pragma solidity 0.4.23;


/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
    if (a == 0) {
      return 0;
    }
    c = a * b;
    assert(c / a == b);
    return c;
  }

  /**
  * @dev Integer division of two numbers, truncating the quotient.
  */
  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // assert(b > 0); // Solidity automatically throws 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 a / b;
  }

  /**
  * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
    c = a + b;
    assert(c >= a);
    return c;
  }
}


/**
 * @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 public owner;


  event OwnershipRenounced(address indexed previousOwner);
  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);


  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  constructor() public {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @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 {
    require(newOwner != address(0));
    emit OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }

  /**
   * @dev Allows the current owner to relinquish control of the contract.
   */
  function renounceOwnership() public onlyOwner {
    emit OwnershipRenounced(owner);
    owner = address(0);
  }
}


/**
 * @title Roles
 * @author Francisco Giordano (@frangio)
 * @dev Library for managing addresses assigned to a Role.
 *      See RBAC.sol for example usage.
 */
library Roles {
  struct Role {
    mapping (address => bool) bearer;
  }

  /**
   * @dev give an address access to this role
   */
  function add(Role storage role, address addr)
    internal
  {
    role.bearer[addr] = true;
  }

  /**
   * @dev remove an address' access to this role
   */
  function remove(Role storage role, address addr)
    internal
  {
    role.bearer[addr] = false;
  }

  /**
   * @dev check if an address has this role
   * // reverts
   */
  function check(Role storage role, address addr)
    view
    internal
  {
    require(has(role, addr));
  }

  /**
   * @dev check if an address has this role
   * @return bool
   */
  function has(Role storage role, address addr)
    view
    internal
    returns (bool)
  {
    return role.bearer[addr];
  }
}


/**
 * @title RBAC (Role-Based Access Control)
 * @author Matt Condon (@Shrugs)
 * @dev Stores and provides setters and getters for roles and addresses.
 * @dev Supports unlimited numbers of roles and addresses.
 * @dev See //contracts/mocks/RBACMock.sol for an example of usage.
 * This RBAC method uses strings to key roles. It may be beneficial
 *  for you to write your own implementation of this interface using Enums or similar.
 * It's also recommended that you define constants in the contract, like ROLE_ADMIN below,
 *  to avoid typos.
 */
contract RBAC {
  using Roles for Roles.Role;

  mapping (string => Roles.Role) private roles;

  event RoleAdded(address addr, string roleName);
  event RoleRemoved(address addr, string roleName);

  /**
   * @dev reverts if addr does not have role
   * @param addr address
   * @param roleName the name of the role
   * // reverts
   */
  function checkRole(address addr, string roleName)
    view
    public
  {
    roles[roleName].check(addr);
  }

  /**
   * @dev determine if addr has role
   * @param addr address
   * @param roleName the name of the role
   * @return bool
   */
  function hasRole(address addr, string roleName)
    view
    public
    returns (bool)
  {
    return roles[roleName].has(addr);
  }

  /**
   * @dev add a role to an address
   * @param addr address
   * @param roleName the name of the role
   */
  function addRole(address addr, string roleName)
    internal
  {
    roles[roleName].add(addr);
    emit RoleAdded(addr, roleName);
  }

  /**
   * @dev remove a role from an address
   * @param addr address
   * @param roleName the name of the role
   */
  function removeRole(address addr, string roleName)
    internal
  {
    roles[roleName].remove(addr);
    emit RoleRemoved(addr, roleName);
  }

  /**
   * @dev modifier to scope access to a single role (uses msg.sender as addr)
   * @param roleName the name of the role
   * // reverts
   */
  modifier onlyRole(string roleName)
  {
    checkRole(msg.sender, roleName);
    _;
  }

  /**
   * @dev modifier to scope access to a set of roles (uses msg.sender as addr)
   * @param roleNames the names of the roles to scope access to
   * // reverts
   *
   * @TODO - when solidity supports dynamic arrays as arguments to modifiers, provide this
   *  see: https://github.com/ethereum/solidity/issues/2467
   */
  // modifier onlyRoles(string[] roleNames) {
  //     bool hasAnyRole = false;
  //     for (uint8 i = 0; i < roleNames.length; i++) {
  //         if (hasRole(msg.sender, roleNames[i])) {
  //             hasAnyRole = true;
  //             break;
  //         }
  //     }

