contract CoinWin is Ownable, Pausable, IERC20 {
    using SafeMath for uint256;

    string private _name = "CoinWin";
    string private _symbol = "BS3";
    uint256 private _decimals = 18;                // 18 decimals
    uint256 private _cap = 734133197 * 10 **_decimals;   
    uint256 private _totalSupply;

    mapping (address => bool) private _minter;
    event Mint(address indexed to, uint256 value);
    event MinterChanged(address account, bool state);

    mapping (address => uint256) private _balances;
    mapping (address => mapping (address => uint256)) private _allowed;

    event Donate(address indexed account, uint256 amount);

    /**
     * @dev Constructor
     */
    constructor() public {
        _minter[msg.sender] = true;
    }

    /**
     * @dev donate
     */
    function () external payable {
        emit Donate(msg.sender, msg.value);
    }


    /**
     * @return the name of the token.
     */
    function name() public view returns (string memory) {
        return _name;
    }

    /**
     * @return the symbol of the token.
     */
    function symbol() public view returns (string memory) {
        return _symbol;
    }

    /**
     * @return the number of decimals of the token.
     */
    function decimals() public view returns (uint256) {
        return _decimals;
    }

    /**
     * @return the cap for the token minting.
     */
    function cap() public view returns (uint256) {
        return _cap;
    }

    /**
     * @dev Total number of tokens in existence.
     */
    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev Gets the balance of the specified address.
     * @param owner The address to query the balance of.
     * @return A uint256 representing the amount owned by the passed address.
     */
    function balanceOf(address owner) public view returns (uint256) {
        return _balances[owner];
    }

    /**
     * @dev Function to check the amount of tokens that an owner allowed to a spender.
     * @param owner address The address which owns the funds.
     * @param spender address The address which will spend the funds.
     * @return A uint256 specifying the amount of tokens still available for the spender.
     */
    function allowance(address owner, address spender) public view returns (uint256) {
        return _allowed[owner][spender];
    }

    /**
     * @dev Transfer token to a specified address.
     * @param to The address to transfer to.
     * @param value The amount to be transferred.
     */
    function transfer(address to, uint256 value) public whenNotPaused returns (bool) {
        // Normal Transfer
        _transfer(msg.sender, to, value);
        return true;
    }

    /**
     * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     */
    function approve(address spender, uint256 value) public returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    /**
     * @dev Increase the amount of tokens that an owner allowed to a spender.
     * @param spender The address which will spend the funds.
     * @param addedValue The amount of tokens to increase the allowance by.
     */
    function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
        _approve(msg.sender, spender, _allowed[msg.sender][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Decrease the amount of tokens that an owner allowed to a spender.
     * @param spender The address which will spend the funds.
     * @param subtractedValue The amount of tokens to decrease the allowance by.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
        _approve(msg.sender, spender, _allowed[msg.sender][spender].sub(subtractedValue));
        return true;
    }
    /**
     * @dev Transfer tokens from one address to another.
     * @param from address The address which you want to send tokens from
     * @param to address The address which you want to transfer to
     * @param value uint256 the amount of tokens to be transferred
     */
    function transferFrom(address from, address to, uint256 value) public whenNotPaused returns (bool) {
        require(_allowed[from][msg.sender] >= value);
        _transfer(from, to, value);
        _approve(from, msg.sender, _allowed[from][msg.sender].sub(value));
        return true;
    }

    /**
     * @dev Transfer token for a specified addresses.
     * @param from The address to transfer from.
     * @param to The address to transfer to.
     * @param value The amount to be transferred.
     */
    function _transfer(address from, address to, uint256 value) internal {
        require(to != address(0));

        _balances[from] = _balances[from].sub(value);
        _balances[to] = _balances[to].add(value);
        emit Transfer(from, to, value);
    }

    /**
     * @dev Approve an address to spend another addresses' tokens.
     * @param owner The address that owns the tokens.
     * @param spender The address that will spend the tokens.
     * @param value The number of tokens that can be spent.
     */
    function _approve(address owner, address spender, uint256 value) internal {
        require(owner != address(0));
        require(spender != address(0));

        _allowed[owner][spender] = value;
        emit Approval(owner, spender, value);
    }


    /**
     * @dev Throws if called by account not a minter.
     */
    modifier onlyMinter() {
        require(_minter[msg.sender]);
        _;
    }

    /**
     * @dev Returns true if the given account is minter.
     */
    function isMinter(address account) public view returns (bool) {
        return _minter[account];
    }

    /**
     * @dev Set a minter state
     */
    function setMinterState(address account, bool state) external onlyOwner {
        _minter[account] = state;
        emit MinterChanged(account, state);
    }

    /**
     * @dev Function to mint tokens
     * @param to The address that will receive the minted tokens.
     * @param value The amount of tokens to mint.
     * @return A boolean that indicates if the operation was successful.
     */
    function mint(address to, uint256 value) public onlyMinter returns (bool) {
        _mint(to, value);
        return true;
    }

    /**
     * @dev Internal function that mints an amount of the token and assigns it to an account.
     * @param account The account that will receive the created tokens.
     * @param value The amount that will be created.
     */
    function _mint(address account, uint256 value) internal {
        require(_totalSupply.add(value) <= _cap);
        require(account != address(0));

        _totalSupply = _totalSupply.add(value);
        _balances[account] = _balances[account].add(value);
        emit Mint(account, value);
        emit Transfer(address(0), account, value);
    }
}
/**
 * @title CoinWin Main Contract
 */
function _approve(address owner, address spender, uint256 value) internal {
        require(owner != address(0));
        require(spender != address(0));

        _allowed[owner][spender] = value;
        emit Approval(owner, spender, value);
    }
/**
 * @dev Approve an address to spend another addresses' tokens.
 * @param owner The address that owns the tokens.
 * @param spender The address that will spend the tokens.
 * @param value The number of tokens that can be spent.
 */