// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.13;

// OpenZeppelin Contracts (last updated v4.6.0) (proxy/Proxy.sol)

/**
 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
 * be specified by overriding the virtual {_implementation} function.
 *
 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
 * different contract through the {_delegate} function.
 *
 * The success and return data of the delegated call will be returned back to the caller of the proxy.
 */
abstract contract Proxy {
    /**
     * @dev Delegates the current call to `implementation`.
     *
     * This function does not return to its internal call site, it will return directly to the external caller.
     */
    function _delegate(address implementation) internal virtual {
        assembly {
            // Copy msg.data. We take full control of memory in this inline assembly
            // block because it will not return to Solidity code. We overwrite the
            // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize())

            // Call the implementation.
            // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)

            // Copy the returned data.
            returndatacopy(0, 0, returndatasize())

            switch result
            // delegatecall returns 0 on error.
            case 0 {
                revert(0, returndatasize())
            }
            default {
                return(0, returndatasize())
            }
        }
    }

    /**
     * @dev This is a virtual function that should be overridden so it returns the address to which the fallback function
     * and {_fallback} should delegate.
     */
    function _implementation() internal view virtual returns (address);

    /**
     * @dev Delegates the current call to the address returned by `_implementation()`.
     *
     * This function does not return to its internal call site, it will return directly to the external caller.
     */
    function _fallback() internal virtual {
        _beforeFallback();
        _delegate(_implementation());
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
     * function in the contract matches the call data.
     */
    fallback() external payable virtual {
        _fallback();
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
     * is empty.
     */
    receive() external payable virtual {
        _fallback();
    }

    /**
     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
     * call, or as part of the Solidity `fallback` or `receive` functions.
     *
     * If overridden should call `super._beforeFallback()`.
     */
    function _beforeFallback() internal virtual {}
}

/// @title IERC1967Upgrade
/// @author Rohan Kulkarni
/// @notice The external ERC1967Upgrade events and errors
interface IERC1967Upgrade {
    ///                                                          ///
    ///                            EVENTS                        ///
    ///                                                          ///

    /// @notice Emitted when the implementation is upgraded
    /// @param impl The address of the implementation
    event Upgraded(address impl);

    ///                                                          ///
    ///                            ERRORS                        ///
    ///                                                          ///

    /// @dev Reverts if an implementation is an invalid upgrade
    /// @param impl The address of the invalid implementation
    error INVALID_UPGRADE(address impl);

    /// @dev Reverts if an implementation upgrade is not stored at the storage slot of the original
    error UNSUPPORTED_UUID();

    /// @dev Reverts if an implementation does not support ERC1822 proxiableUUID()
    error ONLY_UUPS();
}

// OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)

/**
 * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
 * proxy whose upgrades are fully controlled by the current implementation.
 */
interface IERC1822Proxiable {
    /**
     * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
     * address.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy.
     */
    function proxiableUUID() external view returns (bytes32);
}

// OpenZeppelin Contracts (last updated v4.7.0) (utils/StorageSlot.sol)

/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlot {
    struct AddressSlot {
        address value;
    }

    struct BooleanSlot {
        bool value;
    }

    struct Bytes32Slot {
        bytes32 value;
    }

    struct Uint256Slot {
        uint256 value;
    }

    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }
}

/// @title EIP712
/// @author Rohan Kulkarni
/// @notice Modified from OpenZeppelin Contracts v4.7.3 (utils/Address.sol)
/// - Uses custom errors `INVALID_TARGET()` & `DELEGATE_CALL_FAILED()`
/// - Adds util converting address to bytes32
library Address {
    ///                                                          ///
    ///                            ERRORS                        ///
    ///                                                          ///

    /// @dev Reverts if the target of a delegatecall is not a contract
    error INVALID_TARGET();

    /// @dev Reverts if a delegatecall has failed
    error DELEGATE_CALL_FAILED();

    ///                                                          ///
    ///                           FUNCTIONS                      ///
    ///                                                          ///

    /// @dev Utility to convert an address to bytes32
    function toBytes32(address _account) internal pure returns (bytes32) {
        return bytes32(uint256(uint160(_account)) << 96);
    }

    /// @dev If an address is a contract
    function isContract(address _account) internal view returns (bool rv) {
        assembly {
            rv := gt(extcodesize(_account), 0)
        }
    }

