contract ERC721BasicToken is ERC721Basic, acl {
    using SafeMath for uint256;
    using AddressUtils for address;

    uint public numTokensTotal;

  // Mapping from token ID to owner
    mapping (uint256 => address) internal tokenOwner;

  // Mapping from token ID to approved address
    mapping (uint256 => address) internal tokenApprovals;

  // Mapping from owner to number of owned token
    mapping (address => uint256) internal ownedTokensCount;

  // Mapping from owner to operator approvals
    mapping (address => mapping (address => bool)) internal operatorApprovals;

  /**
   * @dev Guarantees msg.sender is owner of the given token
   * @param _tokenId uint256 ID of the token to validate its ownership belongs to msg.sender
   */
    modifier onlyOwnerOf(uint256 _tokenId) {
        require(ownerOf(_tokenId) == msg.sender);
        _;
    }

  /**
   * @dev Checks msg.sender can transfer a token, by being owner, approved, or operator
   * @param _tokenId uint256 ID of the token to validate
   */
    modifier canTransfer(uint256 _tokenId) {
        require(isApprovedOrOwner(msg.sender, _tokenId));
        _;
    }

  /**
   * @dev Gets the balance of the specified address
   * @param _owner address to query the balance of
   * @return uint256 representing the amount owned by the passed address
   */
    function balanceOf(address _owner) public view returns (uint256) {
        require(_owner != address(0));
        return ownedTokensCount[_owner];
    }

  /**
   * @dev Gets the owner of the specified token ID
   * @param _tokenId uint256 ID of the token to query the owner of
   * @return owner address currently marked as the owner of the given token ID
   */
    function ownerOf(uint256 _tokenId) public view returns (address) {
        address owner = tokenOwner[_tokenId];
     /* require(owner != address(0)); */
        return owner;
    }

  /**
   * @dev Returns whether the specified token exists
   * @param _tokenId uint256 ID of the token to query the existence of
   * @return whether the token exists
   */
    function exists(uint256 _tokenId) public view returns (bool) {
        address owner = tokenOwner[_tokenId];
        return owner != address(0);
    }

  /**
   * @dev Approves another address to transfer the given token ID
   * @dev The zero address indicates there is no approved address.
   * @dev There can only be one approved address per token at a given time.
   * @dev Can only be called by the token owner or an approved operator.
   * @param _to address to be approved for the given token ID
   * @param _tokenId uint256 ID of the token to be approved
   */
    function approve(address _to, uint256 _tokenId) public {
        address owner = tokenOwner[_tokenId];

        tokenApprovals[_tokenId] = _to;

        require(_to != ownerOf(_tokenId));
        require(msg.sender == owner || isApprovedForAll(owner, msg.sender));

        tokenApprovals[_tokenId] = _to;
        emit Approval(owner, _to, _tokenId);
    }

  /**
   * @dev Gets the approved address for a token ID, or zero if no address set
   * @param _tokenId uint256 ID of the token to query the approval of
   * @return address currently approved for the given token ID
   */
    function getApproved(uint256 _tokenId) public view returns (address) {
        return tokenApprovals[_tokenId];
    }

  /**
   * @dev Sets or unsets the approval of a given operator
   * @dev An operator is allowed to transfer all tokens of the sender on their behalf
   * @param _to operator address to set the approval
   * @param _approved representing the status of the approval to be set
   */
    function setApprovalForAll(address _to, bool _approved) public {
        require(_to != msg.sender);
        operatorApprovals[msg.sender][_to] = _approved;
        emit ApprovalForAll(msg.sender, _to, _approved);
    }

    function isApprovedForAll(address _owner, address _operator) public view returns (bool) {
        return operatorApprovals[_owner][_operator];
    }

