pragma solidity 0.4.15;

/*    
    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/>.
 */

 
/// @dev `Owned` is a base level contract that assigns an `owner` that can be
///  later changed
contract Owned {

    /// @dev `owner` is the only address that can call a function with this
    /// modifier
    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    address public owner;

    /// @notice The Constructor assigns the message sender to be `owner`
    function Owned() {
        owner = msg.sender;
    }

    address public newOwner;

    /// @notice `owner` can step down and assign some other address to this role
    /// @param _newOwner The address of the new owner. 0x0 can be used to create
    function changeOwner(address _newOwner) onlyOwner {
        if(msg.sender == owner) {
            owner = _newOwner;
        }
    }
}



/**
 * Math operations with safety checks
 */
library SafeMath {
  function mul(uint a, uint b) internal returns (uint) {
    uint c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }

  function div(uint a, uint b) internal returns (uint) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }

  function sub(uint a, uint b) internal returns (uint) {
    assert(b <= a);
    return a - b;
  }

  function add(uint a, uint b) internal returns (uint) {
    uint c = a + b;
    assert(c >= a);
    return c;
  }

  function max64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a >= b ? a : b;
  }

  function min64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a < b ? a : b;
  }

  function max256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a >= b ? a : b;
  }

  function min256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a < b ? a : b;
  }
}






/// @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) 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) 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)
        returns(bool);
}

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() { controller = msg.sender;}

    /// @notice Changes the controller of the contract
    /// @param _newController The new controller of the contract
    function changeController(address _newController) onlyController {
        controller = _newController;
    }
}

contract ApproveAndCallFallBack {
    function receiveApproval(address from, uint256 _amount, address _token, bytes _data);
}

/// @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_0.1'; //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
    function MiniMeToken(
        address _tokenFactory,
        address _parentToken,
        uint _parentSnapShotBlock,
        string _tokenName,
        uint8 _decimalUnits,
        string _tokenSymbol,
        bool _transfersEnabled
    ) {
        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) 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
    ) 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) 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) 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
    ) 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
    ) 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() 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) 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) 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
        ) 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
    ) 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 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) 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) 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 ()  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) 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
    ) returns (MiniMeToken) 
    {
        MiniMeToken newToken = new MiniMeToken(
            this,
            _parentToken,
            _snapshotBlock,
            _tokenName,
            _decimalUnits,
            _tokenSymbol,
            _transfersEnabled
            );

        newToken.changeController(msg.sender);
        return newToken;
    }
}


contract SHP is MiniMeToken {
    // @dev SHP constructor
    function SHP(address _tokenFactory)
            MiniMeToken(
                _tokenFactory,
                0x0,                             // no parent token
                0,                               // no snapshot block number from parent
                "Sharpe Platform Token",         // Token name
                18,                              // Decimals
                "SHP",                           // Symbol
                true                             // Enable transfers
            ) {}
}





/// @title Vesting trustee
contract Trustee is Owned {
    using SafeMath for uint256;

    // The address of the SHP ERC20 token.
    SHP public shp;

    struct Grant {
        uint256 value;
        uint256 start;
        uint256 cliff;
        uint256 end;
        uint256 transferred;
        bool revokable;
    }

    // Grants holder.
    mapping (address => Grant) public grants;

    // Total tokens available for vesting.
    uint256 public totalVesting;

    event NewGrant(address indexed _from, address indexed _to, uint256 _value);
    event UnlockGrant(address indexed _holder, uint256 _value);
    event RevokeGrant(address indexed _holder, uint256 _refund);

    /// @dev Constructor that initializes the address of the SHP contract.
    /// @param _shp SHP The address of the previously deployed SHP smart contract.
    function Trustee(SHP _shp) {
        require(_shp != address(0));
        shp = _shp;
    }

    /// @dev Grant tokens to a specified address.
    /// @param _to address The address to grant tokens to.
    /// @param _value uint256 The amount of tokens to be granted.
    /// @param _start uint256 The beginning of the vesting period.
    /// @param _cliff uint256 Duration of the cliff period.
    /// @param _end uint256 The end of the vesting period.
    /// @param _revokable bool Whether the grant is revokable or not.
    function grant(address _to, uint256 _value, uint256 _start, uint256 _cliff, uint256 _end, bool _revokable)
        public onlyOwner {
        require(_to != address(0));
        require(_value > 0);

        // Make sure that a single address can be granted tokens only once.
        require(grants[_to].value == 0);

        // Check for date inconsistencies that may cause unexpected behavior.
        require(_start <= _cliff && _cliff <= _end);

        // Check that this grant doesn't exceed the total amount of tokens currently available for vesting.
        require(totalVesting.add(_value) <= shp.balanceOf(address(this)));

        // Assign a new grant.
        grants[_to] = Grant({
            value: _value,
            start: _start,
            cliff: _cliff,
            end: _end,
            transferred: 0,
            revokable: _revokable
        });

        // Tokens granted, reduce the total amount available for vesting.
        totalVesting = totalVesting.add(_value);

        NewGrant(msg.sender, _to, _value);
    }

    /// @dev Revoke the grant of tokens of a specifed address.
    /// @param _holder The address which will have its tokens revoked.
    function revoke(address _holder) public onlyOwner {
        Grant grant = grants[_holder];

        require(grant.revokable);

        // Send the remaining SHP back to the owner.
        uint256 refund = grant.value.sub(grant.transferred);

        // Remove the grant.
        delete grants[_holder];

        totalVesting = totalVesting.sub(refund);
        shp.transfer(msg.sender, refund);

        RevokeGrant(_holder, refund);
    }

    /// @dev Calculate the total amount of vested tokens of a holder at a given time.
    /// @param _holder address The address of the holder.
    /// @param _time uint256 The specific time.
    /// @return a uint256 representing a holder's total amount of vested tokens.
    function vestedTokens(address _holder, uint256 _time) public constant returns (uint256) {
        Grant grant = grants[_holder];
        if (grant.value == 0) {
            return 0;
        }

        return calculateVestedTokens(grant, _time);
    }

    /// @dev Calculate amount of vested tokens at a specifc time.
    /// @param _grant Grant The vesting grant.
    /// @param _time uint256 The time to be checked
    /// @return An uint256 representing the amount of vested tokens of a specific grant.
    ///   |                         _/--------   vestedTokens rect
    ///   |                       _/
    ///   |                     _/
    ///   |                   _/
    ///   |                 _/
    ///   |                /
    ///   |              .|
    ///   |            .  |
    ///   |          .    |
    ///   |        .      |
    ///   |      .        |
    ///   |    .          |
    ///   +===+===========+---------+----------> time
    ///     Start       Cliff      End
    function calculateVestedTokens(Grant _grant, uint256 _time) private constant returns (uint256) {
        // If we're before the cliff, then nothing is vested.
        if (_time < _grant.cliff) {
            return 0;
        }

