {TransferShares} events
     */
    function _emitTransferEvents(address _from, address _to, uint256 _tokenAmount, uint256 _sharesAmount) internal {
        emit Transfer(_from, _to, _tokenAmount);
        emit TransferShares(_from, _to, _sharesAmount);
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

import "@openzeppelin/contracts/access/AccessControl.sol";
import "@openzeppelin/contracts/utils/Pausable.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

import "./PCT.sol";
import "./utils/SafeMath.sol";

import "./interfaces/ISPCT.sol";
import "./interfaces/ISPCTPriceOracle.sol";

/**
 * @title Interest-bearing ERC20-like token for Anzen protocol.
 */

contract PCTPool is PCT, AccessControl, Pausable {
    using SafeERC20 for IERC20;
    using SafeMath for uint256;

    bytes32 public constant POOL_MANAGER_ROLE = keccak256("POOL_MANAGER_ROLE");

    // Restricting call deposit and redeem in the same block.
    mapping(address => uint256) private _status;

    // Interest mode
    bool public mode = false;

    // Used to calculate total executed shares.
    uint256 public executedShares;
    // Used to calculate total pooled SPCT.
    uint256 public totalPooledSPCT;
    // Used to calculate collateral rate.
    uint256 public collateralRate = 1;

    // Fee Zone
    uint256 public constant FEE_COEFFICIENT = 1e8;
    // Fee should be less than 1%.
    uint256 public constant maxMintFeeRate = FEE_COEFFICIENT / 100;
    uint256 public constant maxRedeemFeeRate = FEE_COEFFICIENT / 100;
    uint256 public mintFeeRate;
    uint256 public redeemFeeRate;
    // Protocol treasury should be a mulsig wallet.
    address public treasury;

    // Lend token
    IERC20 public usdc;
    // Collateral token
    ISPCT public spct;
    // Price oracle
    ISPCTPriceOracle public oracle;

    event ModeSwitch(bool mode, uint256 timestamp);

    event Deposit(address indexed user, uint256 amount, uint256 timestamp);
    event Redeem(address indexed user, uint256 amount, uint256 timestamp);
    event Mint(address indexed user, uint256 amount, uint256 timestamp);
    event Burn(address indexed user, uint256 amount, uint256 timestamp);

    event mintFeeRateChanged(uint256 newFeeRate, uint256 timestamp);
    event redeemFeeRateChanged(uint256 newFeeRate, uint256 timestamp);
    event treasuryChanged(address newTreasury, uint256 timestamp);
    event oracleChanged(address newOracle, uint256 timestamp);

    constructor(address admin, IERC20 _usdc, ISPCT _spct, ISPCTPriceOracle _oracle)
        ERC20("Private Credit Token", "PCT")
    {
        _grantRole(DEFAULT_ADMIN_ROLE, admin);
        usdc = _usdc;
        spct = _spct;
        oracle = _oracle;
    }

    modifier checkCollateralRate() {
        _checkCollateralRate();
        _;
    }

    modifier checkRebasing() {
        _checkRebasing();
        _;
    }

    /**
     * @notice Check collateral rate.
     */
    function _checkCollateralRate() internal {
        if (oracle.getPrice() / 1e18 < collateralRate) {
            _pause();
            revert("UNDER_COLLATERAL_RATE,SMART_CONTRACT_IS_PAUSED_NOW");
        }
    }

    /**
     * @notice Check rebasing.
     */
    function _checkRebasing() internal {
        totalPooledSPCT = spct.getPooledUSDByShares(executedShares);
    }

    /**
     * @notice Pause the contract. Revert if already paused.
     */
    function pause() external onlyRole(DEFAULT_ADMIN_ROLE) {
        _pause();
    }

    /**
     * @notice Unpause the contract. Revert if already unpaused.
     */
    function unpause() external onlyRole(DEFAULT_ADMIN_ROLE) {
        _unpause();
    }

    /**
     * @notice Switch to interest mode.
     * Emits a `ModeSwitch` event.
     */
    function switchMode() external onlyRole(DEFAULT_ADMIN_ROLE) {
        mode = !mode;
        emit ModeSwitch(mode, block.timestamp);
    }

    /**
     * @notice deposit USDC. (borrow USDC from user and deposit collateral)
     * Emits a `Deposit` event.
     *
     * @param _amount the amount of USDC
     */
    function deposit(uint256 _amount) external whenNotPaused checkCollateralRate checkRebasing {
        require(mode == false, "PLEASE_MIGRATE_TO_NEW_VERSION");
        require(_amount > 0, "DEPOSIT_AMOUNT_IS_ZERO");
        require(_status[tx.origin] != block.number, "FUNCTION_RESTRICTION");

        usdc.transferFrom(msg.sender, address(this), _amount);
        usdc.approve(address(spct), _amount); // approve for depositing collateral

