contract ERC1155Metadata {

  // URI's default URI prefix
  string internal baseMetadataURI;
  event URI(string _uri, uint256 indexed _id);


  /***********************************|
  |     Metadata Public Function s    |
  |__________________________________*/

  /**
   * @notice A distinct Uniform Resource Identifier (URI) for a given token.
   * @dev URIs are defined in RFC 3986.
   *      URIs are assumed to be deterministically generated based on token ID
   *      Token IDs are assumed to be represented in their hex format in URIs
   * @return URI string
   */
  function uri(uint256 _id) public view returns (string memory) {
    return string(abi.encodePacked(baseMetadataURI, _uint2str(_id), ".json"));
  }


  /***********************************|
  |    Metadata Internal Functions    |
  |__________________________________*/

  /**
   * @notice Will emit default URI log event for corresponding token _id
   * @param _tokenIDs Array of IDs of tokens to log default URI
   */
  function _logURIs(uint256[] memory _tokenIDs) internal {
    string memory baseURL = baseMetadataURI;
    string memory tokenURI;

    for (uint256 i = 0; i < _tokenIDs.length; i++) {
      tokenURI = string(abi.encodePacked(baseURL, _uint2str(_tokenIDs[i]), ".json"));
      emit URI(tokenURI, _tokenIDs[i]);
    }
  }

  /**
   * @notice Will emit a specific URI log event for corresponding token
   * @param _tokenIDs IDs of the token corresponding to the _uris logged
   * @param _URIs    The URIs of the specified _tokenIDs
   */
  function _logURIs(uint256[] memory _tokenIDs, string[] memory _URIs) internal {
    require(_tokenIDs.length == _URIs.length, "ERC1155Metadata#_logURIs: INVALID_ARRAYS_LENGTH");
    for (uint256 i = 0; i < _tokenIDs.length; i++) {
      emit URI(_URIs[i], _tokenIDs[i]);
    }
  }

  /**
   * @notice Will update the base URL of token's URI
   * @param _newBaseMetadataURI New base URL of token's URI
   */
  function _setBaseMetadataURI(string memory _newBaseMetadataURI) internal {
    baseMetadataURI = _newBaseMetadataURI;
  }


  /***********************************|
  |    Utility Internal Functions     |
  |__________________________________*/

  /**
   * @notice Convert uint256 to string
   * @param _i Unsigned integer to convert to string
   */
  function _uint2str(uint256 _i) internal pure returns (string memory _uintAsString) {
    if (_i == 0) {
      return "0";
    }

    uint256 j = _i;
    uint256 ii = _i;
    uint256 len;

    // Get number of bytes
    while (j != 0) {
      len++;
      j /= 10;
    }

    bytes memory bstr = new bytes(len);
    uint256 k = len - 1;

    // Get each individual ASCII
    while (ii != 0) {
      bstr[k--] = byte(uint8(48 + ii % 10));
      ii /= 10;
    }

    // Convert to string
    return string(bstr);
  }

}
/**
 * @notice Contract that handles metadata related methods.
 * @dev Methods assume a deterministic generation of URI based on token IDs.
 *      Methods also assume that URI uses hex representation of token IDs.
 */
function _logURIs(uint256[] memory _tokenIDs) internal {
    string memory baseURL = baseMetadataURI;
    string memory tokenURI;

    for (uint256 i = 0; i < _tokenIDs.length; i++) {
      tokenURI = string(abi.encodePacked(baseURL, _uint2str(_tokenIDs[i]), ".json"));
      emit URI(tokenURI, _tokenIDs[i]);
    }
  }
/**
 * @notice Will emit default URI log event for corresponding token _id
 * @param _tokenIDs Array of IDs of tokens to log default URI
 */