        // If we're after the end of the vesting period - everything is vested;
        if (_time >= _grant.end) {
            return _grant.value;
        }

        // Interpolate all vested tokens: vestedTokens = tokens/// (time - start) / (end - start)
         return _grant.value.mul(_time.sub(_grant.start)).div(_grant.end.sub(_grant.start));
    }

    /// @dev Unlock vested tokens and transfer them to their holder.
    /// @return a uint256 representing the amount of vested tokens transferred to their holder.
    function unlockVestedTokens() public {
        Grant grant = grants[msg.sender];
        require(grant.value != 0);

        // Get the total amount of vested tokens, acccording to grant.
        uint256 vested = calculateVestedTokens(grant, now);
        if (vested == 0) {
            return;
        }

        // Make sure the holder doesn't transfer more than what he already has.
        uint256 transferable = vested.sub(grant.transferred);
        if (transferable == 0) {
            return;
        }

        grant.transferred = grant.transferred.add(transferable);
        totalVesting = totalVesting.sub(transferable);
        shp.transfer(msg.sender, transferable);

        UnlockGrant(msg.sender, transferable);
    }
}


contract TokenSale is Owned, TokenController {
    using SafeMath for uint256;
    
    SHP public shp;
    Trustee public trustee;

    address public etherEscrowAddress;
    address public bountyAddress;
    address public trusteeAddress;

    uint256 public founderTokenCount = 0;
    uint256 public reserveTokenCount = 0;
    uint256 public shpExchangeRate = 0;

    uint256 constant public CALLER_EXCHANGE_SHARE = 40;
    uint256 constant public RESERVE_EXCHANGE_SHARE = 30;
    uint256 constant public FOUNDER_EXCHANGE_SHARE = 20;
    uint256 constant public BOUNTY_EXCHANGE_SHARE = 10;
    uint256 constant public MAX_GAS_PRICE = 5000000000000;

    bool public paused;
    bool public closed;
    bool public allowTransfer;

    mapping(address => bool) public approvedAddresses;

    event Contribution(uint256 etherAmount, address _caller);
    event NewSale(address indexed caller, uint256 etherAmount, uint256 tokensGenerated);
    event SaleClosed(uint256 when);
    
    modifier notPaused() {
        require(!paused);
        _;
    }

    modifier notClosed() {
        require(!closed);
        _;
    }

    modifier isValidated() {
        require(msg.sender != 0x0);
        require(msg.value > 0);
        require(!isContract(msg.sender)); 
        require(tx.gasprice <= MAX_GAS_PRICE);
        _;
    }

    function setShpExchangeRate(uint256 _shpExchangeRate) public onlyOwner {
        shpExchangeRate = _shpExchangeRate;
    }

    function setAllowTransfer(bool _allowTransfer) public onlyOwner {
        allowTransfer = _allowTransfer;
    }

    /// @notice This method sends the Ether received to the Ether escrow address
    /// and generates the calculated number of SHP tokens, sending them to the caller's address.
    /// It also generates the founder's tokens and the reserve tokens at the same time.
    function doBuy(
        address _caller,
        uint256 etherAmount
    )
        internal
    {

        Contribution(etherAmount, _caller);

        uint256 callerExchangeRate = shpExchangeRate.mul(CALLER_EXCHANGE_SHARE).div(100);
        uint256 reserveExchangeRate = shpExchangeRate.mul(RESERVE_EXCHANGE_SHARE).div(100);
        uint256 founderExchangeRate = shpExchangeRate.mul(FOUNDER_EXCHANGE_SHARE).div(100);
        uint256 bountyExchangeRate = shpExchangeRate.mul(BOUNTY_EXCHANGE_SHARE).div(100);

        uint256 callerTokens = etherAmount.mul(callerExchangeRate);
        uint256 callerTokensWithDiscount = applyDiscount(etherAmount, callerTokens);

        uint256 reserveTokens = etherAmount.mul(reserveExchangeRate);
        uint256 founderTokens = etherAmount.mul(founderExchangeRate);
        uint256 bountyTokens = etherAmount.mul(bountyExchangeRate);
        uint256 vestingTokens = founderTokens.add(reserveTokens);

        founderTokenCount = founderTokenCount.add(founderTokens);
        reserveTokenCount = reserveTokenCount.add(reserveTokens);

        shp.generateTokens(_caller, callerTokensWithDiscount);
        shp.generateTokens(bountyAddress, bountyTokens);
        shp.generateTokens(trusteeAddress, vestingTokens);

        NewSale(_caller, etherAmount, callerTokensWithDiscount);
        NewSale(trusteeAddress, etherAmount, vestingTokens);
        NewSale(bountyAddress, etherAmount, bountyTokens);

        etherEscrowAddress.transfer(etherAmount);
        updateCounters(etherAmount);
    }

    /// @notice Allows the owner to manually mint some SHP to an address if something goes wrong
    /// @param _tokens the number of tokens to mint
    /// @param _destination the address to send the tokens to
    function mintTokens(
        uint256 _tokens, 
        address _destination
    ) 
        onlyOwner 
    {
        shp.generateTokens(_destination, _tokens);
        NewSale(_destination, 0, _tokens);
    }

    /// @notice Allows the owner to manually destroy some SHP to an address if something goes wrong
    /// @param _tokens the number of tokens to mint
    /// @param _destination the address to send the tokens to
    function destroyTokens(
        uint256 _tokens, 
        address _destination
    ) 
        onlyOwner 
    {
        shp.destroyTokens(_destination, _tokens);
    }

    /// @notice Applies the discount based on the discount tiers
    /// @param _etherAmount The amount of ether used to evaluate the tier the contribution lies within
    /// @param _contributorTokens The tokens allocated based on the contribution
    function applyDiscount(uint256 _etherAmount, uint256 _contributorTokens) internal constant returns (uint256);

    /// @notice Updates the counters for the amount of Ether paid
    /// @param _etherAmount the amount of Ether paid
    function updateCounters(uint256 _etherAmount) internal;
    
