pragma solidity ^0.4.24;

// 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/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/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: openzeppelin-solidity/contracts/utils/ReentrancyGuard.sol

/**
 * @title Helps contracts guard against reentrancy attacks.
 * @author Remco Bloemen <remco@2π.com>, Eenae <alexey@mixbytes.io>
 * @dev If you mark a function `nonReentrant`, you should also
 * mark it `external`.
 */
contract ReentrancyGuard {

  /// @dev counter to allow mutex lock with only one SSTORE operation
  uint256 private _guardCounter;

  constructor() internal {
    // The counter starts at one to prevent changing it from zero to a non-zero
    // value, which is a more expensive operation.
    _guardCounter = 1;
  }

  /**
   * @dev Prevents a contract from calling itself, directly or indirectly.
   * Calling a `nonReentrant` function from another `nonReentrant`
   * function is not supported. It is possible to prevent this from happening
   * by making the `nonReentrant` function external, and make it call a
   * `private` function that does the actual work.
   */
  modifier nonReentrant() {
    _guardCounter += 1;
    uint256 localCounter = _guardCounter;
    _;
    require(localCounter == _guardCounter);
  }

}

// File: openzeppelin-solidity/contracts/crowdsale/Crowdsale.sol

/**
 * @title Crowdsale
 * @dev Crowdsale is a base contract for managing a token crowdsale,
 * allowing investors to purchase tokens with ether. This contract implements
 * such functionality in its most fundamental form and can be extended to provide additional
 * functionality and/or custom behavior.
 * The external interface represents the basic interface for purchasing tokens, and conform
 * the base architecture for crowdsales. They are *not* intended to be modified / overridden.
 * The internal interface conforms the extensible and modifiable surface of crowdsales. Override
 * the methods to add functionality. Consider using 'super' where appropriate to concatenate
 * behavior.
 */
contract Crowdsale is ReentrancyGuard {
  using SafeMath for uint256;
  using SafeERC20 for IERC20;

  // The token being sold
  IERC20 private _token;

  // Address where funds are collected
  address private _wallet;

  // How many token units a buyer gets per wei.
  // The rate is the conversion between wei and the smallest and indivisible token unit.
  // So, if you are using a rate of 1 with a ERC20Detailed token with 3 decimals called TOK
  // 1 wei will give you 1 unit, or 0.001 TOK.
  uint256 private _rate;

  // Amount of wei raised
  uint256 private _weiRaised;

  /**
   * Event for token purchase logging
   * @param purchaser who paid for the tokens
   * @param beneficiary who got the tokens
   * @param value weis paid for purchase
   * @param amount amount of tokens purchased
   */
  event TokensPurchased(
    address indexed purchaser,
    address indexed beneficiary,
    uint256 value,
    uint256 amount
  );

  /**
   * @param rate Number of token units a buyer gets per wei
   * @dev The rate is the conversion between wei and the smallest and indivisible
   * token unit. So, if you are using a rate of 1 with a ERC20Detailed token
   * with 3 decimals called TOK, 1 wei will give you 1 unit, or 0.001 TOK.
   * @param wallet Address where collected funds will be forwarded to
   * @param token Address of the token being sold
   */
  constructor(uint256 rate, address wallet, IERC20 token) internal {
    require(rate > 0);
    require(wallet != address(0));
    require(token != address(0));

    _rate = rate;
    _wallet = wallet;
    _token = token;
  }

  // -----------------------------------------
  // Crowdsale external interface
  // -----------------------------------------

  /**
   * @dev fallback function ***DO NOT OVERRIDE***
   * Note that other contracts will transfer fund with a base gas stipend
   * of 2300, which is not enough to call buyTokens. Consider calling
   * buyTokens directly when purchasing tokens from a contract.
   */
  function () external payable {
    buyTokens(msg.sender);
  }

  /**
   * @return the token being sold.
   */
  function token() public view returns(IERC20) {
    return _token;
  }

  /**
   * @return the address where funds are collected.
   */
  function wallet() public view returns(address) {
    return _wallet;
  }

  /**
   * @return the number of token units a buyer gets per wei.
   */
  function rate() public view returns(uint256) {
    return _rate;
  }

