pragma solidity ^0.4.24;

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
  address private _owner;

  event OwnershipTransferred(
    address indexed previousOwner,
    address indexed newOwner
  );

  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  constructor() internal {
    _owner = msg.sender;
    emit OwnershipTransferred(address(0), _owner);
  }

  /**
   * @return the address of the owner.
   */
  function owner() public view returns(address) {
    return _owner;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */

  modifier onlyOwner() {
    require(isOwner());
    _;
  }

  /**
   * @return true if `msg.sender` is the owner of the contract.
   */
  function isOwner() public view returns(bool) {
    return msg.sender == _owner;
  }

  /**
   * @dev Allows the current owner to relinquish control of the contract.
   * @notice Renouncing to ownership will leave the contract without an owner.
   * It will not be possible to call the functions with the `onlyOwner`
   * modifier anymore.
   */

  function renounceOwnership() public onlyOwner {
    emit OwnershipTransferred(_owner, address(0));
    _owner = address(0);
  }

  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param newOwner The address to transfer ownership to.
   */

  function transferOwnership(address newOwner) public onlyOwner {
    _transferOwnership(newOwner);
  }

  /**
   * @dev Transfers control of the contract to a newOwner.
   * @param newOwner The address to transfer ownership to.
   */

  function _transferOwnership(address newOwner) internal {
    require(newOwner != address(0));
    emit OwnershipTransferred(_owner, newOwner);
    _owner = newOwner;
  }
}

/*
 * Haltable
 *
 * Abstract contract that allows children to implement an
 * emergency stop mechanism. Differs from Pausable by requiring a state.
 *
 * Originally envisioned in FirstBlood ICO contract.
 */

contract Haltable is Ownable {
  bool public halted = false;

  modifier inNormalState {
    require(!halted);
    _;
  }

  modifier inEmergencyState {
    require(halted);
    _;
  }

  // called by the owner on emergency, triggers stopped state
  function halt() external onlyOwner inNormalState {
    halted = true;
  }

  // called by the owner on end of emergency, returns to normal state
  function unhalt() external onlyOwner inEmergencyState {
    halted = false;
  }
}

/**
 * @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;
  }
}

/**
 * @title SafeMath
 * @dev Math operations with safety checks that revert on error
 */

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * See https://github.com/ethereum/EIPs/issues/179
 */
contract ERC20Basic {
  function totalSupply() public view returns (uint256);
  function balanceOf(address who) public view returns (uint256);
  function transfer(address to, uint256 value) public returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);
}

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
  function allowance(address owner, address spender)
    public view returns (uint256);

  function transferFrom(address from, address to, uint256 value)
    public returns (bool);

  function approve(address spender, uint256 value) public returns (bool);
  event Approval(
    address indexed owner,
    address indexed spender,
    uint256 value
  );
}

/**
 * @title DetailedERC20 token
 * @dev The decimals are only for visualization purposes.
 * All the operations are done using the smallest and indivisible token unit,
 * just as on Ethereum all the operations are done in wei.
 */
contract DetailedERC20 is ERC20 {
  string public name;
  string public symbol;
  uint8 public decimals;

  constructor(string _name, string _symbol, uint8 _decimals) public {
    name = _name;
    symbol = _symbol;
    decimals = _decimals;
  }
}

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  uint256 totalSupply_;

  /**
  * @dev Total number of tokens in existence
  */
  function totalSupply() public view returns (uint256) {
    return totalSupply_;
  }

  /**
  * @dev Transfer token for a specified address
  * @param _to The address to transfer to.
  * @param _value The amount to be transferred.
  */
  function transfer(address _to, uint256 _value) public returns (bool) {
    require(_to != address(0));
    require(_value <= balances[msg.sender]);

    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    emit Transfer(msg.sender, _to, _value);
    return true;
  }

  /**
  * @dev Gets the balance of the specified address.
  * @param _owner The address to query the the balance of.
  * @return An uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) public view returns (uint256) {
    return balances[_owner];
  }

