// File: openzeppelin-solidity/contracts/math/SafeMath.sol

pragma solidity ^0.5.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     * - Multiplication cannot 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, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0, "SafeMath: modulo by zero");
        return a % b;
    }
}

// File: openzeppelin-solidity/contracts/math/Math.sol

pragma solidity ^0.5.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow, so we distribute
        return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
    }
}

// File: openzeppelin-solidity/contracts/ownership/Ownable.sol

pragma solidity ^0.5.0;

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be aplied to your functions to restrict their use to
 * the owner.
 */
contract Ownable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(isOwner(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Returns true if the caller is the current owner.
     */
    function isOwner() public view returns (bool) {
        return msg.sender == _owner;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * > Note: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public onlyOwner {
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     */
    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: @daostack/infra/contracts/Reputation.sol

pragma solidity ^0.5.11;



/**
 * @title Reputation system
 * @dev A DAO has Reputation System which allows peers to rate other peers in order to build trust .
 * A reputation is use to assign influence measure to a DAO'S peers.
 * Reputation is similar to regular tokens but with one crucial difference: It is non-transferable.
 * The Reputation contract maintain a map of address to reputation value.
 * It provides an onlyOwner functions to mint and burn reputation _to (or _from) a specific address.
 */

contract Reputation is Ownable {

    uint8 public decimals = 18;             //Number of decimals of the smallest unit
    // Event indicating minting of reputation to an address.
    event Mint(address indexed _to, uint256 _amount);
    // Event indicating burning of reputation for an address.
    event Burn(address indexed _from, uint256 _amount);

      /// @dev `Checkpoint` is the structure that attaches a block number to a
      ///  given value, the block number attached is the one that last changed the
      ///  value
    struct Checkpoint {

    // `fromBlock` is the block number that the value was generated from
        uint128 fromBlock;

          // `value` is the amount of reputation at a specific block number
        uint128 value;
    }

      // `balances` is the map that tracks the balance of each address, in this
      //  contract when the balance changes the block number that the change
      //  occurred is also included in the map
    mapping (address => Checkpoint[]) balances;

      // Tracks the history of the `totalSupply` of the reputation
    Checkpoint[] totalSupplyHistory;

    /// @notice Constructor to create a Reputation
    constructor(
    ) public
    {
    }

    /// @dev This function makes it easy to get the total number of reputation
    /// @return The total number of reputation
    function totalSupply() public view returns (uint256) {
        return totalSupplyAt(block.number);
    }

  ////////////////
  // Query balance and totalSupply in History
  ////////////////
    /**
    * @dev return the reputation amount of a given owner
    * @param _owner an address of the owner which we want to get his reputation
    */
    function balanceOf(address _owner) public view returns (uint256 balance) {
        return balanceOfAt(_owner, block.number);
    }

      /// @dev Queries the balance of `_owner` at a specific `_blockNumber`
      /// @param _owner The address from which the balance will be retrieved
      /// @param _blockNumber The block number when the balance is queried
      /// @return The balance at `_blockNumber`
    function balanceOfAt(address _owner, uint256 _blockNumber)
    public view returns (uint256)
    {
        if ((balances[_owner].length == 0) || (balances[_owner][0].fromBlock > _blockNumber)) {
            return 0;
          // This will return the expected balance during normal situations
        } else {
            return getValueAt(balances[_owner], _blockNumber);
        }
    }

      /// @notice Total amount of reputation at a specific `_blockNumber`.
      /// @param _blockNumber The block number when the totalSupply is queried
      /// @return The total amount of reputation at `_blockNumber`
    function totalSupplyAt(uint256 _blockNumber) public view returns(uint256) {
        if ((totalSupplyHistory.length == 0) || (totalSupplyHistory[0].fromBlock > _blockNumber)) {
            return 0;
          // This will return the expected totalSupply during normal situations
        } else {
            return getValueAt(totalSupplyHistory, _blockNumber);
        }
    }

      /// @notice Generates `_amount` reputation that are assigned to `_owner`
      /// @param _user The address that will be assigned the new reputation
      /// @param _amount The quantity of reputation generated
      /// @return True if the reputation are generated correctly
    function mint(address _user, uint256 _amount) public onlyOwner returns (bool) {
        uint256 curTotalSupply = totalSupply();
        require(curTotalSupply + _amount >= curTotalSupply); // Check for overflow
        uint256 previousBalanceTo = balanceOf(_user);
        require(previousBalanceTo + _amount >= previousBalanceTo); // Check for overflow
        updateValueAtNow(totalSupplyHistory, curTotalSupply + _amount);
        updateValueAtNow(balances[_user], previousBalanceTo + _amount);
        emit Mint(_user, _amount);
        return true;
    }

      /// @notice Burns `_amount` reputation from `_owner`
      /// @param _user The address that will lose the reputation
      /// @param _amount The quantity of reputation to burn
      /// @return True if the reputation are burned correctly
    function burn(address _user, uint256 _amount) public onlyOwner returns (bool) {
        uint256 curTotalSupply = totalSupply();
        uint256 amountBurned = _amount;
        uint256 previousBalanceFrom = balanceOf(_user);
        if (previousBalanceFrom < amountBurned) {
            amountBurned = previousBalanceFrom;
        }
        updateValueAtNow(totalSupplyHistory, curTotalSupply - amountBurned);
        updateValueAtNow(balances[_user], previousBalanceFrom - amountBurned);
        emit Burn(_user, amountBurned);
        return true;
    }

  ////////////////
  // Internal helper functions to query and set a value in a snapshot array
  ////////////////