        // Due to different precisions, convert it to PCT.
        uint256 convertToSPCT = _amount.mul(1e12);
        // Get mint rate from spct for calculating.
        uint256 spctMintFeeRate = spct.mintFeeRate();

        // calculate fee with PCT
        if (mintFeeRate == 0) {
            if (spctMintFeeRate == 0) {
                _mintPCT(msg.sender, convertToSPCT);

                spct.deposit(_amount);
            } else {
                uint256 spctFeeAmount = convertToSPCT.mul(spctMintFeeRate).div(FEE_COEFFICIENT);
                uint256 spctAmountAfterFee = convertToSPCT.sub(spctFeeAmount);

                _mintPCT(msg.sender, spctAmountAfterFee);

                spct.deposit(_amount);
            }
        } else {
            if (spctMintFeeRate == 0) {
                uint256 feeAmount = convertToSPCT.mul(mintFeeRate).div(FEE_COEFFICIENT);
                uint256 amountAfterFee = convertToSPCT.sub(feeAmount);

                _mintPCT(msg.sender, amountAfterFee);

                if (feeAmount != 0) {
                    _mintPCT(treasury, feeAmount);
                }

                spct.deposit(_amount);
            } else {
                uint256 spctFeeAmount = convertToSPCT.mul(spctMintFeeRate).div(FEE_COEFFICIENT);
                uint256 spctAmountAfterFee = convertToSPCT.sub(spctFeeAmount);
                uint256 feeAmount = spctAmountAfterFee.mul(mintFeeRate).div(FEE_COEFFICIENT);
                uint256 amountAfterFee = spctAmountAfterFee.sub(feeAmount);

                _mintPCT(msg.sender, amountAfterFee);

                if (feeAmount != 0) {
                    _mintPCT(treasury, feeAmount);
                }

                spct.deposit(_amount);
            }
        }

        _status[tx.origin] = block.number;
        emit Deposit(msg.sender, _amount, block.timestamp);
    }

    /**
     * @notice redeem PCT. (get back USDC from borrower and release collateral)
     * 6 decimal input
     * Emits a `Redeem` event.
     *
     * @param _amount the amount of PCT.
     */
    function redeem(uint256 _amount) external whenNotPaused checkCollateralRate checkRebasing {
        require(spct.reserveUSD().mul(1e12) >= _amount, "RESERVE_INSUFFICIENT");
        require(_amount > 0, "REDEEM_AMOUNT_IS_ZERO");
        require(_status[tx.origin] != block.number, "FUNCTION_RESTRICTION");

        // Due to different precisions, convert it to PCT.
        uint256 convertToUSDC;
        // Get redeem rate from spct for calculating.
        uint256 spctRedeemFeeRate = spct.redeemFeeRate();

        // calculate fee with PCT
        if (redeemFeeRate == 0) {
            if (spctRedeemFeeRate == 0) {
                _burnPCT(msg.sender, _amount);

                spct.redeem(_amount);
                convertToUSDC = _amount.div(1e12);
                usdc.transfer(msg.sender, convertToUSDC);
            } else {
                uint256 spctFeeAmount = _amount.mul(spctRedeemFeeRate).div(FEE_COEFFICIENT);
                uint256 spctAmountAfterFee = _amount.sub(spctFeeAmount);

                _burnPCT(msg.sender, _amount);

                spct.redeem(_amount);
                convertToUSDC = spctAmountAfterFee.div(1e12);
                usdc.transfer(msg.sender, convertToUSDC);
            }
        } else {
            if (spctRedeemFeeRate == 0) {
                uint256 feeAmount = _amount.mul(redeemFeeRate).div(FEE_COEFFICIENT);
                uint256 amountAfterFee = _amount.sub(feeAmount);

                _burnPCT(msg.sender, amountAfterFee);

                if (feeAmount != 0) {
                    _transfer(msg.sender, treasury, feeAmount);
                }

                spct.redeem(amountAfterFee);
                convertToUSDC = amountAfterFee.div(1e12);
                usdc.transfer(msg.sender, convertToUSDC);
            } else {
                uint256 feeAmount = _amount.mul(redeemFeeRate).div(FEE_COEFFICIENT);
                uint256 amountAfterFee = _amount.sub(feeAmount);
                uint256 spctFeeAmount = amountAfterFee.mul(spctRedeemFeeRate).div(FEE_COEFFICIENT);
                uint256 spctAmountAfterFee = amountAfterFee.sub(spctFeeAmount);