  /**
   * @return the amount of wei raised.
   */
  function weiRaised() public view returns (uint256) {
    return _weiRaised;
  }

  /**
   * @dev low level token purchase ***DO NOT OVERRIDE***
   * This function has a non-reentrancy guard, so it shouldn't be called by
   * another `nonReentrant` function.
   * @param beneficiary Recipient of the token purchase
   */
  function buyTokens(address beneficiary) public nonReentrant payable {

    uint256 weiAmount = msg.value;
    _preValidatePurchase(beneficiary, weiAmount);

    // calculate token amount to be created
    uint256 tokens = _getTokenAmount(weiAmount);

    // update state
    _weiRaised = _weiRaised.add(weiAmount);

    _processPurchase(beneficiary, tokens);
    emit TokensPurchased(
      msg.sender,
      beneficiary,
      weiAmount,
      tokens
    );

    _updatePurchasingState(beneficiary, weiAmount);

    _forwardFunds();
    _postValidatePurchase(beneficiary, weiAmount);
  }

  // -----------------------------------------
  // Internal interface (extensible)
  // -----------------------------------------

  /**
   * @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met. Use `super` in contracts that inherit from Crowdsale to extend their validations.
   * Example from CappedCrowdsale.sol's _preValidatePurchase method:
   *   super._preValidatePurchase(beneficiary, weiAmount);
   *   require(weiRaised().add(weiAmount) <= cap);
   * @param beneficiary Address performing the token purchase
   * @param weiAmount Value in wei involved in the purchase
   */
  function _preValidatePurchase(
    address beneficiary,
    uint256 weiAmount
  )
    internal
    view
  {
    require(beneficiary != address(0));
    require(weiAmount != 0);
  }

  /**
   * @dev Validation of an executed purchase. Observe state and use revert statements to undo rollback when valid conditions are not met.
   * @param beneficiary Address performing the token purchase
   * @param weiAmount Value in wei involved in the purchase
   */
  function _postValidatePurchase(
    address beneficiary,
    uint256 weiAmount
  )
    internal
    view
  {
    // optional override
  }

  /**
   * @dev Source of tokens. Override this method to modify the way in which the crowdsale ultimately gets and sends its tokens.
   * @param beneficiary Address performing the token purchase
   * @param tokenAmount Number of tokens to be emitted
   */
  function _deliverTokens(
    address beneficiary,
    uint256 tokenAmount
  )
    internal
  {
    _token.safeTransfer(beneficiary, tokenAmount);
  }

  /**
   * @dev Executed when a purchase has been validated and is ready to be executed. Doesn't necessarily emit/send tokens.
   * @param beneficiary Address receiving the tokens
   * @param tokenAmount Number of tokens to be purchased
   */
  function _processPurchase(
    address beneficiary,
    uint256 tokenAmount
  )
    internal
  {
    _deliverTokens(beneficiary, tokenAmount);
  }

  /**
   * @dev Override for extensions that require an internal state to check for validity (current user contributions, etc.)
   * @param beneficiary Address receiving the tokens
   * @param weiAmount Value in wei involved in the purchase
   */
  function _updatePurchasingState(
    address beneficiary,
    uint256 weiAmount
  )
    internal
  {
    // optional override
  }

  /**
   * @dev Override to extend the way in which ether is converted to tokens.
   * @param weiAmount Value in wei to be converted into tokens
   * @return Number of tokens that can be purchased with the specified _weiAmount
   */
  function _getTokenAmount(uint256 weiAmount)
    internal view returns (uint256)
  {
    return weiAmount.mul(_rate);
  }

  /**
   * @dev Determines how ETH is stored/forwarded on purchases.
   */
  function _forwardFunds() internal {
    _wallet.transfer(msg.value);
  }
}

// File: openzeppelin-solidity/contracts/crowdsale/validation/TimedCrowdsale.sol

/**
 * @title TimedCrowdsale
 * @dev Crowdsale accepting contributions only within a time frame.
 */
contract TimedCrowdsale is Crowdsale {
  using SafeMath for uint256;

  uint256 private _openingTime;
  uint256 private _closingTime;

