pragma solidity ^0.4.18;

/*
    Copyright 2017, Jordi Baylina

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/// @title MyEtherWallet Campaign Contract
/// @author Jordi Baylina and Arthur Lunn
/// @dev This contract controls the issuance of tokens for the MiniMe Token
///  Contract. This version specifically acts as a Campaign manager for raising
///  funds for non-profit causes, but it can be customized for any variety of
///  purposes.

/// @dev Basic contract to allow a contract to be controlled by a `controller`
contract Controlled {

    /// @notice The address of the controller is the only address that can call
    ///  a function with this modifier
    modifier onlyController { require(msg.sender == controller); _; }

    address public controller;

    function Controlled() public { controller = msg.sender;}

    /// @notice Changes the controller of the contract
    /// @param _newController The new controller of the contract
    function changeController(address _newController) public onlyController {
        controller = _newController;
    }
}

////////////////////////////////////////////////////////////////////////////////

/// @dev The token controller contract must implement these functions
contract TokenController {

    /// @notice Called when `_owner` sends ether to the MiniMe Token contract
    /// @param _owner The address that sent the ether to create tokens
    /// @return True if the ether is accepted, false if it throws
    function proxyPayment(address _owner) public payable returns(bool);

    /// @notice Notifies the controller about a token transfer allowing the
    ///  controller to react if desired
    /// @param _from The origin of the transfer
    /// @param _to The destination of the transfer
    /// @param _amount The amount of the transfer
    /// @return False if the controller does not authorize the transfer
    function onTransfer(address _from, address _to, uint _amount) public returns(bool);

    /// @notice Notifies the controller about an approval allowing the
    ///  controller to react if desired
    /// @param _owner The address that calls `approve()`
    /// @param _spender The spender in the `approve()` call
    /// @param _amount The amount in the `approve()` call
    /// @return False if the controller does not authorize the approval
    function onApprove(address _owner, address _spender, uint _amount) public
        returns(bool);
}

////////////////////////////////////////////////////////////////////////////////

/// @dev A simple contract to allow data to be properly attached in the 
///  `approveAndCall()`
contract ApproveAndCallFallBack {
    function receiveApproval(
        address from,
        uint256 _amount,
        address _token,
        bytes _data
    ) public;
}

////////////////////////////////////////////////////////////////////////////////

/// @dev The actual token contract, the default controller is the msg.sender
///  that deploys the contract, so usually this token will be deployed by a
///  token controller contract, which Giveth will call a "Campaign"
contract MiniMeToken is Controlled {

    string public name;                //The Token's name: e.g. DigixDAO Tokens
    uint8 public decimals;             //Number of decimals of the smallest unit
    string public symbol;              //An identifier: e.g. REP
    string public version = 'MMT_0.2'; //An arbitrary versioning scheme


    /// @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 tokens at a specific block number
        uint128 value;
    }

    // `parentToken` is the Token address that was cloned to produce this token;
    //  it will be 0x0 for a token that was not cloned
    MiniMeToken public parentToken;

    // `parentSnapShotBlock` is the block number from the Parent Token that was
    //  used to determine the initial distribution of the Clone Token
    uint public parentSnapShotBlock;

    // `creationBlock` is the block number that the Clone Token was created
    uint public creationBlock;

    // `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;

    // `allowed` tracks any extra transfer rights as in all ERC20 tokens
    mapping (address => mapping (address => uint256)) allowed;

    // Tracks the history of the `totalSupply` of the token
    Checkpoint[] totalSupplyHistory;

    // Flag that determines if the token is transferable or not.
    bool public transfersEnabled;

    // The factory used to create new clone tokens
    MiniMeTokenFactory public tokenFactory;