    /// @notice Parent constructor. This needs to be extended from the child contracts
    /// @param _etherEscrowAddress the address that will hold the crowd funded Ether
    /// @param _bountyAddress the address that will hold the bounty scheme SHP
    /// @param _trusteeAddress the address that will hold the vesting SHP
    /// @param _shpExchangeRate the initial SHP exchange rate
    function TokenSale (
        address _etherEscrowAddress,
        address _bountyAddress,
        address _trusteeAddress,
        uint256 _shpExchangeRate
    ) {
        etherEscrowAddress = _etherEscrowAddress;
        bountyAddress = _bountyAddress;
        trusteeAddress = _trusteeAddress;
        shpExchangeRate = _shpExchangeRate;
        trustee = Trustee(_trusteeAddress);
        paused = true;
        closed = false;
        allowTransfer = false;
    }

    /// @notice Sets the SHP token smart contract
    /// @param _shp the SHP token contract address
    function setShp(address _shp) public onlyOwner {
        shp = SHP(_shp);
    }

    /// @notice Transfers ownership of the token smart contract and trustee
    /// @param _tokenController the address of the new token controller
    /// @param _trusteeOwner the address of the new trustee owner
    function transferOwnership(address _tokenController, address _trusteeOwner) public onlyOwner {
        require(closed);
        require(_tokenController != 0x0);
        require(_trusteeOwner != 0x0);
        shp.changeController(_tokenController);
        trustee.changeOwner(_trusteeOwner);
    }

    /// @notice Internal function to determine if an address is a contract
    /// @param _caller The address being queried
    /// @return True if `caller` is a contract
    function isContract(address _caller) internal constant returns (bool) {
        uint size;
        assembly { size := extcodesize(_caller) }
        return size > 0;
    }

    /// @notice Pauses the contribution if there is any issue
    function pauseContribution() public onlyOwner {
        paused = true;
    }

    /// @notice Resumes the contribution
    function resumeContribution() public onlyOwner {
        paused = false;
    }

    //////////
    // MiniMe Controller Interface functions
    //////////

    // In between the offering and the network. Default settings for allowing token transfers.
    function proxyPayment(address) public payable returns (bool) {
        return allowTransfer;
    }

    function onTransfer(address, address, uint256) public returns (bool) {
        return allowTransfer;
    }

    function onApprove(address, address, uint256) public returns (bool) {
        return allowTransfer;
    }
}

contract SharpeCrowdsale is TokenSale {
    using SafeMath for uint256;
 
    uint256 public etherPaid = 0;
    uint256 public totalContributions = 0;

    uint256 constant public FIRST_TIER_DISCOUNT = 5;
    uint256 constant public SECOND_TIER_DISCOUNT = 10;
    uint256 constant public THIRD_TIER_DISCOUNT = 20;
    uint256 constant public FOURTH_TIER_DISCOUNT = 30;

    uint256 public minPresaleContributionEther;
    uint256 public maxPresaleContributionEther;
    uint256 public minDiscountEther;
    uint256 public firstTierDiscountUpperLimitEther;
    uint256 public secondTierDiscountUpperLimitEther;
    uint256 public thirdTierDiscountUpperLimitEther;
    
    enum ContributionState {Paused, Resumed}
    event ContributionStateChanged(address caller, ContributionState contributionState);
    enum AllowedContributionState {Whitelisted, NotWhitelisted, AboveWhitelisted, BelowWhitelisted, WhitelistClosed}
    event AllowedContributionCheck(uint256 contribution, AllowedContributionState allowedContributionState);
    event ValidContributionCheck(uint256 contribution, bool isContributionValid);
    event DiscountApplied(uint256 etherAmount, uint256 tokens, uint256 discount);
    event ContributionRefund(uint256 etherAmount, address _caller);
    event CountersUpdated(uint256 preSaleEtherPaid, uint256 totalContributions);
    event WhitelistedUpdated(uint256 plannedContribution, bool contributed);
    event WhitelistedCounterUpdated(uint256 whitelistedPlannedContributions, uint256 usedContributions);

    modifier isValidContribution() {
        require(validContribution());
        _;
    }

    /// @notice called only once when the contract is initialized
    /// @param _etherEscrowAddress the address that will hold the crowd funded Ether
    /// @param _bountyAddress the address that will hold the bounty SHP
    /// @param _trusteeAddress the address that will hold the vesting SHP
    /// @param _minDiscountEther Lower discount limit (WEI)
    /// @param _firstTierDiscountUpperLimitEther First discount limits (WEI)
    /// @param _secondTierDiscountUpperLimitEther Second discount limits (WEI)
    /// @param _thirdTierDiscountUpperLimitEther Third discount limits (WEI)
    /// @param _minPresaleContributionEther Lower contribution range (WEI)
    /// @param _maxPresaleContributionEther Upper contribution range (WEI)
    /// @param _shpExchangeRate The initial SHP exchange rate
    function SharpeCrowdsale(
        address _etherEscrowAddress,
        address _bountyAddress,
        address _trusteeAddress,
        uint256 _minDiscountEther,
        uint256 _firstTierDiscountUpperLimitEther,
        uint256 _secondTierDiscountUpperLimitEther,
        uint256 _thirdTierDiscountUpperLimitEther,
        uint256 _minPresaleContributionEther,
        uint256 _maxPresaleContributionEther,
        uint256 _shpExchangeRate)
        TokenSale (
            _etherEscrowAddress,
            _bountyAddress,
            _trusteeAddress,
            _shpExchangeRate
        )
    {
        minDiscountEther = _minDiscountEther;
        firstTierDiscountUpperLimitEther = _firstTierDiscountUpperLimitEther;
        secondTierDiscountUpperLimitEther = _secondTierDiscountUpperLimitEther;
        thirdTierDiscountUpperLimitEther = _thirdTierDiscountUpperLimitEther;
        minPresaleContributionEther = _minPresaleContributionEther;
        maxPresaleContributionEther = _maxPresaleContributionEther;
    }

    /// @notice Allows the owner to peg Ether values
    /// @param _minDiscountEther Lower discount limit (WEI)
    /// @param _firstTierDiscountUpperLimitEther First discount limits (WEI)
    /// @param _secondTierDiscountUpperLimitEther Second discount limits (WEI)
    /// @param _thirdTierDiscountUpperLimitEther Third discount limits (WEI)
    /// @param _minPresaleContributionEther Lower contribution range (WEI)
    /// @param _maxPresaleContributionEther Upper contribution range (WEI)
    function pegEtherValues(
        uint256 _minDiscountEther,
        uint256 _firstTierDiscountUpperLimitEther,
        uint256 _secondTierDiscountUpperLimitEther,
        uint256 _thirdTierDiscountUpperLimitEther,
        uint256 _minPresaleContributionEther,
        uint256 _maxPresaleContributionEther
    ) 
        onlyOwner
    {
        minDiscountEther = _minDiscountEther;
        firstTierDiscountUpperLimitEther = _firstTierDiscountUpperLimitEther;
        secondTierDiscountUpperLimitEther = _secondTierDiscountUpperLimitEther;
        thirdTierDiscountUpperLimitEther = _thirdTierDiscountUpperLimitEther;
        minPresaleContributionEther = _minPresaleContributionEther;
        maxPresaleContributionEther = _maxPresaleContributionEther;
    }

