pragma solidity ^0.4.25;

// File: openzeppelin-solidity/contracts/access/Roles.sol

/**
 * @title Roles
 * @dev Library for managing addresses assigned to a Role.
 */
library Roles {
  struct Role {
    mapping (address => bool) bearer;
  }

  /**
   * @dev give an account access to this role
   */
  function add(Role storage role, address account) internal {
    require(account != address(0));
    require(!has(role, account));

    role.bearer[account] = true;
  }

  /**
   * @dev remove an account's access to this role
   */
  function remove(Role storage role, address account) internal {
    require(account != address(0));
    require(has(role, account));

    role.bearer[account] = false;
  }

  /**
   * @dev check if an account has this role
   * @return bool
   */
  function has(Role storage role, address account)
    internal
    view
    returns (bool)
  {
    require(account != address(0));
    return role.bearer[account];
  }
}

// File: openzeppelin-solidity/contracts/access/roles/SignerRole.sol

contract SignerRole {
  using Roles for Roles.Role;

  event SignerAdded(address indexed account);
  event SignerRemoved(address indexed account);

  Roles.Role private signers;

  constructor() internal {
    _addSigner(msg.sender);
  }

  modifier onlySigner() {
    require(isSigner(msg.sender));
    _;
  }

  function isSigner(address account) public view returns (bool) {
    return signers.has(account);
  }

  function addSigner(address account) public onlySigner {
    _addSigner(account);
  }

  function renounceSigner() public {
    _removeSigner(msg.sender);
  }

  function _addSigner(address account) internal {
    signers.add(account);
    emit SignerAdded(account);
  }

  function _removeSigner(address account) internal {
    signers.remove(account);
    emit SignerRemoved(account);
  }
}

// File: openzeppelin-solidity/contracts/cryptography/ECDSA.sol

/**
 * @title Elliptic curve signature operations
 * @dev Based on https://gist.github.com/axic/5b33912c6f61ae6fd96d6c4a47afde6d
 * TODO Remove this library once solidity supports passing a signature to ecrecover.
 * See https://github.com/ethereum/solidity/issues/864
 */

library ECDSA {

  /**
   * @dev Recover signer address from a message by using their signature
   * @param hash bytes32 message, the hash is the signed message. What is recovered is the signer address.
   * @param signature bytes signature, the signature is generated using web3.eth.sign()
   */
  function recover(bytes32 hash, bytes signature)
    internal
    pure
    returns (address)
  {
    bytes32 r;
    bytes32 s;
    uint8 v;

    // Check the signature length
    if (signature.length != 65) {
      return (address(0));
    }

    // Divide the signature in r, s and v variables
    // ecrecover takes the signature parameters, and the only way to get them
    // currently is to use assembly.
    // solium-disable-next-line security/no-inline-assembly
    assembly {
      r := mload(add(signature, 0x20))
      s := mload(add(signature, 0x40))
      v := byte(0, mload(add(signature, 0x60)))
    }

    // Version of signature should be 27 or 28, but 0 and 1 are also possible versions
    if (v < 27) {
      v += 27;
    }

    // If the version is correct return the signer address
    if (v != 27 && v != 28) {
      return (address(0));
    } else {
      // solium-disable-next-line arg-overflow
      return ecrecover(hash, v, r, s);
    }
  }

  /**
   * toEthSignedMessageHash
   * @dev prefix a bytes32 value with "\x19Ethereum Signed Message:"
   * and hash the result
   */
  function toEthSignedMessageHash(bytes32 hash)
    internal
    pure
    returns (bytes32)
  {
    // 32 is the length in bytes of hash,
    // enforced by the type signature above
    return keccak256(
      abi.encodePacked("\x19Ethereum Signed Message:\n32", hash)
    );
  }
}

