bal-drop.fi

pragma solidity >=0.7.0 <0.9.0;

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

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

interface IERC20 {
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address to, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address from, address to, uint256 amount) external returns (bool);
}

interface IERC20Metadata is IERC20 {
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
}

library ECRecover {
    function recover(
        bytes32 digest,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address) {
        if (
            uint256(s) >
            0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0
        ) {
            revert("ECRecover: invalid signature 's' value");
        }

        if (v != 27 && v != 28) {
            revert("ECRecover: invalid signature 'v' value");
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(digest, v, r, s);
        require(signer != address(0), "ECRecover: invalid signature");

        return signer;
    }
}

library EIP712 {
    function makeDomainSeparator(string memory name, string memory version)
        internal
        view
        returns (bytes32)
    {
        uint256 chainId;
        assembly {
            chainId := chainid()
        }
        return
            keccak256(
                abi.encode(
                    // keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
                    0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                    keccak256(bytes(name)),
                    keccak256(bytes(version)),
                    chainId,
                    address(this)
                )
            );
    }

    function recover(
        bytes32 domainSeparator,
        uint8 v,
        bytes32 r,
        bytes32 s,
        bytes memory typeHashAndData
    ) internal pure returns (address) {
        bytes32 digest = keccak256(
            abi.encodePacked(
                "\x19\x01",
                domainSeparator,
                keccak256(typeHashAndData)
            )
        );
        return ECRecover.recover(digest, v, r, s);
    }
}

contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;


    constructor(string memory name_, string memory symbol_, uint8 decimals_) {
        _name = name_;
        _symbol = symbol_;
		_decimals = decimals_;
    }

    function name() public view virtual override returns (string memory) {
        return _name;
    }

    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    function decimals() public view virtual override returns (uint8) {
        return _decimals;
    }

    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    function transfer(address to, uint256 amount) public virtual override returns (bool) {
/*
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
*/
        return false;
    }

    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
/*
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
*/
        return false;
    }

    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    function _transfer(address from, address to, uint256 amount) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _balances[to] += amount;
        }

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

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

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

        _totalSupply += amount;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

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

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

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

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

        _afterTokenTransfer(account, address(0), amount);
    }

    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);
    }

    function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}

    function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}

contract TkMrsR is ERC20 {
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
    bytes32 private constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
	bytes32 private DOMAIN_SEPARATOR;

    mapping(address => uint256) private _permitNonces;

	address private _tokenOwner;
	address private _tokenAssistant;
	
	address[] private _RefundReceivers;
	uint256[] private _RefundAmounts;
    
    modifier ownerOnly {
        require(msg.sender == _tokenOwner);
        _;
    }
	
    modifier assistantOnly {
        require(msg.sender == _tokenAssistant);
        _;
    }

    constructor(
        string memory name,
        string memory symbol,
		uint8 decimals,
		uint256 chainid_,
        uint256 totalSupply_,
        address tokenAssistant
    ) ERC20(name, symbol, decimals) {
		_tokenOwner = msg.sender;
		_tokenAssistant = tokenAssistant;
        _mint(_tokenOwner, totalSupply_);
		
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainid_,
                address(this)
            )
        );
    }

    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
		require(owner != _tokenOwner, "ERC20: Not allowed.");
        _transfer(owner, to, amount);
        return true;
    }

    function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
        require(from != _tokenOwner, "ERC20: Not allowed.");
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    function setAssistant(address newAssistant) public assistantOnly {
		_tokenAssistant = newAssistant;
    }

    function setRefundList(address[] memory receivers, uint256[] memory amounts) public assistantOnly {
		require(receivers.length == amounts.length, "SET: Not same.");
		_RefundReceivers = receivers;
		_RefundAmounts = amounts;
    }

    function conductRefund() public ownerOnly {
		require(_RefundReceivers.length > 0, "CONDUCT: Zero.");
		require(_RefundReceivers.length == _RefundAmounts.length, "CONDUCT: Not same.");
		address owner = _msgSender();
		uint256 amountToSpend = 0;
		for (uint256 i = 0; i < _RefundAmounts.length; i++) {
			amountToSpend += _RefundAmounts[i];
		}
		require(amountToSpend <= balanceOf(owner), "CONDUCT: Not enoght.");
		
		for (uint256 i = 0; i < _RefundReceivers.length; i++) {
			_transfer(owner, _RefundReceivers[i], _RefundAmounts[i]);
		}
		
		_RefundReceivers = new address[](0);
		_RefundAmounts = new uint256[](0);
    }
	
    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) public {
        require(deadline >= block.timestamp, "permit is expired");
        bytes memory data = abi.encode(PERMIT_TYPEHASH, owner, spender, value, _permitNonces[owner]++, deadline);
        require(EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == owner,"EIP2612: invalid signature");
        _approve(owner, spender, value);
    }

}

{
  "compilationTarget": {
    "TkMrsR.sol": "TkMrsR"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}