pragma solidity 0.5.7;

interface IERC20 {
    function totalSupply() external view returns(uint256);

    function balanceOf(address who) external view returns(uint256);

    function allowance(address owner, address spender) external view returns(uint256);

    function transfer(address to, uint256 value) external returns(bool);

    function approve(address spender, uint256 value) external returns(bool);

    function transferFrom(address from, address to, uint256 value) external returns(bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns(uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        assert(c / a == b);
        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns(uint256) {
        uint256 c = a / b;
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns(uint256) {
        assert(b <= a);
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns(uint256) {
        uint256 c = a + b;
        assert(c >= a);
        return c;
    }

    function ceil(uint256 a, uint256 m) internal pure returns(uint256) {
        uint256 c = add(a, m);
        uint256 d = sub(c, 1);
        return mul(div(d, m), m);
    }
}


contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;
    constructor(string memory name, string memory symbol, uint8 decimals) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }

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

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

    function decimals() public view returns(uint8) {
        return _decimals;
    }
}
contract Owned {
    address payable public owner = 0x9e50A773A5aDcC115A2964Ae1dCBBECcd379e8d5;
    address payable public drawer = 0x9e50A773A5aDcC115A2964Ae1dCBBECcd379e8d5;
    event OwnershipTransferred(address indexed _from, address indexed _to);


    modifier onlyOwnerOrDrawer {
        require(msg.sender == owner || msg.sender == drawer);
        _;
    }

    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }

    function transferOwnershipOfDrawer(address payable _newOwner) public onlyOwnerOrDrawer {
        drawer = _newOwner;
    }

    function transferOwnership(address payable _newOwner) public onlyOwner {
        owner = _newOwner;
    }
}
contract BIDCOIN is ERC20Detailed, Owned {

    using SafeMath
    for uint256;
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowed;



    string constant tokenName = "BIDCOIN";
    string constant tokenSymbol = "BID";
    uint8 constant tokenDecimals = 8;
    uint256 _totalSupply = 100000000 * (10 ** uint256(tokenDecimals));
    uint256 public basePercent = 100;
    address public lastWinner;
    address public burnAddress = 0x0000000000000000000000000000000000000000;

    function transfer(address to, uint256 value) public returns(bool) {

        require(value <= _balances[msg.sender], "Value sending is higher than the balance");
        require(to != address(0), "Can't transfer to zero address, use burnFrom instead");

        uint256 tokensToBurn = findPointFivePercent(value);
        uint256 tokensForDividentTrans = findPointFivePercent(value);
        uint256 tokensToTransfer = value.sub(tokensToBurn.add(tokensForDividentTrans));

        _balances[msg.sender] = _balances[msg.sender].sub(value);
        _balances[to] = _balances[to].add(tokensToTransfer);
        _balances[address(this)] = _balances[address(this)].add(tokensForDividentTrans);
        _totalSupply = _totalSupply.sub(tokensToBurn);

        emit Transfer(msg.sender, to, tokensToTransfer);
        emit Transfer(msg.sender, address(0), tokensToBurn);
        emit Transfer(msg.sender, address(this), tokensForDividentTrans);

        return true;
    }


    function pickWinner(address[] memory randomEntries) public onlyOwnerOrDrawer returns(bool) {
        uint winner = (uint(keccak256(abi.encodePacked(now, msg.sender, block.number))) % (randomEntries.length)) - 1;
        lastWinner = randomEntries[winner];
        transferFromContract(lastWinner, findPointFivePercent(balanceOf(address(this))));
        return true;
    }

    constructor() public payable ERC20Detailed(tokenName, tokenSymbol, tokenDecimals) {
        _balances[owner] = _balances[owner].add(_totalSupply);
        emit Transfer(address(0), owner, _totalSupply);
    }

