Fix

contracts/SNTGiveaway.sol

@@ -1,8 +1,964 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.4.23;
+
+interface ApproveAndCallFallBack {
+    function receiveApproval(
+        address from,
+        uint256 _amount,
+        address _token,
+        bytes _data
+    ) external;
+}
+
+
+contract Controlled {
+
+    mapping(address => bool) controllers;
+
+    /// @notice The address of the controller is the only address that can call
+    ///  a function with this modifier
+    modifier onlyController { 
+        require(controllers[msg.sender]); 
+        _; 
+    }
+
+    address public controller;
+
+    constructor() internal { 
+        controllers[msg.sender] = true; 
+    }
+
+    function changeControllerAccess(address _controller, bool _access) public onlyController {
+        controllers[_controller] = _access;
+    }
+    
+    function changeController(address _newController) public onlyController {
+        controllers[msg.sender] = false;
+        controllers[_newController] = true;
+    }
+
+}
+
+
+
+
+
+/*
+    Copyright 2016, 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 MiniMeToken Contract
+ * @author Jordi Baylina
+ * @dev This token contract's goal is to make it easy for anyone to clone this
+ *  token using the token distribution at a given block, this will allow DAO's
+ *  and DApps to upgrade their features in a decentralized manner without
+ *  affecting the original token
+ * @dev It is ERC20 compliant, but still needs to under go further testing.
+ */
+
+
+
+/**
+ * @dev The token controller contract must implement these functions
+ */
+interface 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) external 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) external 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) external
+        returns(bool);
+}
+
+
+
+
+
+
+// Abstract contract for the full ERC 20 Token standard
+// https://github.com/ethereum/EIPs/issues/20
+
+interface ERC20Token {
+
+    /**
+     * @notice send `_value` token to `_to` from `msg.sender`
+     * @param _to The address of the recipient
+     * @param _value The amount of token to be transferred
+     * @return Whether the transfer was successful or not
+     */
+    function transfer(address _to, uint256 _value) external returns (bool success);
+
+    /**
+     * @notice `msg.sender` approves `_spender` to spend `_value` tokens
+     * @param _spender The address of the account able to transfer the tokens
+     * @param _value The amount of tokens to be approved for transfer
+     * @return Whether the approval was successful or not
+     */
+    function approve(address _spender, uint256 _value) external returns (bool success);
+
+    /**
+     * @notice send `_value` token to `_to` from `_from` on the condition it is approved by `_from`
+     * @param _from The address of the sender
+     * @param _to The address of the recipient
+     * @param _value The amount of token to be transferred
+     * @return Whether the transfer was successful or not
+     */
+    function transferFrom(address _from, address _to, uint256 _value) external returns (bool success);
+
+    /**
+     * @param _owner The address from which the balance will be retrieved
+     * @return The balance
+     */
+    function balanceOf(address _owner) external view returns (uint256 balance);
+
+    /**
+     * @param _owner The address of the account owning tokens
+     * @param _spender The address of the account able to transfer the tokens
+     * @return Amount of remaining tokens allowed to spent
+     */
+    function allowance(address _owner, address _spender) external view returns (uint256 remaining);
+
+    /**
+     * @notice return total supply of tokens
+     */
+    function totalSupply() external view returns (uint256 supply);
+
+    event Transfer(address indexed _from, address indexed _to, uint256 _value);
+    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
+}
+
+
+contract MiniMeTokenInterface is ERC20Token {
+
+    /**
+     * @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
+    ) 
+        external 
+        returns (bool success);
+
+    /**    
+     * @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);
+
+    /**    
+     * @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
+        returns (bool);
+
+    /**
+     * @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
+    ) 
+        public
+        returns (bool);
+
+    /**        
+     * @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;
+
+    /**    
+     * @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;
+
+    /**
+     * @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);
+
+    /**
+     * @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 view returns(uint);
+
+}
+
+
+
+
+////////////////
+// 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;
+    }
+}
+
+/**
+ * @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 MiniMeTokenInterface, 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_0.1"; //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
+     */
+    constructor(
