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



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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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



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

pragma solidity ^0.8.0;

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

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

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

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
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);
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol



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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

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

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



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

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

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

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}

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



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

pragma solidity ^0.8.0;

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

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

// File: contracts/dapp-game/CflatsDappRequirements.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;

import "@openzeppelin/contracts/access/IAccessControl.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "./errors/CflatsDatabaseErrors.sol";
import "./ICflatsDappRequirements.sol";


abstract contract CflatsDappRequirements is ICflatsDappRequirements, Context
{
    bytes32 private constant _DEFAULT_ADMIN_ROLE = 0x00;
    ICflatsDatabase private immutable _DATABASE;
    constructor(ICflatsDatabase database)
    {
        _DATABASE = database;
    }


    function getDatabase() public view returns (ICflatsDatabase)
    {
        return _DATABASE;
    }



    modifier onlyNotBlacklisted()
    {
        _requireNotBlacklisted(_msgSender());
        _;
    }

    modifier onlyAdmin()
    {
        _requireNotBlacklisted(_msgSender());
        _;
    }

    modifier onlyOperator()
    {
        _requireOperator(_msgSender());
        _;
    }

    modifier onlyDeveloper()
    {
        _requireDeveloper(_msgSender());
        _;
    }



    function _requireAdmin(address user) private view
    {
        _requireNotBlacklisted(user);
        
        if(IAccessControl(address(_DATABASE)).hasRole(_DEFAULT_ADMIN_ROLE, user) != true)
        {
            revert OnlyOperatorCanCallThisFunction();
        }
    }

    function _requireOperator(address user) private view
    {
        _requireNotBlacklisted(user);
        
        if(IAccessControl(address(_DATABASE)).hasRole(_DATABASE.OPERATOR_ROLE(), user) != true)
        {
            revert OnlyOperatorCanCallThisFunction();
        }
    }

    function _requireDeveloper(address user) private view
    {
        _requireNotBlacklisted(user);
        
        if(IAccessControl(address(_DATABASE)).hasRole(_DATABASE.DEVELOPER_ROLE(), user) != true)
        {
            revert OnlyOperatorCanCallThisFunction();
        }
    }

    function _requireNotBlacklisted(address user) private view 
    {
        if(_DATABASE.isBlacklisted(user))
        {
            revert BlacklistedError();
        }
    }
}

// File: contracts/dapp-game/database/ICflatsDatabase.sol



// SPDX-License-Identifier: MIT

/// @author Tient Technologies (Twitter:https://twitter.com/tient_tech | Github:https://github.com/Tient-Technologies | | LinkedIn:https://www.linkedin.com/company/tient-technologies/)
/// @dev NiceArti (https://github.com/NiceArti)
/// To maintain developer you can also donate to this address - 0xDc3d3fA1aEbd13fF247E5F5D84A08A495b3215FB
/// @title The interface for implementing the CflatsDatabase smart contract 
/// with a full description of each function and their implementation 
/// is presented to your attention.

pragma solidity ^0.8.18;

interface ICflatsDatabase 
{
    /// @dev Emitted when new user is added
    ///`user` is the address of account that should be added
    event UserInserted(address indexed user);


    /// @dev Emitted when user is removed
    /// `user` is the address of account that should be removed
    event UserRemoved(address indexed user);


    /// @dev Emitted when user is added in blacklist
    /// `user` is the address of account that should be added in blacklist
    event UserBlacklisted(address indexed user);


    /// @dev Emitted when user is removed from blacklist
    /// `user` is the address of account that should be removed from blacklist
    event UserRemovedFromBlacklist(address indexed user);