  //     require(hasAnyRole);

  //     _;
  // }
}


/**
 * @title Whitelist
 * @dev The Whitelist contract has a whitelist of addresses, and provides basic authorization control functions.
 * @dev This simplifies the implementation of "user permissions".
 */
contract Whitelist is Ownable, RBAC {
  event WhitelistedAddressAdded(address addr);
  event WhitelistedAddressRemoved(address addr);

  string public constant ROLE_WHITELISTED = "whitelist";

  /**
   * @dev Throws if called by any account that's not whitelisted.
   */
  modifier onlyWhitelisted() {
    checkRole(msg.sender, ROLE_WHITELISTED);
    _;
  }

  /**
   * @dev add an address to the whitelist
   * @param addr address
   * @return true if the address was added to the whitelist, false if the address was already in the whitelist
   */
  function addAddressToWhitelist(address addr)
    onlyOwner
    public
  {
    addRole(addr, ROLE_WHITELISTED);
    emit WhitelistedAddressAdded(addr);
  }

  /**
   * @dev getter to determine if address is in whitelist
   */
  function whitelist(address addr)
    public
    view
    returns (bool)
  {
    return hasRole(addr, ROLE_WHITELISTED);
  }

  /**
   * @dev add addresses to the whitelist
   * @param addrs addresses
   * @return true if at least one address was added to the whitelist,
   * false if all addresses were already in the whitelist
   */
  function addAddressesToWhitelist(address[] addrs)
    onlyOwner
    public
  {
    for (uint256 i = 0; i < addrs.length; i++) {
      addAddressToWhitelist(addrs[i]);
    }
  }

  /**
   * @dev remove an address from the whitelist
   * @param addr address
   * @return true if the address was removed from the whitelist,
   * false if the address wasn't in the whitelist in the first place
   */
  function removeAddressFromWhitelist(address addr)
    onlyOwner
    public
  {
    removeRole(addr, ROLE_WHITELISTED);
    emit WhitelistedAddressRemoved(addr);
  }

  /**
   * @dev remove addresses from the whitelist
   * @param addrs addresses
   * @return true if at least one address was removed from the whitelist,
   * false if all addresses weren't in the whitelist in the first place
   */
  function removeAddressesFromWhitelist(address[] addrs)
    onlyOwner
    public
  {
    for (uint256 i = 0; i < addrs.length; i++) {
      removeAddressFromWhitelist(addrs[i]);
    }
  }

}


/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * @dev 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 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 {
  function safeTransfer(ERC20Basic token, address to, uint256 value) internal {
    require(token.transfer(to, value));
  }

  function safeTransferFrom(
    ERC20 token,
    address from,
    address to,
    uint256 value
  )
    internal
  {
    require(token.transferFrom(from, to, value));
  }

  function safeApprove(ERC20 token, address spender, uint256 value) internal {
    require(token.approve(spender, value));
  }
}


contract PresaleSecond is Ownable {
    using SafeMath for uint256;
    using SafeERC20 for ERC20;

    uint256 public maxcap;      // sale hardcap
    uint256 public exceed;      // indivisual hardcap
    uint256 public minimum;     // indivisual softcap
    uint256 public rate;        // exchange rate

    bool public paused = false;   // is sale paused?
    bool public ignited = false;  // is sale started?
    uint256 public weiRaised = 0; // check sale status

    address public wallet;      // wallet for withdrawal
    address public distributor; // contract for release, refund
    Whitelist public List;      // whitelist
    ERC20 public Token;         // token

    constructor (
        uint256 _maxcap,
        uint256 _exceed,
        uint256 _minimum,
        uint256 _rate,
        address _wallet,
        address _distributor,
        address _whitelist,
        address _token
    )
        public
    {
        require(_wallet != address(0));
        require(_whitelist != address(0));
        require(_distributor != address(0));
        require(_token != address(0));

        maxcap = _maxcap;
        exceed = _exceed;
        minimum = _minimum;
        rate = _rate;

        wallet = _wallet;
        distributor = _distributor;

        Token = ERC20(_token);
        List = Whitelist(_whitelist);
    }

    /* fallback function */
    function () external payable {
        collect();
    }