}

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * https://github.com/ethereum/EIPs/issues/20
 * Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */

contract StandardToken is DetailedERC20, BasicToken {

  mapping (address => mapping (address => uint256)) internal allowed;


  /**
   * @dev Transfer tokens from one address to another
   * @param _from address The address which you want to send tokens from
   * @param _to address The address which you want to transfer to
   * @param _value uint256 the amount of tokens to be transferred
   */
  function transferFrom(
    address _from,
    address _to,
    uint256 _value
  )
    public
    returns (bool)
  {
    require(_to != address(0));
    require(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    emit Transfer(_from, _to, _value);
    return true;
  }

  /**
   * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
   * Beware that changing an allowance with this method brings the risk that someone may use both the old
   * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
   * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   * @param _spender The address which will spend the funds.
   * @param _value The amount of tokens to be spent.
   */
  function approve(address _spender, uint256 _value) public returns (bool) {
    allowed[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
  }

  /**
   * @dev Function to check the amount of tokens that an owner allowed to a spender.
   * @param _owner address The address which owns the funds.
   * @param _spender address The address which will spend the funds.
   * @return A uint256 specifying the amount of tokens still available for the spender.
   */
  function allowance(
    address _owner,
    address _spender
   )
    public
    view
    returns (uint256)
  {
    return allowed[_owner][_spender];
  }

  /**
   * @dev Increase the amount of tokens that an owner allowed to a spender.
   * approve should be called when allowed[_spender] == 0. To increment
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   * @param _spender The address which will spend the funds.
   * @param _addedValue The amount of tokens to increase the allowance by.
   */
  function increaseApproval(
    address _spender,
    uint256 _addedValue
  )
    public
    returns (bool)
  {
    allowed[msg.sender][_spender] = (
      allowed[msg.sender][_spender].add(_addedValue));
    emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

  /**
   * @dev Decrease the amount of tokens that an owner allowed to a spender.
   * approve should be called when allowed[_spender] == 0. To decrement
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   * @param _spender The address which will spend the funds.
   * @param _subtractedValue The amount of tokens to decrease the allowance by.
   */
  function decreaseApproval(
    address _spender,
    uint256 _subtractedValue
  )
    public
    returns (bool)
  {
    uint256 oldValue = allowed[msg.sender][_spender];
    if (_subtractedValue > oldValue) {
      allowed[msg.sender][_spender] = 0;
    } else {
      allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
    }
    emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

}

contract ZEON is StandardToken { //!

  constructor() public DetailedERC20("ZEON", "ZEON", 18) { //!
    totalSupply_ = 50000000000000000000000000000;
    balances[msg.sender] = totalSupply_;
    emit Transfer(address(0), msg.sender, totalSupply_);
  }
}

contract InvestorWhiteList is Ownable {
  mapping (address => bool) public investorWhiteList;

  mapping (address => address) public referralList;

  function InvestorWhiteList() {

  }

  function addInvestorToWhiteList(address investor) external onlyOwner {
    require(investor != 0x0 && !investorWhiteList[investor]);
    investorWhiteList[investor] = true;
  }

  function removeInvestorFromWhiteList(address investor) external onlyOwner {
    require(investor != 0x0 && investorWhiteList[investor]);
    investorWhiteList[investor] = false;
  }

  //when new user will contribute ICO contract will automatically send bonus to referral
  function addReferralOf(address investor, address referral) external onlyOwner {
    require(investor != 0x0 && referral != 0x0 && referralList[investor] == 0x0 && investor != referral);
    referralList[investor] = referral;
  }

  function isAllowed(address investor) constant external returns (bool result) {
    return investorWhiteList[investor];
  }

  function getReferralOf(address investor) constant external returns (address result) {
    return referralList[investor];
  }
}

contract PriceReceiver {
  address public ethPriceProvider;

  modifier onlyEthPriceProvider() {
    require(msg.sender == ethPriceProvider);
    _;
  }

  function receiveEthPrice(uint ethUsdPrice) external;

  function setEthPriceProvider(address provider) external;