    
    /// @dev Table cell of default user data in database
    ///
    /// `_account` is the address of oae also account address is an id of user
    /// `_role` is the current role for user, by default is USER_ROLE
    ///
    /// There are four types of roles:
    /// `DEFAULT_ADMIN_ROLE` - role granted only for admin of database
    /// `USER_ROLE` - default role for any user added in database
    /// `OPERATOR_ROLE` - role for special mechanisms/bots that should autamatically do
    /// special intermediate calls that are not allowed for USER_ROLE
    /// `DEVELOPER_ROLE` - the same accessibility role as OPERATOR_ROLE the difference is
    /// that this role is intended exclusively for tests on the testnet and 
    /// should not be used in the mainnet network
    struct User
    {
        address _account;
        bytes32 _role;
    }




    //************************* startregion: VARIABLES  *************************//

    /// @dev OAE wallet for team
    ///
    /// This wallet is used as a collection of fees, funds, 
    /// donations, to support the project development team
    /// @return address of team wallet
    function TEAM_WALLET() external view returns (address);


    
    /// @dev This role is given to all users who, for whatever reason,
    /// violate the rules of the project, scammers, fraudsters
    /// @return 0x000000000000000000000000000000000000000000000000000000000000dead
    function BLACKLISTED_ROLE() external view returns (bytes32);


    /// @dev The role is given to bots to automate some processes or 
    /// to be used as intermediaries between the user and the contract
    /// 
    /// NOTE: OPERATOR_ROLE can be granted for other contracts as well as for
    /// intermediate parties as bots
    ///
    /// @return 0x0000000000000000000000000000000000000000000000000000000000000001
    function OPERATOR_ROLE() external view returns (bytes32);


    
    /// @dev The role is intended only for tests on the testnet,
    /// to check the correct operability of the contract
    ///
    /// NOTE: should be only used on testnet
    ///
    /// @return 0x0000000000000000000000000000000000000000000000000000000000000002
    function DEVELOPER_ROLE() external view returns (bytes32);


    
    /// @dev Default role for any user added in database
    /// @return 0x0000000000000000000000000000000000000000000000000000000000000003
    function USER_ROLE() external view returns (bytes32);

    //************************* endregion: VARIABLES  *************************//




    //************************* startregion: CALLABLE FUNCTIONS  *************************//

    /// @dev Returns true for account that is added is blacklist  
    /// @param user - account address of user saved in db
    /// @return false if user not registered in db or not blacklisted
    function isBlacklisted(address user) external view returns (bool);


    /// @dev Returns true if user was added in database and not removed
    /// @param user - account address of user saved in db
    /// @return false if user is not registered in db
    function userExists(address user) external view returns (bool);


    /// @dev Returns table cell of user by it's account address
    /// @param user - account address of user saved in db
    /// @return table cell with user data
    function getUserByAccountAddress(address user) external view returns (User memory);


    /// @dev Returns count of all users that was added in database table
    function getUsersCount() external view returns (uint256);
    
    //************************* startregion: CALLABLE FUNCTIONS  *************************//




    //************************* startregion: SEND FUNCTIONS  *************************//
    
    /// @dev Adds user by account address
    /// @custom:accessibility OPERATOR_ROLE
    /// NOTE: it's highly access function callable only via OPERATOR_ROLE
    /// Also only never added accounts will be added without dubbing
    ///
    /// @return true if transaction is successfull or user 
    /// has never been added in database before
    function addUser(address user) external returns (bool);


    /// @dev Adds many users by account addresses
    /// @custom:accessibility OPERATOR_ROLE
    /// NOTE: it's highly access function callable only via OPERATOR_ROLE
    /// Also only never added accounts will be added without dubbing
    /// 
    /// @return true if transaction is successfull
    function addUsersBatch(address[] calldata users) external returns (bool);


    /// @dev Remove user by account address
    /// @custom:accessibility OPERATOR_ROLE
    /// @custom:requires user to be existed in database otherwise it will revert with
    /// error UserDoesNotExistsError(address user)
    ///
    /// NOTE: it's highly access function callable only via OPERATOR_ROLE
    /// Only existed users can be removed from database
    ///
    /// @return true if transaction is successfull or user is unique in database
    function removeUser(address user) external returns (bool);