    /// @notice This function fires when someone sends Ether to the address of this contract.
    /// The ETH will be exchanged for SHP and it ensures contributions cannot be made from known addresses.
    function ()
        public
        payable
        isValidated
        notClosed
        notPaused
    {
        require(msg.value > 0);
        doBuy(msg.sender, msg.value);
    }

    /// @notice Public function enables closing of the pre-sale manually if necessary
    function closeSale() public onlyOwner {
        closed = true;
        SaleClosed(now);
    }

    /// @notice Ensure the contribution is valid
    /// @return Returns whether the contribution is valid or not
    function validContribution() private returns (bool) {
        bool isContributionValid = msg.value >= minPresaleContributionEther && msg.value <= maxPresaleContributionEther;
        ValidContributionCheck(msg.value, isContributionValid);
        return isContributionValid;
    }

    /// @notice Applies the discount based on the discount tiers
    /// @param _etherAmount The amount of ether used to evaluate the tier the contribution lies within
    /// @param _contributorTokens The tokens allocated based on the contribution
    function applyDiscount(
        uint256 _etherAmount, 
        uint256 _contributorTokens
    )
        internal
        constant
        returns (uint256)
    {

        uint256 discount = 0;

        if (_etherAmount > minDiscountEther && _etherAmount <= firstTierDiscountUpperLimitEther) {
            discount = _contributorTokens.mul(FIRST_TIER_DISCOUNT).div(100); // 5%
        } else if (_etherAmount > firstTierDiscountUpperLimitEther && _etherAmount <= secondTierDiscountUpperLimitEther) {
            discount = _contributorTokens.mul(SECOND_TIER_DISCOUNT).div(100); // 10%
        } else if (_etherAmount > secondTierDiscountUpperLimitEther && _etherAmount <= thirdTierDiscountUpperLimitEther) {
            discount = _contributorTokens.mul(THIRD_TIER_DISCOUNT).div(100); // 20%
        } else if (_etherAmount > thirdTierDiscountUpperLimitEther) {
            discount = _contributorTokens.mul(FOURTH_TIER_DISCOUNT).div(100); // 30%
        }

        DiscountApplied(_etherAmount, _contributorTokens, discount);
        return discount.add(_contributorTokens);
    }

    /// @notice Updates the counters for the amount of Ether paid
    /// @param _etherAmount the amount of Ether paid
    function updateCounters(uint256 _etherAmount) internal {
        etherPaid = etherPaid.add(_etherAmount);
        totalContributions = totalContributions.add(1);
        CountersUpdated(etherPaid, _etherAmount);
    }
}

pragma solidity 0.4.15;


/// @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) 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) 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)
        returns(bool);
}

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() { controller = msg.sender;}

    /// @notice Changes the controller of the contract
    /// @param _newController The new controller of the contract
    function changeController(address _newController) onlyController {
        controller = _newController;
    }
}

contract ApproveAndCallFallBack {
    function receiveApproval(address from, uint256 _amount, address _token, bytes _data);
}

/// @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_0.1'; //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
    function MiniMeToken(
        address _tokenFactory,
        address _parentToken,
        uint _parentSnapShotBlock,
        string _tokenName,
        uint8 _decimalUnits,
        string _tokenSymbol,
        bool _transfersEnabled
    ) {
        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) 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
    ) 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) 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) 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
    ) 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
    ) 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() 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) 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) 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
        ) 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
    ) 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 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) 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) 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 ()  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) 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
    ) returns (MiniMeToken) 
    {
        MiniMeToken newToken = new MiniMeToken(
            this,
            _parentToken,
            _snapshotBlock,
            _tokenName,
            _decimalUnits,
            _tokenSymbol,
            _transfersEnabled
            );

        newToken.changeController(msg.sender);
        return newToken;
    }
}

contract SHP is MiniMeToken {
    // @dev SHP constructor
    function SHP(address _tokenFactory)
            MiniMeToken(
                _tokenFactory,
                0x0,                             // no parent token
                0,                               // no snapshot block number from parent
                "Sharpe Platform Token",         // Token name
                18,                              // Decimals
                "SHP",                           // Symbol
                true                             // Enable transfers
            ) {}
}

pragma solidity 0.4.15;


/// @title Multisignature wallet - Allows multiple parties to agree on transactions before execution.
/// @author Stefan George - <stefan.george@consensys.net>
contract MultiSigWallet {

    /*
     *  Events
     */
    event Confirmation(address indexed sender, uint indexed transactionId);
    event Revocation(address indexed sender, uint indexed transactionId);
    event Submission(uint indexed transactionId);
    event Execution(uint indexed transactionId);
    event ExecutionFailure(uint indexed transactionId);
    event Deposit(address indexed sender, uint value);
    event OwnerAddition(address indexed owner);
    event OwnerRemoval(address indexed owner);
    event RequirementChange(uint required);

    /*
     *  Constants
     */
    uint constant public MAX_OWNER_COUNT = 50;

    /*
     *  Storage
     */
    mapping (uint => Transaction) public transactions;
    mapping (uint => mapping (address => bool)) public confirmations;
    mapping (address => bool) public isOwner;
    address[] public owners;
    uint public required;
    uint public transactionCount;

    struct Transaction {
        address destination;
        uint value;
        bytes data;
        bool executed;
    }

    /*
     *  Modifiers
     */
    modifier onlyWallet() {
        if (msg.sender != address(this))
            throw;
        _;
    }

    modifier ownerDoesNotExist(address owner) {
        if (isOwner[owner])
            throw;
        _;
    }

    modifier ownerExists(address owner) {
        if (!isOwner[owner])
            throw;
        _;
    }

    modifier transactionExists(uint transactionId) {
        if (transactions[transactionId].destination == 0)
            throw;
        _;
    }

    modifier confirmed(uint transactionId, address owner) {
        if (!confirmations[transactionId][owner])
            throw;
        _;
    }

    modifier notConfirmed(uint transactionId, address owner) {
        if (confirmations[transactionId][owner])
            throw;
        _;
    }

    modifier notExecuted(uint transactionId) {
        if (transactions[transactionId].executed)
            throw;
        _;
    }

    modifier notNull(address _address) {
        if (_address == 0)
            throw;
        _;
    }

    modifier validRequirement(uint ownerCount, uint _required) {
        if (   ownerCount > MAX_OWNER_COUNT
            || _required > ownerCount
            || _required == 0
            || ownerCount == 0)
            throw;
        _;
    }

