pragma solidity 0.4.21;

// File: zeppelin-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 public owner;


  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);


  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  function Ownable() 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));
    OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }

}

// File: zeppelin-solidity/contracts/math/SafeMath.sol

/**
 * @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) {
    if (a == 0) {
      return 0;
    }
    uint256 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 c;
  }

  /**
  * @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) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}

// File: zeppelin-solidity/contracts/token/ERC20/ERC20Basic.sol

/**
 * @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);
}

// File: zeppelin-solidity/contracts/token/ERC20/BasicToken.sol

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  uint256 totalSupply_;

  /**
  * @dev total number of tokens in existence
  */
  function totalSupply() public view returns (uint256) {
    return totalSupply_;
  }

  /**
  * @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) {
    require(_to != address(0));
    require(_value <= balances[msg.sender]);

    // SafeMath.sub will throw if there is not enough balance.
    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    Transfer(msg.sender, _to, _value);
    return true;
  }

  /**
  * @dev Gets the balance of the specified address.
  * @param _owner The address to query the the balance of.
  * @return An uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) public view returns (uint256 balance) {
    return balances[_owner];
  }

}

// File: zeppelin-solidity/contracts/token/ERC20/ERC20.sol

/**
 * @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);
}

// File: zeppelin-solidity/contracts/token/ERC20/StandardToken.sol

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * @dev https://github.com/ethereum/EIPs/issues/20
 * @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) internal allowed;


  /**
   * @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) {
    require(_to != address(0));
    require(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    Transfer(_from, _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) {
    allowed[msg.sender][_spender] = _value;
    Approval(msg.sender, _spender, _value);
    return true;
  }

  /**
   * @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 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 increaseApproval(address _spender, uint _addedValue) public returns (bool) {
    allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
    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 decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
    uint oldValue = allowed[msg.sender][_spender];
    if (_subtractedValue > oldValue) {
      allowed[msg.sender][_spender] = 0;
    } else {
      allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
    }
    Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

}

// File: zeppelin-solidity/contracts/token/ERC20/MintableToken.sol

/**
 * @title Mintable token
 * @dev Simple ERC20 Token example, with mintable token creation
 * @dev Issue: * https://github.com/OpenZeppelin/zeppelin-solidity/issues/120
 * Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol
 */
contract MintableToken is StandardToken, Ownable {
  event Mint(address indexed to, uint256 amount);
  event MintFinished();

  bool public mintingFinished = false;


  modifier canMint() {
    require(!mintingFinished);
    _;
  }

  /**
   * @dev Function to mint tokens
   * @param _to The address that will receive the minted tokens.
   * @param _amount The amount of tokens to mint.
   * @return A boolean that indicates if the operation was successful.
   */
  function mint(address _to, uint256 _amount) onlyOwner canMint public returns (bool) {
    totalSupply_ = totalSupply_.add(_amount);
    balances[_to] = balances[_to].add(_amount);
    Mint(_to, _amount);
    Transfer(address(0), _to, _amount);
    return true;
  }

  /**
   * @dev Function to stop minting new tokens.
   * @return True if the operation was successful.
   */
  function finishMinting() onlyOwner canMint public returns (bool) {
    mintingFinished = true;
    MintFinished();
    return true;
  }
}

// File: contracts/ZerochainToken.sol

contract ZerochainToken is MintableToken {
    string public constant name = "0chain";
    string public constant symbol = "ZCN";
    uint8 public constant decimals = 10;
}

// File: zeppelin-solidity/contracts/lifecycle/Pausable.sol

/**
 * @title Pausable
 * @dev Base contract which allows children to implement an emergency stop mechanism.
 */
contract Pausable is Ownable {
  event Pause();
  event Unpause();

  bool public paused = false;


  /**
   * @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() onlyOwner whenNotPaused public {
    paused = true;
    Pause();
  }

  /**
   * @dev called by the owner to unpause, returns to normal state
   */
  function unpause() onlyOwner whenPaused public {
    paused = false;
    Unpause();
  }
}

// File: zeppelin-solidity/contracts/ownership/rbac/Roles.sol

/**
 * @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];
  }
}

// File: zeppelin-solidity/contracts/ownership/rbac/RBAC.sol

/**
 * @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.
 * 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);

  /**
   * A constant role name for indicating admins.
   */
  string public constant ROLE_ADMIN = "admin";

  /**
   * @dev constructor. Sets msg.sender as admin by default
   */
  function RBAC()
    public
  {
    addRole(msg.sender, ROLE_ADMIN);
  }

  /**
   * @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 adminAddRole(address addr, string roleName)
    onlyAdmin
    public
  {
    addRole(addr, roleName);
  }

  /**
   * @dev remove a role from an address
   * @param addr address
   * @param roleName the name of the role
   */
  function adminRemoveRole(address addr, string roleName)
    onlyAdmin
    public
  {
    removeRole(addr, roleName);
  }

  /**
   * @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);
    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);
    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 admins
   * // reverts
   */
  modifier onlyAdmin()
  {
    checkRole(msg.sender, ROLE_ADMIN);
    _;
  }

  /**
   * @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);

  //     _;
  // }
}

// File: contracts/MultipleTokenVesting.sol

/**
 * @title MultipleTokenVesting
 * @dev A token holder contract that can release its token balance gradually like a
 * typical vesting scheme, for multiple users with a cliff and vesting period.
 */
contract MultipleTokenVesting is Pausable, RBAC {
    using SafeMath for uint256;

    event Released(address indexed beneficiary, uint256 indexed amount);
    event Vested(address indexed beneficiary, uint256 indexed amount);
    event Activated();
    event VestingFinished();
    event Airdrop(address indexed beneficiary);