                _burnPCT(msg.sender, amountAfterFee);

                if (feeAmount != 0) {
                    _transfer(msg.sender, treasury, feeAmount);
                }

                spct.redeem(amountAfterFee);
                convertToUSDC = spctAmountAfterFee.div(1e12);
                usdc.transfer(msg.sender, convertToUSDC);
            }
        }

        _status[tx.origin] = block.number;
        emit Redeem(msg.sender, _amount, block.timestamp);
    }

    /**
     * @notice total pooled SPCT.
     */
    function _getTotalPooledSPCT() internal view override returns (uint256) {
        return spct.getPooledUSDByShares(executedShares);
    }

    /**
     * @dev mint PCT for _receiver.
     * Emits `Mint` and `Transfer` event.
     *
     * @param _receiver address to receive SPCT.
     * @param _amount the amount of SPCT.
     */
    function _mintPCT(address _receiver, uint256 _amount) internal {
        uint256 sharesAmount = getSharesByPooledSPCT(_amount);
        if (sharesAmount == 0) {
            // 1 PCT shares are equal to 1 USDC.
            sharesAmount = _amount;
        }
        _mintShares(_receiver, sharesAmount);

        executedShares = executedShares.add(sharesAmount);
        totalPooledSPCT = totalPooledSPCT.add(_amount);
        emit Mint(msg.sender, _amount, block.timestamp);
        emit Transfer(address(0), _receiver, _amount);
    }

    /**
     * @dev burn PCT from _receiver.
     * Emits `Burn` and `Transfer` event.
     *
     * @param _account address to burn PCT from.
     * @param _amount the amount of PCT.
     */
    function _burnPCT(address _account, uint256 _amount) internal {
        uint256 sharesAmount = getSharesByPooledSPCT(_amount);
        require(sharesAmount > 0, "SHARES_AMOUNT_IS_ZERO");
        _burnShares(_account, sharesAmount);

        executedShares = executedShares.sub(sharesAmount);
        totalPooledSPCT = totalPooledSPCT.sub(_amount);
        emit Burn(msg.sender, _amount, block.timestamp);
        emit Transfer(_account, address(0), _amount);
    }

    /**
     * @notice Mint fee.
     *
     * @param newMintFeeRate new mint fee rate.
     */
    function setMintFeeRate(uint256 newMintFeeRate) external onlyRole(POOL_MANAGER_ROLE) {
        require(newMintFeeRate <= maxMintFeeRate, "SHOULD_BE_LESS_THAN_1P");
        mintFeeRate = newMintFeeRate;
        emit mintFeeRateChanged(mintFeeRate, block.timestamp);
    }

    /**
     * @notice Redeem fee.
     *
     * @param newRedeemFeeRate new redeem fee rate.
     */
    function setRedeemFeeRate(uint256 newRedeemFeeRate) external onlyRole(POOL_MANAGER_ROLE) {
        require(newRedeemFeeRate <= maxRedeemFeeRate, "SHOULD_BE_LESS_THAN_1P");
        redeemFeeRate = newRedeemFeeRate;
        emit redeemFeeRateChanged(redeemFeeRate, block.timestamp);
    }

    /**
     * @notice Treasury address.
     *
     * @param newTreasury new treasury address.
     */
    function setTreasury(address newTreasury) external onlyRole(POOL_MANAGER_ROLE) {
        require(newTreasury != address(0), "SET_UP_TO_ZERO_ADDR");
        treasury = newTreasury;
        emit treasuryChanged(treasury, block.timestamp);
    }

    /**
     * @notice Oracle address.
     *
     * @param newOracle new Oracle address.
     */
    function setOracle(address newOracle) external onlyRole(POOL_MANAGER_ROLE) {
        require(newOracle != address(0), "SET_UP_TO_ZERO_ADDR");
        oracle = ISPCTPriceOracle(newOracle);
        emit oracleChanged(newOracle, block.timestamp);
    }

    /**
     * @notice Rescue ERC20 tokens locked up in this contract.
     * @param token ERC20 token contract address.
     * @param to recipient address.
     * @param amount amount to withdraw.
     */
    function rescueERC20(IERC20 token, address to, uint256 amount) external onlyRole(POOL_MANAGER_ROLE) {
        // If is SPCT, check total pooled amount first.
        if (address(token) == address(spct)) {
            require(amount <= spct.balanceOf(address(this)).sub(totalPooledSPCT), "SPCT_RESCUE_AMOUNT_EXCEED_DEBIT");
        }
        token.safeTransfer(to, amount);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/Pausable.sol)

pragma solidity ^0.8.20;

import {Context} from "../utils/Context.sol";

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    bool private _paused;

    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    /**
     * @dev The operation failed because the contract is paused.
     */
    error EnforcedPause();

