feat: add metadataOf in sbt

Author: Yash Agrawal

contracts/SBT.sol

@@ -106,14 +106,16 @@ contract SBT is ISBT, ERC721EnumerableUpgradeable {
 	}
 
 	function _tokenURI(uint256 tokenId) private view returns (string memory) {
+		require(tokenId < currentIndex(), "Token not found");
+
 		(
 			string memory name,
 			string memory description,
 			string memory tokenUriImage,
 			StringAttribute[] memory stringAttributes,
 			NumberAttribute[] memory numberAttributes
 		) = abi.decode(
-				_sbtdata[tokenId],
+				metadataOf(tokenId),
 				(string, string, string, StringAttribute[], NumberAttribute[])
 			);
 
@@ -230,6 +232,13 @@ contract SBT is ISBT, ERC721EnumerableUpgradeable {
 		return super.totalSupply();
 	}
 
+	function metadataOf(
+		uint256 tokenId
+	) public view override returns (bytes memory) {
+		require(tokenId < currentIndex(), "Token not found");
+		return _sbtdata[tokenId];
+	}
+
 	function owner() external view returns (address) {
 		return ProxyAdmin(_proxyAdmin).owner();
 	}

contracts/interfaces/ISBT.sol

@@ -111,4 +111,11 @@ interface ISBT {
 	 * @return uint256 current token id
 	 */
 	function currentIndex() external view returns (uint256);
+
+	/*
+	 * @dev get mapped metadata bytes of token id
+	 * @param tokenId the token id of the NFT
+	 * @return bytes The mapped metadata bytes
+	 */
+	function metadataOf(uint256 tokenId) external view returns (bytes memory);
 }