Refund contract

refund.sol

/*
This file is part of the DAO.

The DAO is free software: you can redistribute it and/or modify
it under the terms of the GNU lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

The DAO is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU lesser General Public License for more details.

You should have received a copy of the GNU lesser General Public License
along with the DAO.  If not, see <http://www.gnu.org/licenses/>.
*/

// TODO: all constants need to be double checked
import "github.com/slockit/DAO/DAO.sol";

contract Refund {
    DAO constant public mainDAO = DAO(0xbb9bc244d798123fde783fcc1c72d3bb8c189413);
    uint constant public totalSupply = 11538165987024671407837618;
    uint constant public totalWeiSupply = 11898333978710775162018627;

function withdraw(address donateExtraBalanceTo){
        uint balance = mainDAO.balanceOf(msg.sender);

        // The msg.sender must call approve(this, balance) beforehand so that
        // transferFrom() will work and not throw. We need transferFrom()
        // instead of transfer() due to the msg.sender in the latter ending
        // up to be the contract
        if (!mainDAO.transferFrom(msg.sender, this, balance)
            || !msg.sender.send(balance)
            || !donateExtraBalanceTo.send(balance * totalWeiSupply / totalSupply - balance)) {

            throw;
        }
    }
}