contract LogicBase is HasNoContracts {

    /// The ERC-165 interface signature for ERC-721.
    ///  Ref: https://github.com/ethereum/EIPs/issues/165
    ///  Ref: https://github.com/ethereum/EIPs/issues/721
    bytes4 constant InterfaceSignature_NFC = bytes4(0x9f40b779);

    // Reference to contract tracking NFT ownership
    ERC721 public nonFungibleContract;

    // Reference to storage contract
    StorageBase public storageContract;

    function LogicBase(address _nftAddress, address _storageAddress) public {
        // paused by default
        paused = true;

        setNFTAddress(_nftAddress);

        require(_storageAddress != address(0));
        storageContract = StorageBase(_storageAddress);
    }

    // Very dangerous action, only when new contract has been proved working
    // Requires storageContract already transferOwnership to the new contract
    // This method is only used to transfer the balance to owner
    function destroy() external onlyOwner whenPaused {
        address storageOwner = storageContract.owner();
        // owner of storageContract must not be the current contract otherwise the storageContract will forever not accessible
        require(storageOwner != address(this));
        // Transfers the current balance to the owner and terminates the contract
        selfdestruct(owner);
    }

    // Very dangerous action, only when new contract has been proved working
    // Requires storageContract already transferOwnership to the new contract
    // This method is only used to transfer the balance to the new contract
    function destroyAndSendToStorageOwner() external onlyOwner whenPaused {
        address storageOwner = storageContract.owner();
        // owner of storageContract must not be the current contract otherwise the storageContract will forever not accessible
        require(storageOwner != address(this));
        // Transfers the current balance to the new owner of the storage contract and terminates the contract
        selfdestruct(storageOwner);
    }

    // override to make sure everything is initialized before the unpause
    function unpause() public onlyOwner whenPaused {
        // can not unpause when the logic contract is not initialzed
        require(nonFungibleContract != address(0));
        require(storageContract != address(0));
        // can not unpause when ownership of storage contract is not the current contract
        require(storageContract.owner() == address(this));

        super.unpause();
    }

    function setNFTAddress(address _nftAddress) public onlyOwner {
        require(_nftAddress != address(0));
        ERC721 candidateContract = ERC721(_nftAddress);
        require(candidateContract.supportsInterface(InterfaceSignature_NFC));
        nonFungibleContract = candidateContract;
    }

    // Withdraw balance to the Core Contract
    function withdrawBalance() external returns (bool) {
        address nftAddress = address(nonFungibleContract);
        // either Owner or Core Contract can trigger the withdraw
        require(msg.sender == owner || msg.sender == nftAddress);
        // The owner has a method to withdraw balance from multiple contracts together,
        // use send here to make sure even if one withdrawBalance fails the others will still work
        bool res = nftAddress.send(address(this).balance);
        return res;
    }

    function withdrawBalanceFromStorageContract() external returns (bool) {
        address nftAddress = address(nonFungibleContract);
        // either Owner or Core Contract can trigger the withdraw
        require(msg.sender == owner || msg.sender == nftAddress);
        // The owner has a method to withdraw balance from multiple contracts together,
        // use send here to make sure even if one withdrawBalance fails the others will still work
        bool res = storageContract.withdrawBalance();
        return res;
    }
}
function unpause() public onlyOwner whenPaused {
        // can not unpause when the logic contract is not initialzed
        require(nonFungibleContract != address(0));
        require(storageContract != address(0));
        // can not unpause when ownership of storage contract is not the current contract
        require(storageContract.owner() == address(this));

        super.unpause();
    }
// override to make sure everything is initialized before the unpause