pragma solidity ^0.5.0;

contract Context {
    constructor () internal { }

    function _msgSender() internal view returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view returns (bytes memory) {
        this;
        return msg.data;
    }
}

contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    function owner() public view returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(isOwner(), "Ownable: caller is not the owner");
        _;
    }

    function isOwner() public view returns (bool) {
        return _msgSender() == _owner;
    }

    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    function transferOwnership(address newOwner) public onlyOwner {
        _transferOwnership(newOwner);
    }

    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

library Address {
    function isContract(address account) internal view returns (bool) {
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

    function toPayable(address account) internal pure returns (address payable) {
        return address(uint160(account));
    }

    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call.value(amount)("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
}

interface IERC20 {
    function totalSupply() external view returns (uint256);

    function balanceOf(address account) external view returns (uint256);

    function transfer(address recipient, uint256 amount) external returns (bool);

    function allowance(address owner, address spender) external view returns (uint256);

    function approve(address spender, uint256 amount) external returns (bool);

    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(address indexed owner, address indexed spender, uint256 value);
}

library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;

        return c;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function callOptionalReturn(IERC20 token, bytes memory data) private {
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) {
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

contract ReentrancyGuard {
    bool private _notEntered;

    constructor () internal {
        _notEntered = true;
    }

    modifier nonReentrant() {
        require(_notEntered, "ReentrancyGuard: reentrant call");

        _notEntered = false;

        _;

        _notEntered = true;
    }
}

contract Crowdsale is Context, ReentrancyGuard {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    IERC20 private _token;

    address payable private _wallet;

    uint256 private _rate;

    uint256 private _weiRaised;

    event TokensPurchased(address indexed purchaser, address indexed beneficiary, uint256 value, uint256 amount);

    constructor (uint256 rate, address payable wallet, IERC20 token) public {
        require(rate > 0, "Crowdsale: rate is 0");
        require(wallet != address(0), "Crowdsale: wallet is the zero address");
        require(address(token) != address(0), "Crowdsale: token is the zero address");

        _rate = rate;
        _wallet = wallet;
        _token = token;
    }

    function () external payable {
        buyTokens(_msgSender());
    }

    function token() public view returns (IERC20) {
        return _token;
    }

    function wallet() public view returns (address payable) {
        return _wallet;
    }

    function rate() public view returns (uint256) {
        return _rate;
    }

    function weiRaised() public view returns (uint256) {
        return _weiRaised;
    }

    function buyTokens(address beneficiary) public nonReentrant payable {
        uint256 weiAmount = msg.value;
        _preValidatePurchase(beneficiary, weiAmount);

        uint256 tokens = _getTokenAmount(weiAmount);

        _weiRaised = _weiRaised.add(weiAmount);

        _processPurchase(beneficiary, tokens);
        emit TokensPurchased(_msgSender(), beneficiary, weiAmount, tokens);

        _updatePurchasingState(beneficiary, weiAmount);

        _forwardFunds();
        _postValidatePurchase(beneficiary, weiAmount);
    }

    function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
        require(beneficiary != address(0), "Crowdsale: beneficiary is the zero address");
        require(weiAmount != 0, "Crowdsale: weiAmount is 0");
        this;
    }

    function _postValidatePurchase(address beneficiary, uint256 weiAmount) internal view {

    }

    function _deliverTokens(address beneficiary, uint256 tokenAmount) internal {
        _token.safeTransfer(beneficiary, tokenAmount);
    }

    function _processPurchase(address beneficiary, uint256 tokenAmount) internal {
        _deliverTokens(beneficiary, tokenAmount);
    }

    function _updatePurchasingState(address beneficiary, uint256 weiAmount) internal {

    }

    function _getTokenAmount(uint256 weiAmount) internal view returns (uint256) {
        return weiAmount.mul(_rate);
    }

    function _forwardFunds() internal {
        _wallet.transfer(msg.value);
    }
}

library Math {
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
    }
}

contract AllowanceCrowdsale is Crowdsale {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    address private _tokenWallet;

    constructor (address tokenWallet) public {
        require(tokenWallet != address(0), "AllowanceCrowdsale: token wallet is the zero address");
        _tokenWallet = tokenWallet;
    }

    function tokenWallet() public view returns (address) {
        return _tokenWallet;
    }

    function remainingTokens() public view returns (uint256) {
        return Math.min(token().balanceOf(_tokenWallet), token().allowance(_tokenWallet, address(this)));
    }

    function _deliverTokens(address beneficiary, uint256 tokenAmount) internal {
        token().safeTransferFrom(_tokenWallet, beneficiary, tokenAmount);
    }
}

contract TimedCrowdsale is Crowdsale {
    using SafeMath for uint256;

    uint256 private _openingTime;
    uint256 private _closingTime;

    event TimedCrowdsaleExtended(uint256 prevClosingTime, uint256 newClosingTime);

    modifier onlyWhileOpen {
        require(isOpen(), "TimedCrowdsale: not open");
        _;
    }

    constructor (uint256 openingTime, uint256 closingTime) public {
        require(openingTime >= block.timestamp, "TimedCrowdsale: opening time is before current time");
        require(closingTime > openingTime, "TimedCrowdsale: opening time is not before closing time");