      /// @dev `getValueAt` retrieves the number of reputation at a given block number
      /// @param checkpoints The history of values being queried
      /// @param _block The block number to retrieve the value at
      /// @return The number of reputation being queried
    function getValueAt(Checkpoint[] storage checkpoints, uint256 _block) internal view returns (uint256) {
        if (checkpoints.length == 0) {
            return 0;
        }

          // Shortcut for the actual value
        if (_block >= checkpoints[checkpoints.length-1].fromBlock) {
            return checkpoints[checkpoints.length-1].value;
        }
        if (_block < checkpoints[0].fromBlock) {
            return 0;
        }

          // Binary search of the value in the array
        uint256 min = 0;
        uint256 max = checkpoints.length-1;
        while (max > min) {
            uint256 mid = (max + min + 1) / 2;
            if (checkpoints[mid].fromBlock<=_block) {
                min = mid;
            } else {
                max = mid-1;
            }
        }
        return checkpoints[min].value;
    }

      /// @dev `updateValueAtNow` used to update the `balances` map and the
      ///  `totalSupplyHistory`
      /// @param checkpoints The history of data being updated
      /// @param _value The new number of reputation
    function updateValueAtNow(Checkpoint[] storage checkpoints, uint256 _value) internal {
        require(uint128(_value) == _value); //check value is in the 128 bits bounderies
        if ((checkpoints.length == 0) || (checkpoints[checkpoints.length - 1].fromBlock < block.number)) {
            Checkpoint storage newCheckPoint = checkpoints[checkpoints.length++];
            newCheckPoint.fromBlock = uint128(block.number);
            newCheckPoint.value = uint128(_value);
        } else {
            Checkpoint storage oldCheckPoint = checkpoints[checkpoints.length-1];
            oldCheckPoint.value = uint128(_value);
        }
    }
}

// File: openzeppelin-solidity/contracts/token/ERC20/IERC20.sol

pragma solidity ^0.5.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
 * the optional functions; to access them see `ERC20Detailed`.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a `Transfer` event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through `transferFrom`. This is
     * zero by default.
     *
     * This value changes when `approve` or `transferFrom` are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * > 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
     *
     * Emits an `Approval` event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a `Transfer` event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to `approve`. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: openzeppelin-solidity/contracts/token/ERC20/ERC20.sol

pragma solidity ^0.5.0;



/**
 * @dev Implementation of the `IERC20` interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using `_mint`.
 * For a generic mechanism see `ERC20Mintable`.
 *
 * *For a detailed writeup see our guide [How to implement supply
 * mechanisms](https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226).*
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an `Approval` event is emitted on calls to `transferFrom`.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard `decreaseAllowance` and `increaseAllowance`
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See `IERC20.approve`.
 */
contract ERC20 is IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    /**
     * @dev See `IERC20.totalSupply`.
     */
    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See `IERC20.balanceOf`.
     */
    function balanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See `IERC20.transfer`.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public returns (bool) {
        _transfer(msg.sender, recipient, amount);
        return true;
    }

    /**
     * @dev See `IERC20.allowance`.
     */
    function allowance(address owner, address spender) public view returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See `IERC20.approve`.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 value) public returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    /**
     * @dev See `IERC20.transferFrom`.
     *
     * Emits an `Approval` event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of `ERC20`;
     *
     * Requirements:
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `value`.
     * - the caller must have allowance for `sender`'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount));
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to `approve` that can be used as a mitigation for
     * problems described in `IERC20.approve`.
     *
     * Emits an `Approval` event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
        _approve(msg.sender, spender, _allowances[msg.sender][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to `approve` that can be used as a mitigation for
     * problems described in `IERC20.approve`.
     *
     * Emits an `Approval` event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
        _approve(msg.sender, spender, _allowances[msg.sender][spender].sub(subtractedValue));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to `transfer`, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a `Transfer` event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _balances[sender] = _balances[sender].sub(amount);
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a `Transfer` event with `from` set to the zero address.
     *
     * Requirements
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal {
        require(account != address(0), "ERC20: mint to the zero address");

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

     /**
     * @dev Destoys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a `Transfer` event with `to` set to the zero address.
     *
     * Requirements
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 value) internal {
        require(account != address(0), "ERC20: burn from the zero address");

        _totalSupply = _totalSupply.sub(value);
        _balances[account] = _balances[account].sub(value);
        emit Transfer(account, address(0), value);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
     *
     * This is internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an `Approval` event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 value) internal {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    /**
     * @dev Destoys `amount` tokens from `account`.`amount` is then deducted
     * from the caller's allowance.
     *
     * See `_burn` and `_approve`.
     */
    function _burnFrom(address account, uint256 amount) internal {
        _burn(account, amount);
        _approve(account, msg.sender, _allowances[account][msg.sender].sub(amount));
    }
}

// File: openzeppelin-solidity/contracts/token/ERC20/ERC20Burnable.sol

pragma solidity ^0.5.0;


/**
 * @dev Extension of `ERC20` that allows token holders to destroy both their own
 * tokens and those that they have an allowance for, in a way that can be
 * recognized off-chain (via event analysis).
 */
contract ERC20Burnable is ERC20 {
    /**
     * @dev Destoys `amount` tokens from the caller.
     *
     * See `ERC20._burn`.
     */
    function burn(uint256 amount) public {
        _burn(msg.sender, amount);
    }

    /**
     * @dev See `ERC20._burnFrom`.
     */
    function burnFrom(address account, uint256 amount) public {
        _burnFrom(account, amount);
    }
}

