// Vulnerability label: overflow
pragma solidity ^0.4.25;

contract EtherStateEquivalentToken {
    address public owner;
    mapping (address => uint256) public tokenBalance;
    mapping (address => uint256) public refBalance;
    
    uint256 public tokenPrice = 0.0004 ether; 
    uint256 public tokenSupply = 0;
    uint256 constant public softCap =  2500000 ether;
    uint256 constant public hardCap = 10000000 ether;
    uint256 public start;
    uint256 public softCapMoment = 0;
    uint256 public softCapPeriod = 1483300; //17 * 24 * 60 * 60;
    uint256 public hardCapPeriod = softCapPeriod;
    uint256 public investedTotal = 0;
    
    bool public softCapReached = false;
    
    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }
    
    modifier softCapFailed {
        require(now > start + softCapPeriod && !softCapReached);
        _;
    }
    
    constructor() public {
        owner = msg.sender;
        start = now;
    }
    
    function() public payable {
        invest(msg.sender, msg.value, 0x0, 0x0);
    }
    
    function buy(address ref1, address ref2) public payable {
        /* 
            Function Enhamster
        */
        
        require(msg.value > 0);
        
        invest(msg.sender, msg.value, ref1, ref2);
    }
    
    function invest(address investor, uint256 value, address ref1, address ref2) internal {
        /* 
            Внутренняя функция покупки токенов, вызывается из головного метода и метода buy.
        */
        
        uint256 tokens = value / tokenPrice * 1 ether;
        require (tokens + tokenSupply <= hardCap); /* нельзя чтобы образовался tokenSupply, превосходящий 10 000 000 EST */
        if (softCapMoment > 0) require(now < softCapMoment + hardCapPeriod); /* после периода Hard Cap токены нельзя покупать */
        
        tokenBalance[investor] += tokens;
        tokenSupply += tokens;
        
        if (tokenSupply >= softCap) {
            softCapReached = true;
            softCapMoment = now;
        }
        
        uint256 ref1Money = value * 6 / 100;
        uint256 ref2Money = value * 3 / 100;
        uint256 ownerMoney = value - ref1Money - ref2Money;
        
        if (ref1 != 0x0 && tokenBalance[ref1] >= 125 ether) {
            refBalance[ref1] += ref1Money;
        } else {
            refBalance[owner] += ref1Money;
        }
        if (ref2 != 0x0 && tokenBalance[ref2] >= 125 ether) {
            refBalance[ref2] += ref2Money;
        } else {
            refBalance[owner] += ref2Money;
        }
        refBalance[owner] += ownerMoney;
        
        investedTotal += value;
         
        emit OnInvest(investor, value, tokens, ref1, ref2, now);
    }
    
    function withdraw() public {
        /* 
            Вывод средств с реферального баланса, возможен только в случае достижения Soft Cap. Этот же метод 
            используется owner'ом контракта для вывода средств.
        */
        
        require(softCapReached);
        uint256 value = refBalance[msg.sender];
        require(value > 0);
        
        refBalance[msg.sender] = 0;
        
        msg.sender.transfer(value);
        emit OnWithdraw(msg.sender, value, now);
    }
    
    function withdrawAmount(uint256 amount) public {
        /* 
            Вывод средств с реферального баланса, с указанием определённой суммы.
        */
        require(amount > 0);
        require(softCapReached);
        uint256 value = refBalance[msg.sender];
        require(value >= amount);
        
        refBalance[msg.sender] = value-amount;
        
        msg.sender.transfer(amount);
        emit OnWithdraw(msg.sender, amount, now);
    }
    
    function withdrawAmountTo(uint256 amount, address receiver) public {
        /* 
            Вывод средств с реферального баланса определённой суммы в пользу другого адреса.
        */
        require(amount > 0);
        require(softCapReached);
        uint256 value = refBalance[msg.sender];
        require(value >= amount);
        
        refBalance[msg.sender] = value-amount;
        
        receiver.transfer(amount);
        emit OnWithdrawTo(msg.sender, receiver, amount, now);
    }
    
    function deinvest() public softCapFailed {
        /* 
            Вывод средств инвестора в случае провала softCap. Модификатор проверяет время и не позволяет 
            выводить средства до завершения периода softCapPeriod, а также в случае, если Soft Cap был выполнен.
        */
            
        uint256 tokens = tokenBalance[msg.sender];
        require(tokens > 0);
        
        tokenBalance[msg.sender] = 0;
        tokenSupply -= tokens;
        uint256 money = tokens * tokenPrice / 1e18;
        msg.sender.transfer(money);
        emit OnDeinvest(msg.sender, tokens, money, now);
    }
    
    function goESM() public { 
        /*  
            Обмен на токены Ether State Main. При вызове этого метода, все токены EST будут сожжены,
            и сформируется соответствующий Event.
        */
       
        require(softCapReached);
        uint256 tokens = tokenBalance[msg.sender];
        require(tokens > 0);
        
        tokenBalance[msg.sender] = 0;
        tokenSupply -= tokens;
        emit OnExchangeForESM(msg.sender, tokens, now);
    }

    function transfer(address receiver) public {
        uint256 tokens = tokenBalance[msg.sender];
        require(tokens > 0);

        tokenBalance[msg.sender] = 0;
        tokenBalance[receiver] += tokens;

        emit OnTransfer(msg.sender, receiver, tokens, now);
    }
    
    event OnInvest (
        address investor,
        uint256 value,
        uint256 tokensGranted,
        address ref1,
        address ref2,
        uint256 timestamp
    );
    
    event OnWithdraw (
        address indexed investor,
        uint256 value,
        uint256 timestamp
    );

    event OnWithdrawTo (
        address indexed investor,
        address indexed receiver,
        uint256 value,
        uint256 timestamp
    );
    
    event OnDeinvest (
        address indexed investor,
        uint256 tokensBurned,
        uint256 value,
        uint256 timestamp
    );
    
    event OnExchangeForESM (
        address indexed investor,
        uint256 tokensBurned,
        uint256 timestamp
    );

    event OnTransfer (
        address investorA,
        address investorB,
        uint256 tokens,
        uint256 timestamp
    );
}