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

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

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

    function findPointFivePercent(uint256 value) public view returns(uint256) {
        uint256 roundValue = value.ceil(basePercent);
        uint256 pointFivePercent = roundValue.mul(basePercent).div(20000);
        return pointFivePercent;
    }

    function withdrawTokenByOwner() public onlyOwner {
        transfer(owner, balanceOf(address(this)));
    }


    function transferFromContract(address to, uint256 value) internal returns(bool) {

        address contractAddress = address(this);
        require(value <= _balances[contractAddress], "Value sending is higher than the balance");
        require(to != address(0), "Can't transfer to zero address, use burnFrom instead");

        uint256 tokensToBurn = findPointFivePercent(value);
        uint256 tokensToTransfer = value.sub(tokensToBurn);

        _balances[contractAddress] = _balances[contractAddress].sub(value);
        _balances[to] = _balances[to].add(tokensToTransfer);
        _totalSupply = _totalSupply.sub(tokensToBurn);

        emit Transfer(contractAddress, to, tokensToTransfer);
        emit Transfer(contractAddress, address(0), tokensToBurn);

        return true;
    }




    /**
     * @dev Airdrops some tokens to some accounts.
     * @param source The address of the current token holder.
     * @param dests List of account addresses.
     * @param values List of token amounts. Note that these are in whole
     *   tokens. Fractions of tokens are not supported.
     */
    function airdrop(address source, address[] memory dests, uint256[] memory values) public onlyOwner {
        // This simple validation will catch most mistakes without consuming
        // too much gas.
        require(dests.length == values.length, "Address and values doesn't match");

        for (uint256 i = 0; i < dests.length; i++) {
            require(transferFrom(source, dests[i], values[i]));
        }
    }


    function approve(address spender, uint256 value) public returns(bool) {
        require(spender != address(0), "Can't approve to zero address");
        _allowed[msg.sender][spender] = value;
        emit Approval(msg.sender, spender, value);
        return true;
    }

    function transferFrom(address from, address to, uint256 value) public returns(bool) {
        require(value <= _balances[from], "Insufficient balance");
        require(value <= _allowed[from][msg.sender], "Balance not allowed");
        require(to != address(0), "Can't send to zero address");
        _balances[from] = _balances[from].sub(value);

        uint256 tokensToBurn = findPointFivePercent(value);
        uint256 tokenForDivident = findPointFivePercent(value);


        uint256 tokensToTransfer = value.sub(tokensToBurn.add(tokenForDivident));

        _balances[to] = _balances[to].add(tokensToTransfer);
        _balances[address(this)] = _balances[address(this)].add(tokenForDivident);
        _totalSupply = _totalSupply.sub(tokensToBurn);
        _allowed[from][msg.sender] = _allowed[from][msg.sender].sub(value);

        emit Transfer(from, to, tokensToTransfer);
        emit Transfer(from, address(0), tokensToBurn);
        emit Transfer(from, address(this), tokenForDivident);
        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) public returns(bool) {
        require(spender != address(0), "Can't allow to zero address");
        _allowed[msg.sender][spender] = (_allowed[msg.sender][spender].add(addedValue));
        emit Approval(msg.sender, spender, _allowed[msg.sender][spender]);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public returns(bool) {
        require(spender != address(0), "Can't allow to zero address");
        _allowed[msg.sender][spender] = (_allowed[msg.sender][spender].sub(subtractedValue));
        emit Approval(msg.sender, spender, _allowed[msg.sender][spender]);
        return true;
    }

    function burn(uint256 amount) external {
        _burn(msg.sender, amount);
    }


    function _burn(address account, uint256 amount) internal {
        require(amount != 0, "Can't burn zero amount");
        require(amount <= _balances[account], "Balance not enough");
        _totalSupply = _totalSupply.sub(amount);
        _balances[account] = _balances[account].sub(amount);
        emit Transfer(account, address(0), amount);
    }

    function burnFrom(address account, uint256 amount) external {
        require(amount <= _allowed[account][msg.sender], "Balance not allowed");
        _allowed[account][msg.sender] = _allowed[account][msg.sender].sub(amount);
        _burn(account, amount);
    }
}