// File: contracts/controller/DAOToken.sol

pragma solidity ^0.5.11;





/**
 * @title DAOToken, base on zeppelin contract.
 * @dev ERC20 compatible token. It is a mintable, burnable token.
 */

contract DAOToken is ERC20, ERC20Burnable, Ownable {

    string public name;
    string public symbol;
    // solhint-disable-next-line const-name-snakecase
    uint8 public constant decimals = 18;
    uint256 public cap;

    /**
    * @dev Constructor
    * @param _name - token name
    * @param _symbol - token symbol
    * @param _cap - token cap - 0 value means no cap
    */
    constructor(string memory _name, string memory _symbol, uint256 _cap)
    public {
        name = _name;
        symbol = _symbol;
        cap = _cap;
    }

    /**
     * @dev Function to mint tokens
     * @param _to The address that will receive the minted tokens.
     * @param _amount The amount of tokens to mint.
     */
    function mint(address _to, uint256 _amount) public onlyOwner returns (bool) {
        if (cap > 0)
            require(totalSupply().add(_amount) <= cap);
        _mint(_to, _amount);
        return true;
    }
}

// File: openzeppelin-solidity/contracts/utils/Address.sol

pragma solidity ^0.5.0;

/**
 * @dev Collection of functions related to the address type,
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * This test is non-exhaustive, and there may be false-negatives: during the
     * execution of a contract's constructor, its address will be reported as
     * not containing a contract.
     *
     * > It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies in extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }
}

// File: contracts/libs/SafeERC20.sol

/*

SafeERC20 by daostack.
The code is based on a fix by SECBIT Team.

USE WITH CAUTION & NO WARRANTY

REFERENCE & RELATED READING
- https://github.com/ethereum/solidity/issues/4116
- https://medium.com/@chris_77367/explaining-unexpected-reverts-starting-with-solidity-0-4-22-3ada6e82308c
- https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca
- https://gist.github.com/BrendanChou/88a2eeb80947ff00bcf58ffdafeaeb61

*/
pragma solidity ^0.5.11;



library SafeERC20 {
    using Address for address;

    bytes4 constant private TRANSFER_SELECTOR = bytes4(keccak256(bytes("transfer(address,uint256)")));
    bytes4 constant private TRANSFERFROM_SELECTOR = bytes4(keccak256(bytes("transferFrom(address,address,uint256)")));
    bytes4 constant private APPROVE_SELECTOR = bytes4(keccak256(bytes("approve(address,uint256)")));

    function safeTransfer(address _erc20Addr, address _to, uint256 _value) internal {

        // Must be a contract addr first!
        require(_erc20Addr.isContract());

        (bool success, bytes memory returnValue) =
        // solhint-disable-next-line avoid-low-level-calls
        _erc20Addr.call(abi.encodeWithSelector(TRANSFER_SELECTOR, _to, _value));
        // call return false when something wrong
        require(success);
        //check return value
        require(returnValue.length == 0 || (returnValue.length == 32 && (returnValue[31] != 0)));
    }

    function safeTransferFrom(address _erc20Addr, address _from, address _to, uint256 _value) internal {

        // Must be a contract addr first!
        require(_erc20Addr.isContract());

        (bool success, bytes memory returnValue) =
        // solhint-disable-next-line avoid-low-level-calls
        _erc20Addr.call(abi.encodeWithSelector(TRANSFERFROM_SELECTOR, _from, _to, _value));
        // call return false when something wrong
        require(success);
        //check return value
        require(returnValue.length == 0 || (returnValue.length == 32 && (returnValue[31] != 0)));
    }

    function safeApprove(address _erc20Addr, address _spender, uint256 _value) internal {

        // Must be a contract addr first!
        require(_erc20Addr.isContract());

        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero.
        require((_value == 0) || (IERC20(_erc20Addr).allowance(address(this), _spender) == 0));

        (bool success, bytes memory returnValue) =
        // solhint-disable-next-line avoid-low-level-calls
        _erc20Addr.call(abi.encodeWithSelector(APPROVE_SELECTOR, _spender, _value));
        // call return false when something wrong
        require(success);
        //check return value
        require(returnValue.length == 0 || (returnValue.length == 32 && (returnValue[31] != 0)));
    }
}

// File: contracts/controller/Avatar.sol

pragma solidity ^0.5.11;







/**
 * @title An Avatar holds tokens, reputation and ether for a controller
 */
contract Avatar is Ownable {
    using SafeERC20 for address;

    string public orgName;
    DAOToken public nativeToken;
    Reputation public nativeReputation;

    event GenericCall(address indexed _contract, bytes _data, uint _value, bool _success);
    event SendEther(uint256 _amountInWei, address indexed _to);
    event ExternalTokenTransfer(address indexed _externalToken, address indexed _to, uint256 _value);
    event ExternalTokenTransferFrom(address indexed _externalToken, address _from, address _to, uint256 _value);
    event ExternalTokenApproval(address indexed _externalToken, address _spender, uint256 _value);
    event ReceiveEther(address indexed _sender, uint256 _value);
    event MetaData(string _metaData);

    /**
    * @dev the constructor takes organization name, native token and reputation system
    and creates an avatar for a controller
    */
    constructor(string memory _orgName, DAOToken _nativeToken, Reputation _nativeReputation) public {
        orgName = _orgName;
        nativeToken = _nativeToken;
        nativeReputation = _nativeReputation;
    }

    /**
    * @dev enables an avatar to receive ethers
    */
    function() external payable {
        emit ReceiveEther(msg.sender, msg.value);
    }