    /// @dev Remove many users from database
    /// @custom:accessibility DEFAULT_ADMIN_ROLE
    /// @custom:requires user to be existed in database otherwise it will revert with
    /// error UserDoesNotExistsError(address user)
    ///
    /// NOTE: it's highly access function callable only via DEFAULT_ADMIN_ROLE
    /// Only existed users can be removed from database
    ///
    /// @return true if transaction is successfull or user is unique in database
    function removeUsersBatch(address[] memory users) external returns (bool);


    /// @dev Adds the user to the blacklist, thereby blocking and severely 
    /// restricting the user from calling most functions
    /// @custom:accessibility OPERATOR_ROLE
    ///
    /// NOTE: it's highly access function callable only via OPERATOR_ROLE
    ///
    /// @return true if user has never been added in blacklist before
    function addUserInBlacklist(address user) external returns (bool);


    /// @dev Removes user from the blacklist
    /// @custom:accessibility OPERATOR_ROLE
    ///
    /// NOTE: it's highly access function callable only via OPERATOR_ROLE
    ///
    /// @return true if user ever been added in blacklist before
    function removeUserFromBlacklist(address user) external returns (bool);

    //************************* startregion: SEND FUNCTIONS  *************************//
}

// File: contracts/dapp-game/errors/CflatsDatabaseErrors.sol



// SPDX-License-Identifier: MIT

/// @author Tient Technologies (Twitter:https://twitter.com/tient_tech | Github:https://github.com/Tient-Technologies | LinkedIn:https://www.linkedin.com/company/tient-technologies/)
/// @dev NiceArti (https://github.com/NiceArti)
/// To maintain developer you can also donate to this address - 0xDc3d3fA1aEbd13fF247E5F5D84A08A495b3215FB
/// @title Error constants for CflatsDatabase contract
pragma solidity ^0.8.18;

import "./Errors.sol";

error BlacklistedError();
error OnlyOperatorCanCallThisFunction();
error UserDoesNotExistsError(address user);
error UsersToDeleteExceedAmountOfDatabaseInsertedUsers();
// File: contracts/dapp-game/errors/Errors.sol



// SPDX-License-Identifier: MIT

/// @author Tient Technologies (Twitter:https://twitter.com/tient_tech | Github:https://github.com/Tient-Technologies | LinkedIn:https://www.linkedin.com/company/tient-technologies/)
/// @dev NiceArti (https://github.com/NiceArti)
/// To maintain developer you can also donate to this address - 0xDc3d3fA1aEbd13fF247E5F5D84A08A495b3215FB
/// @title Error constants for Cflats project
pragma solidity ^0.8.18;

error ZeroAddress();
error ThisContractAddress();
error NotErc721();
error InvalidCurrentDate();
// File: contracts/dapp-game/exchange/CflatsExchange.sol



// SPDX-License-Identifier: MIT

/// @author Tient Technologies (Twitter:https://twitter.com/tient_tech | Github:https://github.com/Tient-Technologies | | LinkedIn:https://www.linkedin.com/company/tient-technologies/)
/// @dev NiceArti (https://github.com/NiceArti)
/// To maintain developer you can also donate to this address - 0xDc3d3fA1aEbd13fF247E5F5D84A08A495b3215FB
/// @title The CflatsExchange contract is used for exchanging tokens to $CFLAT token
/// The contract was inspired by UniswapV2

pragma solidity ^0.8.18;

import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "../../harvest/Harvest.sol";
import "../database/ICflatsDatabase.sol";
import "../CflatsDappRequirements.sol";
import "./ICflatsExchange.sol";


contract CflatsExchange is ICflatsExchange, CflatsDappRequirements, Harvest
{
    using SafeERC20 for IERC20;
    address public immutable ACCENT_TOKEN;

    error ExchangeTokenIsAlreadyAddedError();
    error ExchangeTokenPairIsNotCreatedError();
    error ExchangeTokenRateZeroError();
    error ExchangeTokenScopeZeroError();
    error SwapAmountIsTooSmallError();


    mapping(address tokenIn =>
        mapping(address tokenOut => CflatsExchangerInfo exchanger)
    ) private _exchangeInfo;


    constructor(
        address accentToken,
        ICflatsDatabase database
    ) CflatsDappRequirements(database)
    {
        ACCENT_TOKEN = accentToken;
    }