// File: openzeppelin-solidity/contracts/drafts/SignatureBouncer.sol

/**
 * @title SignatureBouncer
 * @author PhABC, Shrugs and aflesher
 * @dev SignatureBouncer allows users to submit a signature as a permission to
 * do an action.
 * If the signature is from one of the authorized signer addresses, the
 * signature is valid.
 * Note that SignatureBouncer offers no protection against replay attacks, users
 * must add this themselves!
 *
 * Signer addresses can be individual servers signing grants or different
 * users within a decentralized club that have permission to invite other
 * members. This technique is useful for whitelists and airdrops; instead of
 * putting all valid addresses on-chain, simply sign a grant of the form
 * keccak256(abi.encodePacked(`:contractAddress` + `:granteeAddress`)) using a
 * valid signer address.
 * Then restrict access to your crowdsale/whitelist/airdrop using the
 * `onlyValidSignature` modifier (or implement your own using _isValidSignature).
 * In addition to `onlyValidSignature`, `onlyValidSignatureAndMethod` and
 * `onlyValidSignatureAndData` can be used to restrict access to only a given
 * method or a given method with given parameters respectively.
 * See the tests in SignatureBouncer.test.js for specific usage examples.
 *
 * @notice A method that uses the `onlyValidSignatureAndData` modifier must make
 * the _signature parameter the "last" parameter. You cannot sign a message that
 * has its own signature in it so the last 128 bytes of msg.data (which
 * represents the length of the _signature data and the _signaature data itself)
 * is ignored when validating. Also non fixed sized parameters make constructing
 * the data in the signature much more complex.
 * See https://ethereum.stackexchange.com/a/50616 for more details.
 */
contract SignatureBouncer is SignerRole {
  using ECDSA for bytes32;

  // Function selectors are 4 bytes long, as documented in
  // https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector
  uint256 private constant _METHOD_ID_SIZE = 4;
  // Signature size is 65 bytes (tightly packed v + r + s), but gets padded to 96 bytes
  uint256 private constant _SIGNATURE_SIZE = 96;

  constructor() internal {}

  /**
   * @dev requires that a valid signature of a signer was provided
   */
  modifier onlyValidSignature(bytes signature)
  {
    require(_isValidSignature(msg.sender, signature));
    _;
  }

  /**
   * @dev requires that a valid signature with a specifed method of a signer was provided
   */
  modifier onlyValidSignatureAndMethod(bytes signature)
  {
    require(_isValidSignatureAndMethod(msg.sender, signature));
    _;
  }

  /**
   * @dev requires that a valid signature with a specifed method and params of a signer was provided
   */
  modifier onlyValidSignatureAndData(bytes signature)
  {
    require(_isValidSignatureAndData(msg.sender, signature));
    _;
  }

  /**
   * @dev is the signature of `this + sender` from a signer?
   * @return bool
   */
  function _isValidSignature(address account, bytes signature)
    internal
    view
    returns (bool)
  {
    return _isValidDataHash(
      keccak256(abi.encodePacked(address(this), account)),
      signature
    );
  }

  /**
   * @dev is the signature of `this + sender + methodId` from a signer?
   * @return bool
   */
  function _isValidSignatureAndMethod(address account, bytes signature)
    internal
    view
    returns (bool)
  {
    bytes memory data = new bytes(_METHOD_ID_SIZE);
    for (uint i = 0; i < data.length; i++) {
      data[i] = msg.data[i];
    }
    return _isValidDataHash(
      keccak256(abi.encodePacked(address(this), account, data)),
      signature
    );
  }

  /**
    * @dev is the signature of `this + sender + methodId + params(s)` from a signer?
    * @notice the signature parameter of the method being validated must be the "last" parameter
    * @return bool
    */
  function _isValidSignatureAndData(address account, bytes signature)
    internal
    view
    returns (bool)
  {
    require(msg.data.length > _SIGNATURE_SIZE);
    bytes memory data = new bytes(msg.data.length - _SIGNATURE_SIZE);
    for (uint i = 0; i < data.length; i++) {
      data[i] = msg.data[i];
    }
    return _isValidDataHash(
      keccak256(abi.encodePacked(address(this), account, data)),
      signature
    );
  }

