🪪 Profile Registry & QuizScoresV2

Profiles (name + X username) used to live inside each event's QuizScores contract. That meant a participant had a separate profile per event, and nothing outside the quiz could use it.

Now there is one shared ProfileRegistry.sol, used by:

• QuizScoresV2.sol: one per event, stores scores only
• FeedContract.sol: submissions and votes on the Feed

The three earlier events keep their v1 QuizScores contracts and leaderboards unchanged. They are marked legacy: true in src/config/events.js.

How the pieces fit

                 ┌──────────────────────┐
                 │   ProfileRegistry    │  name + X username per wallet
                 └──────────▲───────────┘
          isRegistered /    │    getProfilesBatch
          getProfile        │
      ┌─────────────────────┼─────────────────────┐
      │                     │                     │
┌─────┴────────┐   ┌────────┴──────┐    ┌─────────┴─────┐
│ QuizScoresV2 │   │ QuizScoresV2  │    │ FeedContract  │
│  (event N)   │   │  (event N+1)  │    │               │
└──────────────┘   └───────────────┘    └───────────────┘

Legacy (read-only from the portal's point of view):
QuizScores v1 (ATLAS) · QuizScores v1 (DBIT) · QuizScores v1 (Hacktoberfest)

ProfileRegistry

Function	Who	Description
register(name, xUsername)	Anyone	Same rules as v1: name ≤ 64, X username ≤ 32, case-insensitive unique, permanent. Only open after finalizeMigration()
migrateFrom(legacy, start, count)	Owner, before finalize	Copies profiles from a v1 contract by reading getLeaderboardBatch on-chain
finalizeMigration()	Owner, once	Closes migration permanently and opens registration
isRegistered(wallet)	View
getProfile(wallet)	View	Reverts if not registered
getProfilesBatch(wallets[])	View	Names, X usernames and a registered flag for each wallet
getProfileCount() / getProfilesPage(start, count)	View	Enumeration

Trust model

migrateFrom reads profile data directly from the legacy contract, so the owner can't insert made-up profiles. The owner only decides the order and timing. After finalizeMigration() the owner has no special powers left.

Migration rules

• A wallet that is already registered is skipped (MigrationSkipped, reason 1).
• A wallet whose X username is already held by another wallet is skipped (reason 2). v1 contracts only enforced uniqueness per event, so the same handle can exist across events.
• Migrate the newest event first. The first write wins, so a wallet registered at several events keeps its most recent name, and a contested handle goes to its most recent claimant.
• Skipped participants still show normally on their legacy leaderboard. To use the Feed or future quizzes, they register again with a different handle.

QuizScoresV2

Same anti-cheat model as v1, minus profile storage:

Change vs. v1	Detail
Constructor	(address admin, address profileRegistry)
Registration	Removed. submitScore requires registry.isRegistered(msg.sender)
isRegistered(wallet)	Pass-through to the registry (used by api/quiz/start.js)
Leaderboard	A wallet is listed after its first score. getLeaderboardBatch returns (wallets[], batchScores[]); names come from registry.getProfilesBatch
getScores(wallet)	Replaces getParticipant
Signed message	keccak256(contract, chainId, wallet, quizId, score, nonce)

The signed message now includes the contract address and chain ID. In v1, every event contract started nonces at 0 and the message didn't name the contract, so a signature issued for one event could be replayed on another. api/quiz/complete.js detects whether VITE_CONTRACT_ADDRESS is a v1 or v2 contract (only v2 has registry()) and signs the matching format.

Deployment runbook (Remix)

All contracts compile with Solidity 0.8.19+. Use Injected Provider - MetaMask on Sepolia.

1. Wait for the last legacy event to close

Anyone who registers on a v1 contract after its migration batch has run won't be carried over. Run migration once Hacktoberfest (rtta1cub) registrations are closed. You can re-run migrateFrom with a later start offset at any time before finalizing.

2. Deploy and migrate the registry

1. Deploy ProfileRegistry.sol with (forwarderAddress) (see Gasless Transactions; 0x0000000000000000000000000000000000000000 disables gasless calls). The deploying wallet becomes the owner.

2. For each legacy contract, newest first, call migrateFrom(address, start, count) in batches of ~30–50:

   Order	Event	Contract
   1	Hacktoberfest Hack Day Mumbai	0x487cb8c812e4177107884799fdbe61a2b4374c73
   2	DBIT Mumbai	0xb54c3d5fea76dae38e615cc1ecf7024c7afc1b2d
   3	ATLAS SkillTech	0xb5456aDfa33BD3c94A6E021541d73Abc26A19138

   Use getParticipantCount() on each legacy contract to know how many batches to run.

3. Check MigrationSkipped events on Etherscan and compare getProfileCount() with what you expect.

4. Call finalizeMigration(). This can't be undone.

3. Deploy the feed

Deploy FeedContract.sol with (registryAddress, forwarderAddress). The deploying wallet becomes the moderator (see Feed).

4. Point the portal at the new contracts

VITE_PROFILE_REGISTRY_ADDRESS=0xYourProfileRegistry
VITE_FEED_CONTRACT_ADDRESS=0xYourFeedContract

Once VITE_PROFILE_REGISTRY_ADDRESS is set, the wallet connects, reads profiles and registers through the registry. Without it, the portal falls back to the old behaviour (profiles on VITE_CONTRACT_ADDRESS).

warning

Only set VITE_PROFILE_REGISTRY_ADDRESS after finalizeMigration(). Before that, new users can't register.

5. Next event

1. Deploy QuizScoresV2.sol with (adminAddress, registryAddress, forwarderAddress).
2. Append it to src/config/events.js without legacy: true.
3. Point VITE_CONTRACT_ADDRESS at it. No API change is needed; the signing format is detected automatically.

Testing in the Remix VM

Run this before touching Sepolia (Remix VM environment, several accounts):

1. Deploy two v1 QuizScores contracts. Register overlapping wallets, including the same wallet on both with different names, and two wallets with the same X handle (different case) on different contracts.
2. Deploy ProfileRegistry(0x0). Confirm register reverts with Registration not open yet.
3. migrateFrom the newer contract, then the older one. Check that:
   • the shared wallet has the newer name
   • the clashing handle went to the newer contract's wallet, and the other got MigrationSkipped with reason 2
   • re-running a batch changes nothing
4. finalizeMigration. Confirm migrateFrom now reverts, register works, and a taken handle in different case is rejected.
5. Deploy QuizScoresV2(admin, registry, 0x0). Sign a score from the admin account and submit it. Deploy a second V2 and confirm the same signature is rejected there.
6. Deploy FeedContract(registry, 0x0) and run the checks in Feed → Testing.