  /**
   * @dev Reverts if not in crowdsale time range.
   */
  modifier onlyWhileOpen {
    require(isOpen());
    _;
  }

  /**
   * @dev Constructor, takes crowdsale opening and closing times.
   * @param openingTime Crowdsale opening time
   * @param closingTime Crowdsale closing time
   */
  constructor(uint256 openingTime, uint256 closingTime) internal {
    // solium-disable-next-line security/no-block-members
    require(openingTime >= block.timestamp);
    require(closingTime > openingTime);

    _openingTime = openingTime;
    _closingTime = closingTime;
  }

  /**
   * @return the crowdsale opening time.
   */
  function openingTime() public view returns(uint256) {
    return _openingTime;
  }

  /**
   * @return the crowdsale closing time.
   */
  function closingTime() public view returns(uint256) {
    return _closingTime;
  }

  /**
   * @return true if the crowdsale is open, false otherwise.
   */
  function isOpen() public view returns (bool) {
    // solium-disable-next-line security/no-block-members
    return block.timestamp >= _openingTime && block.timestamp <= _closingTime;
  }

  /**
   * @dev Checks whether the period in which the crowdsale is open has already elapsed.
   * @return Whether crowdsale period has elapsed
   */
  function hasClosed() public view returns (bool) {
    // solium-disable-next-line security/no-block-members
    return block.timestamp > _closingTime;
  }

  /**
   * @dev Extend parent behavior requiring to be within contributing period
   * @param beneficiary Token purchaser
   * @param weiAmount Amount of wei contributed
   */
  function _preValidatePurchase(
    address beneficiary,
    uint256 weiAmount
  )
    internal
    onlyWhileOpen
    view
  {
    super._preValidatePurchase(beneficiary, weiAmount);
  }

}

// File: openzeppelin-solidity/contracts/crowdsale/distribution/PostDeliveryCrowdsale.sol

/**
 * @title PostDeliveryCrowdsale
 * @dev Crowdsale that locks tokens from withdrawal until it ends.
 */
contract PostDeliveryCrowdsale is TimedCrowdsale {
  using SafeMath for uint256;

  mapping(address => uint256) private _balances;

  constructor() internal {}

  /**
   * @dev Withdraw tokens only after crowdsale ends.
   * @param beneficiary Whose tokens will be withdrawn.
   */
  function withdrawTokens(address beneficiary) public {
    require(hasClosed());
    uint256 amount = _balances[beneficiary];
    require(amount > 0);
    _balances[beneficiary] = 0;
    _deliverTokens(beneficiary, amount);
  }

  /**
   * @return the balance of an account.
   */
  function balanceOf(address account) public view returns(uint256) {
    return _balances[account];
  }

  /**
   * @dev Overrides parent by storing balances instead of issuing tokens right away.
   * @param beneficiary Token purchaser
   * @param tokenAmount Amount of tokens purchased
   */
  function _processPurchase(
    address beneficiary,
    uint256 tokenAmount
  )
    internal
  {
    _balances[beneficiary] = _balances[beneficiary].add(tokenAmount);
  }

}

// File: openzeppelin-solidity/contracts/crowdsale/price/IncreasingPriceCrowdsale.sol

/**
 * @title IncreasingPriceCrowdsale
 * @dev Extension of Crowdsale contract that increases the price of tokens linearly in time.
 * Note that what should be provided to the constructor is the initial and final _rates_, that is,
 * the amount of tokens per wei contributed. Thus, the initial rate must be greater than the final rate.
 */
contract IncreasingPriceCrowdsale is TimedCrowdsale {
  using SafeMath for uint256;

  uint256 private _initialRate;
  uint256 private _finalRate;

  /**
   * @dev Constructor, takes initial and final rates of tokens received per wei contributed.
   * @param initialRate Number of tokens a buyer gets per wei at the start of the crowdsale
   * @param finalRate Number of tokens a buyer gets per wei at the end of the crowdsale
   */
  constructor(uint256 initialRate, uint256 finalRate) internal {
    require(finalRate > 0);
    require(initialRate > finalRate);
    _initialRate = initialRate;
    _finalRate = finalRate;
  }

