pragma solidity ^0.4.11;

contract hadcoin_ico{

    // Introducing the total number of hadcoin tokens available for sealed
    uint public max_hadcoins = 1000000;

    // Introducing the USD to hadcoin conversion rate
    uint public usd_to_hadcoins = 1000;

    // Introducing the total number of hadcoins that have been bought by the investors
    uint public total_hadcoins_bought = 0;

    // Mapping from the investor address to its equity in hadcoins and USD
    mapping(address => uint) equity_hadcoins;
    mapping(address => uint) equity_usd;

    // Checking if an investor can buy Hadcoins
    modifier can_buy_hadcoins(uint usd_invested) {
        require(usd_invested * usd_to_hadcoins + total_hadcoins_bought <= max_hadcoins);
        _;
    }

    // Getting the equity in Hadcoins of an investor
    function equity_in_hadcoins(address investor) external constant returns(uint){
        return equity_hadcoins[investor];
    }


    // Getting the equity in USD of an investor
       function equity_in_usd(address investor) external constant returns(uint){
        return equity_usd[investor];
    }

    //Buy Hadcoins
    function buy_hadcoins(address investor ,uint usd_invested) external
     can_buy_hadcoins(usd_invested)
    {
       uint hadcoins_bought = usd_invested * usd_to_hadcoins;
        equity_hadcoins[investor] += hadcoins_bought;
        equity_usd[investor] =  equity_hadcoins[investor] / 1000;
        total_hadcoins_bought += hadcoins_bought;
    }

    // Selling Hadcoin
    function sell_hadcoins(address investor,uint hadcoins_sold) external{
        equity_hadcoins[investor] -= hadcoins_sold;
        equity_usd[investor] =  equity_hadcoins[investor] / 1000;
        total_hadcoins_bought -= hadcoins_sold;
    }


}