generateTokenId

This view function generates a unique token ID for an event access level based on the event registerer's address, event ID, and access level. It takes three parameters:

• eventId: The unique identifier for the event.

• eventRegisterer: The address of the entity registering the event.

• accessLevel: The access level for which the token ID is generated.

// Some code
```remix-solidity
/**
    GenerateTokenId: Generate a unique token ID for an event access level based on the event registerer's address, event ID, and access level.
    @param eventRegisterer: The address of the entity registering the event.
    @param eventId: The unique identifier for the event.
    @param accessLevel: The access level for which the token ID is generated.
    @return tokenId: The generated unique token ID.

    Format: eventId, registerer, accessLevel
    */
    function generateTokenId(
        string calldata eventId,
        address eventRegisterer,
        string calldata accessLevel
    ) public view returns (uint256) {
        // Convert event registerer's address to a hexadecimal string
        string memory addressToString = Strings.toHexString(
            uint256(uint160(eventRegisterer)),
            20
        );
        // Concatenate all strings using abi.encodePacked
        string memory concatenatedString = string(
            abi.encodePacked(eventId, addressToString, accessLevel)
        );

        // Generate token ID using keccak256 hash of the concatenated string
        uint256 tokenId = uint256(keccak256(bytes(concatenatedString)));

        // Check if the generated token ID already exists for the event
        if (checkTokenIdExistsForEventId(eventId, tokenId))
            revert DecastGating__TokenIdAlreadyExists();

        return tokenId;
    }
```

Explanation:

The function begins by converting the event registerer's address to a hexadecimal string using the toHexString function provided by the Strings library. This conversion ensures that the address is represented as a string.

Next, it concatenates the event ID, the hexadecimal representation of the event registerer's address, and the access level using the abi.encodePacked function. This concatenated string serves as the basis for generating the token ID.

The token ID is generated by taking the keccak256 hash of the concatenated string. This hash operation ensures that the generated token ID is unique for the combination of event ID, event registerer's address, and access level.

Before returning the generated token ID, the function checks if the token ID already exists for the specified event using the checkTokenIdExistsForEventId function. If a token ID collision is detected, indicating that the generated token ID already exists for the event, the function reverts the transaction with an appropriate error message.

Finally, if no collision is detected, the function returns the generated token ID, ensuring that it is unique within the context of the specified event.