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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

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



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

pragma solidity ^0.8.0;

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

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

// File: contracts/Limiter.sol



import './Proxy.sol';

pragma solidity 0.8.9;

contract Limiter is Proxy {
  constructor(
    address _bridgeIn,
    address _bridgeOut,
    address _admin,
    address _implementation
  ) Proxy(_implementation) {
    require(
      _bridgeIn != address(0) && _bridgeOut != address(0) && _admin != address(0),
      'invalid input'
    );
    delegateTo(
      _implementation,
      abi.encodeWithSignature('initialize(address,address,address)', _bridgeIn, _bridgeOut, _admin)
    );
  }

  function delegateTo(address callee, bytes memory data) internal returns (bytes memory) {
    (bool success, bytes memory returnData) = callee.delegatecall(data);
    assembly {
      if eq(success, 0) {
        revert(add(returnData, 0x20), returndatasize())
      }
    }
    return returnData;
  }

  receive() external payable {}

  fallback() external payable {
    // delegate all other functions to current implementation
    (bool success, ) = _implementation.delegatecall(msg.data);
    assembly {
      let free_mem_ptr := mload(0x40)
      returndatacopy(free_mem_ptr, 0, returndatasize())
      switch success
      case 0 {
        revert(free_mem_ptr, returndatasize())
      }
      default {
        return(free_mem_ptr, returndatasize())
      }
    }
  }
}

// File: contracts/Proxy.sol



import "@openzeppelin/contracts/access/Ownable.sol";
pragma solidity 0.8.9;

contract ProxyStorage is Ownable {
    address internal _implementation;
}

contract Proxy is ProxyStorage {
    event ProxyUpdated(address indexed _new, address indexed _old);
    event OwnerUpdate(address _prevOwner, address _newOwner);

    constructor(address _proxyTo) {
        updateImplementation(_proxyTo);
    }

    function updateImplementation(address _newImplementation) public onlyOwner {
        require(_newImplementation != address(0x0), "INVALID_PROXY_ADDRESS");
        require(
            isContract(_newImplementation),
            "DESTINATION_ADDRESS_IS_NOT_A_CONTRACT"
        );
        emit ProxyUpdated(_newImplementation, _implementation);
        _implementation = _newImplementation;
    }

    function implementation() external view returns (address) {
        return _implementation;
    }

    function isContract(address _target) internal view returns (bool) {
        if (_target == address(0)) {
            return false;
        }

        uint256 size;
        assembly {
            size := extcodesize(_target)
        }
        return size > 0;
    }
}