    /// @dev Performs a delegatecall on an address
    function functionDelegateCall(
        address _target,
        bytes memory _data
    ) internal returns (bytes memory) {
        if (!isContract(_target)) revert INVALID_TARGET();

        (bool success, bytes memory returndata) = _target.delegatecall(_data);

        return verifyCallResult(success, returndata);
    }

    /// @dev Verifies a delegatecall was successful
    function verifyCallResult(
        bool _success,
        bytes memory _returndata
    ) internal pure returns (bytes memory) {
        if (_success) {
            return _returndata;
        } else {
            if (_returndata.length > 0) {
                assembly {
                    let returndata_size := mload(_returndata)

                    revert(add(32, _returndata), returndata_size)
                }
            } else {
                revert DELEGATE_CALL_FAILED();
            }
        }
    }
}

/// @title ERC1967Upgrade
/// @author Rohan Kulkarni
/// @notice Modified from OpenZeppelin Contracts v4.7.3 (proxy/ERC1967/ERC1967Upgrade.sol)
/// - Uses custom errors declared in IERC1967Upgrade
/// - Removes ERC1967 admin and beacon support
abstract contract ERC1967Upgrade is IERC1967Upgrade {
    ///                                                          ///
    ///                          CONSTANTS                       ///
    ///                                                          ///

    /// @dev bytes32(uint256(keccak256('eip1967.proxy.rollback')) - 1)
    bytes32 private constant _ROLLBACK_SLOT =
        0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;

    /// @dev bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1)
    bytes32 internal constant _IMPLEMENTATION_SLOT =
        0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    ///                                                          ///
    ///                          FUNCTIONS                       ///
    ///                                                          ///

    /// @dev Upgrades to an implementation with security checks for UUPS proxies and an additional function call
    /// @param _newImpl The new implementation address
    /// @param _data The encoded function call
    function _upgradeToAndCallUUPS(
        address _newImpl,
        bytes memory _data,
        bool _forceCall
    ) internal {
        if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
            _setImplementation(_newImpl);
        } else {
            try IERC1822Proxiable(_newImpl).proxiableUUID() returns (
                bytes32 slot
            ) {
                if (slot != _IMPLEMENTATION_SLOT) revert UNSUPPORTED_UUID();
            } catch {
                revert ONLY_UUPS();
            }

            _upgradeToAndCall(_newImpl, _data, _forceCall);
        }
    }

    /// @dev Upgrades to an implementation with an additional function call
    /// @param _newImpl The new implementation address
    /// @param _data The encoded function call
    function _upgradeToAndCall(
        address _newImpl,
        bytes memory _data,
        bool _forceCall
    ) internal {
        _upgradeTo(_newImpl);

        if (_data.length > 0 || _forceCall) {
            Address.functionDelegateCall(_newImpl, _data);
        }
    }

    /// @dev Performs an implementation upgrade
    /// @param _newImpl The new implementation address
    function _upgradeTo(address _newImpl) internal {
        _setImplementation(_newImpl);

        emit Upgraded(_newImpl);
    }

    /// @dev Stores the address of an implementation
    /// @param _impl The implementation address
    function _setImplementation(address _impl) private {
        if (!Address.isContract(_impl)) revert INVALID_UPGRADE(_impl);

        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = _impl;
    }

    /// @dev The address of the current implementation
    function _getImplementation() internal view returns (address) {
        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }
}

/// @title ERC1967Proxy
/// @author Rohan Kulkarni
/// @notice Modified from OpenZeppelin Contracts v4.7.3 (proxy/ERC1967/ERC1967Proxy.sol)
/// - Inherits a modern, minimal ERC1967Upgrade
contract ERC1967Proxy is IERC1967Upgrade, Proxy, ERC1967Upgrade {
    ///                                                          ///
    ///                         CONSTRUCTOR                      ///
    ///                                                          ///

    /// @dev Initializes the proxy with an implementation contract and encoded function call
    /// @param _logic The implementation address
    /// @param _data The encoded function call
    constructor(address _logic, bytes memory _data) payable {
        _upgradeToAndCall(_logic, _data, false);
    }

    ///                                                          ///
    ///                          FUNCTIONS                       ///
    ///                                                          ///

    /// @dev The address of the current implementation
    function _implementation()
        internal
        view
        virtual
        override
        returns (address)
    {
        return ERC1967Upgrade._getImplementation();
    }
}

contract TokenProxy is ERC1967Proxy {
    constructor(address logic, bytes memory data) ERC1967Proxy(logic, data) {}
}