contract ElcoinICO {

  // Constants
  // =========

  uint256 public constant tokensPerEth = 300; // ELC per ETH
  uint256 public constant tokenLimit = 60 * 1e6 * 1e18;
  uint256 public constant tokensForSale = tokenLimit * 50 / 100;
  uint256 public presaleSold = 0;
  uint256 public startTime = 1511038800; // 19 November 2017 18:00 UTC
  uint256 public endTime = 1517778000; // 05 February 2018 18:00 UTC

  // Events
  // ======

  event RunIco();
  event PauseIco();
  event FinishIco(address team, address foundation, address advisors, address bounty);


  // State variables
  // ===============

  ELC public elc;

  address public team;
  modifier teamOnly { require(msg.sender == team); _; }

  enum IcoState { Presale, Running, Paused, Finished }
  IcoState public icoState = IcoState.Presale;


  // Constructor
  // ===========

  function ElcoinICO(address _team) public {
    team = _team;
    elc = new ELC(this, tokenLimit);
  }


  // Public functions
  // ================

  // Here you can buy some tokens (just don't forget to provide enough gas).
  function() external payable {
    buyFor(msg.sender);
  }


  function buyFor(address _investor) public payable {
    require(icoState == IcoState.Running);
    require(msg.value > 0);
    buy(_investor, msg.value);
  }


  function getPresaleTotal(uint256 _value) public constant returns (uint256) {
     if(_value < 10 ether) {
      return _value * tokensPerEth;
    }

    if(_value >= 10 ether && _value < 100 ether) {
      return calcPresaleDiscount(_value, 3);
    }

    if(_value >= 100 ether && _value < 1000 ether) {
      return calcPresaleDiscount(_value, 5);
    }

    if(_value >= 1000 ether) {
      return calcPresaleDiscount(_value, 10);
    }
  }

function getTimeBonus(uint time) public constant returns (uint) {
        if (time < startTime + 1 weeks) return 200;
        if (time < startTime + 2 weeks) return 150;
        if (time < startTime + 3 weeks) return 100;
        if (time < startTime + 4 weeks) return 50;
        return 0;
    }

  function getTotal(uint256 _value) public constant returns (uint256) {
    uint256 _elcValue = _value * tokensPerEth;
    uint256 _bonus = getBonus(_elcValue, elc.totalSupply() - presaleSold);

    return _elcValue + _bonus;
  }


  function getBonus(uint256 _elcValue, uint256 _sold) public constant returns (uint256) {
    uint256[8] memory _bonusPattern = [ uint256(150), 130, 110, 90, 70, 50, 30, 10 ];
    uint256 _step = (tokensForSale - presaleSold) / 10;
    uint256 _bonus = 0;

    for(uint8 i = 0; i < _bonusPattern.length; ++i) {
      uint256 _min = _step * i;
      uint256 _max = _step * (i + 1);
      if(_sold >= _min && _sold < _max) {
        uint256 _bonusPart = min(_elcValue, _max - _sold);
        _bonus += _bonusPart * _bonusPattern[i] / 1000;
        _elcValue -= _bonusPart;
        _sold  += _bonusPart;
      }
    }

    return _bonus;
  }


  // Priveleged functions
  // ====================

  function mintForEarlyInvestors(address[] _investors, uint256[] _values) external teamOnly {
    require(_investors.length == _values.length);
    for (uint256 i = 0; i < _investors.length; ++i) {
      mintPresaleTokens(_investors[i], _values[i]);
    }
  }


  function mintFor(address _investor, uint256 _elcValue) external teamOnly {
    require(icoState != IcoState.Finished);
    require(elc.totalSupply() + _elcValue <= tokensForSale);

    elc.mint(_investor, _elcValue);
  }


  function withdrawEther(uint256 _value) external teamOnly {
    team.transfer(_value);
  }


  // Save tokens from contract
  function withdrawToken(address _tokenContract, uint256 _value) external teamOnly {
    ERC20 _token = ERC20(_tokenContract);
    _token.transfer(team, _value);
  }


  function withdrawTokenFromElc(address _tokenContract, uint256 _value) external teamOnly {
    elc.withdrawToken(_tokenContract, team, _value);
  }


  // ICO state management: start / pause / finish
  // --------------------------------------------

  function startIco() external teamOnly {
    require(icoState == IcoState.Presale || icoState == IcoState.Paused);
    icoState = IcoState.Running;
    RunIco();
  }


  function pauseIco() external teamOnly {
    require(icoState == IcoState.Running);
    icoState = IcoState.Paused;
    PauseIco();
  }


  function finishIco(address _team, address _foundation, address _advisors, address _bounty) external teamOnly {
    require(icoState == IcoState.Running || icoState == IcoState.Paused);

    icoState = IcoState.Finished;
    uint256 _teamFund = elc.totalSupply() * 2 / 2;

    uint256 _den = 10000;
    elc.mint(_team, _teamFund * 4000 / _den);
    elc.mint(_foundation, _teamFund * 4000 / _den);
    elc.mint(_advisors, _teamFund * 1000 / _den);
    elc.mint(_bounty, _teamFund  * 1000 / _den);

    elc.defrost();

    FinishIco(_team, _foundation, _advisors, _bounty);
  }


  // Private functions
  // =================

  function mintPresaleTokens(address _investor, uint256 _value) internal {
    require(icoState == IcoState.Presale);
    require(_value > 0);

    uint256 _elcValue = getPresaleTotal(_value);

    uint256 timeBonusAmount = _elcValue * getTimeBonus(now) / 1000;

     _elcValue += timeBonusAmount;

    require(elc.totalSupply() + _elcValue <= tokensForSale);

    elc.mint(_investor, _elcValue);
    presaleSold += _elcValue;
  }


  function calcPresaleDiscount(uint256 _value, uint256 _percent) internal constant returns (uint256) {
    return _value * tokensPerEth * 100 / (100 - _percent);
  }

  function min(uint256 a, uint256 b) internal constant returns (uint256) {
    return a < b ? a : b;
  }

  function buy(address _investor, uint256 _value) internal {
    uint256 _total = getTotal(_value);

    require(elc.totalSupply() + _total <= tokensForSale);

    elc.mint(_investor, _total);
  }
}
function startIco() external teamOnly {
  require(icoState == IcoState.Presale || icoState == IcoState.Paused);
  icoState = IcoState.Running;
  RunIco();
}

// ICO state management: start / pause / finish
// --------------------------------------------