}

// Sale of unsold tokens [smart-contract]

contract ZEONPrivateSale is Haltable, PriceReceiver {

  using SafeMath for uint;

  string public constant name = "ZEONPrivateSale";

  ZEON public token;

  address public beneficiary;

  InvestorWhiteList public investorWhiteList;

  uint public constant TokenUsdRate = 50; //0.5 cents for one token
  uint public constant MonthsInSeconds = 2629746;

  uint public ethUsdRate;

  uint public collected = 0;

  uint public tokensSold = 0;

  uint public startTime; 

  uint public endTime;

  bool public crowdsaleFinished = false;

  mapping (address => uint) public deposited;

  event NewContribution(address indexed holder, uint tokenAmount, uint etherAmount);

  event NewReferralTransfer(address indexed investor, address indexed referral, uint tokenAmount);

  modifier icoActive() {
    require(now >= startTime && now < endTime);
    _;
  }

  modifier icoEnded() {
    require(now >= endTime);
    _;
  }

  function ZEONPrivateSale(
    address _token,
    address _beneficiary,
    address _investorWhiteList,
    uint _baseEthUsdPrice,

    uint _startTime
  ) {
    token = ZEON (_token); //token's smart name
    beneficiary = _beneficiary;
    investorWhiteList = InvestorWhiteList(_investorWhiteList);

    startTime = _startTime;
    endTime = startTime.add(MonthsInSeconds.mul(12));

    ethUsdRate = _baseEthUsdPrice;
  }

  function() payable {
    doPurchase();
  }

  function withdraw() external onlyOwner {
    token.transfer(beneficiary, token.balanceOf(this));
  }

  function calculateTokens(uint ethReceived) internal view returns (uint) {
    uint actualTokenUsdRate = TokenUsdRate.add(TokenUsdRate.mul((now - startTime).mul(1000).div(MonthsInSeconds).div(100).mul(10)).div(1000));
    
    return ethReceived.mul(ethUsdRate.mul(100)).div(actualTokenUsdRate);
  }

  function calculateReferralBonus(uint amountTokens) internal view returns (uint) {
    return amountTokens.mul(8).div(100);
  }

  function receiveEthPrice(uint ethUsdPrice) external onlyEthPriceProvider {
    require(ethUsdPrice > 0);
    ethUsdRate = ethUsdPrice;
  }

  function setEthPriceProvider(address provider) external onlyOwner {
    require(provider != 0x0);
    ethPriceProvider = provider;
  }

  function setNewWhiteList(address newWhiteList) external onlyOwner {
    require(newWhiteList != 0x0);
    investorWhiteList = InvestorWhiteList(newWhiteList);
  }

  function doPurchase() private icoActive inNormalState {
    require(!crowdsaleFinished);

    uint tokens = calculateTokens(msg.value); 

    uint newTokensSold = tokensSold.add(tokens);

    uint referralBonus = 0;
    referralBonus = calculateReferralBonus(tokens);

    address referral = investorWhiteList.getReferralOf(msg.sender);

    if (referralBonus > 0 && referral != 0x0) {
      newTokensSold = newTokensSold.add(referralBonus);
    }

    collected = collected.add(msg.value);

    tokensSold = newTokensSold;

    deposited[msg.sender] = deposited[msg.sender].add(msg.value);

    token.transfer(msg.sender, tokens);
    NewContribution(msg.sender, tokens, msg.value);

    if (referralBonus > 0 && referral != 0x0) {
      token.transfer(referral, referralBonus);
      NewReferralTransfer(msg.sender, referral, referralBonus);
    }
    
    beneficiary.transfer(msg.value);
  }


  function transferOwnership(address newOwner) onlyOwner icoEnded {
    super.transferOwnership(newOwner);
  }
}