    //************************* startregion: CALLABLE FUNCTIONS  *************************//

    function getExchangeInfo(address exchangeToken)
        public
        view
        returns (CflatsExchangerInfo memory)
    {
        return _exchangeInfo[exchangeToken][ACCENT_TOKEN];
    }


    function getAmountsOut(
        address exchangeToken,
        uint256 amountsIn
    ) public view returns (uint256)
    {
        // standart token accurancy for native evm chain coin
        uint8 exchangeTokenDecimals = 18;

        // token accurancy for native evm chain coin
        if(exchangeToken != address(0))
        {
            exchangeTokenDecimals = IERC20Metadata(exchangeToken).decimals();
        }


        uint8 accentTokenDecimals = IERC20Metadata(ACCENT_TOKEN).decimals();
        uint256 currentExchangeRate = getExchangeInfo(exchangeToken).currentExchangeRate;


        // if token decimals are equal so just return amounts out without
        // doing magic with exchange token accurancy 
        if(accentTokenDecimals == exchangeTokenDecimals)
        {
            return amountsIn * currentExchangeRate;
        }


        // if the accurancy is not equal we doing magic
        uint256 accurancyDifference = exchangeTokenDecimals > accentTokenDecimals ? 
            exchangeTokenDecimals - accentTokenDecimals : 
            accentTokenDecimals - exchangeTokenDecimals;


        // if `exchangeTokenDecimals` is greather than `accentTokenDecimals`
        // we remove excessive accurancy to `exchangeToken` and return the number of tokens that the user will receive
        if(exchangeTokenDecimals > accentTokenDecimals)
        {
            return amountsIn / 10**accurancyDifference * currentExchangeRate;
        }

        // if `exchangeTokenDecimals` is less than `accentTokenDecimals`
        // we add accurancy to `exchangeToken` and return the number of tokens that the user will receive
        return amountsIn * 10**accurancyDifference * currentExchangeRate;
    }

    //************************* endregion: CALLABLE FUNCTIONS  *************************//




    //************************* startregion: SEND FUNCTIONS  *************************//
    function addNewExchangeTokenPair(
        address exchangeToken, 
        uint256 exchangeRate,
        uint256 scopedTokenReserves,
        uint256 minSwapAmount
    ) external onlyOperator
    {
        if(getExchangeInfo(exchangeToken).minExchangeRate > 0)
        {
            revert ExchangeTokenIsAlreadyAddedError();
        }
        if(exchangeRate == 0)
        {
            revert ExchangeTokenRateZeroError();
        }
        if(scopedTokenReserves == 0)
        {
            revert ExchangeTokenScopeZeroError();
        }

        _exchangeInfo[exchangeToken][ACCENT_TOKEN] = CflatsExchangerInfo(
            scopedTokenReserves,
            scopedTokenReserves,
            minSwapAmount,
            exchangeRate,
            exchangeRate
        );
    }

    function deleteExchangeTokenPair(address exchangeToken) external 
    {
        delete _exchangeInfo[exchangeToken][ACCENT_TOKEN];
    }


    function swapExactTokensForTokens(address exchangeToken, uint256 amountsIn) external 
    {
        CflatsExchangerInfo memory _cflatsExchangerInfo = getExchangeInfo(exchangeToken);

        if(_cflatsExchangerInfo.minExchangeRate == 0)
        {
            revert ExchangeTokenPairIsNotCreatedError();
        }
        if(amountsIn < _cflatsExchangerInfo.minSwapAmount)
        {
            revert SwapAmountIsTooSmallError();
        }