    /// @dev Fallback function allows to deposit ether.
    function()
        payable
    {
        if (msg.value > 0)
            Deposit(msg.sender, msg.value);
    }

    /*
     * Public functions
     */
    /// @dev Contract constructor sets initial owners and required number of confirmations.
    /// @param _owners List of initial owners.
    /// @param _required Number of required confirmations.
    function MultiSigWallet(address[] _owners, uint _required)
        public
        validRequirement(_owners.length, _required)
    {
        for (uint i=0; i<_owners.length; i++) {
            if (isOwner[_owners[i]] || _owners[i] == 0)
                throw;
            isOwner[_owners[i]] = true;
        }
        owners = _owners;
        required = _required;
    }

    /// @dev Allows to add a new owner. Transaction has to be sent by wallet.
    /// @param owner Address of new owner.
    function addOwner(address owner)
        public
        onlyWallet
        ownerDoesNotExist(owner)
        notNull(owner)
        validRequirement(owners.length + 1, required)
    {
        isOwner[owner] = true;
        owners.push(owner);
        OwnerAddition(owner);
    }

    /// @dev Allows to remove an owner. Transaction has to be sent by wallet.
    /// @param owner Address of owner.
    function removeOwner(address owner)
        public
        onlyWallet
        ownerExists(owner)
    {
        isOwner[owner] = false;
        for (uint i=0; i<owners.length - 1; i++)
            if (owners[i] == owner) {
                owners[i] = owners[owners.length - 1];
                break;
            }
        owners.length -= 1;
        if (required > owners.length)
            changeRequirement(owners.length);
        OwnerRemoval(owner);
    }

    /// @dev Allows to replace an owner with a new owner. Transaction has to be sent by wallet.
    /// @param owner Address of owner to be replaced.
    /// @param newOwner Address of new owner.
    function replaceOwner(address owner, address newOwner)
        public
        onlyWallet
        ownerExists(owner)
        ownerDoesNotExist(newOwner)
    {
        for (uint i=0; i<owners.length; i++)
            if (owners[i] == owner) {
                owners[i] = newOwner;
                break;
            }
        isOwner[owner] = false;
        isOwner[newOwner] = true;
        OwnerRemoval(owner);
        OwnerAddition(newOwner);
    }

    /// @dev Allows to change the number of required confirmations. Transaction has to be sent by wallet.
    /// @param _required Number of required confirmations.
    function changeRequirement(uint _required)
        public
        onlyWallet
        validRequirement(owners.length, _required)
    {
        required = _required;
        RequirementChange(_required);
    }

    /// @dev Allows an owner to submit and confirm a transaction.
    /// @param destination Transaction target address.
    /// @param value Transaction ether value.
    /// @param data Transaction data payload.
    /// @return Returns transaction ID.
    function submitTransaction(address destination, uint value, bytes data)
        public
        returns (uint transactionId)
    {
        transactionId = addTransaction(destination, value, data);
        confirmTransaction(transactionId);
    }

    /// @dev Allows an owner to confirm a transaction.
    /// @param transactionId Transaction ID.
    function confirmTransaction(uint transactionId)
        public
        ownerExists(msg.sender)
        transactionExists(transactionId)
        notConfirmed(transactionId, msg.sender)
    {
        confirmations[transactionId][msg.sender] = true;
        Confirmation(msg.sender, transactionId);
        executeTransaction(transactionId);
    }

    /// @dev Allows an owner to revoke a confirmation for a transaction.
    /// @param transactionId Transaction ID.
    function revokeConfirmation(uint transactionId)
        public
        ownerExists(msg.sender)
        confirmed(transactionId, msg.sender)
        notExecuted(transactionId)
    {
        confirmations[transactionId][msg.sender] = false;
        Revocation(msg.sender, transactionId);
    }

    /// @dev Allows anyone to execute a confirmed transaction.
    /// @param transactionId Transaction ID.
    function executeTransaction(uint transactionId)
        public
        ownerExists(msg.sender)
        confirmed(transactionId, msg.sender)
        notExecuted(transactionId)
    {
        if (isConfirmed(transactionId)) {
            Transaction tx = transactions[transactionId];
            tx.executed = true;
            if (tx.destination.call.value(tx.value)(tx.data))
                Execution(transactionId);
            else {
                ExecutionFailure(transactionId);
                tx.executed = false;
            }
        }
    }

    /// @dev Returns the confirmation status of a transaction.
    /// @param transactionId Transaction ID.
    /// @return Confirmation status.
    function isConfirmed(uint transactionId)
        public
        constant
        returns (bool)
    {
        uint count = 0;
        for (uint i=0; i<owners.length; i++) {
            if (confirmations[transactionId][owners[i]])
                count += 1;
            if (count == required)
                return true;
        }
    }

    /*
     * Internal functions
     */
    /// @dev Adds a new transaction to the transaction mapping, if transaction does not exist yet.
    /// @param destination Transaction target address.
    /// @param value Transaction ether value.
    /// @param data Transaction data payload.
    /// @return Returns transaction ID.
    function addTransaction(address destination, uint value, bytes data)
        internal
        notNull(destination)
        returns (uint transactionId)
    {
        transactionId = transactionCount;
        transactions[transactionId] = Transaction({
            destination: destination,
            value: value,
            data: data,
            executed: false
        });
        transactionCount += 1;
        Submission(transactionId);
    }

    /*
     * Web3 call functions
     */
    /// @dev Returns number of confirmations of a transaction.
    /// @param transactionId Transaction ID.
    /// @return Number of confirmations.
    function getConfirmationCount(uint transactionId)
        public
        constant
        returns (uint count)
    {
        for (uint i=0; i<owners.length; i++)
            if (confirmations[transactionId][owners[i]])
                count += 1;
    }

    /// @dev Returns total number of transactions after filers are applied.
    /// @param pending Include pending transactions.
    /// @param executed Include executed transactions.
    /// @return Total number of transactions after filters are applied.
    function getTransactionCount(bool pending, bool executed)
        public
        constant
        returns (uint count)
    {
        for (uint i=0; i<transactionCount; i++)
            if (   pending && !transactions[i].executed
                || executed && transactions[i].executed)
                count += 1;
    }

    /// @dev Returns list of owners.
    /// @return List of owner addresses.
    function getOwners()
        public
        constant
        returns (address[])
    {
        return owners;
    }