////////////////
// Constructor
////////////////

    /// @notice Constructor to create a MiniMeToken
    /// @param _tokenFactory The address of the MiniMeTokenFactory contract that
    ///  will create the Clone token contracts, the token factory needs to be
    ///  deployed first
    /// @param _parentToken Address of the parent token, set to 0x0 if it is a
    ///  new token
    /// @param _parentSnapShotBlock Block of the parent token that will
    ///  determine the initial distribution of the clone token, set to 0 if it
    ///  is a new token
    /// @param _tokenName Name of the new token
    /// @param _decimalUnits Number of decimals of the new token
    /// @param _tokenSymbol Token Symbol for the new token
    /// @param _transfersEnabled If true, tokens will be able to be transferred
    function MiniMeToken(
        address _tokenFactory,
        address _parentToken,
        uint _parentSnapShotBlock,
        string _tokenName,
        uint8 _decimalUnits,
        string _tokenSymbol,
        bool _transfersEnabled
    ) public {
        tokenFactory = MiniMeTokenFactory(_tokenFactory);
        name = _tokenName;                                 // Set the name
        decimals = _decimalUnits;                          // Set the decimals
        symbol = _tokenSymbol;                             // Set the symbol
        parentToken = MiniMeToken(_parentToken);
        parentSnapShotBlock = _parentSnapShotBlock;
        transfersEnabled = _transfersEnabled;
        creationBlock = block.number;
    }


///////////////////
// ERC20 Methods
///////////////////

    /// @notice Send `_amount` tokens to `_to` from `msg.sender`
    /// @param _to The address of the recipient
    /// @param _amount The amount of tokens to be transferred
    /// @return Whether the transfer was successful or not
    function transfer(address _to, uint256 _amount) public returns (bool success) {
        require(transfersEnabled);
        return doTransfer(msg.sender, _to, _amount);
    }

    /// @notice Send `_amount` tokens to `_to` from `_from` on the condition it
    ///  is approved by `_from`
    /// @param _from The address holding the tokens being transferred
    /// @param _to The address of the recipient
    /// @param _amount The amount of tokens to be transferred
    /// @return True if the transfer was successful
    function transferFrom(address _from, address _to, uint256 _amount
    ) public returns (bool success) {

        // The controller of this contract can move tokens around at will,
        //  this is important to recognize! Confirm that you trust the
        //  controller of this contract, which in most situations should be
        //  another open source smart contract or 0x0
        if (msg.sender != controller) {
            require(transfersEnabled);

            // The standard ERC 20 transferFrom functionality
            if (allowed[_from][msg.sender] < _amount) return false;
            allowed[_from][msg.sender] -= _amount;
        }
        return doTransfer(_from, _to, _amount);
    }

    /// @dev This is the actual transfer function in the token contract, it can
    ///  only be called by other functions in this contract.
    /// @param _from The address holding the tokens being transferred
    /// @param _to The address of the recipient
    /// @param _amount The amount of tokens to be transferred
    /// @return True if the transfer was successful
    function doTransfer(address _from, address _to, uint _amount
    ) internal returns(bool) {

           if (_amount == 0) {
               return true;
           }

           require(parentSnapShotBlock < block.number);

           // Do not allow transfer to 0x0 or the token contract itself
           require((_to != 0) && (_to != address(this)));

           // If the amount being transfered is more than the balance of the
           //  account the transfer returns false
           var previousBalanceFrom = balanceOfAt(_from, block.number);
           if (previousBalanceFrom < _amount) {
               return false;
           }

           // Alerts the token controller of the transfer
           if (isContract(controller)) {
               require(TokenController(controller).onTransfer(_from, _to, _amount));
           }

           // First update the balance array with the new value for the address
           //  sending the tokens
           updateValueAtNow(balances[_from], previousBalanceFrom - _amount);

           // Then update the balance array with the new value for the address
           //  receiving the tokens
           var previousBalanceTo = balanceOfAt(_to, block.number);
           require(previousBalanceTo + _amount >= previousBalanceTo); // Check for overflow
           updateValueAtNow(balances[_to], previousBalanceTo + _amount);

           // An event to make the transfer easy to find on the blockchain
           Transfer(_from, _to, _amount);

           return true;
    }

    /// @param _owner The address that's balance is being requested
    /// @return The balance of `_owner` at the current block
    function balanceOf(address _owner) public constant returns (uint256 balance) {
        return balanceOfAt(_owner, block.number);
    }

