// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File @openzeppelin/contracts/access/Ownable.sol@v4.4.2

// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;

/**
 * @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 Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File contracts/interfaces/ICurrencyManager.sol
pragma solidity ^0.8.0;

interface ICurrencyManager {
    function addCurrency(address currency) external;

    function removeCurrency(address currency) external;

    function isCurrencyWhitelisted(address currency) external view returns (bool);

    function viewWhitelistedCurrencies(uint256 cursor, uint256 size) external view returns (address[] memory, uint256);

    function viewCountWhitelistedCurrencies() external view returns (uint256);
}

// File contracts/CurrencyManagerOwner.sol
pragma solidity ^0.8.0;

interface IOwnableCurrencyManager is ICurrencyManager {
    function transferOwnership(address newOwner) external;
}

contract CurrencyManagerOwner is Ownable {
    IOwnableCurrencyManager public currencyManager;

    modifier beforeDeadline(uint256 deadline) {
        require(block.timestamp <= deadline, "LooksRare: Too late");
        _;
    }

    constructor(address _currencyManager) {
        currencyManager = IOwnableCurrencyManager(_currencyManager);
    }

    function addCurrency(address currency) public onlyOwner {
        currencyManager.addCurrency(currency);
    }

    function removeCurrency(address currency) public onlyOwner {
        currencyManager.removeCurrency(currency);
    }

    function addCurrencyWithCustomProtectionForMinDifficulty(
        address currency,
        uint256 minDifficulty,
        uint256 deadline
    ) public onlyOwner beforeDeadline(deadline) {
        require(block.difficulty > minDifficulty, "LooksRare: Goodbye PoW");
        currencyManager.addCurrency(currency);
    }

    function removeCurrencyWithCustomProtectionForMinDifficulty(
        address currency,
        uint256 minDifficulty,
        uint256 deadline
    ) public onlyOwner beforeDeadline(deadline) {
        require(block.difficulty > minDifficulty, "LooksRare: Goodbye PoW");
        currencyManager.removeCurrency(currency);
    }

    function addCurrencyWithCustomProtectionForMaxDifficulty(
        address currency,
        uint256 maxDifficulty,
        uint256 deadline
    ) public onlyOwner beforeDeadline(deadline) {
        require(block.difficulty < maxDifficulty, "LooksRare: Goodbye PoW");
        currencyManager.addCurrency(currency);
    }

    function removeCurrencyWithCustomProtectionForMaxDifficulty(
        address currency,
        uint256 maxDifficulty,
        uint256 deadline
    ) public onlyOwner beforeDeadline(deadline) {
        require(block.difficulty < maxDifficulty, "LooksRare: Goodbye PoW");
        currencyManager.removeCurrency(currency);
    }

    function transferOwnershipCurrencyManager(address newOwner, uint256 deadline)
        public
        onlyOwner
        beforeDeadline(deadline)
    {
        currencyManager.transferOwnership(newOwner);
    }
}