// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/Arth/Arth.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

import {IARTH} from './IARTH.sol';
import {IARTHController} from './IARTHController.sol';
import {IERC20} from '../ERC20/IERC20.sol';
import {ERC20Custom} from '../ERC20/ERC20Custom.sol';
import {SafeMath} from '../utils/math/SafeMath.sol';
import {IAnyswapV4Token} from '../ERC20/IAnyswapV4Token.sol';
import {AnyswapV4Token} from '../ERC20/AnyswapV4Token.sol';

/**
 * @title  ARTHStablecoin.
 * @author MahaDAO.
 */
contract ARTHStablecoin is AnyswapV4Token, IARTH {
    using SafeMath for uint256;

    // bytes32 public constant GOVERNANCE_ROLE = keccak256('GOVERNANCE_ROLE');
    // bytes32 public constant OWNERSHIP_ROLE = keccak256('GOVERNANCE_ROLE');

    address public governance;
    IARTHController public controller;

    uint8 public constant override decimals = 18;
    string public constant symbol = 'ARTH';
    string public constant name = 'ARTH Valuecoin';
    bool public allowRebase = true;

    /// @dev ARTH v1 already in circulation.
    uint256 private INITIAL_AMOUNT_SUPPLY = 25_000_000 ether;
    uint256 public gonsPerFragment = 1e6;

    event Rebase(uint256 supply);
    event PoolBurned(address indexed from, address indexed to, uint256 amount);
    event PoolMinted(address indexed from, address indexed to, uint256 amount);

    modifier onlyPools() {
        require(controller.isPool(msg.sender), 'ARTH: not an approved pool');
        _;
    }

    modifier onlyByOwnerOrGovernance() {
        require(
            msg.sender == owner() || msg.sender == governance,
            'ARTH: not owner or governance'
        );
        _;
    }

    modifier requireValidRecipient(address _recipient) {
        require(
            _recipient != address(0) && _recipient != address(this),
            'ARTH: Cannot transfer tokens directly to the ARTH token contract or the zero address'
        );
        _;
    }

    constructor() AnyswapV4Token(name) {
        _mint(_msgSender(), INITIAL_AMOUNT_SUPPLY);
        _setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
    }

    function transferAndCall(
        address to,
        uint256 value,
        bytes calldata data
    )
        public
        override(IAnyswapV4Token, AnyswapV4Token)
        requireValidRecipient(to)
        returns (bool)
    {
        return super.transferAndCall(to, value, data);
    }

    function transferWithPermit(
        address target,
        address to,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    )
        public
        override(IAnyswapV4Token, AnyswapV4Token)
        requireValidRecipient(to)
        returns (bool)
    {
        return super.transferWithPermit(target, to, value, deadline, v, r, s);
    }

    function transfer(address to, uint256 value)
        public
        virtual
        override(IERC20, ERC20Custom)
        requireValidRecipient(to)
        returns (bool)
    {
        return super.transfer(to, value);
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    )
        public
        virtual
        override(IERC20, ERC20Custom)
        requireValidRecipient(recipient)
        onlyNonBlacklisted(_msgSender())
        returns (bool)
    {
        return super.transferFrom(sender, recipient, amount);
    }

    function revokeRebase() public onlyByOwnerOrGovernance {
        allowRebase = false;
    }

    function totalSupply()
        public
        view
        override(ERC20Custom, IERC20)
        returns (uint256)
    {
        return _totalSupply.div(gonsPerFragment);
    }

    function rebase(uint256 _newGonsPerFragment)
        external
        onlyByOwnerOrGovernance
        returns (uint256)
    {
        require(allowRebase, 'Arth: rebase is revoked');
        gonsPerFragment = _newGonsPerFragment;

        emit Rebase(totalSupply());
        return totalSupply();
    }

    function balanceOf(address account)
        public
        view
        override(IERC20, ERC20Custom)
        returns (uint256)
    {
        return _balances[account].div(gonsPerFragment);
    }

    function _mint(address account, uint256 amount)
        internal
        override
        onlyNonBlacklisted(account)
    {
        require(account != address(0), 'ERC20: mint to the zero address');

        uint256 gonValues = amount.mul(gonsPerFragment);

        _totalSupply = _totalSupply.add(gonValues);
        _balances[account] = _balances[account].add(gonValues);

        emit Transfer(address(0), account, amount);
    }

    function _burn(address account, uint256 amount)
        internal
        override
        onlyNonBlacklisted(account)
    {
        require(account != address(0), 'ERC20: burn from the zero address');

        uint256 gonValues = amount.mul(gonsPerFragment);