  /**
   * @dev Transfers the ownership of a given token ID to another address
   * @dev Usage of this method is discouraged, use `safeTransferFrom` whenever possible
   * @dev Requires the msg sender to be the owner, approved, or operator
   * @param _from current owner of the token
   * @param _to address to receive the ownership of the given token ID
   * @param _tokenId uint256 ID of the token to be transferred
  */
    function transferFrom(address _from, address _to, uint256 _tokenId) public canTransfer(_tokenId) {
        require(_from != address(0));
        require(_to != address(0));

        clearApproval(_from, _tokenId);
        removeTokenFrom(_from, _tokenId);
        addTokenTo(_to, _tokenId);

        emit Transfer(_from, _to, _tokenId);
    }



  /**
   * @dev Returns whether the given spender can transfer a given token ID
   * @param _spender address of the spender to query
   * @param _tokenId uint256 ID of the token to be transferred
   * @return bool whether the msg.sender is approved for the given token ID,
   *  is an operator of the owner, or is the owner of the token
   */
    function isApprovedOrOwner(address _spender, uint256 _tokenId) public view returns (bool) {
        address owner = ownerOf(_tokenId);
        return _spender == owner || getApproved(_tokenId) == _spender || isApprovedForAll(owner, _spender);
    }

  /**
   * @dev Internal function to mint a new token
   * @dev Reverts if the given token ID already exists
   * @param _to The address that will own the minted token
   * @param _tokenId uint256 ID of the token to be minted by the msg.sender
   * @dev _check(2) checks msg.sender == ADMIN
   */
    function _mint(address _to, uint256 _tokenId) external check(2) {
        require(_to != address(0));
        addTokenTo(_to, _tokenId);
        numTokensTotal = numTokensTotal.add(1);
        emit Transfer(address(0), _to, _tokenId);
    }

  /**
   * @dev Internal function to burn a specific token
   * @dev Reverts if the token does not exist
   * @param _tokenId uint256 ID of the token being burned by the msg.sender
   */
    function _burn(address _owner, uint256 _tokenId) external check(2) {
        clearApproval(_owner, _tokenId);
        removeTokenFrom(_owner, _tokenId);
        numTokensTotal = numTokensTotal.sub(1);
        emit Transfer(_owner, address(0), _tokenId);
    }

  /**
   * @dev Internal function to clear current approval of a given token ID
   * @dev Reverts if the given address is not indeed the owner of the token
   * @param _owner owner of the token
   * @param _tokenId uint256 ID of the token to be transferred
   */
    function clearApproval(address _owner, uint256 _tokenId) internal {
        require(ownerOf(_tokenId) == _owner);
        if (tokenApprovals[_tokenId] != address(0)) {
            tokenApprovals[_tokenId] = address(0);
            emit Approval(_owner, address(0), _tokenId);
        }
    }

  /**
   * @dev Internal function to add a token ID to the list of a given address
   * @param _to address representing the new owner of the given token ID
   * @param _tokenId uint256 ID of the token to be added to the tokens list of the given address
   */
    function addTokenTo(address _to, uint256 _tokenId) internal {
        require(tokenOwner[_tokenId] == address(0));
        tokenOwner[_tokenId] = _to;
        ownedTokensCount[_to] = ownedTokensCount[_to].add(1);
    }

  /**
   * @dev Internal function to remove a token ID from the list of a given address
   * @param _from address representing the previous owner of the given token ID
   * @param _tokenId uint256 ID of the token to be removed from the tokens list of the given address
   */
    function removeTokenFrom(address _from, uint256 _tokenId) internal {
        require(ownerOf(_tokenId) == _from);
        ownedTokensCount[_from] = ownedTokensCount[_from].sub(1);
        tokenOwner[_tokenId] = address(0);
    }
}
/**
 * @title ERC721 Non-Fungible Token Standard basic implementation
 * @dev edited verison of Open Zepplin implementation
 * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
 * @dev edited _mint & isApprovedOrOwner modifiers
 */
function approve(address _to, uint256 _tokenId) public {
    address owner = tokenOwner[_tokenId];

    tokenApprovals[_tokenId] = _to;

    require(_to != ownerOf(_tokenId));
    require(msg.sender == owner || isApprovedForAll(owner, msg.sender));

    tokenApprovals[_tokenId] = _to;
    emit Approval(owner, _to, _tokenId);
}

/**
 * @dev Approves another address to transfer the given token ID
 * @dev The zero address indicates there is no approved address.
 * @dev There can only be one approved address per token at a given time.
 * @dev Can only be called by the token owner or an approved operator.
 * @param _to address to be approved for the given token ID
 * @param _tokenId uint256 ID of the token to be approved
 */