  /**
   * @dev internal function to convert a hash to an eth signed message
   * and then recover the signature and check it against the signer role
   * @return bool
   */
  function _isValidDataHash(bytes32 hash, bytes signature)
    internal
    view
    returns (bool)
  {
    address signer = hash
      .toEthSignedMessageHash()
      .recover(signature);

    return signer != address(0) && isSigner(signer);
  }
}

// File: openzeppelin-solidity/contracts/token/ERC20/IERC20.sol

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
interface IERC20 {
  function totalSupply() external view returns (uint256);

  function balanceOf(address who) external view returns (uint256);

  function allowance(address owner, address spender)
    external view returns (uint256);

  function transfer(address to, uint256 value) external returns (bool);

  function approve(address spender, uint256 value)
    external returns (bool);

  function transferFrom(address from, address to, uint256 value)
    external returns (bool);

  event Transfer(
    address indexed from,
    address indexed to,
    uint256 value
  );

  event Approval(
    address indexed owner,
    address indexed spender,
    uint256 value
  );
}

// File: openzeppelin-solidity/contracts/math/SafeMath.sol

/**
 * @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;
  }
}

// File: openzeppelin-solidity/contracts/token/ERC20/ERC20.sol

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md
 * Originally based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract ERC20 is IERC20 {
  using SafeMath for uint256;

  mapping (address => uint256) private _balances;

  mapping (address => mapping (address => uint256)) private _allowed;

  uint256 private _totalSupply;

  /**
  * @dev Total number of tokens in existence
  */
  function totalSupply() public view returns (uint256) {
    return _totalSupply;
  }

  /**
  * @dev Gets the balance of the specified address.
  * @param owner The address to query 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];
  }

  /**
   * @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 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) {
    _transfer(msg.sender, 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) {
    require(spender != address(0));

    _allowed[msg.sender][spender] = value;
    emit Approval(msg.sender, spender, value);
    return true;
  }

  /**
   * @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(value <= _allowed[from][msg.sender]);

    _allowed[from][msg.sender] = _allowed[from][msg.sender].sub(value);
    _transfer(from, to, value);
    return true;
  }

  /**
   * @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 increaseAllowance(
    address spender,
    uint256 addedValue
  )
    public
    returns (bool)
  {
    require(spender != address(0));

    _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 decreaseAllowance(
    address spender,
    uint256 subtractedValue
  )
    public
    returns (bool)
  {
    require(spender != address(0));

    _allowed[msg.sender][spender] = (
      _allowed[msg.sender][spender].sub(subtractedValue));
    emit Approval(msg.sender, spender, _allowed[msg.sender][spender]);
    return true;
  }

  /**
  * @dev Transfer token for a specified addresses
  * @param from The address to transfer from.
  * @param to The address to transfer to.
  * @param value The amount to be transferred.
  */
  function _transfer(address from, address to, uint256 value) internal {
    require(value <= _balances[from]);
    require(to != address(0));

    _balances[from] = _balances[from].sub(value);
    _balances[to] = _balances[to].add(value);
    emit Transfer(from, to, value);
  }

  /**
   * @dev Internal function that mints an amount of the token and assigns it to
   * an account. This encapsulates the modification of balances such that the
   * proper events are emitted.
   * @param account The account that will receive the created tokens.
   * @param value The amount that will be created.
   */
  function _mint(address account, uint256 value) internal {
    require(account != 0);
    _totalSupply = _totalSupply.add(value);
    _balances[account] = _balances[account].add(value);
    emit Transfer(address(0), account, value);
  }

  /**
   * @dev Internal function that burns an amount of the token of a given
   * account.
   * @param account The account whose tokens will be burnt.
   * @param value The amount that will be burnt.
   */
  function _burn(address account, uint256 value) internal {
    require(account != 0);
    require(value <= _balances[account]);

    _totalSupply = _totalSupply.sub(value);
    _balances[account] = _balances[account].sub(value);
    emit Transfer(account, address(0), value);
  }

  /**
   * @dev Internal function that burns an amount of the token of a given
   * account, deducting from the sender's allowance for said account. Uses the
   * internal burn function.
   * @param account The account whose tokens will be burnt.
   * @param value The amount that will be burnt.
   */
  function _burnFrom(address account, uint256 value) internal {
    require(value <= _allowed[account][msg.sender]);

    // Should https://github.com/OpenZeppelin/zeppelin-solidity/issues/707 be accepted,
    // this function needs to emit an event with the updated approval.
    _allowed[account][msg.sender] = _allowed[account][msg.sender].sub(
      value);
    _burn(account, value);
  }
}