        // exchange tokens transferring to sender their amounts by exchange rate
        uint256 transferAmount = getAmountsOut(exchangeToken, amountsIn);
        IERC20(exchangeToken).safeTransferFrom(msg.sender, address(this), amountsIn);
        IERC20(ACCENT_TOKEN).safeTransfer(msg.sender, transferAmount);
        
        // updating info for `exchangeToken`
        _update(exchangeToken);

        emit Exchanged(exchangeToken, ACCENT_TOKEN, amountsIn, transferAmount);
    }


    function swapExactEthForTokens() external payable
    {
        address exchangeToken = address(0);
        CflatsExchangerInfo memory _cflatsExchangerInfo = getExchangeInfo(exchangeToken);

        if(_cflatsExchangerInfo.minExchangeRate == 0)
        {
            revert ExchangeTokenPairIsNotCreatedError();
        }

        uint256 amountsIn = msg.value;
        if(amountsIn < _cflatsExchangerInfo.minSwapAmount)
        {
            revert SwapAmountIsTooSmallError();
        }

        // exchange tokens transferring to sender their amounts by exchange rate
        uint256 transferAmount = getAmountsOut(exchangeToken, amountsIn);
        IERC20(ACCENT_TOKEN).safeTransfer(msg.sender, transferAmount);

        // updating info for `exchangeToken`
        _update(exchangeToken);

        emit Exchanged(exchangeToken, ACCENT_TOKEN, amountsIn, transferAmount);
    }

    //************************* endregion: SEND FUNCTIONS  *************************//




    //************************* startregion: HELPER FUNCTIONS  *************************//

    function _update(
        address exchangeToken
    ) private 
    {
        CflatsExchangerInfo storage _cflatsExchangerInfo = _exchangeInfo[exchangeToken][ACCENT_TOKEN];
        uint256 currentExchangeTokenReserves = _getExchangeTokenCurrentReserves(exchangeToken);

        if(currentExchangeTokenReserves >= _cflatsExchangerInfo.scopedTokenReserves)
        {
            uint256 currentReservesScope = _cflatsExchangerInfo.scopedTokenReserves;
            uint256 currentExchangeRate = _cflatsExchangerInfo.currentExchangeRate;

            // adds five percent from prev scope
            unchecked
            {
                _cflatsExchangerInfo.scopedTokenReserves += currentReservesScope / 20;

                // exchange rate increases to five percents
                _cflatsExchangerInfo.currentExchangeRate -= currentExchangeRate / 20;
            }
        }
        // this state will activate only when owner will claim funds so settings will be setted to default
        else if(currentExchangeTokenReserves == 0 && (_cflatsExchangerInfo.scopedTokenReserves > _cflatsExchangerInfo.minScopedTokenReserves))
        {
            _cflatsExchangerInfo.scopedTokenReserves = _cflatsExchangerInfo.minScopedTokenReserves;
            _cflatsExchangerInfo.currentExchangeRate = _cflatsExchangerInfo.minExchangeRate;
        }
    }


    function _getExchangeTokenCurrentReserves(address exchangeToken) private view returns(uint256)
    {
        // get current balance for ERC20 tokens
        if(exchangeToken != address(0))
        {
            return IERC20(exchangeToken).balanceOf(address(this));
        }

        // get current balance for native chain token
        return address(this).balance;
    }

    //************************* endregion: HELPER FUNCTIONS  *************************//
}
// File: contracts/dapp-game/exchange/ICflatsExchange.sol



// SPDX-License-Identifier: MIT

/// @author Tient Technologies (Twitter:https://twitter.com/tient_tech | Github:https://github.com/Tient-Technologies | | LinkedIn:https://www.linkedin.com/company/tient-technologies/)
/// @dev NiceArti (https://github.com/NiceArti)
/// To maintain developer you can also donate to this address - 0xDc3d3fA1aEbd13fF247E5F5D84A08A495b3215FB
/// @title The interface for implementing the CflatsExchange smart contract 
/// with a full description of each function and their implementation 
/// is presented to your attention.