        _openingTime = openingTime;
        _closingTime = closingTime;
    }

    function openingTime() public view returns (uint256) {
        return _openingTime;
    }

    function closingTime() public view returns (uint256) {
        return _closingTime;
    }

    function isOpen() public view returns (bool) {
        return block.timestamp >= _openingTime && block.timestamp <= _closingTime;
    }

    function hasClosed() public view returns (bool) {
        return block.timestamp > _closingTime;
    }

    function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal onlyWhileOpen view {
        super._preValidatePurchase(beneficiary, weiAmount);
    }

    function _extendTime(uint256 newClosingTime) internal {
        require(!hasClosed(), "TimedCrowdsale: already closed");
        require(newClosingTime > _closingTime, "TimedCrowdsale: new closing time is before current closing time");

        emit TimedCrowdsaleExtended(_closingTime, newClosingTime);
        _closingTime = newClosingTime;
    }
}

interface ISmartexOracle {
  function currentETHPrice() external view returns (uint256);
  function lastETHPriceUpdate() external view returns (uint256);

  function currentTokenPrice() external view returns (uint256);
  function lastTokenPriceUpdate() external view returns (uint256);

  function setETHPrice(uint256 price) external;
  function updateTokenPrice() external;

  event ETHPriceUpdated(uint256 price, uint256 timestamp);
  event TokenPriceUpdated(uint256 price, uint256 timestamp);
}

contract SmartexCrowdsale is Ownable, AllowanceCrowdsale, TimedCrowdsale {
  using Address for address;

  address payable private _secondWallet;

  ISmartexOracle private _oracle;

  uint256 constant private _firstEdge = 50 ether;
  uint256 constant private _secondEdge = 100 ether;

  constructor(address payable wallet, address payable secondWallet, IERC20 token)
    public
    AllowanceCrowdsale(_msgSender())
    TimedCrowdsale(now, now + 3 days)
    Crowdsale(8 * (10 ** 7), wallet, token)
  {
    _secondWallet = secondWallet;
  }

  function secondWallet() public view returns (address payable) {
    return _secondWallet;
  }

  function setOracle(ISmartexOracle oracle) public onlyOwner {
    _oracle = oracle;
  }

  function oracle() public view returns (ISmartexOracle) {
    return _oracle;
  }

  function extendTime(uint256 newClosingTime) public onlyOwner {
    super._extendTime(newClosingTime);
  }

  function getWeiAmount(uint256 tokens) public view returns (uint256) {
    return _getWeiAmount(tokens);
  }

  function getTokenAmount(uint256 weiAmount) public view returns (uint256) {
    return _getTokenAmount(weiAmount);
  }


  function _getWeiAmount(uint256 tokens) internal view returns (uint256) {
    return tokens.mul(rate()).div(_oracle.currentETHPrice());
  }

  function _getTokenAmount(uint256 weiAmount) internal view returns (uint256) {
    return weiAmount.mul(_oracle.currentETHPrice()).div(rate());
  }

  function _forwardFunds() internal {
    (uint256 ownerPayment, uint256 walletsPayment) = _splitPayment();

    owner().toPayable().transfer(ownerPayment);

    if (walletsPayment > 0) {
      uint256 firstWalletPayment = walletsPayment.div(2);
      uint256 secondWalletPayment = walletsPayment.sub(firstWalletPayment);

      wallet().transfer(firstWalletPayment);
      secondWallet().transfer(secondWalletPayment);
    }
  }

  function _splitPayment() internal returns (uint256, uint256) {
    uint256 raised = weiRaised();
    uint256 prevRaised = raised.sub(msg.value);

    if (raised <= _firstEdge) {
      return (msg.value, 0);
    }

    uint256 toSplit = msg.value;
    uint256 diff = 0;
    uint8 percent;
    uint256 edge;

    if (raised > _firstEdge && raised <= _secondEdge) {
      edge = _firstEdge;
      percent = 80;
    } else {
      edge = _secondEdge;
      percent = 70;
    }

    if (prevRaised < edge) {
      diff = edge.sub(prevRaised);
      toSplit = toSplit.sub(diff);
    }

    uint256 ownerPayment = toSplit.mul(percent).div(100);
    uint256 walletsPayment = toSplit.sub(ownerPayment);

    return (ownerPayment.add(diff), walletsPayment);
  }
}