// File: openzeppelin-solidity/contracts/token/ERC20/ERC20Burnable.sol

/**
 * @title Burnable Token
 * @dev Token that can be irreversibly burned (destroyed).
 */
contract ERC20Burnable is ERC20 {

  /**
   * @dev Burns a specific amount of tokens.
   * @param value The amount of token to be burned.
   */
  function burn(uint256 value) public {
    _burn(msg.sender, value);
  }

  /**
   * @dev Burns a specific amount of tokens from the target address and decrements allowance
   * @param from address The address which you want to send tokens from
   * @param value uint256 The amount of token to be burned
   */
  function burnFrom(address from, uint256 value) public {
    _burnFrom(from, value);
  }
}

// File: openzeppelin-solidity/contracts/token/ERC20/SafeERC20.sol

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure.
 * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {

  using SafeMath for uint256;

  function safeTransfer(
    IERC20 token,
    address to,
    uint256 value
  )
    internal
  {
    require(token.transfer(to, value));
  }

  function safeTransferFrom(
    IERC20 token,
    address from,
    address to,
    uint256 value
  )
    internal
  {
    require(token.transferFrom(from, to, value));
  }

  function safeApprove(
    IERC20 token,
    address spender,
    uint256 value
  )
    internal
  {
    // safeApprove should only be called when setting an initial allowance, 
    // or when resetting it to zero. To increase and decrease it, use 
    // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
    require((value == 0) || (token.allowance(msg.sender, spender) == 0));
    require(token.approve(spender, value));
  }

  function safeIncreaseAllowance(
    IERC20 token,
    address spender,
    uint256 value
  )
    internal
  {
    uint256 newAllowance = token.allowance(address(this), spender).add(value);
    require(token.approve(spender, newAllowance));
  }

  function safeDecreaseAllowance(
    IERC20 token,
    address spender,
    uint256 value
  )
    internal
  {
    uint256 newAllowance = token.allowance(address(this), spender).sub(value);
    require(token.approve(spender, newAllowance));
  }
}

// File: contracts/misc/DutchAuction.sol

/// @title Dutch auction contract - distribution of XRT tokens using an auction.
/// @author Stefan George - <stefan.george@consensys.net>
/// @author Airalab - <research@aira.life> 
contract DutchAuction is SignatureBouncer {
    using SafeERC20 for ERC20Burnable;

    /*
     *  Events
     */
    event BidSubmission(address indexed sender, uint256 amount);

    /*
     *  Constants
     */
    uint constant public WAITING_PERIOD = 0; // 1 days;

    /*
     *  Storage
     */
    ERC20Burnable public token;
    address public ambix;
    address public wallet;
    address public owner;
    uint public maxTokenSold;
    uint public ceiling;
    uint public priceFactor;
    uint public startBlock;
    uint public endTime;
    uint public totalReceived;
    uint public finalPrice;
    mapping (address => uint) public bids;
    Stages public stage;

    /*
     *  Enums
     */
    enum Stages {
        AuctionDeployed,
        AuctionSetUp,
        AuctionStarted,
        AuctionEnded,
        TradingStarted
    }

    /*
     *  Modifiers
     */
    modifier atStage(Stages _stage) {
        // Contract on stage
        require(stage == _stage);
        _;
    }

    modifier isOwner() {
        // Only owner is allowed to proceed
        require(msg.sender == owner);
        _;
    }

    modifier isWallet() {
        // Only wallet is allowed to proceed
        require(msg.sender == wallet);
        _;
    }

    modifier isValidPayload() {
        require(msg.data.length == 4 || msg.data.length == 164);
        _;
    }

    modifier timedTransitions() {
        if (stage == Stages.AuctionStarted && calcTokenPrice() <= calcStopPrice())
            finalizeAuction();
        if (stage == Stages.AuctionEnded && now > endTime + WAITING_PERIOD)
            stage = Stages.TradingStarted;
        _;
    }

    /*
     *  Public functions
     */
    /// @dev Contract constructor function sets owner.
    /// @param _wallet Multisig wallet.
    /// @param _maxTokenSold Auction token balance.
    /// @param _ceiling Auction ceiling.
    /// @param _priceFactor Auction price factor.
    constructor(address _wallet, uint _maxTokenSold, uint _ceiling, uint _priceFactor)
        public
    {
        require(_wallet != 0 && _ceiling > 0 && _priceFactor > 0);

        owner = msg.sender;
        wallet = _wallet;
        maxTokenSold = _maxTokenSold;
        ceiling = _ceiling;
        priceFactor = _priceFactor;
        stage = Stages.AuctionDeployed;
    }

