pragma solidity ^0.4.24;


/**
 * @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)
    internal
    view
  {
    require(has(_role, _addr));
  }

  /**
   * @dev check if an address has this role
   * @return bool
   */
  function has(Role storage _role, address _addr)
    internal
    view
    returns (bool)
  {
    return _role.bearer[_addr];
  }
}



/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * 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 RBAC (Role-Based Access Control)
 * @author Matt Condon (@Shrugs)
 * @dev Stores and provides setters and getters for roles and addresses.
 * Supports unlimited numbers of roles and addresses.
 * 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.
 */
contract RBAC {
  using Roles for Roles.Role;

  mapping (string => Roles.Role) private roles;

  event RoleAdded(address indexed operator, string role);
  event RoleRemoved(address indexed operator, string role);

  /**
   * @dev reverts if addr does not have role
   * @param _operator address
   * @param _role the name of the role
   * // reverts
   */
  function checkRole(address _operator, string _role)
    public
    view
  {
    roles[_role].check(_operator);
  }

  /**
   * @dev determine if addr has role
   * @param _operator address
   * @param _role the name of the role
   * @return bool
   */
  function hasRole(address _operator, string _role)
    public
    view
    returns (bool)
  {
    return roles[_role].has(_operator);
  }

  /**
   * @dev add a role to an address
   * @param _operator address
   * @param _role the name of the role
   */
  function addRole(address _operator, string _role)
    internal
  {
    roles[_role].add(_operator);
    emit RoleAdded(_operator, _role);
  }

  /**
   * @dev remove a role from an address
   * @param _operator address
   * @param _role the name of the role
   */
  function removeRole(address _operator, string _role)
    internal
  {
    roles[_role].remove(_operator);
    emit RoleRemoved(_operator, _role);
  }

  /**
   * @dev modifier to scope access to a single role (uses msg.sender as addr)
   * @param _role the name of the role
   * // reverts
   */
  modifier onlyRole(string _role)
  {
    checkRole(msg.sender, _role);
    _;
  }

  /**
   * @dev modifier to scope access to a set of roles (uses msg.sender as addr)
   * @param _roles 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[] _roles) {
  //     bool hasAnyRole = false;
  //     for (uint8 i = 0; i < _roles.length; i++) {
  //         if (hasRole(msg.sender, _roles[i])) {
  //             hasAnyRole = true;
  //             break;
  //         }
  //     }

  //     require(hasAnyRole);

  //     _;
  // }
}



/**
 * @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 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 OwnershipRenounced(owner);
    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 Operable
* @dev Adds operator role to SC functionality
*/
contract Operable is Ownable, RBAC {
    // role key
    string public constant ROLE_OPERATOR = "operator";

    /**
    * @dev Reverts in case account is not Operator role
    */
    modifier hasOperatePermission() {
        require(hasRole(msg.sender, ROLE_OPERATOR));
        _;
    }

    /**
    * @dev Reverts in case account is not Owner or Operator role
    */
    modifier hasOwnerOrOperatePermission() {
        require(msg.sender == owner || hasRole(msg.sender, ROLE_OPERATOR));
        _;
    }

    /**
    * @dev getter to determine if address is in whitelist
    */
    function operator(address _operator) public view returns (bool) {
        return hasRole(_operator, ROLE_OPERATOR);
    }

    /**
    * @dev Method to add accounts with Operator role
    * @param _operator address that will receive Operator role access
    */
    function addOperator(address _operator) onlyOwner public {
        addRole(_operator, ROLE_OPERATOR);
    }

    /**
    * @dev Method to remove accounts with Operator role
    * @param _operator address that will loose Operator role access
    */
    function removeOperator(address _operator) onlyOwner public {
        removeRole(_operator, ROLE_OPERATOR);
    }
}





/**
 * @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 FlipNpik Airdrop Tool.
 */
contract FlipNpikAirdrop is Operable {
    // FlipNpik token address
    ERC20 public token;

    /**
    * @param _token Token address
    * @param _owner Smart contract owner address
    */
    constructor (ERC20 _token, address _owner) public {
        require(_token != address(0), "Token address is invalid.");
        token = _token;

        require(_owner != address(0), "Owner address is invalid.");
        owner = _owner;
    }
    
    /**
    * @dev Distibutes tokens based on provided lists of wallets and values
    * @param _wallets List of wallets
    * @param _values List of values
    */
    function distribute(address[] _wallets, uint256[] _values) external hasOwnerOrOperatePermission returns(bool) {
        require(_wallets.length == _values.length, "Lists are of different length.");
        for (uint256 j = 0; j < _wallets.length; ++j) {
            token.transferFrom(msg.sender, _wallets[j], _values[j]);
        }
        return true;
    }
}