    /// @notice `msg.sender` approves `_spender` to spend `_amount` tokens on
    ///  its behalf. This is a modified version of the ERC20 approve function
    ///  to be a little bit safer
    /// @param _spender The address of the account able to transfer the tokens
    /// @param _amount The amount of tokens to be approved for transfer
    /// @return True if the approval was successful
    function approve(address _spender, uint256 _amount) public returns (bool success) {
        require(transfersEnabled);

        // To change the approve amount you first have to reduce the addresses`
        //  allowance to zero by calling `approve(_spender,0)` if it is not
        //  already 0 to mitigate the race condition described here:
        //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
        require((_amount == 0) || (allowed[msg.sender][_spender] == 0));

        // Alerts the token controller of the approve function call
        if (isContract(controller)) {
            require(TokenController(controller).onApprove(msg.sender, _spender, _amount));
        }

        allowed[msg.sender][_spender] = _amount;
        Approval(msg.sender, _spender, _amount);
        return true;
    }

    /// @dev This function makes it easy to read the `allowed[]` map
    /// @param _owner The address of the account that owns the token
    /// @param _spender The address of the account able to transfer the tokens
    /// @return Amount of remaining tokens of _owner that _spender is allowed
    ///  to spend
    function allowance(address _owner, address _spender
    ) public constant returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }

    /// @notice `msg.sender` approves `_spender` to send `_amount` tokens on
    ///  its behalf, and then a function is triggered in the contract that is
    ///  being approved, `_spender`. This allows users to use their tokens to
    ///  interact with contracts in one function call instead of two
    /// @param _spender The address of the contract able to transfer the tokens
    /// @param _amount The amount of tokens to be approved for transfer
    /// @return True if the function call was successful
    function approveAndCall(address _spender, uint256 _amount, bytes _extraData
    ) public returns (bool success) {
        require(approve(_spender, _amount));

        ApproveAndCallFallBack(_spender).receiveApproval(
            msg.sender,
            _amount,
            this,
            _extraData
        );

        return true;
    }

    /// @dev This function makes it easy to get the total number of tokens
    /// @return The total number of tokens
    function totalSupply() public constant returns (uint) {
        return totalSupplyAt(block.number);
    }


////////////////
// Query balance and totalSupply in History
////////////////

    /// @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, uint _blockNumber) public constant
        returns (uint) {

        // These next few lines are used when the balance of the token is
        //  requested before a check point was ever created for this token, it
        //  requires that the `parentToken.balanceOfAt` be queried at the
        //  genesis block for that token as this contains initial balance of
        //  this token
        if ((balances[_owner].length == 0)
            || (balances[_owner][0].fromBlock > _blockNumber)) {
            if (address(parentToken) != 0) {
                return parentToken.balanceOfAt(_owner, min(_blockNumber, parentSnapShotBlock));
            } else {
                // Has no parent
                return 0;
            }

        // This will return the expected balance during normal situations
        } else {
            return getValueAt(balances[_owner], _blockNumber);
        }
    }

    /// @notice Total amount of tokens at a specific `_blockNumber`.
    /// @param _blockNumber The block number when the totalSupply is queried
    /// @return The total amount of tokens at `_blockNumber`
    function totalSupplyAt(uint _blockNumber) public constant returns(uint) {

        // These next few lines are used when the totalSupply of the token is
        //  requested before a check point was ever created for this token, it
        //  requires that the `parentToken.totalSupplyAt` be queried at the
        //  genesis block for this token as that contains totalSupply of this
        //  token at this block number.
        if ((totalSupplyHistory.length == 0)
            || (totalSupplyHistory[0].fromBlock > _blockNumber)) {
            if (address(parentToken) != 0) {
                return parentToken.totalSupplyAt(min(_blockNumber, parentSnapShotBlock));
            } else {
                return 0;
            }