+        address _tokenFactory,
+        address _parentToken,
+        uint _parentSnapShotBlock,
+        string _tokenName,
+        uint8 _decimalUnits,
+        string _tokenSymbol,
+        bool _transfersEnabled
+    ) 
+        public
+    {
+        require(_tokenFactory != address(0)); //if not set, clone feature will not work properly
+        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
+        uint256 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
+        uint256 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
+        emit Transfer(_from, _to, _amount);
+
+        return true;
+    }
+
+    function doApprove(
+        address _from,
+        address _spender,
+        uint256 _amount
+    )
+        internal 
+        returns (bool)
+    {
+        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[_from][_spender] == 0));
+
+        // Alerts the token controller of the approve function call
+        if (isContract(controller)) {
+            require(TokenController(controller).onApprove(_from, _spender, _amount));
+        }
+
+        allowed[_from][_spender] = _amount;
+        emit Approval(_from, _spender, _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) external view 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) external returns (bool success) {
+        doApprove(msg.sender, _spender, _amount);
+    }
+
+    /**
+     * @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
+    ) 
+        external
+        view
+        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
+    ) 
+        external 
+        returns (bool success)
+    {
+        require(doApprove(msg.sender, _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() external view 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
+        view
+        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 view 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)
+        {
+        uint snapshotBlock = _snapshotBlock;
+        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
+        emit 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 = totalSupplyAt(block.number);
+        require(curTotalSupply + _amount >= curTotalSupply); // Check for overflow
+        uint previousBalanceTo = balanceOfAt(_owner, block.number);
+        require(previousBalanceTo + _amount >= previousBalanceTo); // Check for overflow
+        updateValueAtNow(totalSupplyHistory, curTotalSupply + _amount);
+        updateValueAtNow(balances[_owner], previousBalanceTo + _amount);
+        emit 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
+    ) 
+        public
+        onlyController
+        returns (bool)
+    {
+        uint curTotalSupply = totalSupplyAt(block.number);
+        require(curTotalSupply >= _amount);
+        uint previousBalanceFrom = balanceOfAt(_owner, block.number);
+        require(previousBalanceFrom >= _amount);
+        updateValueAtNow(totalSupplyHistory, curTotalSupply - _amount);
+        updateValueAtNow(balances[_owner], previousBalanceFrom - _amount);
+        emit 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
+    ) 
+        view
+        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) internal view 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) 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(address(this).balance);
+            return;
+        }
+
+        MiniMeToken token = MiniMeToken(_token);
+        uint balance = token.balanceOf(address(this));
+        token.transfer(controller, balance);
+        emit 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
+    );
+
+}
+/**
+ * @title MerkleProof
+ * @dev Merkle proof verification based on
+ * https://github.com/ameensol/merkle-tree-solidity/blob/master/src/MerkleProof.sol
+ */
+library MerkleProof {
+  /**
+   * @dev Verifies a Merkle proof proving the existence of a leaf in a Merkle tree. Assumes that each pair of leaves
+   * and each pair of pre-images are sorted.
+   * @param _proof Merkle proof containing sibling hashes on the branch from the leaf to the root of the Merkle tree
+   * @param _root Merkle root
+   * @param _leaf Leaf of Merkle tree
+   */
+  function verifyProof(
+    bytes32[] _proof,
+    bytes32 _root,
+    bytes32 _leaf
+  )
+    internal
+    pure
+    returns (bool)
+  {
+    bytes32 computedHash = _leaf;
+
+    for (uint256 i = 0; i < _proof.length; i++) {
+      bytes32 proofElement = _proof[i];
+
+      if (computedHash < proofElement) {
+        // Hash(current computed hash + current element of the proof)
+        computedHash = keccak256(abi.encodePacked(computedHash, proofElement));
+      } else {
+        // Hash(current element of the proof + current computed hash)
+        computedHash = keccak256(abi.encodePacked(proofElement, computedHash));
+      }
+    }
+
+    // Check if the computed hash (root) is equal to the provided root
+    return computedHash == _root;
+  }
+}
 
-import "common/Controlled.sol";
-import "token/MiniMeToken.sol";
-import "common/MerkleProof.sol";
 
 contract SNTGiveaway is Controlled {