    /// @dev Setup function sets external contracts' addresses.
    /// @param _token Token address.
    /// @param _ambix Distillation cube address.
    function setup(ERC20Burnable _token, address _ambix)
        public
        isOwner
        atStage(Stages.AuctionDeployed)
    {
        // Validate argument
        require(address(_token) != 0 && _ambix != 0);

        token = _token;
        ambix = _ambix;

        // Validate token balance
        require(token.balanceOf(this) == maxTokenSold);

        stage = Stages.AuctionSetUp;
    }

    /// @dev Starts auction and sets startBlock.
    function startAuction()
        public
        isWallet
        atStage(Stages.AuctionSetUp)
    {
        stage = Stages.AuctionStarted;
        startBlock = block.number;
    }

    /// @dev Calculates current token price.
    /// @return Returns token price.
    function calcCurrentTokenPrice()
        public
        timedTransitions
        returns (uint)
    {
        if (stage == Stages.AuctionEnded || stage == Stages.TradingStarted)
            return finalPrice;
        return calcTokenPrice();
    }

    /// @dev Returns correct stage, even if a function with timedTransitions modifier has not yet been called yet.
    /// @return Returns current auction stage.
    function updateStage()
        public
        timedTransitions
        returns (Stages)
    {
        return stage;
    }

    /// @dev Allows to send a bid to the auction.
    /// @param signature KYC approvement
    function bid(bytes signature)
        public
        payable
        isValidPayload
        timedTransitions
        atStage(Stages.AuctionStarted)
        onlyValidSignature(signature)
        returns (uint amount)
    {
        require(msg.value > 0);
        amount = msg.value;

        address receiver = msg.sender;

        // Prevent that more than 90% of tokens are sold. Only relevant if cap not reached.
        uint maxWei = maxTokenSold * calcTokenPrice() / 10**9 - totalReceived;
        uint maxWeiBasedOnTotalReceived = ceiling - totalReceived;
        if (maxWeiBasedOnTotalReceived < maxWei)
            maxWei = maxWeiBasedOnTotalReceived;

        // Only invest maximum possible amount.
        if (amount > maxWei) {
            amount = maxWei;
            // Send change back to receiver address.
            receiver.transfer(msg.value - amount);
        }

        // Forward funding to ether wallet
        wallet.transfer(amount);

        bids[receiver] += amount;
        totalReceived += amount;
        emit BidSubmission(receiver, amount);

        // Finalize auction when maxWei reached
        if (amount == maxWei)
            finalizeAuction();
    }

    /// @dev Claims tokens for bidder after auction.
    function claimTokens()
        public
        isValidPayload
        timedTransitions
        atStage(Stages.TradingStarted)
    {
        address receiver = msg.sender;
        uint tokenCount = bids[receiver] * 10**9 / finalPrice;
        bids[receiver] = 0;
        token.safeTransfer(receiver, tokenCount);
    }

    /// @dev Calculates stop price.
    /// @return Returns stop price.
    function calcStopPrice()
        view
        public
        returns (uint)
    {
        return totalReceived * 10**9 / maxTokenSold + 1;
    }

    /// @dev Calculates token price.
    /// @return Returns token price.
    function calcTokenPrice()
        view
        public
        returns (uint)
    {
        return priceFactor * 10**18 / (block.number - startBlock + 7500) + 1;
    }

    /*
     *  Private functions
     */
    function finalizeAuction()
        private
    {
        stage = Stages.AuctionEnded;
        finalPrice = totalReceived == ceiling ? calcTokenPrice() : calcStopPrice();
        uint soldTokens = totalReceived * 10**9 / finalPrice;

        if (totalReceived == ceiling) {
            // Auction contract transfers all unsold tokens to Ambix contract
            token.safeTransfer(ambix, maxTokenSold - soldTokens);
        } else {
            // Auction contract burn all unsold tokens
            token.burn(maxTokenSold - soldTokens);
        }

        endTime = now;
    }
}