[FEATURE]: Add Indexed Parameters to Events for Efficient Off-Chain Querying

[rohans02]

Feature and its Use Cases

Problem

Critical event parameters are not indexed, making off-chain filtering inefficient for frontends, indexers, and analytics tools.

Current (inefficient):

// Factory.sol
event TNTCreated(address indexed owner, address tntAddress);  // ❌ tntAddress not indexed

// TNT.sol
event TokenIssued(address indexed issuer, address indexed user, uint256 tokenId);  // ❌ tokenId not indexed
event TokenRevoked(address indexed revoker, uint256 tokenId);  // ❌ tokenId not indexed

Without indexing, clients must fetch ALL events and filter client-side:

// ❌ Inefficient: Download all events, filter locally
const all = await factory.queryFilter(factory.filters.TNTCreated());
const filtered = all.filter(e => e.args.tntAddress === myAddress);

Solution

Add indexed to 3 parameters across 2 files:

// Factory.sol (Line ~15)
event TNTCreated(address indexed owner, address indexed tntAddress);  // ✅

// TNT.sol (Lines ~38-39)
event TokenIssued(address indexed issuer, address indexed user, uint256 indexed tokenId);  // ✅
event TokenRevoked(address indexed revoker, uint256 indexed tokenId);  // ✅

After (efficient):

// ✅ Filter at RPC/node level
const filtered = await factory.queryFilter(
  factory.filters.TNTCreated(null, specificTNTAddress)
);

Benefits

1. Efficient Filtering - Query specific TNT addresses/token IDs at node level
2. Improved Indexing - The Graph and similar tools can create DB indexes
3. Reduced RPC Load - No need to download all events for client-side filtering
4. Better Analytics - Track specific contracts/tokens without full scans

Gas Cost: +375 gas per indexed parameter (~1,125 gas total increase per TNT creation)

Testing

Create test/EventIndexing.test.js:

1. Verify TNTCreated has 3 topics (signature + 2 indexed params)
2. Verify TokenIssued has 4 topics (signature + 3 indexed params)
3. Verify TokenRevoked has 3 topics (signature + 2 indexed params)
4. Test filtering by indexed parameters
5. Measure gas cost increase

Technical Details

Files to modify:

• contracts/src/Factory.sol - TNTCreated event
• contracts/src/TNT.sol - TokenIssued, TokenRevoked events

Additional Context

No response

Code of Conduct

• I have joined the Discord server and will post updates there
• I have searched existing issues to avoid duplicates