    /// @dev Returns array with owner addresses, which confirmed transaction.
    /// @param transactionId Transaction ID.
    /// @return Returns array of owner addresses.
    function getConfirmations(uint transactionId)
        public
        constant
        returns (address[] _confirmations)
    {
        address[] memory confirmationsTemp = new address[](owners.length);
        uint count = 0;
        uint i;
        for (i=0; i<owners.length; i++)
            if (confirmations[transactionId][owners[i]]) {
                confirmationsTemp[count] = owners[i];
                count += 1;
            }
        _confirmations = new address[](count);
        for (i=0; i<count; i++)
            _confirmations[i] = confirmationsTemp[i];
    }

    /// @dev Returns list of transaction IDs in defined range.
    /// @param from Index start position of transaction array.
    /// @param to Index end position of transaction array.
    /// @param pending Include pending transactions.
    /// @param executed Include executed transactions.
    /// @return Returns array of transaction IDs.
    function getTransactionIds(uint from, uint to, bool pending, bool executed)
        public
        constant
        returns (uint[] _transactionIds)
    {
        uint[] memory transactionIdsTemp = new uint[](transactionCount);
        uint count = 0;
        uint i;
        for (i=0; i<transactionCount; i++)
            if (   pending && !transactions[i].executed
                || executed && transactions[i].executed)
            {
                transactionIdsTemp[count] = i;
                count += 1;
            }
        _transactionIds = new uint[](to - from);
        for (i=from; i<to; i++)
            _transactionIds[i - from] = transactionIdsTemp[i];
    }
}

pragma solidity 0.4.15;

/**
 * Math operations with safety checks
 */
library SafeMath {
  function mul(uint a, uint b) internal returns (uint) {
    uint c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }

  function div(uint a, uint b) internal returns (uint) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }

  function sub(uint a, uint b) internal returns (uint) {
    assert(b <= a);
    return a - b;
  }

  function add(uint a, uint b) internal returns (uint) {
    uint c = a + b;
    assert(c >= a);
    return c;
  }

  function max64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a >= b ? a : b;
  }

  function min64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a < b ? a : b;
  }

  function max256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a >= b ? a : b;
  }

  function min256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a < b ? a : b;
  }
}


/// @dev `Owned` is a base level contract that assigns an `owner` that can be
///  later changed
contract Owned {

    /// @dev `owner` is the only address that can call a function with this
    /// modifier
    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    address public owner;

    /// @notice The Constructor assigns the message sender to be `owner`
    function Owned() {
        owner = msg.sender;
    }

    address public newOwner;

    /// @notice `owner` can step down and assign some other address to this role
    /// @param _newOwner The address of the new owner. 0x0 can be used to create
    function changeOwner(address _newOwner) onlyOwner {
        if(msg.sender == owner) {
            owner = _newOwner;
        }
    }
}

/*
    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
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) 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) 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)
        returns(bool);
}

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() { controller = msg.sender;}

    /// @notice Changes the controller of the contract
    /// @param _newController The new controller of the contract
    function changeController(address _newController) onlyController {
        controller = _newController;
    }
}

contract ApproveAndCallFallBack {
    function receiveApproval(address from, uint256 _amount, address _token, bytes _data);
}

/// @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_0.1'; //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
    function MiniMeToken(
        address _tokenFactory,
        address _parentToken,
        uint _parentSnapShotBlock,
        string _tokenName,
        uint8 _decimalUnits,
        string _tokenSymbol,
        bool _transfersEnabled
    ) {
        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) 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
    ) 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) 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) 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
    ) 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
    ) 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() 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) 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) 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
        ) 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
    ) 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 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) 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) 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 ()  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) 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
    ) returns (MiniMeToken) 
    {
        MiniMeToken newToken = new MiniMeToken(
            this,
            _parentToken,
            _snapshotBlock,
            _tokenName,
            _decimalUnits,
            _tokenSymbol,
            _transfersEnabled
            );

        newToken.changeController(msg.sender);
        return newToken;
    }
}

contract SHP is MiniMeToken {
    // @dev SHP constructor
    function SHP(address _tokenFactory)
            MiniMeToken(
                _tokenFactory,
                0x0,                             // no parent token
                0,                               // no snapshot block number from parent
                "Sharpe Platform Token",         // Token name
                18,                              // Decimals
                "SHP",                           // Symbol
                true                             // Enable transfers
            ) {}
}

/// @title Vesting trustee
contract Trustee is Owned {
    using SafeMath for uint256;

    // The address of the SHP ERC20 token.
    SHP public shp;

    struct Grant {
        uint256 value;
        uint256 start;
        uint256 cliff;
        uint256 end;
        uint256 transferred;
        bool revokable;
    }

    // Grants holder.
    mapping (address => Grant) public grants;

    // Total tokens available for vesting.
    uint256 public totalVesting;

    event NewGrant(address indexed _from, address indexed _to, uint256 _value);
    event UnlockGrant(address indexed _holder, uint256 _value);
    event RevokeGrant(address indexed _holder, uint256 _refund);

    /// @dev Constructor that initializes the address of the SHP contract.
    /// @param _shp SHP The address of the previously deployed SHP smart contract.
    function Trustee(SHP _shp) {
        require(_shp != address(0));
        shp = _shp;
    }

    /// @dev Grant tokens to a specified address.
    /// @param _to address The address to grant tokens to.
    /// @param _value uint256 The amount of tokens to be granted.
    /// @param _start uint256 The beginning of the vesting period.
    /// @param _cliff uint256 Duration of the cliff period.
    /// @param _end uint256 The end of the vesting period.
    /// @param _revokable bool Whether the grant is revokable or not.
    function grant(address _to, uint256 _value, uint256 _start, uint256 _cliff, uint256 _end, bool _revokable)
        public onlyOwner {
        require(_to != address(0));
        require(_value > 0);

        // Make sure that a single address can be granted tokens only once.
        require(grants[_to].value == 0);

        // Check for date inconsistencies that may cause unexpected behavior.
        require(_start <= _cliff && _cliff <= _end);

        // Check that this grant doesn't exceed the total amount of tokens currently available for vesting.
        require(totalVesting.add(_value) <= shp.balanceOf(address(this)));

        // Assign a new grant.
        grants[_to] = Grant({
            value: _value,
            start: _start,
            cliff: _cliff,
            end: _end,
            transferred: 0,
            revokable: _revokable
        });

        // Tokens granted, reduce the total amount available for vesting.
        totalVesting = totalVesting.add(_value);