    /**
    * @dev perform a generic call to an arbitrary contract
    * @param _contract  the contract's address to call
    * @param _data ABI-encoded contract call to call `_contract` address.
    * @param _value value (ETH) to transfer with the transaction
    * @return bool    success or fail
    *         bytes - the return bytes of the called contract's function.
    */
    function genericCall(address _contract, bytes memory _data, uint256 _value)
    public
    onlyOwner
    returns(bool success, bytes memory returnValue) {
      // solhint-disable-next-line avoid-call-value
        (success, returnValue) = _contract.call.value(_value)(_data);
        emit GenericCall(_contract, _data, _value, success);
    }

    /**
    * @dev send ethers from the avatar's wallet
    * @param _amountInWei amount to send in Wei units
    * @param _to send the ethers to this address
    * @return bool which represents success
    */
    function sendEther(uint256 _amountInWei, address payable _to) public onlyOwner returns(bool) {
        _to.transfer(_amountInWei);
        emit SendEther(_amountInWei, _to);
        return true;
    }

    /**
    * @dev external token transfer
    * @param _externalToken the token contract
    * @param _to the destination address
    * @param _value the amount of tokens to transfer
    * @return bool which represents success
    */
    function externalTokenTransfer(IERC20 _externalToken, address _to, uint256 _value)
    public onlyOwner returns(bool)
    {
        address(_externalToken).safeTransfer(_to, _value);
        emit ExternalTokenTransfer(address(_externalToken), _to, _value);
        return true;
    }

    /**
    * @dev external token transfer from a specific account
    * @param _externalToken the token contract
    * @param _from the account to spend token from
    * @param _to the destination address
    * @param _value the amount of tokens to transfer
    * @return bool which represents success
    */
    function externalTokenTransferFrom(
        IERC20 _externalToken,
        address _from,
        address _to,
        uint256 _value
    )
    public onlyOwner returns(bool)
    {
        address(_externalToken).safeTransferFrom(_from, _to, _value);
        emit ExternalTokenTransferFrom(address(_externalToken), _from, _to, _value);
        return true;
    }

    /**
    * @dev externalTokenApproval approve the spender address to spend a specified amount of tokens
    *      on behalf of msg.sender.
    * @param _externalToken the address of the Token Contract
    * @param _spender address
    * @param _value the amount of ether (in Wei) which the approval is referring to.
    * @return bool which represents a success
    */
    function externalTokenApproval(IERC20 _externalToken, address _spender, uint256 _value)
    public onlyOwner returns(bool)
    {
        address(_externalToken).safeApprove(_spender, _value);
        emit ExternalTokenApproval(address(_externalToken), _spender, _value);
        return true;
    }

    /**
    * @dev metaData emits an event with a string, should contain the hash of some meta data.
    * @param _metaData a string representing a hash of the meta data
    * @return bool which represents a success
    */
    function metaData(string memory _metaData) public onlyOwner returns(bool) {
        emit MetaData(_metaData);
        return true;
    }


}

// File: contracts/globalConstraints/GlobalConstraintInterface.sol

pragma solidity ^0.5.11;


contract GlobalConstraintInterface {

    enum CallPhase { Pre, Post, PreAndPost }

    function pre( address _scheme, bytes32 _params, bytes32 _method ) public returns(bool);
    function post( address _scheme, bytes32 _params, bytes32 _method ) public returns(bool);
    /**
     * @dev when return if this globalConstraints is pre, post or both.
     * @return CallPhase enum indication  Pre, Post or PreAndPost.
     */
    function when() public returns(CallPhase);
}

// File: contracts/controller/ControllerInterface.sol

pragma solidity ^0.5.11;



/**
 * @title Controller contract
 * @dev A controller controls the organizations tokens ,reputation and avatar.
 * It is subject to a set of schemes and constraints that determine its behavior.
 * Each scheme has it own parameters and operation permissions.
 */
interface ControllerInterface {

    /**
     * @dev Mint `_amount` of reputation that are assigned to `_to` .
     * @param  _amount amount of reputation to mint
     * @param _to beneficiary address
     * @return bool which represents a success
    */
    function mintReputation(uint256 _amount, address _to, address _avatar)
    external
    returns(bool);

    /**
     * @dev Burns `_amount` of reputation from `_from`
     * @param _amount amount of reputation to burn
     * @param _from The address that will lose the reputation
     * @return bool which represents a success
     */
    function burnReputation(uint256 _amount, address _from, address _avatar)
    external
    returns(bool);

    /**
     * @dev mint tokens .
     * @param  _amount amount of token to mint
     * @param _beneficiary beneficiary address
     * @param _avatar address
     * @return bool which represents a success
     */
    function mintTokens(uint256 _amount, address _beneficiary, address _avatar)
    external
    returns(bool);

  /**
   * @dev register or update a scheme
   * @param _scheme the address of the scheme
   * @param _paramsHash a hashed configuration of the usage of the scheme
   * @param _permissions the permissions the new scheme will have
   * @param _avatar address
   * @return bool which represents a success
   */
    function registerScheme(address _scheme, bytes32 _paramsHash, bytes4 _permissions, address _avatar)
    external
    returns(bool);

    /**
     * @dev unregister a scheme
     * @param _avatar address
     * @param _scheme the address of the scheme
     * @return bool which represents a success
     */
    function unregisterScheme(address _scheme, address _avatar)
    external
    returns(bool);

