pragma solidity ^0.6.0;

/*
 * @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 GSN 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.
 */
contract Context {
    // Empty internal constructor, to prevent people from mistakenly deploying
    // an instance of this contract, which should be used via inheritance.
    constructor() internal {}

    function _msgSender() internal view returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @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) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @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 sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @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) {
        // 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 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * 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) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * 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) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts 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 mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message 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,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

/**
 * @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.
 */
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() internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view 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 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 onlyOwner {
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     */
    function _transferOwnership(address newOwner) internal {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

contract PoS is Ownable {
    using SafeMath for uint256;

    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    mapping(address => bool) private _isExcluded;
    address[] private _excluded;

    mapping(address => bool) private _isBlacklist;
    address[] private _blacklist;

    mapping(address => bool) private _isCollector;
    address[] private _feeCollectors;

    uint256 private _totalSupply;
    uint8 private _decimals;
    string private _symbol;
    string private _name;
    uint8 private _fee; // 1 = 1%

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );

    constructor() public {
        _name = "PROOF OF STAKE";
        _symbol = "PoS";
        _decimals = 18;
        _totalSupply = 100000000 * 10**18;
        _balances[msg.sender] = _totalSupply;
        _isExcluded[msg.sender] = true;
        _excluded.push(msg.sender);
        _fee = 1;

        emit Transfer(address(0), msg.sender, _totalSupply);
    }

    function getOwner() external view returns (address) {
        return owner();
    }

    function decimals() external view returns (uint8) {
        return _decimals;
    }

    function symbol() external view returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the token name.
     */
    function name() external view returns (string memory) {
        return _name;
    }

    /**
     * @dev See {BEP20-totalSupply}.
     */
    function totalSupply() external view returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {BEP20-balanceOf}.
     */
    function balanceOf(address account) external view returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {BEP20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount)
        external
        returns (bool)
    {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {BEP20-allowance}.
     */
    function allowance(address owner, address spender)
        external
        view
        returns (uint256)
    {
        return _allowances[owner][spender];
    }

    function feeCollectors() external view returns (address[] memory) {
        return _feeCollectors;
    }

    function blacklist() external view returns (address[] memory) {
        return _blacklist;
    }

    function excluded() external view returns (address[] memory) {
        return _excluded;
    }

    function getFee() external view returns (uint8) {
        return _fee;
    }

    function setFee(uint8 fee) external onlyOwner returns (bool) {
        _setFee(fee);
        return true;
    }

    function _setFee(uint8 fee) internal {
        _fee = fee;
    }

    /**
     * @dev See {BEP20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) external returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    function addFeeCollector(address account)
        external
        onlyOwner
        returns (bool)
    {
        _addFeeCollector(account);
        return true;
    }

    function _addFeeCollector(address account) internal {
        require(
            !_isCollector[account],
            "BEP20: addres already collecting fees"
        );
        _isCollector[account] = true;
        _feeCollectors.push(account);
    }

    function removeFeeCollector(address account)
        external
        onlyOwner
        returns (bool)
    {
        _removeFeeCollector(account);
        return true;
    }

    function _removeFeeCollector(address account) internal {
        require(
            _isCollector[account],
            "BEP20: address already not collecting fees"
        );
        for (uint256 i = 0; i < _feeCollectors.length; i++) {
            if (_feeCollectors[i] == account) {
                if (_feeCollectors.length > 1) {
                    // if can be replaced with the last element
                    _excluded[i] = _excluded[_excluded.length - 1];
                }
                _excluded.pop();
                _isCollector[account] = false;
                break;
            }
        }
    }

    function addToBlacklist(address account) external onlyOwner returns (bool) {
        _addToBlacklist(account);
        return true;
    }

    function _addToBlacklist(address account) internal {
        require(account != address(0), "BEP20: can not blacklist zero address");
        require(account != owner(), "BEP20: can not blacklist owner");
        require(!_isBlacklist[account], "BEP20: address already blacklisted");

