contract etherstar is ERC165, IERC721, IERC721Metadata, Pausable, MinterRole {

    using SafeMath for uint256;
    using Address for address;
    using Strings for string;

    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;
    /*
     * 0x80ac58cd ===
     *     bytes4(keccak256('balanceOf(address)')) ^
     *     bytes4(keccak256('ownerOf(uint256)')) ^
     *     bytes4(keccak256('approve(address,uint256)')) ^
     *     bytes4(keccak256('getApproved(uint256)')) ^
     *     bytes4(keccak256('setApprovalForAll(address,bool)')) ^
     *     bytes4(keccak256('isApprovedForAll(address,address)')) ^
     *     bytes4(keccak256('transferFrom(address,address,uint256)')) ^
     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) ^
     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)'))
     */

    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;
    /**
     * 0x5b5e139f ===
     *     bytes4(keccak256('name()')) ^
     *     bytes4(keccak256('symbol()')) ^
     *     bytes4(keccak256('tokenURI(uint256)'))
     */

    // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Token URI prefix
    string private _baseTokenURI;

    // Flag representing if metadata migrated to IPFS
    bool private _ipfsMigrated;

    // Token total Supply
    uint256 private _totalSupply;

    // Mapping from token ID to owner
    mapping (uint256 => address) private _tokenOwner;

    // Mapping from token ID to approved address
    mapping (uint256 => address) private _tokenApprovals;

    // Mapping Mapping from token ID to token URI
    mapping(uint256 => string) private _tokenURIs;

    // Mapping Mapping from token ID to token DNAs
    mapping (uint256 => uint256) private _dnas;

    // Mapping Mapping from token ID to token Name
    mapping (uint256 => string) private _tokenNames;

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

    // Mapping from owner to operator approvals
    mapping (address => mapping (address => bool)) private _operatorApprovals;


    event TokenURI(uint256 indexed tokenId, string uri);


    /**
     * @dev Constructor function
     */
    constructor (string memory name, string memory symbol, string memory baseTokenURI) public {
        _name = name;
        _symbol = symbol;
        _totalSupply = 0;
        _baseTokenURI = baseTokenURI;
        _ipfsMigrated = false;

        // register the supported interfaces to conform to ERC721 via ERC165
        _registerInterface(_INTERFACE_ID_ERC721);
        _registerInterface(_INTERFACE_ID_ERC721_METADATA);
    }

    /**
     * @dev Gets the token name
     * @return string representing the token name
     */
    function name() external view returns (string memory) {
        return _name;
    }

    /**
     * @dev Gets the token symbol
     * @return string representing the token symbol
     */
    function symbol() external view returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Gets the total amount of tokens stored by the contract
     * @return uint256 representing the total amount of tokens
     */
    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }

    /**
     * @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) external view returns (bool) {
        return _exists(tokenId);
    }

    /**
     * @dev Sets IPFS migration flag true
     */
    function ipfsMigrationDone() public onlyMinter {
        _ipfsMigrated = true;
    }

    /**
     * @dev public function to set the token URI for a given token
     * Reverts if the token ID does not exist or metadata has migrated to IPFS
     * @param tokenId uint256 ID of the token to set its URI
     * @param uri string URI to assign
     */
    function setTokenURI(uint256 tokenId, string memory uri) public onlyMinter {
        require(!_ipfsMigrated);
        _setTokenURI(tokenId, uri);
    }

    /**
     * @dev Returns the URI for a given token ID
     * Throws if the token ID does not exist. May return an empty string.
     * @param tokenId uint256 ID of the token to query
     */
    function tokenURI(uint256 tokenId) external view returns (string memory) {
        require(_exists(tokenId));

        if (bytes(_tokenURIs[tokenId]).length > 0)
            return _tokenURIs[tokenId];

        return Strings.strConcat(baseTokenURI(),Strings.uint2str(tokenId));
    }

    /**
     * @dev Sets the prefix of token URI
     * @param baseTokenURI token URI prefix to be set
     */
    function setBaseTokenURI(string memory baseTokenURI) public onlyMinter {
        _baseTokenURI = baseTokenURI;
    }

    /**
     * @dev Returns prefix of token URI
     * @return string representing the token URI prefix
     */
    function baseTokenURI() public view returns (string memory) {
        return _baseTokenURI;
    }

    /**
     * @dev Returns the DNA for a given token ID
     * Throws if the token ID does not exist.
     * @param tokenId uint256 ID of the token to query
     */
    function tokenDNA(uint256 tokenId) public view returns (uint256) {
        require(_exists(tokenId));
        return _dnas[tokenId];
    }

    /**
     * @dev Returns the tokenName for a given token ID
     * Throws if the token ID does not exist.
     * @param tokenId uint256 ID of the token to query
     */
    function tokenName(uint256 tokenId) public view returns (string memory) {
        require(_exists(tokenId));
        return _tokenNames[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 Approves another address to transfer the given token ID
     * The zero address indicates there is no approved address.
     * There can only be one approved address per token at a given time.
     * 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 whenNotPaused {
        address owner = ownerOf(tokenId);
        require(to != owner);
        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
     * Reverts if the token ID does not exist.
     * @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) {
        require(_exists(tokenId));
        return _tokenApprovals[tokenId];
    }