    /**
     * @dev unregister the caller's scheme
     * @param _avatar address
     * @return bool which represents a success
     */
    function unregisterSelf(address _avatar) external returns(bool);

    /**
     * @dev add or update Global Constraint
     * @param _globalConstraint the address of the global constraint to be added.
     * @param _params the constraint parameters hash.
     * @param _avatar the avatar of the organization
     * @return bool which represents a success
     */
    function addGlobalConstraint(address _globalConstraint, bytes32 _params, address _avatar)
    external returns(bool);

    /**
     * @dev remove Global Constraint
     * @param _globalConstraint the address of the global constraint to be remove.
     * @param _avatar the organization avatar.
     * @return bool which represents a success
     */
    function removeGlobalConstraint (address _globalConstraint, address _avatar)
    external  returns(bool);

  /**
    * @dev upgrade the Controller
    *      The function will trigger an event 'UpgradeController'.
    * @param  _newController the address of the new controller.
    * @param _avatar address
    * @return bool which represents a success
    */
    function upgradeController(address _newController, Avatar _avatar)
    external returns(bool);

    /**
    * @dev perform a generic call to an arbitrary contract
    * @param _contract  the contract's address to call
    * @param _data ABI-encoded contract call to call `_contract` address.
    * @param _avatar the controller's avatar address
    * @param _value value (ETH) to transfer with the transaction
    * @return bool -success
    *         bytes  - the return value of the called _contract's function.
    */
    function genericCall(address _contract, bytes calldata _data, Avatar _avatar, uint256 _value)
    external
    returns(bool, bytes memory);

  /**
   * @dev send some ether
   * @param _amountInWei the amount of ether (in Wei) to send
   * @param _to address of the beneficiary
   * @param _avatar address
   * @return bool which represents a success
   */
    function sendEther(uint256 _amountInWei, address payable _to, Avatar _avatar)
    external returns(bool);

    /**
    * @dev send some amount of arbitrary ERC20 Tokens
    * @param _externalToken the address of the Token Contract
    * @param _to address of the beneficiary
    * @param _value the amount of ether (in Wei) to send
    * @param _avatar address
    * @return bool which represents a success
    */
    function externalTokenTransfer(IERC20 _externalToken, address _to, uint256 _value, Avatar _avatar)
    external
    returns(bool);

    /**
    * @dev transfer token "from" address "to" address
    *      One must to approve the amount of tokens which can be spend from the
    *      "from" account.This can be done using externalTokenApprove.
    * @param _externalToken the address of the Token Contract
    * @param _from address of the account to send from
    * @param _to address of the beneficiary
    * @param _value the amount of ether (in Wei) to send
    * @param _avatar address
    * @return bool which represents a success
    */
    function externalTokenTransferFrom(
    IERC20 _externalToken,
    address _from,
    address _to,
    uint256 _value,
    Avatar _avatar)
    external
    returns(bool);

    /**
    * @dev externalTokenApproval approve the spender address to spend a specified amount of tokens
    *      on behalf of msg.sender.
    * @param _externalToken the address of the Token Contract
    * @param _spender address
    * @param _value the amount of ether (in Wei) which the approval is referring to.
    * @return bool which represents a success
    */
    function externalTokenApproval(IERC20 _externalToken, address _spender, uint256 _value, Avatar _avatar)
    external
    returns(bool);

    /**
    * @dev metaData emits an event with a string, should contain the hash of some meta data.
    * @param _metaData a string representing a hash of the meta data
    * @param _avatar Avatar
    * @return bool which represents a success
    */
    function metaData(string calldata _metaData, Avatar _avatar) external returns(bool);

    /**
     * @dev getNativeReputation
     * @param _avatar the organization avatar.
     * @return organization native reputation
     */
    function getNativeReputation(address _avatar)
    external
    view
    returns(address);

    function isSchemeRegistered( address _scheme, address _avatar) external view returns(bool);

    function getSchemeParameters(address _scheme, address _avatar) external view returns(bytes32);

    function getGlobalConstraintParameters(address _globalConstraint, address _avatar) external view returns(bytes32);

    function getSchemePermissions(address _scheme, address _avatar) external view returns(bytes4);

    /**
     * @dev globalConstraintsCount return the global constraint pre and post count
     * @return uint256 globalConstraintsPre count.
     * @return uint256 globalConstraintsPost count.
     */
    function globalConstraintsCount(address _avatar) external view returns(uint, uint);

    function isGlobalConstraintRegistered(address _globalConstraint, address _avatar) external view returns(bool);
}

// File: contracts/schemes/Agreement.sol

pragma solidity ^0.5.11;

/**
 * @title A scheme for conduct ERC20 Tokens auction for reputation
 */


contract Agreement {

    bytes32 private agreementHash;

    modifier onlyAgree(bytes32 _agreementHash) {
        require(_agreementHash == agreementHash, "Sender must send the right agreementHash");
        _;
    }

    /**
     * @dev getAgreementHash
     * @return bytes32 agreementHash
     */
    function getAgreementHash() external  view returns(bytes32)
    {
        return agreementHash;
    }

    /**
     * @dev setAgreementHash
     * @param _agreementHash is a hash of agreement required to be added to the TX by participants
     */
    function setAgreementHash(bytes32 _agreementHash) internal
    {
        require(agreementHash == bytes32(0), "Can not set agreement twice");
        agreementHash = _agreementHash;
    }


}

// File: @daostack/infra/contracts/libs/RealMath.sol

pragma solidity ^0.5.11;