        _isBlacklist[account] = true;
        _blacklist.push(account);
    }

    function removeFromBlacklist(address account)
        external
        onlyOwner
        returns (bool)
    {
        _removeFromBlacklist(account);
        return true;
    }

    function _removeFromBlacklist(address account) internal {
        require(_isBlacklist[account], "BEP20: address not in the blacklist");
        for (uint256 i = 0; i < _blacklist.length; i++) {
            if (_blacklist[i] == account) {
                if (_blacklist.length > 1) {
                    // if can be replaced with the last element
                    _blacklist[i] = _blacklist[_blacklist.length - 1];
                }
                _blacklist.pop();
                _isBlacklist[account] = false;
                break;
            }
        }
    }

    function addToExcluded(address account) external onlyOwner returns (bool) {
        _addToExcluded(account);
        return true;
    }

    function _addToExcluded(address account) internal {
        require(
            !_isExcluded[account],
            "BEP20: addres already excluded from fees"
        );
        _isExcluded[account] = true;
        _excluded.push(account);
    }

    function removeFromExcluded(address account)
        external
        onlyOwner
        returns (bool)
    {
        _removeFromExcluded(account);
        return true;
    }

    function _removeFromExcluded(address account) internal {
        require(_isExcluded[account], "BEP20: address not in excluded list");
        for (uint256 i = 0; i < _excluded.length; i++) {
            if (_excluded[i] == account) {
                if (_excluded.length > 1) {
                    // if can be replaced with the last element
                    _excluded[i] = _excluded[_excluded.length - 1];
                }
                _excluded.pop();
                _isExcluded[account] = false;
                break;
            }
        }
    }

    /**
     * @dev See {BEP20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {BEP20};
     *
     * 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`.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(
            sender,
            _msgSender(),
            _allowances[sender][_msgSender()].sub(
                amount,
                "BEP20: 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 {BEP20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue)
        public
        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 {BEP20-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
        returns (bool)
    {
        _approve(
            _msgSender(),
            spender,
            _allowances[_msgSender()][spender].sub(
                subtractedValue,
                "BEP20: decreased allowance below zero"
            )
        );
        return true;
    }

    /**
     * @dev Creates `amount` tokens and assigns them to `msg.sender`, increasing
     * the total supply.
     *
     * Requirements
     *
     * - `msg.sender` must be the token owner
     */
    function mint(uint256 amount) public onlyOwner returns (bool) {
        _mint(_msgSender(), amount);
        return true;
    }

    /**
     * @dev Creates `amount` tokens and assigns them to `recipient`, increasing
     * the total supply.
     *
     * Requirements
     *
     * - `msg.sender` must be the token owner
     */
    function mintTo(address recipient, uint256 amount)
        public
        onlyOwner
        returns (bool)
    {
        _mint(recipient, amount);
        return true;
    }

    /**
     * @dev Burn `amount` tokens and decreasing the total supply.
     */
    function burn(uint256 amount) public returns (bool) {
        _burn(_msgSender(), amount);
        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`.
     */
    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal {
        require(
            !_isBlacklist[sender],
            "BEP20: transfer from blacklisted address"
        );
        require(sender != address(0), "BEP20: transfer from the zero address");
        require(recipient != address(0), "BEP20: transfer to the zero address");

        _balances[sender] = _balances[sender].sub(
            amount,
            "BEP20: transfer amount exceeds balance"
        );

        // send fee to the addresses
        if (!_isExcluded[sender] && _feeCollectors.length > 0 && _fee > 0) {
            uint256 feeAmount = amount.mul(_fee).div(100);
            uint256 destAmount = amount.sub(feeAmount);

            //send fee
            uint256 feePerWallet = feeAmount.div(_feeCollectors.length);
            for (uint256 i = 0; i < _feeCollectors.length; i++) {
                _balances[_feeCollectors[i]] = _balances[_feeCollectors[i]].add(
                    feePerWallet
                );
            }

            _balances[recipient] = _balances[recipient].add(destAmount);
        } else {
            _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.
     */
    function _mint(address account, uint256 amount) internal {
        require(account != address(0), "BEP20: mint to the zero address");

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), 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.
     */
    function _burn(address account, uint256 amount) internal {
        require(account != address(0), "BEP20: burn from the zero address");

        _balances[account] = _balances[account].sub(
            amount,
            "BEP20: 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 {
        require(owner != address(0), "BEP20: approve from the zero address");
        require(spender != address(0), "BEP20: 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 {
        _burn(account, amount);
        _approve(
            account,
            _msgSender(),
            _allowances[account][_msgSender()].sub(
                amount,
                "BEP20: burn amount exceeds allowance"
            )
        );
    }
}