resolve method

@override Future<ResolvedIdentity> resolve(String identity)

Resolves a handle (alice.example, optionally @/at:// prefixed) or a DID (did:plc: / did:web:) to its atproto identity.

Implementation

@override
Future<ResolvedIdentity> resolve(final String identity) async {
  var normalized = identity.trim();
  if (normalized.startsWith('at://')) {
    normalized = normalized.substring('at://'.length);
  }
  if (normalized.startsWith('@')) normalized = normalized.substring(1);
  if (normalized.isEmpty) {
    throw ArgumentError.value(identity, 'identity', 'must not be empty');
  }

  final String did;
  final String? handle;
  if (normalized.startsWith('did:')) {
    did = normalized;
    handle = null;
  } else {
    handle = normalized.toLowerCase();
    did = await _resolveHandle(handle);
  }

  final didDocument = await _resolveDidDocument(did);

  if (handle != null) {
    final alsoKnownAs = didDocument['alsoKnownAs'];
    final claimsHandle =
        alsoKnownAs is List &&
        alsoKnownAs.whereType<String>().any(
          (final aka) => aka.toLowerCase() == 'at://$handle',
        );
    if (!claimsHandle) {
      throw IdentityException(
        'Bidirectional handle verification failed: the DID document for '
        '"$did" does not list "at://$handle" in "alsoKnownAs"',
      );
    }
  }

  return ResolvedIdentity(
    did: did,
    pds: _extractPdsEndpoint(didDocument, did),
    handle: handle,
    signingKey: signingKeyOf(didDocument, did),
  );
}