import 'package:flutter_test/flutter_test.dart';
import 'package:halkyon_app/halkyon_app.dart';
import 'package:halkyon_app/testing.dart';

void main() {
  late FakeAuthGateway gateway;
  late MemorySignedOutMark mark;
  late SessionBloc bloc;

  SessionStateActive anonymous(int number) => SessionStateActive(
    SignedIn(authUserId: 'anonymous-$number', isIdentified: false),
  );

  void start({AuthStatus status = const SignedOut(), bool signedOut = false}) {
    gateway = FakeAuthGateway(status: status);
    mark = MemorySignedOutMark(signedOut);
    bloc = SessionBloc(AuthRepository(gateway, MemorySignInAddresses()), mark);
  }

  tearDown(() => bloc.close());

  test('signs in anonymously at a first start, nobody having signed out '
      'here', () async {
    start();

    bloc.add(const SessionEventStarted());

    await expectLater(
      bloc.stream,
      emitsInOrder([const SessionStateLoading(), anonymous(1)]),
    );
    expect(gateway.signIns, 1);
  });

  test('keeps a stored session instead of creating a second account', () async {
    const stored = SignedIn(authUserId: 'stored', isIdentified: false);
    start(status: stored);

    bloc.add(const SessionEventStarted());

    await expectLater(bloc.stream, emits(const SessionStateActive(stored)));
    expect(gateway.signIns, 0);
  });

  test('reports a failed sign-in and signs in when asked again', () async {
    start();
    gateway.signInError = Exception('No connection');

    bloc.add(const SessionEventStarted());
    await expectLater(
      bloc.stream,
      emitsInOrder([const SessionStateLoading(), const SessionStateFailed()]),
    );

    gateway.signInError = null;
    bloc.add(const SessionEventSignInRequested());
    await expectLater(
      bloc.stream,
      emitsInOrder([const SessionStateLoading(), anonymous(2)]),
    );
  });

  test('after signing out, asks how to start, making no account; the next '
      'start of the app asks again', () async {
    const stored = SignedIn(authUserId: 'stored', isIdentified: false);
    start(status: stored);
    bloc.add(const SessionEventStarted());
    await expectLater(bloc.stream, emits(const SessionStateActive(stored)));

    bloc.add(const SessionEventSignOutRequested());

    await expectLater(
      bloc.stream,
      emitsInOrder([
        const SessionStateLoading(),
        const SessionStateSignedOut(),
      ]),
    );
    // Signing out of an anonymous account deletes it.
    expect(gateway.accountDeletions, 1);
    expect(gateway.signIns, 0);
    expect(mark.signedOut, isTrue);

    await bloc.close();
    bloc = SessionBloc(AuthRepository(gateway, MemorySignInAddresses()), mark)
      ..add(const SessionEventStarted());
    await expectLater(bloc.stream, emits(const SessionStateSignedOut()));
    expect(gateway.signIns, 0);
  });

  test('starting without an account from there signs in anonymously, and '
      'the device is no longer signed out', () async {
    start(signedOut: true);
    bloc.add(const SessionEventStarted());
    await expectLater(bloc.stream, emits(const SessionStateSignedOut()));

    bloc.add(const SessionEventStartedAnonymously());

    await expectLater(
      bloc.stream,
      emitsInOrder([const SessionStateLoading(), anonymous(1)]),
    );
    expect(mark.signedOut, isFalse);
  });

  test('signing in with GitHub from there switches to its person; '
      'cancelled, it asks again', () async {
    start(signedOut: true);
    bloc.add(const SessionEventStarted());
    await expectLater(bloc.stream, emits(const SessionStateSignedOut()));

    bloc.add(const SessionEventGitHubRequested());

    // A password is offered first (ADR 0017, D2), then the person's app.
    const person = SignedIn(authUserId: 'github-person', isIdentified: true);
    await expectLater(
      bloc.stream,
      emitsThrough(const SessionStateGitHubSignedIn(person)),
    );
    bloc.add(const SessionEventPasswordOfferDone());
    await expectLater(bloc.stream, emits(const SessionStateActive(person)));
    expect(gateway.signIns, 0);
    expect(mark.signedOut, isFalse);
  });

  test('a GitHub account nobody here signs in with yet is said so; any '
      'other refusal fails, and nothing is made either way', () async {
    start(signedOut: true);
    bloc.add(const SessionEventStarted());
    await expectLater(bloc.stream, emits(const SessionStateSignedOut()));

    gateway.gitHubError = const GitHubSignInFailed(
      GitHubSignInProblem.unknownAccount,
    );
    bloc.add(const SessionEventGitHubRequested());
    await expectLater(
      bloc.stream,
      emitsInOrder([
        const SessionStateSignedOut(busy: true),
        const SessionStateSignedOut(problem: SignedOutProblem.noGitHubAccount),
      ]),
    );

    gateway.gitHubError = const GitHubSignInFailed(GitHubSignInProblem.refused);
    bloc.add(const SessionEventGitHubRequested());
    await expectLater(
      bloc.stream,
      emitsInOrder([
        const SessionStateSignedOut(busy: true),
        const SessionStateSignedOut(problem: SignedOutProblem.failed),
      ]),
    );
    expect(gateway.signIns, 0);
    expect(gateway.gitHubSwitches, 0);
  });

  test('a session the server ended asks how to start too', () async {
    const stored = SignedIn(authUserId: 'github-1', isIdentified: true);
    start(status: stored);
    bloc.add(const SessionEventStarted());
    await expectLater(bloc.stream, emits(const SessionStateActive(stored)));

    gateway.revokeSession();

    await expectLater(bloc.stream, emits(const SessionStateSignedOut()));
    expect(gateway.signIns, 0);
  });

  test('deleting the account asks how to start', () async {
    const stored = SignedIn(authUserId: 'github-1', isIdentified: true);
    start(status: stored);
    bloc.add(const SessionEventStarted());
    await expectLater(bloc.stream, emits(const SessionStateActive(stored)));

    bloc.add(const SessionEventDeleteRequested());

    await expectLater(
      bloc.stream,
      emitsInOrder([
        const SessionStateLoading(),
        const SessionStateSignedOut(),
      ]),
    );
    expect(gateway.accountDeletions, 1);
    expect(gateway.signIns, 0);
  });
}