//  address
    event Change(address _addr, string _name);

    function setWhitelist(address _whitelist) external onlyOwner {
        require(_whitelist != address(0));

        List = Whitelist(_whitelist);
        emit Change(_whitelist, "whitelist");
    }

    function setDistributor(address _distributor) external onlyOwner {
        require(_distributor != address(0));

        distributor = _distributor;
        emit Change(_distributor, "distributor");

    }

    function setWallet(address _wallet) external onlyOwner {
        require(_wallet != address(0));

        wallet = _wallet;
        emit Change(_wallet, "wallet");
    }

//  sale controller
    event Pause();
    event Resume();
    event Ignite();
    event Extinguish();

    function pause() external onlyOwner {
        paused = true;
        emit Pause();
    }

    function resume() external onlyOwner {
        paused = false;
        emit Resume();
    }

    function ignite() external onlyOwner {
        ignited = true;
        emit Ignite();
    }

    function extinguish() external onlyOwner {
        ignited = false;
        emit Extinguish();
    }

//  collect eth
    event Purchase(address indexed _buyer, uint256 _purchased, uint256 _refund, uint256 _tokens);

    mapping (address => uint256) public buyers;

    function collect() public payable {
        address buyer = msg.sender;
        uint256 amount = msg.value;

        require(ignited && !paused);
        require(List.whitelist(buyer));
        require(buyer != address(0));
        require(buyers[buyer].add(amount) >= minimum);
        require(buyers[buyer] < exceed);
        require(weiRaised < maxcap);

        uint256 purchase;
        uint256 refund;

        (purchase, refund) = getPurchaseAmount(buyer, amount);

        weiRaised = weiRaised.add(purchase);

        if(weiRaised >= maxcap) ignited = false;

        buyers[buyer] = buyers[buyer].add(purchase);
        emit Purchase(buyer, purchase, refund, purchase.mul(rate));

        buyer.transfer(refund);
    }

//  util functions for collect
    function getPurchaseAmount(address _buyer, uint256 _amount)
        private
        view
        returns (uint256, uint256)
    {
        uint256 d1 = maxcap.sub(weiRaised);
        uint256 d2 = exceed.sub(buyers[_buyer]);

        uint256 d = (d1 > d2) ? d2 : d1;

        return (_amount > d) ? (d, _amount.sub(d)) : (_amount, 0);
    }

//  finalize
    bool public finalized = false;

    function finalize() external onlyOwner {
        require(!ignited && !finalized);

        withdrawEther();
        withdrawToken();

        finalized = true;
    }

//  release & release
    event Release(address indexed _to, uint256 _amount);
    event Refund(address indexed _to, uint256 _amount);

    function release(address _addr)
        external
        returns (bool)
    {
        require(!ignited && !finalized);
        require(msg.sender == distributor); // only for distributor
        require(_addr != address(0));

        if(buyers[_addr] == 0) return false;

        uint256 releaseAmount = buyers[_addr].mul(rate);
        buyers[_addr] = 0;

        Token.safeTransfer(_addr, releaseAmount);
        emit Release(_addr, releaseAmount);

        return true;
    }

    // 어떤 모종의 이유로 환불 절차를 밟아야 하는 경우를 상정하여 만들어놓은 안전장치입니다.
    // This exists for safety when we have to run refund process by some reason.
    function refund(address _addr)
        external
        returns (bool)
    {
        require(!ignited && !finalized);
        require(msg.sender == distributor); // only for distributor
        require(_addr != address(0));

        if(buyers[_addr] == 0) return false;

        uint256 refundAmount = buyers[_addr];
        buyers[_addr] = 0;

        _addr.transfer(refundAmount);
        emit Refund(_addr, refundAmount);

        return true;
    }

//  withdraw
    event WithdrawToken(address indexed _from, uint256 _amount);
    event WithdrawEther(address indexed _from, uint256 _amount);

    function withdrawToken() public onlyOwner {
        require(!ignited);
        Token.safeTransfer(wallet, Token.balanceOf(address(this)));
        emit WithdrawToken(wallet, Token.balanceOf(address(this)));
    }

    function withdrawEther() public onlyOwner {
        require(!ignited);
        wallet.transfer(address(this).balance);
        emit WithdrawEther(wallet, address(this).balance);
    }
}