import 'package:flutter_test/flutter_test.dart';
import 'package:marianum_mobile/session/account_codec.dart';
import 'package:marianum_mobile/session/session.dart';
import 'package:marianum_mobile/session/session_codec.dart';

void main() {
  final school = CredentialSession(username: 'max', password: 'pw');
  const guardian = GuardianSession(email: 'eltern@x.de');

  group('AccountIndex.activate', () {
    test('adds an unknown account with its own namespace', () {
      final index = AccountIndex.empty.activate(school, newId: 'a', now: 5);
      expect(index.activeId, 'a');
      final entry = index.active!;
      expect(entry.kind, SessionKeys.kindCredential);
      expect(entry.label, 'max');
      expect(entry.namespace, 'a');
      expect(entry.lastUsed, 5);
    });

    test('legacy account keeps the un-namespaced storage', () {
      final index = AccountIndex.empty.activate(
        school,
        newId: 'a',
        namespace: '',
      );
      expect(index.active!.namespace, '');
    });

    test('a known account is reused instead of duplicated', () {
      final index = AccountIndex.empty
          .activate(school, newId: 'a')
          .activate(guardian, newId: 'b')
          .activate(
            CredentialSession(username: 'max', password: 'new'),
            newId: 'c',
            now: 9,
          );
      expect(index.accounts.map((e) => e.id), ['a', 'b']);
      expect(index.activeId, 'a');
      expect(index.active!.lastUsed, 9);
    });

    test('demo and real account with the same name stay apart', () {
      final index = AccountIndex.empty
          .activate(school, newId: 'a')
          .activate(
            CredentialSession(username: 'max', password: 'demo', isDemo: true),
            newId: 'b',
          );
      expect(index.accounts, hasLength(2));
    });
  });

  group('AccountIndex removal', () {
    final index = AccountIndex.empty
        .activate(school, newId: 'a', now: 1)
        .activate(guardian, newId: 'b', now: 3)
        .select('a', now: 2);

    test('removing the active account leaves none active', () {
      final removed = index.remove('a');
      expect(removed.activeId, isNull);
      expect(removed.accounts.map((e) => e.id), ['b']);
    });

    test('removing an inactive account keeps the active one', () {
      expect(index.remove('b').activeId, 'a');
    });

    test('takeover picks the most recently used remaining account', () {
      final third = index.activate(
        const GuardianSession(email: 'z@x.de'),
        newId: 'c',
        now: 1,
      );
      expect(third.remove('a').mostRecentExcept(null)?.id, 'b');
      expect(index.mostRecentExcept('b')?.id, 'a');
      expect(AccountIndex.empty.mostRecentExcept(null), isNull);
    });
  });

  group('AccountIndex codec', () {
    test('round trip', () {
      final index = AccountIndex.empty
          .activate(school, newId: 'a', namespace: '', now: 1)
          .activate(guardian, newId: 'b', now: 2);
      final decoded = AccountIndex.decode(index.encode());
      expect(decoded.activeId, 'b');
      expect(decoded.accounts, hasLength(2));
      expect(decoded.byId('a')!.namespace, '');
      expect(decoded.byId('b')!.isGuardian, isTrue);
      expect(decoded.byId('b')!.lastUsed, 2);
    });

    test('display name survives rename and round trip', () {
      final index = AccountIndex.empty
          .activate(school, newId: 'a')
          .activate(guardian, newId: 'b')
          .rename('b', 'Erika Muster');
      final decoded = AccountIndex.decode(index.encode());
      expect(decoded.byId('b')!.displayName, 'Erika Muster');
      expect(decoded.byId('a')!.displayName, isNull);
      expect(decoded.activeId, 'b');
    });

    test('garbage decodes to an empty index', () {
      expect(AccountIndex.decode(null).accounts, isEmpty);
      expect(AccountIndex.decode('{nope').accounts, isEmpty);
      expect(AccountIndex.decode('[]').accounts, isEmpty);
    });

    test('malformed entries are skipped', () {
      final decoded = AccountIndex.decode(
        '{"activeId":"a","accounts":[{"id":"a"},'
        '{"id":"b","kind":"guardian","label":"x"}]}',
      );
      expect(decoded.accounts.map((e) => e.id), ['b']);
      expect(decoded.active, isNull);
    });
  });

  group('vault', () {
    test('credential session survives the vault with app passwords', () {
      final session = CredentialSession(
        username: 'max',
        password: 'pw',
        appPassword: 'app',
        appPasswordTalk: 'talk',
        usesLoginFlow: true,
      );
      final fields = decodeVault(
        encodeVault({...sessionVaultFields(session), 'mc_bearer_token': 't'}),
      );
      final restored = decodeSession(fields)! as CredentialSession;
      expect(restored.username, 'max');
      expect(restored.password, 'pw');
      expect(restored.nextcloud.appPassword, 'app');
      expect(restored.nextcloud.appPasswordTalk, 'talk');
      expect(restored.nextcloud.usesLoginFlow, isTrue);
      expect(fields['mc_bearer_token'], 't');
    });

    test('guardian demo session survives the vault', () {
      final fields = decodeVault(
        encodeVault(
          sessionVaultFields(
            const GuardianSession(email: 'e@x.de', isDemo: true),
          ),
        ),
      );
      final restored = decodeSession(fields)! as GuardianSession;
      expect(restored.email, 'e@x.de');
      expect(restored.isDemo, isTrue);
      expect(fields.containsKey(SessionKeys.username), isFalse);
    });

    test('broken vault yields no session', () {
      expect(decodeSession(decodeVault('garbage')), isNull);
    });
  });
}