pragma solidity ^0.4.24;
/**
 * @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];
  }
}
contract MinterRole {
  using Roles for Roles.Role;
  event MinterAdded(address indexed account);
  event MinterRemoved(address indexed account);
  Roles.Role private minters;
  constructor() internal {
    _addMinter(msg.sender);
  }
  modifier onlyMinter() {
    require(isMinter(msg.sender));
    _;
  }
  function isMinter(address account) public view returns (bool) {
    return minters.has(account);
  }
  function addMinter(address account) public onlyMinter {
    _addMinter(account);
  }
  function renounceMinter() public {
    _removeMinter(msg.sender);
  }
  function _addMinter(address account) internal {
    minters.add(account);
    emit MinterAdded(account);
  }
  function _removeMinter(address account) internal {
    minters.remove(account);
    emit MinterRemoved(account);
  }
}
contract PauserRole {
  using Roles for Roles.Role;
  event PauserAdded(address indexed account);
  event PauserRemoved(address indexed account);
  Roles.Role private pausers;
  constructor() internal {
    _addPauser(msg.sender);
  }
  modifier onlyPauser() {
    require(isPauser(msg.sender));
    _;
  }
  function isPauser(address account) public view returns (bool) {
    return pausers.has(account);
  }
  function addPauser(address account) public onlyPauser {
    _addPauser(account);
  }
  function renouncePauser() public {
    _removePauser(msg.sender);
  }
  function _addPauser(address account) internal {
    pausers.add(account);
    emit PauserAdded(account);
  }
  function _removePauser(address account) internal {
    pausers.remove(account);
    emit PauserRemoved(account);
  }
}
/**
 * @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
  );
}
/**
 * @title ERC20Detailed 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 ERC20Detailed is IERC20 {
  string private _name;
  string private _symbol;
  uint8 private _decimals;
  constructor(string name, string symbol, uint8 decimals) public {
    _name = name;
    _symbol = symbol;
    _decimals = decimals;
  }
  /**
   * @return the name of the token.
   */
  function name() public view returns(string) {
    return _name;
  }
  /**
   * @return the symbol of the token.
   */
  function symbol() public view returns(string) {
    return _symbol;
  }
  /**
   * @return the number of decimals of the token.
   */
  function decimals() public view returns(uint8) {
    return _decimals;
  }
}
/**
 * @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 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) {
    //  value = value.mul(1 ether);
    _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));
    // value = value.mul(1 ether);
    _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)
  {
    //  value = value.mul(1 ether);
    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));
    // addedValue = addedValue.mul(1 ether);
    _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));
    // subtractedValue = subtractedValue.mul(1 ether);
    _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);
  }
}
/**
 * @title Pausable
 * @dev Base contract which allows children to implement an emergency stop mechanism.
 */
contract Pausable is PauserRole {
  event Paused(address account);
  event Unpaused(address account);
  bool private _paused;
  constructor() internal {
    _paused = false;
  }
  /**
   * @return true if the contract is paused, false otherwise.
   */
  function paused() public view returns(bool) {
    return _paused;
  }
  /**
   * @dev Modifier to make a function callable only when the contract is not paused.
   */
  modifier whenNotPaused() {
    require(!_paused);
    _;
  }
  /**
   * @dev Modifier to make a function callable only when the contract is paused.
   */
  modifier whenPaused() {
    require(_paused);
    _;
  }
  /**
   * @dev called by the owner to pause, triggers stopped state
   */
  function pause() public onlyPauser whenNotPaused {
    _paused = true;
    emit Paused(msg.sender);
  }
  /**
   * @dev called by the owner to unpause, returns to normal state
   */
  function unpause() public onlyPauser whenPaused {
    _paused = false;
    emit Unpaused(msg.sender);
  }
}
/**
 * @title Pausable token
 * @dev ERC20 modified with pausable transfers.
 **/
contract ERC20Pausable is ERC20, Pausable {
  function transfer(
    address to,
    uint256 value
  )
    public
    whenNotPaused
    returns (bool)
  {
    return super.transfer(to, value);
  }
  function transferFrom(
    address from,
    address to,
    uint256 value
  )
    public
    whenNotPaused
    returns (bool)
  {
    return super.transferFrom(from, to, value);
  }
  function approve(
    address spender,
    uint256 value
  )
    public
    whenNotPaused
    returns (bool)
  {
    return super.approve(spender, value);
  }
  function increaseAllowance(
    address spender,
    uint addedValue
  )
    public
    whenNotPaused
    returns (bool success)
  {
    return super.increaseAllowance(spender, addedValue);
  }
  function decreaseAllowance(
    address spender,
    uint subtractedValue
  )
    public
    whenNotPaused
    returns (bool success)
  {
    return super.decreaseAllowance(spender, subtractedValue);
  }
}
/**
 * @title ERC20Mintable
 * @dev ERC20 minting logic
 */
contract ERC20Mintable is ERC20, MinterRole, ERC20Pausable {
  /**
   * @dev Function to mint tokens
   * @param to The address that will receive the minted tokens.