        // This will return the expected totalSupply during normal situations
        } else {
            return getValueAt(totalSupplyHistory, _blockNumber);
        }
    }

////////////////
// Clone Token Method
////////////////

    /// @notice Creates a new clone token with the initial distribution being
    ///  this token at `_snapshotBlock`
    /// @param _cloneTokenName Name of the clone token
    /// @param _cloneDecimalUnits Number of decimals of the smallest unit
    /// @param _cloneTokenSymbol Symbol of the clone token
    /// @param _snapshotBlock Block when the distribution of the parent token is
    ///  copied to set the initial distribution of the new clone token;
    ///  if the block is zero than the actual block, the current block is used
    /// @param _transfersEnabled True if transfers are allowed in the clone
    /// @return The address of the new MiniMeToken Contract
    function createCloneToken(
        string _cloneTokenName,
        uint8 _cloneDecimalUnits,
        string _cloneTokenSymbol,
        uint _snapshotBlock,
        bool _transfersEnabled
        ) public returns(address) {
        if (_snapshotBlock == 0) _snapshotBlock = block.number;
        MiniMeToken cloneToken = tokenFactory.createCloneToken(
            this,
            _snapshotBlock,
            _cloneTokenName,
            _cloneDecimalUnits,
            _cloneTokenSymbol,
            _transfersEnabled
            );

        cloneToken.changeController(msg.sender);

        // An event to make the token easy to find on the blockchain
        NewCloneToken(address(cloneToken), _snapshotBlock);
        return address(cloneToken);
    }

////////////////
// Generate and destroy tokens
////////////////

    /// @notice Generates `_amount` tokens that are assigned to `_owner`
    /// @param _owner The address that will be assigned the new tokens
    /// @param _amount The quantity of tokens generated
    /// @return True if the tokens are generated correctly
    function generateTokens(address _owner, uint _amount
    ) public onlyController returns (bool) {
        uint curTotalSupply = totalSupply();
        require(curTotalSupply + _amount >= curTotalSupply); // Check for overflow
        uint previousBalanceTo = balanceOf(_owner);
        require(previousBalanceTo + _amount >= previousBalanceTo); // Check for overflow
        updateValueAtNow(totalSupplyHistory, curTotalSupply + _amount);
        updateValueAtNow(balances[_owner], previousBalanceTo + _amount);
        Transfer(0, _owner, _amount);
        return true;
    }


    /// @notice Burns `_amount` tokens from `_owner`
    /// @param _owner The address that will lose the tokens
    /// @param _amount The quantity of tokens to burn
    /// @return True if the tokens are burned correctly
    function destroyTokens(address _owner, uint _amount
    ) onlyController public returns (bool) {
        uint curTotalSupply = totalSupply();
        require(curTotalSupply >= _amount);
        uint previousBalanceFrom = balanceOf(_owner);
        require(previousBalanceFrom >= _amount);
        updateValueAtNow(totalSupplyHistory, curTotalSupply - _amount);
        updateValueAtNow(balances[_owner], previousBalanceFrom - _amount);
        Transfer(_owner, 0, _amount);
        return true;
    }

////////////////
// Enable tokens transfers
////////////////


    /// @notice Enables token holders to transfer their tokens freely if true
    /// @param _transfersEnabled True if transfers are allowed in the clone
    function enableTransfers(bool _transfersEnabled) public onlyController {
        transfersEnabled = _transfersEnabled;
    }

////////////////
// Internal helper functions to query and set a value in a snapshot array
////////////////

    /// @dev `getValueAt` retrieves the number of tokens 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 tokens being queried
    function getValueAt(Checkpoint[] storage checkpoints, uint _block
    ) constant internal returns (uint) {
        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
        uint min = 0;
        uint max = checkpoints.length-1;
        while (max > min) {
            uint 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 tokens
    function updateValueAtNow(Checkpoint[] storage checkpoints, uint _value
    ) internal  {
        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);
           }
    }