        _balances[account] = _balances[account].sub(
            gonValues,
            'ERC20: burn amount exceeds balance'
        );

        _totalSupply = _totalSupply.sub(gonValues);

        emit Transfer(account, address(0), amount);
    }

    /// @notice Used by pools when user redeems.
    function poolBurnFrom(address who, uint256 amount)
        external
        override
        onlyPools
    {
        super._burnFrom(who, amount);
        emit PoolBurned(who, msg.sender, amount);
    }

    /// @notice This function is what other arth pools will call to mint new ARTH
    function poolMint(address who, uint256 amount) external override onlyPools {
        _mint(who, amount);
        emit PoolMinted(msg.sender, who, amount);
    }

    function setArthController(address _controller)
        external
        override
        onlyOwner
    {
        controller = IARTHController(_controller);
    }

    function _transfer(
        address sender,
        address recipient,
        uint256 value
    ) internal override {
        // get amount in underlying
        uint256 gonValues = value.mul(gonsPerFragment);

        // sub from balance of sender
        _balances[sender] = _balances[sender].sub(gonValues);

        // add to balance of receiver
        _balances[recipient] = _balances[recipient].add(gonValues);
        emit Transfer(msg.sender, recipient, value);
    }
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/Arth/IARTH.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {IERC20} from '../ERC20/IERC20.sol';
import {IIncentiveController} from './IIncentive.sol';
import {IAnyswapV4Token} from '../ERC20/IAnyswapV4Token.sol';

interface IARTH is IERC20, IAnyswapV4Token {
    function poolMint(address who, uint256 amount) external;

    function poolBurnFrom(address who, uint256 amount) external;

    function setArthController(address _controller) external;
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/Arth/IARTHController.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

interface IARTHController {
    function toggleCollateralRatio() external;

    function addPool(address pool_address) external;

    function addPools(address[] memory poolAddress) external;

    function removePool(address pool_address) external;

    function getARTHSupply() external view returns (uint256);

    function isPool(address pool) external view returns (bool);

    function getARTHInfo()
        external
        view
        returns (
            uint256,
            uint256,
            uint256,
            uint256,
            uint256,
            uint256,
            uint256,
            // uint256,
            uint256
        );

    function setMintingFee(uint256 fee) external;

    function setMAHAGMUOracle(address oracle) external;

    function setARTHXGMUOracle(address _arthxOracleAddress) external;

    function setFeesParameters(
        uint256 _mintingFee,
        uint256 _buybackFee,
        uint256 _redemptionFee
    ) external;

    function setRedemptionFee(uint256 fee) external;

    function setBuybackFee(uint256 fee) external;

    function setOwner(address _ownerAddress) external;

    function setTimelock(address newTimelock) external;

    function setGlobalCollateralRatio(uint256 _globalCollateralRatio) external;

    function getARTHXPrice() external view returns (uint256);

    function getMintingFee() external view returns (uint256);

    function getMAHAPrice() external view returns (uint256);

    function getBuybackFee() external view returns (uint256);

    function getRedemptionFee() external view returns (uint256);

    function getGlobalCollateralRatio() external view returns (uint256);

    function getARTHXGenesisDiscount() external view returns (uint256);

    function getGlobalCollateralValue() external view returns (uint256);

    function arthPools(address pool) external view returns (bool);

    function setStabilityFee(uint256 val) external;

    function isRedeemPaused() external view returns (bool);

    function isMintPaused() external view returns (bool);

    function isBuybackPaused() external view returns (bool);

    function isRecollaterlizePaused() external view returns (bool);

    function toggleMinting() external;

    function toggleRedeeming() external;

    function toggleRecollateralize() external;

    function toggleBuyBack() external;

    function getStabilityFee() external view returns (uint256);

    // todo add this here
    function mintingFee() external returns (uint256);

    function redemptionFee() external returns (uint256);

    function buybackFee() external returns (uint256);

    function getRecollateralizationDiscount() external returns (uint256);

    function getIsGenesisActive() external view returns (bool);

    function getARTHXGenesisPrice() external view returns (uint256);

    function getTargetCollateralValue() external view returns (uint256);

    function getPercentCollateralized() external view returns (uint256);
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/Arth/IIncentive.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/// @title incentive contract interface
/// @author Fei Protocol
/// @notice Called by FEI token contract when transferring with an incentivized address
/// @dev should be appointed as a Minter or Burner as needed
interface IIncentiveController {
    /// @notice apply incentives on transfer
    /// @param sender the sender address of the FEI
    /// @param receiver the receiver address of the FEI
    /// @param operator the operator (msg.sender) of the transfer
    /// @param amount the amount of FEI transferred
    function incentivize(
        address sender,
        address receiver,
        address operator,
        uint256 amount
    ) external;
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/ERC20/AnyswapV4Token.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

