fix: inherit IERC165 & additional checks in tokenizer

contracts/interfaces/modules/tokenizer/IOwnableERC20.sol

@@ -2,6 +2,7 @@
 pragma solidity 0.8.26;
 
 import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
 
 /// @title Ownable ERC20 Interface
 /// @notice Interface for the Ownable ERC20 token
@@ -29,8 +30,4 @@ interface IOwnableERC20 is IERC20 {
 
     /// @notice Returns the upgradable beacon
     function upgradableBeacon() external view returns (address);
-
-    /// @notice Returns whether the contract supports an interface
-    /// @param interfaceId The interface ID
-    function supportsInterface(bytes4 interfaceId) external view returns (bool);
 }

contracts/interfaces/modules/tokenizer/ITokenizerModule.sol

@@ -27,4 +27,14 @@ interface ITokenizerModule is IModule {
     /// @param initData The initialization data for the token
     /// @return token The address of the newly created token
     function tokenize(address ipId, address tokenTemplate, bytes calldata initData) external returns (address token);
+
+    /// @notice Returns the fractionalized token for an IP
+    /// @param ipId The address of the IP
+    /// @return token The address of the token
+    function getFractionalizedToken(address ipId) external view returns (address token);
+
+    /// @notice Checks if a token template is whitelisted
+    /// @param tokenTemplate The address of the token template
+    /// @return allowed The whitelisting status (true if whitelisted, false if not)
+    function isWhitelistedTokenTemplate(address tokenTemplate) external view returns (bool allowed);
 }

contracts/lib/Errors.sol

@@ -104,17 +104,27 @@ library Errors {
     error TokenizerModule__ZeroTokenTemplate();
 
     /// @notice Token template is not supported.
+    /// @param tokenTemplate The address of the token template that is not supported
     error TokenizerModule__UnsupportedERC20(address tokenTemplate);
 
     /// @notice IP is disputed.
+    /// @param ipId The address of the disputed IP
     error TokenizerModule__DisputedIpId(address ipId);
 
     /// @notice Token template is not whitelisted.
+    /// @param tokenTemplate The address of the token template
     error TokenizerModule__TokenTemplateNotWhitelisted(address tokenTemplate);
 
     /// @notice IP is not registered.
+    /// @param ipId The address of the IP
     error TokenizerModule__IpNotRegistered(address ipId);
 
     /// @notice IP is expired.
+    /// @param ipId The address of the expired IP
     error TokenizerModule__IpExpired(address ipId);
+
+    /// @notice IP is already tokenized.
+    /// @param ipId The address of the already tokenized IP
+    /// @param token The address of the fractionalized token for the IP
+    error TokenizerModule__IpAlreadyTokenized(address ipId, address token);
 }

contracts/modules/tokenizer/TokenizerModule.sol

@@ -2,9 +2,10 @@
 pragma solidity 0.8.26;
 
 import { Strings } from "@openzeppelin/contracts/utils/Strings.sol";
-import { ERC165Checker } from "@openzeppelin/contracts/utils/introspection/ERC165Checker.sol";
 import { BeaconProxy } from "@openzeppelin/contracts/proxy/beacon/BeaconProxy.sol";
+import { ERC165Checker } from "@openzeppelin/contracts/utils/introspection/ERC165Checker.sol";
 import { UUPSUpgradeable } from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
+import { ReentrancyGuardUpgradeable } from "@openzeppelin/contracts-upgradeable/utils/ReentrancyGuardUpgradeable.sol";
 
 import { BaseModule } from "@storyprotocol/core/modules/BaseModule.sol";
 import { AccessControlled } from "@storyprotocol/core/access/AccessControlled.sol";
@@ -27,6 +28,7 @@ contract TokenizerModule is
     BaseModule,
     AccessControlled,
     ProtocolPausableUpgradeable,
+    ReentrancyGuardUpgradeable,
     UUPSUpgradeable
 {
     using Strings for *;
@@ -35,9 +37,11 @@ contract TokenizerModule is
 
     /// @dev Storage structure for the TokenizerModule
     /// @param isWhitelistedTokenTemplate Mapping of token templates to their whitelisting status
+    /// @param fractionalizedTokens Mapping of IP IDs to their fractionalized tokens
     /// @custom:storage-location erc7201:story-protocol-periphery.TokenizerModule
     struct TokenizerModuleStorage {
         mapping(address => bool) isWhitelistedTokenTemplate;
+        mapping(address ipId => address token) fractionalizedTokens;
     }
 
     /// solhint-disable-next-line max-line-length
@@ -76,7 +80,7 @@ contract TokenizerModule is
         emit TokenTemplateWhitelisted(tokenTemplate, allowed);
     }
 
-    /// @notice Tokenizes an IP
+    /// @notice Tokenizes (fractionalizes) an IP
     /// @param ipId The address of the IP
     /// @param tokenTemplate The address of the token template
     /// @param initData The initialization data for the token
@@ -85,12 +89,14 @@ contract TokenizerModule is
         address ipId,
         address tokenTemplate,
         bytes calldata initData
-    ) external verifyPermission(ipId) returns (address token) {
+    ) external verifyPermission(ipId) nonReentrant returns (address token) {
         if (DISPUTE_MODULE.isIpTagged(ipId)) revert Errors.TokenizerModule__DisputedIpId(ipId);
         if (!IP_ASSET_REGISTRY.isRegistered(ipId)) revert Errors.TokenizerModule__IpNotRegistered(ipId);
         if (_isExpiredNow(ipId)) revert Errors.TokenizerModule__IpExpired(ipId);
 
         TokenizerModuleStorage storage $ = _getTokenizerModuleStorage();
+        address existingToken = $.fractionalizedTokens[ipId];
+        if (existingToken != address(0)) revert Errors.TokenizerModule__IpAlreadyTokenized(ipId, existingToken);
         if (!$.isWhitelistedTokenTemplate[tokenTemplate])
             revert Errors.TokenizerModule__TokenTemplateNotWhitelisted(tokenTemplate);
 
@@ -101,9 +107,27 @@ contract TokenizerModule is
             )
         );
 
+        $.fractionalizedTokens[ipId] = token;
+
         emit IPTokenized(ipId, token);
     }
 
+    /// @notice Returns the fractionalized token for an IP
+    /// @param ipId The address of the IP
+    /// @return token The address of the token (0 address if IP has not been tokenized)
+    function getFractionalizedToken(address ipId) external view returns (address token) {
+        TokenizerModuleStorage storage $ = _getTokenizerModuleStorage();
+        return $.fractionalizedTokens[ipId];
+    }
+
+    /// @notice Checks if a token template is whitelisted
+    /// @param tokenTemplate The address of the token template
+    /// @return allowed The whitelisting status (true if whitelisted, false if not)
+    function isWhitelistedTokenTemplate(address tokenTemplate) external view returns (bool allowed) {
+        TokenizerModuleStorage storage $ = _getTokenizerModuleStorage();
+        return $.isWhitelistedTokenTemplate[tokenTemplate];
+    }
+
     /// @dev Check if an IP is expired now
     /// @param ipId The address of the IP
     function _isExpiredNow(address ipId) internal view returns (bool) {