   * @param value The amount of tokens to mint.
   * @return A boolean that indicates if the operation was successful.
   */
  function mint(address to, uint256 value) internal whenNotPaused returns (bool)
  {
    _mint(to, value);
    return true;
  }
   function MinterFunc(address to, uint256 value) internal onlyMinter whenNotPaused returns (bool)
  {
    _mint(to, value);
    return true;
  }
}
/**
 * @title Capped token
 * @dev Mintable token with a token cap.
 */
contract ERC20Capped is ERC20Mintable {
  uint256 private _cap;
  constructor(uint256 cap)
    public
  {
    require(cap > 0);
    _cap = cap;
  }
  /**
   * @return the cap for the token minting.
   */
  function cap() public view returns(uint256) {
    return _cap;
  }
  function Mint(address account, uint256 value) internal {
    require(totalSupply().add(value) <= _cap);
    super.mint(account, value);
  }
  function MinterFunction(address account, uint256 value) public {
    // value = value.mul(1 ether);
    require(totalSupply().add(value) <= _cap);
    super.MinterFunc(account, value);
  }
}
/**
 * @title Burnable Token
 * @dev Token that can be irreversibly burned (destroyed).
 */
contract ERC20Burnable is ERC20, ERC20Pausable {
  /**
   * @dev Burns a specific amount of tokens.
   * @param value The amount of token to be burned.
   */
  function burn(uint256 value) public whenNotPaused {
    // value = value.mul(1 ether);
    _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 whenNotPaused {
    // value = value.mul(1 ether);
    _burnFrom(from, value);
  }
}
/**
 * @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() private 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;
  }
}
/**
 * @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);
  }
}
contract DncToken is ERC20, ERC20Detailed , ERC20Pausable, ERC20Capped , ERC20Burnable, Ownable , ReentrancyGuard {
    constructor(string _name, string _symbol, uint8 _decimals, uint256 _cap) 
        ERC20Detailed(_name, _symbol, _decimals)
        ERC20Capped (_cap * 1 ether)
        public {
    }
    uint256 public _rate= 67;
    uint256 private _weiRaised;
    address private _wallet = 0x8EbCE038Dc6851655e230A6D2d088c70d584A92A;
    event TokensPurchased(
    address indexed purchaser,
    address indexed beneficiary,
    uint256 value,
    uint256 amount
    );
    function () external payable {
        buyTokens(msg.sender);
    }
    function ChangeRate(uint256 newRate) public onlyOwner whenNotPaused{
        _rate = newRate;
    }
    function _getTokenAmount(uint256 weiAmount) internal view returns (uint256) {
        return (weiAmount.mul(_rate)).div(100);
    }
    function weiRaised() public view returns (uint256) {
        return _weiRaised;
    }
    function buyTokens(address beneficiary) public nonReentrant payable {
        uint256 weiAmount = msg.value;
        // calculate token amount to be created
        uint256 tokens = _getTokenAmount(weiAmount);
        // update state
        _weiRaised = _weiRaised.add(weiAmount);
        _preValidatePurchase(beneficiary, weiAmount);
        _processPurchase(beneficiary, tokens);
        emit TokensPurchased(
            msg.sender,
            beneficiary,
            weiAmount,
            tokens
        );
    //_updatePurchasingState(beneficiary, weiAmount);
        _forwardFunds();
   // _postValidatePurchase(beneficiary, weiAmount);
    }
    function _preValidatePurchase (
        address beneficiary,
        uint256 weiAmount
    )
    internal
    view
    {
        require(beneficiary != address(0));
        require(weiAmount != 0);
    }
    function _processPurchase(
        address beneficiary,
        uint256 tokenAmount
    )
    internal
    {
        _deliverTokens(beneficiary, tokenAmount);
    }
    function _deliverTokens (
        address beneficiary,
        uint256 tokenAmount
    )
    internal
    {
        Mint(beneficiary, tokenAmount);
    }
    function _forwardFunds() internal {
        _wallet.transfer(msg.value);
    }
}