import {ERC20Custom} from './ERC20Custom.sol';
import {IAnyswapV4Token} from './IAnyswapV4Token.sol';
import {AccessControl} from '../access/AccessControl.sol';

interface IApprovalReceiver {
    function onTokenApproval(
        address,
        uint256,
        bytes calldata
    ) external returns (bool);
}

interface ITransferReceiver {
    function onTokenTransfer(
        address,
        uint256,
        bytes calldata
    ) external returns (bool);
}

abstract contract AnyswapV4Token is
    ERC20Custom,
    AccessControl,
    IAnyswapV4Token
{
    bytes32 public immutable DOMAIN_SEPARATOR;

    bytes32 public constant BRIDGE_ROLE = keccak256('BRIDGE_ROLE');
    bytes32 public constant PERMIT_TYPEHASH =
        keccak256(
            'Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)'
        );
    bytes32 public constant TRANSFER_TYPEHASH =
        keccak256(
            'Transfer(address owner,address to,uint256 value,uint256 nonce,uint256 deadline)'
        );

    mapping(address => uint256) public override nonces;

    event LogSwapin(
        bytes32 indexed txhash,
        address indexed account,
        uint256 amount
    );

    event LogSwapout(
        address indexed account,
        address indexed bindaddr,
        uint256 amount
    );

    modifier onlyBridge {
        require(
            hasRole(BRIDGE_ROLE, _msgSender()),
            'AnyswapV4Token: forbidden'
        );
        _;
    }

    constructor(string memory name) {
        uint256 chainId;
        assembly {
            chainId := chainid()
        }

        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256(
                    'EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'
                ),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );

        _setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
    }

    function approveAndCall(
        address spender,
        uint256 value,
        bytes calldata data
    ) external override returns (bool) {
        _approve(msg.sender, spender, value);
        return
            IApprovalReceiver(spender).onTokenApproval(msg.sender, value, data);
    }

    function transferAndCall(
        address to,
        uint256 value,
        bytes calldata data
    ) public virtual override returns (bool) {
        require(to != address(0) || to != address(this));

        uint256 balance = balanceOf(msg.sender);
        require(
            balance >= value,
            'AnyswapV3ERC20: transfer amount exceeds balance'
        );

        _transfer(msg.sender, to, value);
        return ITransferReceiver(to).onTokenTransfer(msg.sender, value, data);
    }

    function transferWithPermit(
        address target,
        address to,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual override returns (bool) {
        require(block.timestamp <= deadline, 'AnyswapV3ERC20: Expired permit');

        bytes32 hashStruct =
            keccak256(
                abi.encode(
                    TRANSFER_TYPEHASH,
                    target,
                    to,
                    value,
                    nonces[target]++,
                    deadline
                )
            );

        require(
            _verifyEIP712(target, hashStruct, v, r, s) ||
                _verifyPersonalSign(target, hashStruct, v, r, s)
        );

        // NOTE: is this check needed, was there in the refered contract.
        require(to != address(0) || to != address(this));
        require(
            balanceOf(target) >= value,
            'AnyswapV3ERC20: transfer amount exceeds balance'
        );

        _transfer(target, to, value);
        return true;
    }

    function permit(
        address target,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public override {
        require(block.timestamp <= deadline, 'AnyswapV3ERC20: Expired permit');

        bytes32 hashStruct =
            keccak256(
                abi.encode(
                    PERMIT_TYPEHASH,
                    target,
                    spender,
                    value,
                    nonces[target]++,
                    deadline
                )
            );

        require(
            _verifyEIP712(target, hashStruct, v, r, s) ||
                _verifyPersonalSign(target, hashStruct, v, r, s)
        );

        _approve(target, spender, value);
        emit Approval(target, spender, value);
    }

    /// @dev Only Auth needs to be implemented
    function Swapin(
        bytes32 txhash,
        address account,
        uint256 amount
    ) public override onlyBridge returns (bool) {
        _mint(account, amount);
        emit LogSwapin(txhash, account, amount);
        return true;
    }

    function Swapout(uint256 amount, address bindaddr)
        public
        override
        onlyBridge
        returns (bool)
    {
        require(bindaddr != address(0), 'AnyswapV4ERC20: address(0x0)');

