import 'package:halkyon_base_server/base.dart';
import 'package:serverpod/serverpod.dart';
import 'package:serverpod_auth_idp_server/core.dart';
import 'package:test/test.dart';

import '../support/fixtures.dart';
import '../test_tools/serverpod_test_tools.dart';

void main() {
  withServerpod('Deleting an account', (sessionBuilder, endpoints) {
    late Session session;
    late UuidValue anna;
    late UuidValue annasPhone;
    late UuidValue ben;

    /// What the host's deletions saw, in the order they ran.
    late List<String> seen;

    /// The host's deletions: each notes what it finds of the person while it
    /// runs, and what runs once the deletion holds.
    List<PersonDataDeletion> noting(String name) => [
      (session, person, transaction) async {
        final sessions = await ServerSideSession.db.count(
          session,
          where: (t) => t.authUserId.equals(person),
          transaction: transaction,
        );
        final stillThere = await AuthUser.db.findById(
          session,
          person,
          transaction: transaction,
        );
        seen.add(
          '$name: $sessions sessions, '
          'person ${stillThere == null ? 'gone' : 'there'}',
        );
        return () async {
          final gone = await AuthUser.db.findById(session, person) == null;
          seen.add('after $name: person ${gone ? 'gone' : 'there'}');
        };
      },
    ];

    Future<void> deleteAnna() => endpoints.account.delete(
      sessionBuilder.copyWith(
        authentication: AuthenticationOverride.authenticationInfo(
          anna.uuid,
          {},
          authId: annasPhone.uuid,
        ),
      ),
    );

    setUp(() async {
      seen = [];
      useBase(
        sessionBuilder,
        deletePersonData: [...noting('first'), ...noting('second')],
      );
      session = sessionBuilder.build();
      anna = await newAnonymousPerson(session);
      annasPhone = await signInNewDevice(session, anna);
      await signInNewDevice(session, anna);
      ben = await newAnonymousPerson(session);
      await signInNewDevice(session, ben);
    });

    test('refuses callers who are not signed in', () async {
      await expectLater(
        endpoints.account.delete(
          sessionBuilder.copyWith(
            authentication: AuthenticationOverride.unauthenticated(),
          ),
        ),
        throwsA(isA<ServerpodUnauthenticatedException>()),
      );
      expect(seen, isEmpty);
    });

    test('deletes the caller with their sessions and ways in, and nobody '
        'else', () async {
      await EmailIdentity.db.insert(session, [
        for (final (person, hash) in [(anna, 'a' * 64), (ben, 'b' * 64)])
          EmailIdentity(
            authUserId: person,
            addressHash: hash,
            createdAt: DateTime.now().toUtc(),
          ),
      ]);
      // A GitHub ID left from before (ADR 0020, D36) goes too.
      await GitHubAccount.db.insertRow(
        session,
        GitHubAccount(userIdentifier: '4711', authUserId: anna),
      );

      await deleteAnna();

      expect(await AuthUser.db.findById(session, anna), isNull);
      expect(await _sessionsOf(session, anna), 0);
      expect(await _anonymousAccountsOf(session, anna), 0);
      expect(
        await EmailIdentity.db.count(
          session,
          where: (t) => t.authUserId.equals(anna),
        ),
        0,
      );
      expect(
        await GitHubAccount.db.count(
          session,
          where: (t) => t.authUserId.equals(anna),
        ),
        0,
      );

      expect(await AuthUser.db.findById(session, ben), isNotNull);
      expect(await _sessionsOf(session, ben), 1);
      expect(await _anonymousAccountsOf(session, ben), 1);
      expect(
        await EmailIdentity.db.count(
          session,
          where: (t) => t.authUserId.equals(ben),
        ),
        1,
      );
    });

    test("runs the host's deletions in order, once the sessions ended and "
        'before the person goes, and what they leave for afterwards once '
        'it holds', () async {
      await deleteAnna();

      expect(seen, [
        'first: 0 sessions, person there',
        'second: 0 sessions, person there',
        'after first: person gone',
        'after second: person gone',
      ]);
    });

    test("leaves everything as it was when a host's deletion fails, and "
        'runs nothing afterwards', () async {
      useBase(
        sessionBuilder,
        deletePersonData: [
          ...noting('first'),
          (_, _, _) async => throw StateError('the host failed'),
        ],
      );

      await expectLater(deleteAnna(), throwsA(isA<StateError>()));

      expect(await AuthUser.db.findById(session, anna), isNotNull);
      expect(await _sessionsOf(session, anna), 2);
      expect(await _anonymousAccountsOf(session, anna), 1);
      expect(seen, ['first: 0 sessions, person there']);
    });
  });

  withServerpod('Forgetting sign-up attempts', (sessionBuilder, _) {
    late Session session;
    final now = DateTime.now().toUtc();