    /// @dev Internal function to determine if an address is a contract
    /// @param _addr The address being queried
    /// @return True if `_addr` is a contract
    function isContract(address _addr) constant internal returns(bool) {
        uint size;
        if (_addr == 0) return false;
        assembly {
            size := extcodesize(_addr)
        }
        return size>0;
    }

    /// @dev Helper function to return a min betwen the two uints
    function min(uint a, uint b) pure internal returns (uint) {
        return a < b ? a : b;
    }

    /// @notice The fallback function: If the contract's controller has not been
    ///  set to 0, then the `proxyPayment` method is called which relays the
    ///  ether and creates tokens as described in the token controller contract
    function () public payable {
        require(isContract(controller));
        require(TokenController(controller).proxyPayment.value(msg.value)(msg.sender));
    }

//////////
// Safety Methods
//////////

    /// @notice This method can be used by the controller to extract mistakenly
    ///  sent tokens to this contract.
    /// @param _token The address of the token contract that you want to recover
    ///  set to 0 in case you want to extract ether.
    function claimTokens(address _token) public onlyController {
        if (_token == 0x0) {
            controller.transfer(this.balance);
            return;
        }

        MiniMeToken token = MiniMeToken(_token);
        uint balance = token.balanceOf(this);
        token.transfer(controller, balance);
        ClaimedTokens(_token, controller, balance);
    }

////////////////
// Events
////////////////
    event ClaimedTokens(
        address indexed _token,
        address indexed _controller, 
        uint _amount
        );
    event Transfer(address indexed _from, address indexed _to, uint256 _amount);
    event NewCloneToken(address indexed _cloneToken, uint _snapshotBlock);
    event Approval(
        address indexed _owner,
        address indexed _spender,
        uint256 _amount
        );
}

////////////////////////////////////////////////////////////////////////////////

////////////////
// MiniMeTokenFactory
////////////////

/// @dev This contract is used to generate clone contracts from a contract.
///  In solidity this is the way to create a contract from a contract of the
///  same class
contract MiniMeTokenFactory {

    /// @notice Update the DApp by creating a new token with new functionalities
    ///  the msg.sender becomes the controller of this clone token
    /// @param _parentToken Address of the token being cloned
    /// @param _snapshotBlock Block of the parent token that will
    ///  determine the initial distribution of the clone token
    /// @param _tokenName Name of the new token
    /// @param _decimalUnits Number of decimals of the new token
    /// @param _tokenSymbol Token Symbol for the new token
    /// @param _transfersEnabled If true, tokens will be able to be transferred
    /// @return The address of the new token contract
    function createCloneToken(
        address _parentToken,
        uint _snapshotBlock,
        string _tokenName,
        uint8 _decimalUnits,
        string _tokenSymbol,
        bool _transfersEnabled
    ) public returns (MiniMeToken) {
        MiniMeToken newToken = new MiniMeToken(
            this,
            _parentToken,
            _snapshotBlock,
            _tokenName,
            _decimalUnits,
            _tokenSymbol,
            _transfersEnabled
            );

        newToken.changeController(msg.sender);
        return newToken;
    }
}

////////////////////////////////////////////////////////////////////////////////

/**
 * @title ERC20
 * @dev A standard interface for tokens.
 * @dev https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
 */
contract ERC20 {
  
    /// @dev Returns the total token supply
    function totalSupply() public constant returns (uint256 supply);

    /// @dev Returns the account balance of the account with address _owner
    function balanceOf(address _owner) public constant returns (uint256 balance);

    /// @dev Transfers _value number of tokens to address _to
    function transfer(address _to, uint256 _value) public returns (bool success);

    /// @dev Transfers _value number of tokens from address _from to address _to
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success);

    /// @dev Allows _spender to withdraw from the msg.sender's account up to the _value amount
    function approve(address _spender, uint256 _value) public returns (bool success);

    /// @dev Returns the amount which _spender is still allowed to withdraw from _owner
    function allowance(address _owner, address _spender) public constant returns (uint256 remaining);