  /**
   * The base rate function is overridden to revert, since this crowdsale doens't use it, and
   * all calls to it are a mistake.
   */
  function rate() public view returns(uint256) {
    revert();
  }

  /**
   * @return the initial rate of the crowdsale.
   */
  function initialRate() public view returns(uint256) {
    return _initialRate;
  }

  /**
   * @return the final rate of the crowdsale.
   */
  function finalRate() public view returns (uint256) {
    return _finalRate;
  }

  /**
   * @dev Returns the rate of tokens per wei at the present time.
   * Note that, as price _increases_ with time, the rate _decreases_.
   * @return The number of tokens a buyer gets per wei at a given time
   */
  function getCurrentRate() public view returns (uint256) {
    if (!isOpen()) {
      return 0;
    }

    // solium-disable-next-line security/no-block-members
    uint256 elapsedTime = block.timestamp.sub(openingTime());
    uint256 timeRange = closingTime().sub(openingTime());
    uint256 rateRange = _initialRate.sub(_finalRate);
    return _initialRate.sub(elapsedTime.mul(rateRange).div(timeRange));
  }

  /**
   * @dev Overrides parent method taking into account variable rate.
   * @param weiAmount The value in wei to be converted into tokens
   * @return The number of tokens _weiAmount wei will buy at present time
   */
  function _getTokenAmount(uint256 weiAmount)
    internal view returns (uint256)
  {
    uint256 currentRate = getCurrentRate();
    return currentRate.mul(weiAmount);
  }

}

// File: openzeppelin-solidity/contracts/ownership/Ownable.sol

/**
 * @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;
  }
}

// File: contracts/ICO1.sol

/**
 * @title IncreasingPriceCrowdsale
 * @dev Extension of Crowdsale contract that increases the price of tokens linearly in time.
 * Note that what should be provided to the constructor is the initial and final _rates_, that is,
 * the amount of tokens per wei contributed. Thus, the initial rate must be greater than the final rate.
 */
contract ICO1 is IncreasingPriceCrowdsale, PostDeliveryCrowdsale, Ownable  {
  IERC20 private _token;
  uint256 private _weiRaised;
  uint256 private _tokenSold;

  constructor(address wallet, IERC20 token, uint8 daysAfter, uint256 openingRate, uint256 closingRate)
  Crowdsale(openingRate, wallet, token)
  TimedCrowdsale(now, now + daysAfter * 1 days)
  IncreasingPriceCrowdsale(openingRate, closingRate)
  public {
    _token = IERC20(token);
  }

  function buyTokens(address beneficiary) public nonReentrant payable {
    uint256 weiAmount = msg.value;
    uint256 maxWeiAmount = _getMaxWeiAmount();
    require(maxWeiAmount > 0);
    if (weiAmount >= maxWeiAmount) {
      weiAmount = maxWeiAmount;
    }
    _preValidatePurchase(beneficiary, weiAmount);

    // calculate token amount to be created
    uint256 tokens = _getTokenAmount(weiAmount);

    // update state
    _weiRaised = _weiRaised.add(weiAmount);
    _tokenSold = _tokenSold.add(tokens);

    _processPurchase(beneficiary, tokens);
    emit TokensPurchased(
      msg.sender,
      beneficiary,
      weiAmount,
      tokens
    );

    _updatePurchasingState(beneficiary, weiAmount);

    _forwardFunds();
    _postValidatePurchase(beneficiary, weiAmount);
  }

  function _getTokenAmount(uint256 weiAmount)
    internal view returns (uint256)
  {
    uint256 currentRate = getCurrentRate();
    return currentRate.mul(weiAmount).div(10**13);
  }

  function _getMaxWeiAmount()
    internal view returns (uint256)
  {
    uint256 currentRate = getCurrentRate();
    uint256 icoBalance = _token.balanceOf(address(this));
    uint256 availableBalance = icoBalance - _tokenSold;
    return availableBalance.mul(10**13).div(currentRate);
  }

  function recoverToken(address _tokenAddress) public onlyOwner {
    IERC20 token = IERC20(_tokenAddress);
    uint balance = token.balanceOf(this);
    token.transfer(msg.sender, balance);
  }

  function tokenSold()
    public view returns (uint256)
  {
    return _tokenSold;
  }
}