        _burn(msg.sender, amount);
        emit LogSwapout(msg.sender, bindaddr, amount);
        return true;
    }

    function _verifyEIP712(
        address target,
        bytes32 hashStruct,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal view returns (bool) {
        bytes32 hash =
            keccak256(
                abi.encodePacked('\x19\x01', DOMAIN_SEPARATOR, hashStruct)
            );
        address signer = ecrecover(hash, v, r, s);

        return (signer != address(0) && signer == target);
    }

    /// @dev Builds a _prefixed hash to mimic the behavior of eth_sign.
    function _prefixed(bytes32 hash) internal pure returns (bytes32) {
        return
            keccak256(
                abi.encodePacked('\x19Ethereum Signed Message:\n32', hash)
            );
    }

    function _verifyPersonalSign(
        address target,
        bytes32 hashStruct,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (bool) {
        bytes32 hash = _prefixed(hashStruct);
        address signer = ecrecover(hash, v, r, s);
        return (signer != address(0) && signer == target);
    }
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/ERC20/ERC20Custom.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {IERC20} from './IERC20.sol';
import {Address} from '../utils/Address.sol';
import {Context} from '../utils/Context.sol';
import {SafeMath} from '../utils/math/SafeMath.sol';
import {Pausable} from '../security/Pausable.sol';
import {Ownable} from '../access/Ownable.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}.
 * For a generic mechanism see {ERC20Mintable}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of 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.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
abstract contract ERC20Custom is Pausable, IERC20, Ownable {
    using SafeMath for uint256;

    uint256 internal _totalSupply;

    mapping(address => bool) internal _blacklisted;
    mapping(address => uint256) internal _balances;
    mapping(address => mapping(address => uint256)) internal _allowances;

    /**
     * Modifiers
     */
    modifier onlyNonBlacklisted(address who) {
        require(!getIsBlacklisted(who), 'ERC20Custom: address is blacklisted');
        _;
    }

    /**
     * Constructor.
     */
    constructor() {}

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

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

    /**
     * @dev Returns if an address is blackListed or not.
     */
    function getIsBlacklisted(address who) public view returns (bool) {
        return _blacklisted[who];
    }

    /**
     * @dev Blacklists an address.
     */
    function blacklist(address who) public onlyOwner returns (bool) {
        if (getIsBlacklisted(who)) return true;
        _blacklisted[who] = true;
        return true;
    }

    function pause() public onlyOwner {
        _pause();
    }

    function unpause() public onlyOwner {
        _unpause();
    }

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

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

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.approve(address spender, uint256 amount)
     */
    function approve(address spender, uint256 amount)
        public
        virtual
        override
        returns (bool)
    {
        _approve(_msgSender(), spender, amount);
        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};
     *
     * Requirements:
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for `sender`'s tokens of at least
     * `amount`.
     *
     * NOTE: The `spender i.e msg.sender` and the `owner` both should not be blacklisted.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override onlyNonBlacklisted(_msgSender()) returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(
            sender,
            _msgSender(),
            _allowances[sender][_msgSender()].sub(
                amount,
                'ERC20: transfer amount exceeds allowance'
            )
        );

        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue)
        public
        virtual
        returns (bool)
    {
        _approve(
            _msgSender(),
            spender,
            _allowances[_msgSender()][spender].add(addedValue)
        );
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue)
        public
        virtual
        returns (bool)
    {
        _approve(
            _msgSender(),
            spender,
            _allowances[_msgSender()][spender].sub(
                subtractedValue,
                'ERC20: decreased allowance below zero'
            )
        );
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     *
     * NOTE: The `sender` should not be blacklisted.
     */
    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual whenNotPaused onlyNonBlacklisted(sender) {
        require(sender != address(0), 'ERC20: transfer from the zero address');
        require(recipient != address(0), 'ERC20: transfer to the zero address');

        _beforeTokenTransfer(sender, recipient, amount);

        _balances[sender] = _balances[sender].sub(
            amount,
            'ERC20: transfer amount exceeds balance'
        );
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements
     *
     * - `to` cannot be the zero address.
     *
     *  NOTE: The `account` should not be blacklisted.
     */
    function _mint(address account, uint256 amount)
        internal
        virtual
        onlyNonBlacklisted(account)
    {
        require(account != address(0), 'ERC20: mint to the zero address');

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from the caller.
     *
     * See {ERC20-_burn}.
     */
    function burn(uint256 amount) public virtual {
        _burn(_msgSender(), amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, deducting from the caller's
     * allowance.
     *
     * See {ERC20-_burn} and {ERC20-allowance}.
     *
     * Requirements:
     *
     * - the caller must have allowance for `accounts`'s tokens of at least
     * `amount`.
     *
     * NOTE: The `account` and `burner i.e msg.sender` both should not be blacklisted.
     */
    function burnFrom(address account, uint256 amount)
        public
        virtual
        onlyNonBlacklisted(_msgSender())
    {
        uint256 decreasedAllowance =
            allowance(account, _msgSender()).sub(
                amount,
                'ERC20: burn amount exceeds allowance'
            );