    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

}

////////////////////////////////////////////////////////////////////////////////
/////// The Campaign Contracts
////////////////////////////////////////////////////////////////////////////////

/// @title Owned
/// @author Adrià Massanet <adria@codecontext.io>
/// @notice The Owned contract has an owner address, and provides basic 
///  authorization control functions, this simplifies & the implementation of
///  user permissions; this contract has three work flows for a change in
///  ownership, the first requires the new owner to validate that they have the
///  ability to accept ownership, the second allows the ownership to be
///  directly transfered without requiring acceptance, and the third allows for
///  the ownership to be removed to allow for decentralization 
contract Owned {

    address public owner;
    address public newOwnerCandidate;

    event OwnershipRequested(address indexed by, address indexed to);
    event OwnershipTransferred(address indexed from, address indexed to);
    event OwnershipRemoved();

    /// @dev The constructor sets the `msg.sender` as the`owner` of the contract
    function Owned() {
        owner = msg.sender;
    }

    /// @dev `owner` is the only address that can call a function with this
    /// modifier
    modifier onlyOwner() {
        require (msg.sender == owner);
        _;
    }
    
    /// @dev In this 1st option for ownership transfer `proposeOwnership()` must
    ///  be called first by the current `owner` then `acceptOwnership()` must be
    ///  called by the `newOwnerCandidate`
    /// @notice `onlyOwner` Proposes to transfer control of the contract to a
    ///  new owner
    /// @param _newOwnerCandidate The address being proposed as the new owner
    function proposeOwnership(address _newOwnerCandidate) onlyOwner {
        newOwnerCandidate = _newOwnerCandidate;
        OwnershipRequested(msg.sender, newOwnerCandidate);
    }

    /// @notice Can only be called by the `newOwnerCandidate`, accepts the
    ///  transfer of ownership
    function acceptOwnership() {
        require(msg.sender == newOwnerCandidate);

        address oldOwner = owner;
        owner = newOwnerCandidate;
        newOwnerCandidate = 0x0;

        OwnershipTransferred(oldOwner, owner);
    }

    /// @dev In this 2nd option for ownership transfer `changeOwnership()` can
    ///  be called and it will immediately assign ownership to the `newOwner`
    /// @notice `owner` can step down and assign some other address to this role
    /// @param _newOwner The address of the new owner
    function changeOwnership(address _newOwner) onlyOwner {
        require(_newOwner != 0x0);

        address oldOwner = owner;
        owner = _newOwner;
        newOwnerCandidate = 0x0;

        OwnershipTransferred(oldOwner, owner);
    }

    /// @dev In this 3rd option for ownership transfer `removeOwnership()` can
    ///  be called and it will immediately assign ownership to the 0x0 address;
    ///  it requires a 0xdece be input as a parameter to prevent accidental use
    /// @notice Decentralizes the contract, this operation cannot be undone 
    /// @param _dac `0xdac` has to be entered for this function to work
    function removeOwnership(uint _dac) onlyOwner {
        require(_dac == 0xdac);
        owner = 0x0;
        newOwnerCandidate = 0x0;
        OwnershipRemoved();     
    }
}

////////////////////////////////////////////////////////////////////////////////


/// @dev `Escapable` is a base level contract built off of the `Owned`
///  contract; it creates an escape hatch function that can be called in an
///  emergency that will allow designated addresses to send any ether or tokens
///  held in the contract to an `escapeHatchDestination` as long as they were
///  not blacklisted
contract Escapable is Owned {
    address public escapeHatchCaller;
    address public escapeHatchDestination;
    mapping (address=>bool) private escapeBlacklist; // Token contract addresses

    /// @notice The Constructor assigns the `escapeHatchDestination` and the
    ///  `escapeHatchCaller`
    /// @param _escapeHatchCaller The address of a trusted account or contract
    ///  to call `escapeHatch()` to send the ether in this contract to the
    ///  `escapeHatchDestination` it would be ideal that `escapeHatchCaller`
    ///  cannot move funds out of `escapeHatchDestination`
    /// @param _escapeHatchDestination The address of a safe location (usu a
    ///  Multisig) to send the ether held in this contract; if a neutral address
    ///  is required, the WHG Multisig is an option:
    ///  0x8Ff920020c8AD673661c8117f2855C384758C572 
    function Escapable(address _escapeHatchCaller, address _escapeHatchDestination) {
        escapeHatchCaller = _escapeHatchCaller;
        escapeHatchDestination = _escapeHatchDestination;
    }