        NewGrant(msg.sender, _to, _value);
    }

    /// @dev Revoke the grant of tokens of a specifed address.
    /// @param _holder The address which will have its tokens revoked.
    function revoke(address _holder) public onlyOwner {
        Grant grant = grants[_holder];

        require(grant.revokable);

        // Send the remaining SHP back to the owner.
        uint256 refund = grant.value.sub(grant.transferred);

        // Remove the grant.
        delete grants[_holder];

        totalVesting = totalVesting.sub(refund);
        shp.transfer(msg.sender, refund);

        RevokeGrant(_holder, refund);
    }

    /// @dev Calculate the total amount of vested tokens of a holder at a given time.
    /// @param _holder address The address of the holder.
    /// @param _time uint256 The specific time.
    /// @return a uint256 representing a holder's total amount of vested tokens.
    function vestedTokens(address _holder, uint256 _time) public constant returns (uint256) {
        Grant grant = grants[_holder];
        if (grant.value == 0) {
            return 0;
        }

        return calculateVestedTokens(grant, _time);
    }

    /// @dev Calculate amount of vested tokens at a specifc time.
    /// @param _grant Grant The vesting grant.
    /// @param _time uint256 The time to be checked
    /// @return An uint256 representing the amount of vested tokens of a specific grant.
    ///   |                         _/--------   vestedTokens rect
    ///   |                       _/
    ///   |                     _/
    ///   |                   _/
    ///   |                 _/
    ///   |                /
    ///   |              .|
    ///   |            .  |
    ///   |          .    |
    ///   |        .      |
    ///   |      .        |
    ///   |    .          |
    ///   +===+===========+---------+----------> time
    ///     Start       Cliff      End
    function calculateVestedTokens(Grant _grant, uint256 _time) private constant returns (uint256) {
        // If we're before the cliff, then nothing is vested.
        if (_time < _grant.cliff) {
            return 0;
        }

        // If we're after the end of the vesting period - everything is vested;
        if (_time >= _grant.end) {
            return _grant.value;
        }

        // Interpolate all vested tokens: vestedTokens = tokens/// (time - start) / (end - start)
         return _grant.value.mul(_time.sub(_grant.start)).div(_grant.end.sub(_grant.start));
    }

    /// @dev Unlock vested tokens and transfer them to their holder.
    /// @return a uint256 representing the amount of vested tokens transferred to their holder.
    function unlockVestedTokens() public {
        Grant grant = grants[msg.sender];
        require(grant.value != 0);

        // Get the total amount of vested tokens, acccording to grant.
        uint256 vested = calculateVestedTokens(grant, now);
        if (vested == 0) {
            return;
        }

        // Make sure the holder doesn't transfer more than what he already has.
        uint256 transferable = vested.sub(grant.transferred);
        if (transferable == 0) {
            return;
        }

        grant.transferred = grant.transferred.add(transferable);
        totalVesting = totalVesting.sub(transferable);
        shp.transfer(msg.sender, transferable);

        UnlockGrant(msg.sender, transferable);
    }
}

pragma solidity 0.4.15;


/// @title Multisignature wallet - Allows multiple parties to agree on transactions before execution.
/// @author Stefan George - <stefan.george@consensys.net>
contract MultiSigWallet {

    /*
     *  Events
     */
    event Confirmation(address indexed sender, uint indexed transactionId);
    event Revocation(address indexed sender, uint indexed transactionId);
    event Submission(uint indexed transactionId);
    event Execution(uint indexed transactionId);
    event ExecutionFailure(uint indexed transactionId);
    event Deposit(address indexed sender, uint value);
    event OwnerAddition(address indexed owner);
    event OwnerRemoval(address indexed owner);
    event RequirementChange(uint required);

    /*
     *  Constants
     */
    uint constant public MAX_OWNER_COUNT = 50;

    /*
     *  Storage
     */
    mapping (uint => Transaction) public transactions;
    mapping (uint => mapping (address => bool)) public confirmations;
    mapping (address => bool) public isOwner;
    address[] public owners;
    uint public required;
    uint public transactionCount;

    struct Transaction {
        address destination;
        uint value;
        bytes data;
        bool executed;
    }

    /*
     *  Modifiers
     */
    modifier onlyWallet() {
        if (msg.sender != address(this))
            throw;
        _;
    }

    modifier ownerDoesNotExist(address owner) {
        if (isOwner[owner])
            throw;
        _;
    }

    modifier ownerExists(address owner) {
        if (!isOwner[owner])
            throw;
        _;
    }

    modifier transactionExists(uint transactionId) {
        if (transactions[transactionId].destination == 0)
            throw;
        _;
    }

    modifier confirmed(uint transactionId, address owner) {
        if (!confirmations[transactionId][owner])
            throw;
        _;
    }

    modifier notConfirmed(uint transactionId, address owner) {
        if (confirmations[transactionId][owner])
            throw;
        _;
    }

    modifier notExecuted(uint transactionId) {
        if (transactions[transactionId].executed)
            throw;
        _;
    }

    modifier notNull(address _address) {
        if (_address == 0)
            throw;
        _;
    }

    modifier validRequirement(uint ownerCount, uint _required) {
        if (   ownerCount > MAX_OWNER_COUNT
            || _required > ownerCount
            || _required == 0
            || ownerCount == 0)
            throw;
        _;
    }

    /// @dev Fallback function allows to deposit ether.
    function()
        payable
    {
        if (msg.value > 0)
            Deposit(msg.sender, msg.value);
    }

    /*
     * Public functions
     */
    /// @dev Contract constructor sets initial owners and required number of confirmations.
    /// @param _owners List of initial owners.
    /// @param _required Number of required confirmations.
    function MultiSigWallet(address[] _owners, uint _required)
        public
        validRequirement(_owners.length, _required)
    {
        for (uint i=0; i<_owners.length; i++) {
            if (isOwner[_owners[i]] || _owners[i] == 0)
                throw;
            isOwner[_owners[i]] = true;
        }
        owners = _owners;
        required = _required;
    }

    /// @dev Allows to add a new owner. Transaction has to be sent by wallet.
    /// @param owner Address of new owner.
    function addOwner(address owner)
        public
        onlyWallet
        ownerDoesNotExist(owner)
        notNull(owner)
        validRequirement(owners.length + 1, required)
    {
        isOwner[owner] = true;
        owners.push(owner);
        OwnerAddition(owner);
    }