pragma solidity ^0.8.18;

interface ICflatsExchange 
{
    /// @dev Emitted when user exchanges assets for $CFLAT tokens
    /// `token0` is the address of token to exchange
    /// `token1` is the address of token to receive
    /// `amountsIn` is the amount of tokens to exchange
    /// `amounsOut` is the amount of tokens to receive
    event Exchanged(
        address indexed token0,
        address indexed token1,
        uint256 amountsIn,
        uint256 amounsOut
    );


    /// @dev Structure that stores the specified parameters for an exchanger for a specific asset
    ///
    /// `scopedTokenReserves` is amount of tokens that should be stored to update exchange price
    /// `minScopedTokenReserves` minimal scoped reserves. It will be setted once owner will claim token reserves
    /// `minExchangeRate` minimal exchange rate for token. It will be setted once owner will claim token reserves 
    /// `minSwapAmount` minimal allowed swap amount
    /// `currentExchangeRate` is the last setted exchange rate for token.
    /// It changes every time when `scopedTokenReserves` increases or decreases by 5% 
    struct CflatsExchangerInfo
    {
        uint256 scopedTokenReserves;
        uint256 minScopedTokenReserves;
        uint256 minSwapAmount;
        uint256 minExchangeRate;
        uint256 currentExchangeRate;
    }


    //************************* startregion: VARIABLES  *************************//

    /// @dev immutable variable for token that will be exchanged with other tokens
    /// @return address of token that will be exchanged for
    function ACCENT_TOKEN() external view returns(address);

    //************************* endregion: VARIABLES  *************************//




    //************************* startregion: CALLABLE FUNCTIONS  *************************//

    /// @dev Shows current info for exchanging this token to default token 
    /// @param exchangeToken token that should be exchanged with default token
    /// @return data for exchange token
    function getExchangeInfo(
        address exchangeToken
    ) external view returns (CflatsExchangerInfo memory);


    /// @dev Shows amounts that user will receive for amounts of asset he/she introduce
    /// @param exchangeToken token that should be exchanged with default token
    /// @param amountsIn amount of tokens that should be exchanged
    /// @return amounts of tokens that user will receive after swap
    function getAmountsOut(
        address exchangeToken,
        uint256 amountsIn
    ) external view returns (uint256);

    //************************* startregion: CALLABLE FUNCTIONS  *************************//




    //************************* startregion: SEND FUNCTIONS  *************************//

    /// @dev Sets the settings for the pair between the default token and
    /// the `exchangeToken` that will be active for exchange
    /// @param exchangeToken token that will be active for exchange
    /// @param exchangeRate initial for swap
    /// @param scopedTokenReserves scope for token reserves to update exchange price
    /// NOTE `scopedTokenReserves` will update exchange rate
    /// @param minSwapAmount minimal amount for user to swap
    ///
    /// @custom:requires token to be new, otherwise it will revert with
    /// error ExchangeTokenIsAlreadyAddedError()
    ///
    /// @custom:requires `exchangeRate` and `scopedTokenReserves` to be greather than zero
    /// error ExchangeTokenIsAlreadyAddedError()
    function addNewExchangeTokenPair(
        address exchangeToken, 
        uint256 exchangeRate,
        uint256 scopedTokenReserves,
        uint256 minSwapAmount
    ) external;


    /// @dev Removes info for exchange token pair
    function deleteExchangeTokenPair(address exchangeToken) external;


