add registration logic to manager

packages/zevm-app-contracts/contracts/zeta-points/InvitationManager.sol

@@ -8,6 +8,8 @@ contract InvitationManager {
         bytes32 r;
         bytes32 s;
     }
+    // Records the timestamp when a particular user gets verified.
+    mapping(address => uint256) public userVerificationTimestamps;
 
     // Records the timestamp when a particular user accepted an invitation from an inviter.
     mapping(address => mapping(address => uint256)) public acceptedInvitationsTimestamp;
@@ -21,12 +23,35 @@ contract InvitationManager {
     // Total invites accepted by inviter by day (using the start timestamp of each day as key)
     mapping(address => mapping(uint256 => uint256)) public totalInvitesByInviterByDay;
 
+    error UserAlreadyVerified();
     error UnrecognizedInvitation();
     error IndexOutOfBounds();
-    error InvitationAlreadyAccepted();
+    error CanNotInviteYourself();
+
+    event UserVerified(address indexed userAddress, uint256 verifiedAt);
     event InvitationAccepted(address indexed inviter, address indexed invitee, uint256 timestamp);
 
-    function verifySignature(address inviter, Signature calldata signature) private pure {
+    function _markAsVerified(address user) internal {
+        // Check if the user is already verified
+        if (userVerificationTimestamps[user] > 0) revert UserAlreadyVerified();
+
+        userVerificationTimestamps[user] = block.timestamp;
+        emit UserVerified(user, block.timestamp);
+    }
+
+    function markAsVerified() external {
+        _markAsVerified(msg.sender);
+    }
+
+    function hasBeenVerified(address userAddress) external view returns (bool) {
+        return userVerificationTimestamps[userAddress] > 0;
+    }
+
+    function getVerifiedTimestamp(address userAddress) external view returns (uint256) {
+        return userVerificationTimestamps[userAddress];
+    }
+
+    function _verifySignature(address inviter, Signature calldata signature) private pure {
         bytes32 payloadHash = keccak256(abi.encode(inviter));
         bytes32 messageHash = keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", payloadHash));
 
@@ -35,11 +60,11 @@ contract InvitationManager {
     }
 
     function confirmAndAcceptInvitation(address inviter, Signature calldata signature) external {
-        if (acceptedInvitationsTimestamp[inviter][msg.sender] != 0) revert InvitationAlreadyAccepted();
-
-        verifySignature(inviter, signature);
+        if (inviter == msg.sender) revert CanNotInviteYourself();
+        _verifySignature(inviter, signature);
 
         acceptedInvitationsTimestamp[inviter][msg.sender] = block.timestamp;
+        _markAsVerified(msg.sender);
 
         // Add the invitee to the inviter's list
         inviteeLists[inviter].push(msg.sender);