    /// @dev The addresses preassigned as `escapeHatchCaller` or `owner`
    ///  are the only addresses that can call a function with this modifier
    modifier onlyEscapeHatchCallerOrOwner {
        require ((msg.sender == escapeHatchCaller)||(msg.sender == owner));
        _;
    }

    /// @notice Creates the blacklist of tokens that are not able to be taken
    ///  out of the contract; can only be done at the deployment, and the logic
    ///  to add to the blacklist will be in the constructor of a child contract
    /// @param _token the token contract address that is to be blacklisted 
    function blacklistEscapeToken(address _token) internal {
        escapeBlacklist[_token] = true;
        EscapeHatchBlackistedToken(_token);
    }

    /// @notice Checks to see if `_token` is in the blacklist of tokens
    /// @param _token the token address being queried
    /// @return False if `_token` is in the blacklist and can't be taken out of
    ///  the contract via the `escapeHatch()`
    function isTokenEscapable(address _token) constant public returns (bool) {
        return !escapeBlacklist[_token];
    }

    /// @notice The `escapeHatch()` should only be called as a last resort if a
    /// security issue is uncovered or something unexpected happened
    /// @param _token to transfer, use 0x0 for ether
    function escapeHatch(address _token) public onlyEscapeHatchCallerOrOwner {   
        require(escapeBlacklist[_token]==false);

        uint256 balance;

        /// @dev Logic for ether
        if (_token == 0x0) {
            balance = this.balance;
            escapeHatchDestination.transfer(balance);
            EscapeHatchCalled(_token, balance);
            return;
        }
        /// @dev Logic for tokens
        ERC20 token = ERC20(_token);
        balance = token.balanceOf(this);
        token.transfer(escapeHatchDestination, balance);
        EscapeHatchCalled(_token, balance);
    }

    /// @notice Changes the address assigned to call `escapeHatch()`
    /// @param _newEscapeHatchCaller The address of a trusted account or
    ///  contract to call `escapeHatch()` to send the value in this contract to
    ///  the `escapeHatchDestination`; it would be ideal that `escapeHatchCaller`
    ///  cannot move funds out of `escapeHatchDestination`
    function changeHatchEscapeCaller(address _newEscapeHatchCaller) onlyEscapeHatchCallerOrOwner {
        escapeHatchCaller = _newEscapeHatchCaller;
    }

    event EscapeHatchBlackistedToken(address token);
    event EscapeHatchCalled(address token, uint amount);
}

////////////////////////////////////////////////////////////////////////////////

/// @dev This is designed to control the issuance of a MiniMe Token for a
///  non-profit Campaign. This contract effectively dictates the terms of the
///  funding round.
contract GivethCampaign is TokenController, Owned, Escapable {

    uint public startFundingTime;       // In UNIX Time Format
    uint public endFundingTime;         // In UNIX Time Format
    uint public maximumFunding;         // In wei
    uint public totalCollected;         // In wei
    MiniMeToken public tokenContract;   // The new token for this Campaign
    address public vaultAddress;        // The address to hold the funds donated