        _approve(account, _msgSender(), decreasedAllowance);
        _burn(account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     *
     *  NOTE: The `account` should not be blacklisted.
     */
    function _burn(address account, uint256 amount)
        internal
        virtual
        onlyNonBlacklisted(account)
    {
        require(account != address(0), 'ERC20: burn from the zero address');

        _beforeTokenTransfer(account, address(0), amount);

        _balances[account] = _balances[account].sub(
            amount,
            'ERC20: burn amount exceeds balance'
        );
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
     *
     * This is 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.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), 'ERC20: approve from the zero address');
        require(spender != address(0), 'ERC20: approve to the zero address');

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`.`amount` is then deducted
     * from the caller's allowance.
     *
     * See {_burn} and {_approve}.
     */
    function _burnFrom(address account, uint256 amount)
        internal
        virtual
        onlyNonBlacklisted(_msgSender())
    {
        _burn(account, amount);
        _approve(
            account,
            _msgSender(),
            _allowances[account][_msgSender()].sub(
                amount,
                'ERC20: burn amount exceeds allowance'
            )
        );
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of `from`'s tokens
     * will be to transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of `from`'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:using-hooks.adoc[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/ERC20/IAnyswapV4Token.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

interface IAnyswapV4Token {
    function approveAndCall(
        address spender,
        uint256 value,
        bytes calldata data
    ) external returns (bool);

    function transferAndCall(
        address to,
        uint256 value,
        bytes calldata data
    ) external returns (bool);

    function transferWithPermit(
        address target,
        address to,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (bool);

    function Swapin(
        bytes32 txhash,
        address account,
        uint256 amount
    ) external returns (bool);

    function Swapout(uint256 amount, address bindaddr) external returns (bool);

    function nonces(address owner) external view returns (uint256);

    function permit(
        address target,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
 * the optional functions; to access them see {ERC20Detailed}.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

    /**
     * @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 `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, 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 `sender` to `recipient` 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 sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @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
    );
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/access/AccessControl.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import '../utils/Context.sol';
import '../utils/introspection/ERC165.sol';

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControl {
    function hasRole(bytes32 role, address account)
        external
        view
        returns (bool);

    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    function grantRole(bytes32 role, address account) external;

    function revokeRole(bytes32 role, address account) external;

    function renounceRole(bytes32 role, address account) external;
}

/**
 * @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:
 *
 * ```
 * 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}:
 *
 * ```
 * 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.
 */
abstract contract AccessControl is Context, IAccessControl, ERC165 {
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }

    mapping(bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @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 {_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 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
        override
        returns (bool)
    {
        return _roles[role].members[account];
    }

    /**
     * @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 override 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.
     */
    function grantRole(bytes32 role, address account) public virtual override {
        require(
            hasRole(getRoleAdmin(role), _msgSender()),
            'AccessControl: sender must be an admin to grant'
        );

        _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.
     */
    function revokeRole(bytes32 role, address account) public virtual override {
        require(
            hasRole(getRoleAdmin(role), _msgSender()),
            'AccessControl: sender must be an admin to revoke'
        );

        _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 granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account)
        public
        virtual
        override
    {
        require(
            account == _msgSender(),
            'AccessControl: can only renounce roles for self'
        );

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        emit RoleAdminChanged(role, getRoleAdmin(role), adminRole);
        _roles[role].adminRole = adminRole;
    }

    function _grantRole(bytes32 role, address account) private {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }

    function _revokeRole(bytes32 role, address account) private {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT

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() {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), 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 {
        emit OwnershipTransferred(_owner, address(0));
        _owner = 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'
        );
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/security/Pausable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../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 {
    /**
     * @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);

    bool private _paused;

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

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

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

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

    /**
     * @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());
    }
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @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
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            size := extcodesize(account)
        }
        return size > 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'
        );

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (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 functionCall(target, data, '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'
        );
        require(isContract(target), 'Address: call to non-contract');

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) =
            target.call{value: value}(data);
        return _verifyCallResult(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) {
        require(isContract(target), 'Address: static call to non-contract');

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(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) {
        require(isContract(target), 'Address: delegate call to non-contract');

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) private pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // 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

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT

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) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/utils/introspection/ERC165.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./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);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @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);
}

// File: /home/enamakel/Work/mahadao.com/arthcoin/arthcoin-v2/contracts/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT

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 no longer needed starting with Solidity 0.8. 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 substraction 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. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * 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;
        }
    }
}