UltimateHODL

UltimateHODL.sol

pragma solidity ^0.4.24;

/**
 * @title SafeMath
 * @dev Math operations with safety checks that revert on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, reverts on 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-solidity/pull/522
    if (a == 0) {
      return 0;
    }

    uint256 c = a * b;
    require(c / a == b);

    return c;
  }

  /**
  * @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
  */
  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b > 0); // Solidity only automatically asserts when dividing by 0
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold

    return c;
  }

  /**
  * @dev Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b <= a);
    uint256 c = a - b;

    return c;
  }

  /**
  * @dev Adds two numbers, reverts on overflow.
  */
  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    require(c >= a);

    return c;
  }

  /**
  * @dev Divides two numbers and returns the remainder (unsigned integer modulo),
  * reverts when dividing by zero.
  */
  function mod(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b != 0);
    return a % b;
  }
}

contract UltimateHODL {
    using SafeMath for uint256;

    address public creator = msg.sender;
    uint256 constant private percentRemaining = 90;

    uint256 private totalSupply;
    mapping(address => uint256) private shares;
    
    function balanceOf(address _account) public view returns(uint256) {
        if (shares[_account] == totalSupply) {
            return  address(this).balance;
        }
        return address(this).balance.mul(shares[_account]).mul(percentRemaining).div(totalSupply).div(100);
    }
    
    function () payable {
        if (msg.value > 0) {
            // Deposit
            if (totalSupply == 0) {
                uint256 amount = msg.value;
            } else {
                amount = msg.value.mul(totalSupply).div(address(this).balance.sub(msg.value));
            }
            shares[msg.sender] = shares[msg.sender].add(amount);
            totalSupply = totalSupply.add(amount);
        } else {
            // Withdraw
            amount = balanceOf(msg.sender);
            totalSupply = totalSupply.sub(shares[msg.sender]);
            shares[msg.sender] = 0;
            msg.sender.transfer(amount);
            if (totalSupply > 0) {
                creator.transfer(amount.div(percentRemaining)); // 1%
            } else {
            	  creator.transfer(address(this).balance);
            }
        }
    }
}