    /// @notice 'GivethCampaign()' initiates the Campaign by setting its funding
    ///  parameters; there are several checks to make sure the parameters are 
    ///  acceptable
    /// @param _startFundingTime The UNIX time that the Campaign will be able to
    ///  start receiving funds
    /// @param _endFundingTime The UNIX time that the Campaign will stop being
    ///  able to receive funds
    /// @param _maximumFunding In wei, the Maximum amount that the Campaign can
    ///  receive (currently the max is set at 10,000 ETH for the beta)
    /// @param _vaultAddress The address that will store the donated funds
    /// @param _tokenAddress The token contract address this contract controls
    function GivethCampaign(
        address _escapeHatchCaller,
        address _escapeHatchDestination,        
        uint _startFundingTime,
        uint _endFundingTime,
        uint _maximumFunding,
        address _vaultAddress,
        address _tokenAddress
    ) Escapable(_escapeHatchCaller, _escapeHatchDestination) {
        require(_endFundingTime > now);                // Cannot end in the past
        require(_endFundingTime > _startFundingTime);
        require(_maximumFunding <= 1000000 ether);    // The Beta is limited
        require(_vaultAddress != 0);                // To prevent burning ETH
        startFundingTime = _startFundingTime;
        endFundingTime = _endFundingTime;
        maximumFunding = _maximumFunding;
        tokenContract = MiniMeToken(_tokenAddress);// The deployed Token Contract
        vaultAddress = _vaultAddress;
    }

    /// @notice `finalizeFunding()` ends the Campaign by setting the controller
    ///  to 0, thereby ending the issuance of new tokens and stopping the
    ///  Campaign from receiving more ether; can only be called after the end of
    ///  the funding period.
    function finalizeFunding() {
        require (now >= endFundingTime);
        tokenContract.changeController(0);
    }

    /// @notice `onlyOwner` changes the location that ether is sent
    /// @param _newVaultAddress The address that will receive the ether sent to
    ///  the Campaign
    function setVault(address _newVaultAddress) onlyOwner {
        vaultAddress = _newVaultAddress;
    }

    /// @dev The fallback function is called when ether is sent to the contract,
    ///  it calls `doPayment()` with the address that sent the ether as the
    ///  `_owner`; `payable` is a required solidity modifier for functions to 
    ///  receive ether, without this modifier functions will throw when ether is
    ///  sent to them
    function ()  payable {
        doPayment(msg.sender);
    }

    /// @dev `doPayment()` is an internal function that sends the ether this
    ///  contract receives to the `vault` and creates tokens in the address of
    ///  the `_owner` as long as the Campaign is still accepting funds
    /// @param _owner The address that will hold the newly created tokens
    function doPayment(address _owner) internal {

        // First check that the Campaign is allowed to receive this donation
        require(now>=startFundingTime);
        require(now<=endFundingTime);               // Extra check
        require(tokenContract.controller() != 0);   // Extra check
        require(msg.value != 0);
        require(totalCollected + msg.value <= maximumFunding);

        //Track how much the Campaign has collected
        totalCollected += msg.value;

        //Send the ether to the vault
        require(vaultAddress.send(msg.value));

        // Creates an equal amount of tokens as ether sent; the new tokens are
        //  created in the `_owner` address
        require(tokenContract.generateTokens(_owner, msg.value));

        return;
    }

/////////////////
// TokenController interface
/////////////////

    /// @notice `proxyPayment()` allows the caller to send ether to the Campaign
    ///  and have the tokens created in an address of their choosing
    /// @param _owner The address that will hold the newly created tokens
    function proxyPayment(address _owner) payable returns(bool) {
        doPayment(_owner);
        return true;
    }

    /// @notice Notifies the controller about a transfer, for this Campaign all
    ///  transfers are allowed by default and no extra notifications are needed
    /// @param _from The origin of the transfer
    /// @param _to The destination of the transfer
    /// @param _amount The amount of the transfer
    /// @return False if the controller does not authorize the transfer
    function onTransfer(address _from, address _to, uint _amount) returns(bool) {
        return true;
    }

    /// @notice Notifies the controller about an approval, for this Campaign all
    ///  approvals are allowed by default and no extra notifications are needed
    /// @param _owner The address that calls `approve()`
    /// @param _spender The spender in the `approve()` call
    /// @param _amount The amount in the `approve()` call
    /// @return False if the controller does not authorize the approval
    function onApprove(address _owner, address _spender, uint _amount)
        returns(bool)
    {
        return true;
    }
}