/**
 * RealMath: fixed-point math library, based on fractional and integer parts.
 * Using uint256 as real216x40, which isn't in Solidity yet.
 * Internally uses the wider uint256 for some math.
 *
 * Note that for addition, subtraction, and mod (%), you should just use the
 * built-in Solidity operators. Functions for these operations are not provided.
 *
 */


library RealMath {

    /**
     * How many total bits are there?
     */
    uint256 constant private REAL_BITS = 256;

    /**
     * How many fractional bits are there?
     */
    uint256 constant private REAL_FBITS = 40;

    /**
     * What's the first non-fractional bit
     */
    uint256 constant private REAL_ONE = uint256(1) << REAL_FBITS;

    /**
     * Raise a real number to any positive integer power
     */
    function pow(uint256 realBase, uint256 exponent) internal pure returns (uint256) {

        uint256 tempRealBase = realBase;
        uint256 tempExponent = exponent;

        // Start with the 0th power
        uint256 realResult = REAL_ONE;
        while (tempExponent != 0) {
            // While there are still bits set
            if ((tempExponent & 0x1) == 0x1) {
                // If the low bit is set, multiply in the (many-times-squared) base
                realResult = mul(realResult, tempRealBase);
            }
                // Shift off the low bit
            tempExponent = tempExponent >> 1;
            if (tempExponent != 0) {
                // Do the squaring
                tempRealBase = mul(tempRealBase, tempRealBase);
            }
        }

        // Return the final result.
        return realResult;
    }

    /**
     * Create a real from a rational fraction.
     */
    function fraction(uint216 numerator, uint216 denominator) internal pure returns (uint256) {
        return div(uint256(numerator) * REAL_ONE, uint256(denominator) * REAL_ONE);
    }

    /**
     * Multiply one real by another. Truncates overflows.
     */
    function mul(uint256 realA, uint256 realB) private pure returns (uint256) {
        // When multiplying fixed point in x.y and z.w formats we get (x+z).(y+w) format.
        // So we just have to clip off the extra REAL_FBITS fractional bits.
        uint256 res = realA * realB;
        require(res/realA == realB, "RealMath mul overflow");
        return (res >> REAL_FBITS);
    }

    /**
     * Divide one real by another real. Truncates overflows.
     */
    function div(uint256 realNumerator, uint256 realDenominator) private pure returns (uint256) {
        // We use the reverse of the multiplication trick: convert numerator from
        // x.y to (x+z).(y+w) fixed point, then divide by denom in z.w fixed point.
        return uint256((uint256(realNumerator) * REAL_ONE) / uint256(realDenominator));
    }

}

// File: contracts/schemes/ContinuousLocking4Reputation.sol

pragma solidity ^0.5.11;







/**
 * @title A scheme for continuous locking ERC20 Token for reputation
 */

contract ContinuousLocking4Reputation is Agreement {
    using SafeMath for uint256;
    using SafeERC20 for address;
    using RealMath for uint216;
    using RealMath for uint256;
    using Math for uint256;

    event Redeem(uint256 indexed _lockingId, address indexed _beneficiary, uint256 _amount, uint256 _batchIndex);
    event Release(uint256 indexed _lockingId, address indexed _beneficiary, uint256 _amount);
    event LockToken(address indexed _locker, uint256 indexed _lockingId, uint256 _amount, uint256 _period);
    event ExtendLocking(address indexed _locker, uint256 indexed _lockingId, uint256 _extendPeriod);

    struct Batch {
        uint256 totalScore;
        // A mapping from lockingId to its score
        mapping(uint256=>uint) scores;
    }

    struct Lock {
        uint256 amount;
        uint256 lockingTime;
        uint256 period;
    }

    // A mapping from lockers addresses to their locks
    mapping(address => mapping(uint256=>Lock)) public lockers;
    // A mapping from batch index to batch
    mapping(uint256 => Batch) public batches;

    Avatar public avatar;
    uint256 public reputationRewardLeft; // the amount of reputation that is still left to distribute
    uint256 public startTime; // the time (in secs since epoch) that locking can start (is enable)
    uint256 public redeemEnableTime;
    uint256 public maxLockingBatches;
    uint256 public batchTime; // the length of a batch, in seconds
    IERC20 public token; // the token to be locked
    uint256 public lockCounter; // Total number of locks
    uint256 public totalLockedLeft; // the amount of reputation  that is still left to distribute
    uint256 public repRewardConstA;
    uint256 public repRewardConstB;
    uint256 public batchesIndexCap;

    uint256 constant private REAL_FBITS = 40;
    /**
     * What's the first non-fractional bit
     */

    uint256 constant private REAL_ONE = uint256(1) << REAL_FBITS;
    uint256 constant private BATCHES_INDEX_HARDCAP = 100;
    uint256 constant public MAX_LOCKING_BATCHES_HARDCAP = 24;