    // beneficiaries of tokens with respective amounts of tokens to be released
    mapping (address => uint256) public beneficiaries;
    // beneficiaries of tokens with respective amounts of tokens already released
    mapping (address => uint256) public released;

    ZerochainToken public token;

    uint256 public cliff;
    uint256 public start;
    uint256 public duration;
    bool public isActive = false;
    bool public canIssueIndividual = true;

    uint256 public constant AIRDROP_AMOUNT = 10 * (10 ** 10);
    string public constant UTILITY_ROLE = "utility";
    address public utilityAccount;
    uint256 public hardCap;

    /**
     * @dev Creates a vesting contract and a token.
     * @param _start timestamp for the moment when vesting should be considered as started
     * @param _cliff duration in seconds of the cliff in which tokens will begin to vest
     * @param _duration duration in seconds of the period in which the tokens will vest
     */
    function MultipleTokenVesting(
        uint256 _start,
        uint256 _cliff,
        uint256 _duration,
        address _utilityAccount,
        uint256 _hardCap
    )
    public
    {
        require(_cliff <= _duration);
        require(_utilityAccount != address(0));
        require(_hardCap > 0);

        token = new ZerochainToken();
        duration = _duration;
        cliff = _start.add(_cliff);
        start = _start;
        utilityAccount = _utilityAccount;
        addRole(_utilityAccount, UTILITY_ROLE);
        hardCap = _hardCap;
    }

    function changeUtilityAccount (
        address newAddress
    ) public onlyOwner {
        require(newAddress != address(0));
        removeRole(utilityAccount, UTILITY_ROLE);
        utilityAccount = newAddress;
        addRole(utilityAccount, UTILITY_ROLE);
    }

    function activate() public onlyOwner {
        require(!isActive);
        isActive = true;
        Activated();
    }

    function finalise() public onlyOwner {
        token.finishMinting();
        VestingFinished();
    }

    function stopIssuingIndividualTokens() public onlyOwner {
        require(canIssueIndividual);
        canIssueIndividual = false;
    }

    function issueIndividualTokens(
        address beneficiary,
        uint256 amount
    ) public onlyOwner {
        require(beneficiary != address(0));
        require(amount != 0);
        require(canIssueIndividual);
        require(token.totalSupply().add(amount) <= hardCap);

        token.mint(beneficiary, amount);
    }

    /**
     * @dev Main means of adding information about beneficiaries who should have tokens vested for them.
     * We add users in array to save gas for such operation.
     * @param _beneficiaries user addresses array whose tokens need to be vested.
     * @param _amounts amount of tokens for vesting array which is related to the user with same idx.
     **/
    function addVestingForBeneficiaries(
        address[] _beneficiaries,
        uint256[] _amounts
    ) public onlyRole(UTILITY_ROLE) whenNotPaused {
        require(_beneficiaries.length == _amounts.length);
        for (uint i = 0; i < _beneficiaries.length; i++) {
            addVestingForBeneficiary(_beneficiaries[i], _amounts[i]);
        }
    }

    function releaseMultiple(
        address[] _beneficiaries
    ) public onlyRole(UTILITY_ROLE) whenNotPaused {
        require(isActive);
        for (uint i = 0; i < _beneficiaries.length; i++) {
            release(_beneficiaries[i]);
        }
    }

    function airdropMultiple(
        address[] _beneficiaries
    ) public onlyRole(UTILITY_ROLE) whenNotPaused {
        require(isActive);
        require(block.timestamp >= cliff);
        for (uint i = 0; i < _beneficiaries.length; i++) {
            require(_beneficiaries[i] != address(0));
            airdrop(_beneficiaries[i]);
        }
    }

    /**
     * @dev Calculates the amount that has already vested but hasn't been released yet.
     */
    function releasableAmount() public view returns (uint256) {
        return _releasableAmount(msg.sender);
    }

    /**
     * @dev Calculates the amount that has already vested.
     */
    function vestedAmount() public view returns (uint256) {
        return _vestedAmount(msg.sender);
    }

    /**
     * @notice Transfers vested tokens to beneficiary.
     */
    function release(
        address beneficiary
    ) internal {

        uint256 unreleased = _releasableAmount(beneficiary);

        require(unreleased > 0);

        released[beneficiary] = released[beneficiary].add(unreleased);

        token.transfer(beneficiary, unreleased);

        Released(beneficiary, unreleased);
    }

    function _releasableAmount(
        address beneficiary
    ) internal view returns (uint256) {
        return _vestedAmount(beneficiary).sub(released[beneficiary]);
    }

    function addVestingForBeneficiary(
        address _beneficiary,
        uint256 _amount
    ) internal {
        require(_beneficiary != address(0));
        require(_amount > 0);
        require(beneficiaries[_beneficiary] == 0);
        require(token.totalSupply().add(_amount) <= hardCap);

        beneficiaries[_beneficiary] = _amount;
        token.mint(this, _amount);
        Vested(_beneficiary, _amount);
    }

    function airdrop(
        address _beneficiary
    ) internal {
        require(token.totalSupply().add(AIRDROP_AMOUNT) <= hardCap);

        token.mint(_beneficiary, AIRDROP_AMOUNT);
        Airdrop(_beneficiary);
    }

    function _vestedAmount(
        address beneficiary
    ) internal view returns (uint256) {
        uint256 totalBalance = beneficiaries[beneficiary];

        if (block.timestamp < cliff) {
            return 0;
        } else if (block.timestamp >= start.add(duration)) {
            return totalBalance;
        } else {
            return totalBalance.mul(block.timestamp.sub(start)).div(duration);
        }
    }
}