    /**
     * @dev The operation failed because the contract is not paused.
     */
    error ExpectedPause();

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }

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

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

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

    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        if (paused()) {
            revert EnforcedPause();
        }
    }

    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        if (!paused()) {
            revert ExpectedPause();
        }
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "../IERC20.sol";
import {IERC20Permit} from "../extensions/IERC20Permit.sol";
import {Address} from "../../../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;

    /**
     * @dev An operation with an ERC20 token failed.
     */
    error SafeERC20FailedOperation(address token);

    /**
     * @dev Indicates a failed `decreaseAllowance` request.
     */
    error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        forceApprove(token, spender, oldAllowance + value);
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
     * value, non-reverting calls are assumed to be successful.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
        unchecked {
            uint256 currentAllowance = token.allowance(address(this), spender);
            if (currentAllowance < requestedDecrease) {
                revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
            }
            forceApprove(token, spender, currentAllowance - requestedDecrease);
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
     * to be set to zero before setting it to a non-zero value, such as USDT.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @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);
        if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @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).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        // 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 cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

        (bool success, bytes memory returndata) = address(token).call(data);
        return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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;
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (interfaces/draft-IERC6093.sol)
pragma solidity ^0.8.20;

/**
 * @dev Standard ERC20 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC20 tokens.
 */
interface IERC20Errors {
    /**
     * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param balance Current balance for the interacting account.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC20InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC20InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `spender`’s `allowance`. Used in transfers.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     * @param allowance Amount of tokens a `spender` is allowed to operate with.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC20InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `spender` to be approved. Used in approvals.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC20InvalidSpender(address spender);
}

/**
 * @dev Standard ERC721 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC721 tokens.
 */
interface IERC721Errors {
    /**
     * @dev Indicates that an address can't be an owner. For example, `address(0)` is a forbidden owner in EIP-20.
     * Used in balance queries.
     * @param owner Address of the current owner of a token.
     */
    error ERC721InvalidOwner(address owner);

    /**
     * @dev Indicates a `tokenId` whose `owner` is the zero address.
     * @param tokenId Identifier number of a token.
     */
    error ERC721NonexistentToken(uint256 tokenId);

    /**
     * @dev Indicates an error related to the ownership over a particular token. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param tokenId Identifier number of a token.
     * @param owner Address of the current owner of a token.
     */
    error ERC721IncorrectOwner(address sender, uint256 tokenId, address owner);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC721InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC721InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     * @param tokenId Identifier number of a token.
     */
    error ERC721InsufficientApproval(address operator, uint256 tokenId);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC721InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC721InvalidOperator(address operator);
}

/**
 * @dev Standard ERC1155 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC1155 tokens.
 */
interface IERC1155Errors {
    /**
     * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param balance Current balance for the interacting account.
     * @param needed Minimum amount required to perform a transfer.
     * @param tokenId Identifier number of a token.
     */
    error ERC1155InsufficientBalance(address sender, uint256 balance, uint256 needed, uint256 tokenId);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC1155InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC1155InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     * @param owner Address of the current owner of a token.
     */
    error ERC1155MissingApprovalForAll(address operator, address owner);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC1155InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC1155InvalidOperator(address operator);

    /**
     * @dev Indicates an array length mismatch between ids and values in a safeBatchTransferFrom operation.
     * Used in batch transfers.
     * @param idsLength Length of the array of token identifiers
     * @param valuesLength Length of the array of token amounts
     */
    error ERC1155InvalidArrayLength(uint256 idsLength, uint256 valuesLength);
}

{
  "compilationTarget": {
    "src/PCTPool.sol": "PCTPool"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": [
    ":@chainlink/contracts/=lib/chainlink/contracts/",
    ":@layerzerolabs/solidity-examples/contracts/=lib/solidity-examples/contracts/",
    ":@openzeppelin/contracts-upgradeable/=lib/openzeppelin-contracts-upgradeable/contracts/",
    ":@openzeppelin/contracts/=lib/openzeppelin-contracts/contracts/",
    ":chainlink/=lib/chainlink/contracts/src/v0.6/vendor/@arbitrum/nitro-contracts/src/",
    ":ds-test/=lib/forge-std/lib/ds-test/src/",
    ":erc4626-tests/=lib/openzeppelin-contracts-upgradeable/lib/erc4626-tests/",
    ":forge-std/=lib/forge-std/src/",
    ":openzeppelin-contracts-upgradeable/=lib/openzeppelin-contracts-upgradeable/",
    ":openzeppelin-contracts/=lib/openzeppelin-contracts/",
    ":openzeppelin/=lib/openzeppelin-contracts-upgradeable/contracts/",
    ":solidity-examples/=lib/solidity-examples/contracts/"
  ]
}