    /**
     * @dev initialize
     * @param _avatar the avatar to mint reputation from
     * @param _reputationReward the total amount of reputation that can be minted by this contract
     * @param _startTime locking period start time, in seconds since epoch
     * @param _redeemEnableTime redeem enable time
     * @param _batchTime batch time (in seconds)
     * @param _redeemEnableTime redeem enable time, in seconds since epoch
     *        redeem reputation can be done after this time.
     * @param _maxLockingBatches - maximum number of locking batches that a user can lock (or extend) her tokens for
     * @param _repRewardConstA - the total amount of reputation allocation per batch is calculated by :
     *   _repRewardConstA * ((_repRewardConstB/1000) ** batchIndex)
     * @param _repRewardConstB - the total amount of reputation allocation per batch is calculated by :
     *   _repRewardConstA * ((_repRewardConstB/1000) ** batchIndex). _repRewardConstB must be < 1000
     * @param _batchesIndexCap the length of the locking period (in batches).
     *        This value capped by BATCHES_HARDCAP .
     * @param _token the locking token
     * @param _agreementHash is a hash of agreement required to be added to the TX by participants
     */
    function initialize(
        Avatar _avatar,
        uint256 _reputationReward,
        uint256 _startTime,
        uint256 _batchTime,
        uint256 _redeemEnableTime,
        uint256 _maxLockingBatches,
        uint256 _repRewardConstA,
        uint256 _repRewardConstB,
        uint256 _batchesIndexCap,
        IERC20 _token,
        bytes32 _agreementHash )
    external
    {
        require(avatar == Avatar(0), "can be called only one time");
        require(_avatar != Avatar(0), "avatar cannot be zero");
        // _batchTime should be greater than block interval
        require(_batchTime > 15, "batchTime should be > 15");
        require(_maxLockingBatches <= MAX_LOCKING_BATCHES_HARDCAP,
        "maxLockingBatches should be <= MAX_LOCKING_BATCHES_HARDCAP");
        require(_redeemEnableTime >= _startTime.add(_batchTime),
        "_redeemEnableTime >= _startTime+_batchTime");
        require(_batchesIndexCap <= BATCHES_INDEX_HARDCAP, "_batchesIndexCap > BATCHES_INDEX_HARDCAP");
        token = _token;
        avatar = _avatar;
        startTime = _startTime;
        reputationRewardLeft = _reputationReward;
        redeemEnableTime = _redeemEnableTime;
        maxLockingBatches = _maxLockingBatches;
        batchTime = _batchTime;
        require(_repRewardConstB < 1000, "_repRewardConstB should be < 1000");
        require(repRewardConstA < _reputationReward, "repRewardConstA should be < _reputationReward");
        repRewardConstA = toReal(uint216(_repRewardConstA));
        repRewardConstB = uint216(_repRewardConstB).fraction(uint216(1000));
        batchesIndexCap = _batchesIndexCap;
        super.setAgreementHash(_agreementHash);
    }

    /**
     * @dev redeem reputation function
     * @param _beneficiary the beneficiary to redeem.
     * @param _lockingId the lockingId to redeem from.
     * @return uint256 reputation rewarded
     */
    function redeem(address _beneficiary, uint256 _lockingId) public returns(uint256 reputation) {
        // solhint-disable-next-line not-rely-on-time
        require(now > redeemEnableTime, "now > redeemEnableTime");
        Lock storage locker = lockers[_beneficiary][_lockingId];
        require(locker.lockingTime != 0, "_lockingId does not exist");
        uint256 batchIndexToRedeemFrom = (locker.lockingTime - startTime) / batchTime;
        // solhint-disable-next-line not-rely-on-time
        uint256 currentBatch = (now - startTime) / batchTime;
        uint256 lastBatchIndexToRedeem =  currentBatch.min(batchIndexToRedeemFrom.add(locker.period));
        for (batchIndexToRedeemFrom; batchIndexToRedeemFrom < lastBatchIndexToRedeem; batchIndexToRedeemFrom++) {
            Batch storage locking = batches[batchIndexToRedeemFrom];
            uint256 score = locking.scores[_lockingId];
            if (score > 0) {
                locking.scores[_lockingId] = 0;
                uint256 batchReputationReward = getRepRewardPerBatch(batchIndexToRedeemFrom);
                uint256 repRelation = mul(toReal(uint216(score)), batchReputationReward);
                uint256 redeemForBatch = div(repRelation, toReal(uint216(locking.totalScore)));
                reputation = reputation.add(redeemForBatch);
                emit Redeem(_lockingId, _beneficiary, uint256(fromReal(redeemForBatch)), batchIndexToRedeemFrom);
            }
        }
        reputation = uint256(fromReal(reputation));
        require(reputation > 0, "reputation to redeem is 0");
        // check that the reputation is sum zero
        reputationRewardLeft = reputationRewardLeft.sub(reputation);
        require(
        ControllerInterface(avatar.owner())
        .mintReputation(reputation, _beneficiary, address(avatar)), "mint reputation should succeed");
    }

    /**
     * @dev lock function
     * @param _amount the amount of token to lock
     * @param _period the number of batches that the tokens will be locked for
     * @param _batchIndexToLockIn the batch index in which the locking period starts.
     * Must be the currently active batch.
     * @return lockingId
     */
    function lock(uint256 _amount, uint256 _period, uint256 _batchIndexToLockIn, bytes32 _agreementHash)
    public
    onlyAgree(_agreementHash)
    returns(uint256 lockingId)
    {
        require(_amount > 0, "_amount should be > 0");
        // solhint-disable-next-line not-rely-on-time
        require(now >= startTime, "locking is not enabled yet (it starts at startTime)");
        require(_period <= maxLockingBatches, "_period exceed the maximum allowed");
        require(_period > 0, "_period must be > 0");
        require((_batchIndexToLockIn.add(_period)) <= batchesIndexCap,
        "_batchIndexToLockIn + _period exceed max allowed batches");
        lockCounter = lockCounter.add(1);
        lockingId = lockCounter;