    /**
     * @dev Sets or unsets the approval of a given operator
     * 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 whenNotPaused {
        require(to != msg.sender);
        _operatorApprovals[msg.sender][to] = approved;
        emit ApprovalForAll(msg.sender, to, approved);
    }

    /**
     * @dev Tells whether an operator is approved by a given owner
     * @param owner owner address which you want to query the approval of
     * @param operator operator address which you want to query the approval of
     * @return bool whether the given operator is approved by the given owner
     */
    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
     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible
     * 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 whenNotPaused {
        require(_isApprovedOrOwner(msg.sender, tokenId));

        _transferFrom(from, to, tokenId);
    }

    /**
     * @dev Safely transfers the ownership of a given token ID to another address
     * If the target address is a contract, it must implement `onERC721Received`,
     * which is called upon a safe transfer, and return the magic value
     * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
     * the transfer is reverted.
     *
     * 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 safeTransferFrom(address from, address to, uint256 tokenId) public {
        safeTransferFrom(from, to, tokenId, "");
    }

    /**
     * @dev Safely transfers the ownership of a given token ID to another address
     * If the target address is a contract, it must implement `onERC721Received`,
     * which is called upon a safe transfer, and return the magic value
     * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
     * the transfer is reverted.
     * 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
     * @param _data bytes data to send along with a safe transfer check
     */
    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {
        transferFrom(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, _data));
    }

    /**
     * @dev Public function to mint a new token
     * Reverts if the given token ID already exists
     * @param to address The address that will own the minted token
     * @param tokenId uint256 ID of the token to be minted
     * @param uri string Metadata URI of the token to be minted
     * @param dna  uint256 DNAs of the token to be minted
     */
    function mint(address to, uint256 tokenId, string memory uri, uint256 dna , string memory tokenNms)
        public onlyMinter
    {
        require(tokenId >= 0 && tokenId <= 9999);
        _mint(to, tokenId, uri, dna, tokenNms);
        _totalSupply += 1;
    }

    /**
     * @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) internal view returns (bool) {
        address owner = _tokenOwner[tokenId];
        return owner != address(0);
    }

    /**
     * @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) internal view returns (bool) {
        address owner = ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
    }

    /**
     * @dev Internal function to mint a new token
     * 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
     * @param uri string URI of the token to be minted metadata
     * @param dna  uint256 DNAs of the token to be minted
     */
    function _mint(address to, uint256 tokenId, string memory uri, uint256 dna , string memory tokenNms) internal {
        require(to != address(0));
        require(!_exists(tokenId));

        _tokenOwner[tokenId] = to;
        _ownedTokensCount[to] = _ownedTokensCount[to].add(1);
        _setTokenURI(tokenId, uri);
        _dnas[tokenId] = dna ;
        _tokenNames[tokenId] = tokenNms;

        emit Transfer(address(0), to, tokenId);
    }

    /**
     * @dev Internal function to set the token URI for a given token
     * Reverts if the token ID does not exist
     * @param tokenId uint256 ID of the token to set its URI
     * @param uri string URI to assign
     */
    function _setTokenURI(uint256 tokenId, string memory uri) internal {
        require(_exists(tokenId));
        _tokenURIs[tokenId] = uri;
        emit TokenURI(tokenId, uri);
    }

    /**
     * @dev Internal function to transfer ownership of a given token ID to another address.
     * As opposed to transferFrom, this imposes no restrictions on msg.sender.
     * @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) internal {
        require(ownerOf(tokenId) == from);
        require(to != address(0));

        _clearApproval(tokenId);

        _ownedTokensCount[from] = _ownedTokensCount[from].sub(1);
        _ownedTokensCount[to] = _ownedTokensCount[to].add(1);

        _tokenOwner[tokenId] = to;

        emit Transfer(from, to, tokenId);
    }

    /**
     * @dev Internal function to invoke `onERC721Received` on a target address
     * The call is not executed if the target address is not a contract
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes optional data to send along with the call
     * @return whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)
        internal returns (bool)
    {
        if (!to.isContract()) {
            return true;
        }

        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);
        return (retval == _ERC721_RECEIVED);
    }

    /**
     * @dev Private function to clear current approval of a given token ID
     * @param tokenId uint256 ID of the token to be transferred
     */
    function _clearApproval(uint256 tokenId) private {
        if (_tokenApprovals[tokenId] != address(0)) {
            _tokenApprovals[tokenId] = address(0);
        }
    }
}
/**
 * @title Non-Fungible Token
 * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
 */
function setTokenURI(uint256 tokenId, string memory uri) public onlyMinter {
    require(!_ipfsMigrated);
    _setTokenURI(tokenId, uri);
}

/**
 * @dev public function to set the token URI for a given token
 * Reverts if the token ID does not exist or metadata has migrated to IPFS
 * @param tokenId uint256 ID of the token to set its URI
 * @param uri string URI to assign
 */