    /// @dev Function for exchanging `exchangeToken` in amount of `amountsIn`
    /// to ACCENT_TOKEN by exchange rate
    /// @param exchangeToken token that should be exchanged
    /// @param amountsIn amounts of tokens to exchange
    ///
    /// @custom:requires `exchangeToken` not to be zero address
    /// error ExchangeTokenIsAlreadyAddedError()
    ///
    /// @custom:requires `amountsIn` to be greather than or equal to `minSwapAmount`
    /// error SwapAmountIsTooSmallError()
    ///
    ///
    /// @custom:requires pair to be created otherwise it will revert with
    /// error ExchangeTokenPairIsNotCreatedError()
    function swapExactTokensForTokens(
        address exchangeToken,
        uint256 amountsIn
    ) external;


    /// @dev Function for exchanging `native token` in amount of `value`
    /// to ACCENT_TOKEN by exchange rate
    ///
    /// @custom:requires `value` to be greather than or equal to `minSwapAmount`
    /// error SwapAmountIsTooSmallError()
    ///
    /// @custom:requires pair to be created otherwise it will revert with
    /// error ExchangeTokenPairIsNotCreatedError()
    function swapExactEthForTokens() external payable;

    //************************* startregion: SEND FUNCTIONS  *************************//
}

// File: contracts/dapp-game/ICflatsDappRequirements.sol



/**
* @author NiceArti (https://github.com/NiceArti) 
* To maintain developer you can also donate to this address - 0xDc3d3fA1aEbd13fF247E5F5D84A08A495b3215FB
* @title The interface for implementing the CryptoFlatsNft smart contract 
* with a full description of each function and their implementation 
* is presented to your attention.
*/

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;

import "./database/ICflatsDatabase.sol";

interface ICflatsDappRequirements
{
    function getDatabase() external view returns (ICflatsDatabase);
}
// File: contracts/harvest/Harvest.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;

import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "./IHarvest.sol";


abstract contract Harvest is IHarvest
{
    using SafeERC20 for IERC20;

    // TEAM_WALLET
    address private constant _HARVEST_ADDRESS = 0x1d6B3E373B947319a4B76A851bb17C1dEcCADb1D;


    receive() external payable 
    {
        emit Thanks(msg.sender, msg.value);
    }


    /// the function of collecting tokens that got accidentally
    /// or specifically into a smart contract and were not recorded
    /// in storage
    /// NOTE: this function does not take user's funds from the contract,
    /// but will withdraw those funds that are considered to be
    /// donation and receiving funds!
    function collect(address token) public virtual returns (bool)
    {
        uint256 harvestAmount = _getHarvest(token);

        if(harvestAmount == 0)
        {
            return false;
        }

        if(token == address(0))
        {
            (bool sent, ) = payable(_HARVEST_ADDRESS).call{value: harvestAmount}("");
            require(sent, "Failed to send Ether!");
        }
        else
        {
            IERC20(token).safeTransfer(_HARVEST_ADDRESS, harvestAmount);
        }

        emit HarvestCollected();
        return true;
    }


    /// The main idea is to collect all funds that were sent in contract
    /// accidently or as donation, not to stole a whole contract balance
    /// NOTE: any funds received for a smart contract and not recorded
    /// in the storage are regarded as a donation that the team can take
    function _getHarvest(address token) internal view returns (uint256)
    {
        if(token == address(0))
        {
            return address(this).balance;
        }

        return IERC20Metadata(token).balanceOf(address(this));
    }


    function _extractDonationPercentage(uint256 fullAmount, uint16 percentage) internal pure returns (uint256)
    {
        // accuracy up to two characters
        // 10000 = 100.00
        return fullAmount * percentage / 10000;
    }
}

// File: contracts/harvest/IHarvest.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;

interface IHarvest
{
    event Thanks(address indexed donator, uint256 donation);
    event HarvestCollected();

    /// the function of collecting tokens that got accidentally
    /// or specifically into a smart contract and were not recorded
    /// in storage
    /// NOTE: this function does not take user's funds from the contract,
    /// but will withdraw those funds that are considered to be
    /// donation funds!
    function collect(address token) external returns (bool);
}