        Lock storage locker = lockers[msg.sender][lockingId];
        locker.amount = _amount;
        locker.period = _period;
        // solhint-disable-next-line not-rely-on-time
        locker.lockingTime = now;

        address(token).safeTransferFrom(msg.sender, address(this), _amount);
        // solhint-disable-next-line not-rely-on-time
        uint256 batchIndexToLockIn = (now - startTime) / batchTime;
        require(batchIndexToLockIn == _batchIndexToLockIn,
        "_batchIndexToLockIn must be the one corresponding to the current one");
        //fill in the next batches scores.
        for (uint256 p = 0; p < _period; p++) {
            Batch storage batch = batches[batchIndexToLockIn + p];
            uint256 score = (_period - p).mul(_amount);
            batch.totalScore = batch.totalScore.add(score);
            batch.scores[lockingId] = score;
        }

        totalLockedLeft = totalLockedLeft.add(_amount);
        emit LockToken(msg.sender, lockingId, _amount, _period);
    }

    /**
     * @dev extendLocking function
     * @param _extendPeriod the period to extend the locking. in batchTime.
     * @param _batchIndexToLockIn index of the batch in which to start locking.
     * @param _lockingId the locking id to extend
     */
    function extendLocking(
        uint256 _extendPeriod,
        uint256 _batchIndexToLockIn,
        uint256 _lockingId,
        bytes32 _agreementHash)
    public
    onlyAgree(_agreementHash)
    {
        Lock storage locker = lockers[msg.sender][_lockingId];
        require(locker.lockingTime != 0, "_lockingId does not exist");
        // remainBatchs is the number of future batches that are part of the currently active lock
        uint256 remainBatches =
        ((locker.lockingTime.add(locker.period*batchTime).sub(startTime))/batchTime).sub(_batchIndexToLockIn);
        uint256 batchesCountFromCurrent = remainBatches.add(_extendPeriod);
        require(batchesCountFromCurrent <= maxLockingBatches, "locking period exceeds the maximum allowed");
        require(_extendPeriod > 0, "_extendPeriod must be > 0");
        require((_batchIndexToLockIn.add(batchesCountFromCurrent)) <= batchesIndexCap,
        "_extendPeriod exceed max allowed batches");
        // solhint-disable-next-line not-rely-on-time
        uint256 batchIndexToLockIn = (now - startTime) / batchTime;
        require(batchIndexToLockIn == _batchIndexToLockIn, "locking is not active");
        //fill in the next batch scores.
        for (uint256 p = 0; p < batchesCountFromCurrent; p++) {
            Batch storage batch = batches[batchIndexToLockIn + p];
            uint256 score = (batchesCountFromCurrent - p).mul(locker.amount);
            batch.totalScore = batch.totalScore.add(score).sub(batch.scores[_lockingId]);
            batch.scores[_lockingId] = score;
        }
        locker.period = locker.period.add(_extendPeriod);
        emit ExtendLocking(msg.sender, _lockingId, _extendPeriod);
    }

    /**
     * @dev release function
     * @param _beneficiary the beneficiary for the release
     * @param _lockingId the locking id to release
     * @return bool
     */
    function release(address _beneficiary, uint256 _lockingId) public returns(uint256 amount) {
        Lock storage locker = lockers[_beneficiary][_lockingId];
        require(locker.amount > 0, "no amount left to unlock");
        amount = locker.amount;
        locker.amount = 0;
        // solhint-disable-next-line not-rely-on-time
        require(block.timestamp > locker.lockingTime.add(locker.period*batchTime),
        "locking period is still active");
        totalLockedLeft = totalLockedLeft.sub(amount);
        address(token).safeTransfer(_beneficiary, amount);
        emit Release(_lockingId, _beneficiary, amount);
    }

    /**
     * @dev getRepRewardPerBatch function
     * the calculation is done the following formula:
     * RepReward =  repRewardConstA * (repRewardConstB**_batchIndex)
     * @param _batchIndex the index of the batch to calc rep reward of
     * @return repReward
     */
    function getRepRewardPerBatch(uint256  _batchIndex) public view returns(uint256 repReward) {
        if (_batchIndex <= batchesIndexCap) {
            repReward = mul(repRewardConstA, repRewardConstB.pow(_batchIndex));
        }
    }

    /**
     * @dev getLockingIdScore function
     * return score of lockingId at specific bach index
     * @param _batchIndex batch index
     * @param _lockingId lockingId
     * @return score
     */
    function getLockingIdScore(uint256  _batchIndex, uint256 _lockingId) public view returns(uint256) {
        return batches[_batchIndex].scores[_lockingId];
    }

    /**
     * Multiply one real by another. Truncates overflows.
     */
    function mul(uint256 realA, uint256 realB) private pure returns (uint256) {
        // When multiplying fixed point in x.y and z.w formats we get (x+z).(y+w) format.
        // So we just have to clip off the extra REAL_FBITS fractional bits.
        uint256 res = realA * realB;
        require(res/realA == realB, "RealMath mul overflow");
        return (res >> REAL_FBITS);
    }

    /**
     * Convert an integer to a real. Preserves sign.
     */
    function toReal(uint216 ipart) private pure returns (uint256) {
        return uint256(ipart) * REAL_ONE;
    }

    /**
     * Convert a real to an integer. Preserves sign.
     */
    function fromReal(uint256 _realValue) private pure returns (uint216) {
        return uint216(_realValue / REAL_ONE);
    }

    /**
     * Divide one real by another real. Truncates overflows.
     */
    function div(uint256 realNumerator, uint256 realDenominator) private pure returns (uint256) {
        // We use the reverse of the multiplication trick: convert numerator from
        // x.y to (x+z).(y+w) fixed point, then divide by denom in z.w fixed point.
        return uint256((uint256(realNumerator) * REAL_ONE) / uint256(realDenominator));
    }

}