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 SessionBloc bloc;

  /// An anonymous account's session, left from before they went (ADR 0020,
  /// D25).
  const anonymous = SignedIn(authUserId: 'anonymous-1', isIdentified: false);

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

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

  test('nobody signed in, it asks how to start, making no account (ADR '
      '0020, D4)', () async {
    start();

    bloc.add(const SessionEventStarted());

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

  test('keeps a stored session', () async {
    const stored = SignedIn(authUserId: 'stored', isIdentified: true);
    start(status: stored);

    bloc.add(const SessionEventStarted());

    await expectLater(bloc.stream, emits(const SessionStateActive(stored)));
  });

  test(
    "an anonymous account's session left from before ends as the app "
    'starts: the account deleted, the device asked how to start (D25)',
    () async {
      start(status: anonymous);

      bloc.add(const SessionEventStarted());

      await expectLater(bloc.stream, emits(const SessionStateSignedOut()));
      expect(gateway.accountDeletions, 1);
      expect(gateway.status, const SignedOut());
    },
  );

  test('the instance out of reach, the anonymous session still ends on the '
      "device: the account is left to the instance's pruning", () async {
    start(status: anonymous);
    gateway.deletionError = Exception('No connection');

    bloc.add(const SessionEventStarted());

    await expectLater(bloc.stream, emits(const SessionStateSignedOut()));
    expect(gateway.signOuts, 1);
    expect(gateway.status, const SignedOut());
  });

  test("an anonymous session the device can't even end never opens its "
      'app: the start screen all the same', () async {
    start(status: anonymous);
    gateway
      ..deletionError = Exception('No connection')
      ..signOutError = Exception('The keyring is locked');

    bloc.add(const SessionEventStarted());

    await expectLater(bloc.stream, emits(const SessionStateSignedOut()));
    expect(gateway.status, anonymous);
  });

  test('after signing out, asks how to start, deleting nothing', () async {
    const stored = SignedIn(authUserId: 'stored', isIdentified: true);
    start(status: stored);
    bloc.add(const SessionEventStarted());
    await expectLater(bloc.stream, emits(const SessionStateActive(stored)));

    bloc.add(const SessionEventSignOutRequested());

    // The person's app stays while signing out, never the launch screen in
    // between.
    await expectLater(
      bloc.stream,
      emitsInOrder([
        const SessionStateActive(stored, busy: SessionAction.signOut),
        const SessionStateSignedOut(),
      ]),
    );
    expect(gateway.accountDeletions, 0);
  });

  test('signing in with GitHub from there switches to its person', () async {
    start();
    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)));
  });

  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();
    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.gitHubSwitches, 0);
  });

  test('an account that signs in with its password now, and GitHub having '
      'ended, are each said so, signing nobody in', () async {
    start();
    bloc.add(const SessionEventStarted());
    await expectLater(bloc.stream, emits(const SessionStateSignedOut()));

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

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

  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 SessionStateActive(stored, busy: SessionAction.delete),
        const SessionStateSignedOut(),
      ]),
    );
    expect(gateway.accountDeletions, 1);
  });

  test('a deletion that fails keeps the person signed in, their app in '
      'place, and says so; asked again, it tries again', () 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.deletionError = Exception('No connection');

    bloc.add(const SessionEventDeleteRequested());

    await expectLater(
      bloc.stream,
      emitsInOrder([
        const SessionStateActive(stored, busy: SessionAction.delete),
        const SessionStateActive(stored, problem: SessionProblem.deleteFailed),
      ]),
    );
    expect(gateway.status, stored);

    gateway.deletionError = null;
    bloc.add(const SessionEventDeleteRequested());

    await expectLater(
      bloc.stream,
      emitsInOrder([
        const SessionStateActive(stored, busy: SessionAction.delete),
        const SessionStateSignedOut(),
      ]),
    );
    expect(gateway.accountDeletions, 2);
  });

  test('a sign-out that fails keeps the person signed in, their app in '
      'place, and says so', () 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.signOutError = Exception('The keyring is locked');

    bloc.add(const SessionEventSignOutRequested());

    await expectLater(
      bloc.stream,
      emitsInOrder([
        const SessionStateActive(stored, busy: SessionAction.signOut),
        const SessionStateActive(stored, problem: SessionProblem.signOutFailed),
      ]),
    );
    expect(gateway.status, stored);
  });
}