    /// @dev Allows to remove an owner. Transaction has to be sent by wallet.
    /// @param owner Address of owner.
    function removeOwner(address owner)
        public
        onlyWallet
        ownerExists(owner)
    {
        isOwner[owner] = false;
        for (uint i=0; i<owners.length - 1; i++)
            if (owners[i] == owner) {
                owners[i] = owners[owners.length - 1];
                break;
            }
        owners.length -= 1;
        if (required > owners.length)
            changeRequirement(owners.length);
        OwnerRemoval(owner);
    }

    /// @dev Allows to replace an owner with a new owner. Transaction has to be sent by wallet.
    /// @param owner Address of owner to be replaced.
    /// @param newOwner Address of new owner.
    function replaceOwner(address owner, address newOwner)
        public
        onlyWallet
        ownerExists(owner)
        ownerDoesNotExist(newOwner)
    {
        for (uint i=0; i<owners.length; i++)
            if (owners[i] == owner) {
                owners[i] = newOwner;
                break;
            }
        isOwner[owner] = false;
        isOwner[newOwner] = true;
        OwnerRemoval(owner);
        OwnerAddition(newOwner);
    }

    /// @dev Allows to change the number of required confirmations. Transaction has to be sent by wallet.
    /// @param _required Number of required confirmations.
    function changeRequirement(uint _required)
        public
        onlyWallet
        validRequirement(owners.length, _required)
    {
        required = _required;
        RequirementChange(_required);
    }

    /// @dev Allows an owner to submit and confirm a transaction.
    /// @param destination Transaction target address.
    /// @param value Transaction ether value.
    /// @param data Transaction data payload.
    /// @return Returns transaction ID.
    function submitTransaction(address destination, uint value, bytes data)
        public
        returns (uint transactionId)
    {
        transactionId = addTransaction(destination, value, data);
        confirmTransaction(transactionId);
    }

    /// @dev Allows an owner to confirm a transaction.
    /// @param transactionId Transaction ID.
    function confirmTransaction(uint transactionId)
        public
        ownerExists(msg.sender)
        transactionExists(transactionId)
        notConfirmed(transactionId, msg.sender)
    {
        confirmations[transactionId][msg.sender] = true;
        Confirmation(msg.sender, transactionId);
        executeTransaction(transactionId);
    }

    /// @dev Allows an owner to revoke a confirmation for a transaction.
    /// @param transactionId Transaction ID.
    function revokeConfirmation(uint transactionId)
        public
        ownerExists(msg.sender)
        confirmed(transactionId, msg.sender)
        notExecuted(transactionId)
    {
        confirmations[transactionId][msg.sender] = false;
        Revocation(msg.sender, transactionId);
    }

    /// @dev Allows anyone to execute a confirmed transaction.
    /// @param transactionId Transaction ID.
    function executeTransaction(uint transactionId)
        public
        ownerExists(msg.sender)
        confirmed(transactionId, msg.sender)
        notExecuted(transactionId)
    {
        if (isConfirmed(transactionId)) {
            Transaction tx = transactions[transactionId];
            tx.executed = true;
            if (tx.destination.call.value(tx.value)(tx.data))
                Execution(transactionId);
            else {
                ExecutionFailure(transactionId);
                tx.executed = false;
            }
        }
    }

    /// @dev Returns the confirmation status of a transaction.
    /// @param transactionId Transaction ID.
    /// @return Confirmation status.
    function isConfirmed(uint transactionId)
        public
        constant
        returns (bool)
    {
        uint count = 0;
        for (uint i=0; i<owners.length; i++) {
            if (confirmations[transactionId][owners[i]])
                count += 1;
            if (count == required)
                return true;
        }
    }

    /*
     * Internal functions
     */
    /// @dev Adds a new transaction to the transaction mapping, if transaction does not exist yet.
    /// @param destination Transaction target address.
    /// @param value Transaction ether value.
    /// @param data Transaction data payload.
    /// @return Returns transaction ID.
    function addTransaction(address destination, uint value, bytes data)
        internal
        notNull(destination)
        returns (uint transactionId)
    {
        transactionId = transactionCount;
        transactions[transactionId] = Transaction({
            destination: destination,
            value: value,
            data: data,
            executed: false
        });
        transactionCount += 1;
        Submission(transactionId);
    }

    /*
     * Web3 call functions
     */
    /// @dev Returns number of confirmations of a transaction.
    /// @param transactionId Transaction ID.
    /// @return Number of confirmations.
    function getConfirmationCount(uint transactionId)
        public
        constant
        returns (uint count)
    {
        for (uint i=0; i<owners.length; i++)
            if (confirmations[transactionId][owners[i]])
                count += 1;
    }

    /// @dev Returns total number of transactions after filers are applied.
    /// @param pending Include pending transactions.
    /// @param executed Include executed transactions.
    /// @return Total number of transactions after filters are applied.
    function getTransactionCount(bool pending, bool executed)
        public
        constant
        returns (uint count)
    {
        for (uint i=0; i<transactionCount; i++)
            if (   pending && !transactions[i].executed
                || executed && transactions[i].executed)
                count += 1;
    }

    /// @dev Returns list of owners.
    /// @return List of owner addresses.
    function getOwners()
        public
        constant
        returns (address[])
    {
        return owners;
    }

    /// @dev Returns array with owner addresses, which confirmed transaction.
    /// @param transactionId Transaction ID.
    /// @return Returns array of owner addresses.
    function getConfirmations(uint transactionId)
        public
        constant
        returns (address[] _confirmations)
    {
        address[] memory confirmationsTemp = new address[](owners.length);
        uint count = 0;
        uint i;
        for (i=0; i<owners.length; i++)
            if (confirmations[transactionId][owners[i]]) {
                confirmationsTemp[count] = owners[i];
                count += 1;
            }
        _confirmations = new address[](count);
        for (i=0; i<count; i++)
            _confirmations[i] = confirmationsTemp[i];
    }

    /// @dev Returns list of transaction IDs in defined range.
    /// @param from Index start position of transaction array.
    /// @param to Index end position of transaction array.
    /// @param pending Include pending transactions.
    /// @param executed Include executed transactions.
    /// @return Returns array of transaction IDs.
    function getTransactionIds(uint from, uint to, bool pending, bool executed)
        public
        constant
        returns (uint[] _transactionIds)
    {
        uint[] memory transactionIdsTemp = new uint[](transactionCount);
        uint count = 0;
        uint i;
        for (i=0; i<transactionCount; i++)
            if (   pending && !transactions[i].executed
                || executed && transactions[i].executed)
            {
                transactionIdsTemp[count] = i;
                count += 1;
            }
        _transactionIds = new uint[](to - from);
        for (i=from; i<to; i++)
            _transactionIds[i - from] = transactionIdsTemp[i];
    }
}