    setUp(() => session = sessionBuilder.build());

    test('deletes those the rate limit is done with, with their IP '
        'addresses, and keeps the rest', () async {
      Future<UuidValue> attempt(Duration ago) async =>
          (await RateLimitedRequestAttempt.db.insertRow(
            session,
            RateLimitedRequestAttempt(
              domain: 'password_sign_in',
              source: 'proofs_per_address',
              key: '203.0.113.7',
              ipAddress: '203.0.113.7',
              attemptedAt: now.subtract(ago),
            ),
          )).id!;
      final old = await attempt(const Duration(days: 3));
      final done = await attempt(const Duration(minutes: 61));
      final recent = await attempt(const Duration(minutes: 59));

      // Others may have been left by earlier runs.
      expect(
        await forgetOldSignUpAttempts(session, now: now),
        greaterThanOrEqualTo(2),
      );

      for (final forgotten in [old, done]) {
        expect(
          await RateLimitedRequestAttempt.db.findById(session, forgotten),
          isNull,
        );
      }
      expect(
        await RateLimitedRequestAttempt.db.findById(session, recent),
        isNotNull,
      );
    });
  });

  withServerpod('Pruning anonymous people (ADR 0020, D25)', (
    sessionBuilder,
    _,
  ) {
    late Session session;
    final now = DateTime.now().toUtc();
    DateTime daysAgo(int days) => now.subtract(Duration(days: days));

    /// Whom the host's deletion was asked to delete.
    late List<UuidValue> deletedByHost;

    setUp(() {
      deletedByHost = [];
      useBase(
        sessionBuilder,
        deletePersonData: [
          (_, person, _) async {
            deletedByHost.add(person);
            return null;
          },
        ],
      );
      session = sessionBuilder.build();
    });

    test('the module signs nobody in anonymously', () {
      expect(
        session.serverpod.endpoints.getConnectorByName('anonymousIdp'),
        isNull,
      );
    });

    test(
      'deletes every anonymous account left, however new or lately used, '
      "with the host's data of theirs",
      () async {
        final old = await newAnonymousPerson(session, createdAt: daysAgo(100));
        final recentlyUsed = await newAnonymousPerson(
          session,
          createdAt: daysAgo(100),
        );
        await _lastUsed(session, recentlyUsed, daysAgo(1));
        final newcomer = await newAnonymousPerson(session);
        await signInNewDevice(session, newcomer);

        // Others may have been left by earlier runs.
        expect(await pruneAnonymousPeople(session), greaterThanOrEqualTo(3));

        for (final gone in [old, recentlyUsed, newcomer]) {
          expect(await AuthUser.db.findById(session, gone), isNull);
          expect(await _sessionsOf(session, gone), 0);
        }
        expect(deletedByHost, containsAll([old, recentlyUsed, newcomer]));
      },
    );

    test('deletes nobody but anonymous accounts: never someone identified, '
        "even with an anonymous account's row left, nor anyone without "
        'one', () async {
      final identifiedPerson = (await AuthServices.instance.authUsers.create(
        session,
        scopes: {identified},
      )).id;
      // INSERT INTO "serverpod_auth_idp_anonymous_account" (…) VALUES (…)
      await AnonymousAccount.db.insertRow(
        session,
        AnonymousAccount(authUserId: identifiedPerson, createdAt: daysAgo(400)),
      );
      await _lastUsed(session, identifiedPerson, daysAgo(365));
      final noAnonymousAccount = (await AuthServices.instance.authUsers.create(
        session,
      )).id;

      await pruneAnonymousPeople(session);

      for (final kept in [identifiedPerson, noAnonymousAccount]) {
        expect(await AuthUser.db.findById(session, kept), isNotNull);
        expect(deletedByHost, isNot(contains(kept)));
      }
      expect(await _sessionsOf(session, identifiedPerson), 1);
    });

    test('deletes at most as many as it is given at once', () async {
      for (var i = 0; i < 3; i++) {
        await newAnonymousPerson(session);
      }

      expect(await pruneAnonymousPeople(session, limit: 2), 2);
    });
  });
}

/// Signs [person] in on a device last used at [at].
Future<void> _lastUsed(Session session, UuidValue person, DateTime at) async {
  final device = await signInNewDevice(session, person);
  final row = await ServerSideSession.db.findById(session, device);
  await ServerSideSession.db.updateRow(session, row!.copyWith(lastUsedAt: at));
}

Future<int> _sessionsOf(Session session, UuidValue person) =>
    ServerSideSession.db.count(
      session,
      where: (t) => t.authUserId.equals(person),
    );

Future<int> _anonymousAccountsOf(Session session, UuidValue person) =>
    AnonymousAccount.db.count(
      session,
      where: (t) => t.authUserId.equals(person),
    );