import 'package:flutter_test/flutter_test.dart';
import 'package:halkyon_learn_flutter/src/core/content/rich_content.dart';
import 'package:halkyon_learn_flutter/src/feature/card/data/card_payload.dart';
import 'package:halkyon_learn_flutter/src/feature/card/data/card_repository.dart';
import 'package:halkyon_learn_flutter/src/feature/card/model/card_content.dart';
import 'package:halkyon_learn_flutter/src/feature/learning_path/data/learning_path_repository.dart';
import 'package:halkyon_learn_flutter/src/feature/note/data/note_repository.dart';
import 'package:halkyon_learn_flutter/src/feature/profile/data/profile_repository.dart';
import 'package:halkyon_learn_flutter/src/feature/profile/model/public_profile.dart';
import 'package:halkyon_learn_flutter/src/feature/publish/bloc/publish_bloc.dart';
import 'package:halkyon_learn_flutter/src/feature/publish/data/publish_repository.dart';
import 'package:halkyon_learn_flutter/src/feature/publish/model/publication.dart';
import 'package:halkyon_learn_flutter/src/feature/publish/model/unsettled_item.dart';

import '../../support/fake_card_gateway.dart';
import '../../support/fake_learning_path_gateway.dart';
import '../../support/fake_note_gateway.dart';
import '../../support/fake_profile_gateway.dart';
import '../../support/fake_publish_gateway.dart';
import '../../support/memory_published_store.dart';

RichContent text(String text) => RichContent.plain(text);

CardContent card(String front, String back) =>
    CardContent(front: text(front), back: text(back));

void main() {
  late FakePublishGateway publishing;
  late FakeCardGateway cardGateway;
  late CardRepository cards;
  late List<String> calls;

  setUp(() {
    publishing = FakePublishGateway();
    cardGateway = FakeCardGateway();
    cards = CardRepository(cardGateway);
    calls = [];
  });

  PublishBloc bloc() => PublishBloc(
    PublishRepository(publishing, MemoryPublishedStore()),
    ProfileRepository(
      FakeProfileGateway(
        profile: const PublicProfile(
          handle: 'raisondetredev',
          address: 'raisondetredev@halkyon.eu',
        ),
      ),
    ),
    cards,
    NoteRepository(FakeNoteGateway()),
    LearningPathRepository(FakeLearningPathGateway()),
    studysetId: 'japanese',
    sync: () async => calls.add('sync'),
  );

  /// Publishes through a started [bloc] and returns where it ends.
  Future<PublishStateReady> publish(PublishBloc bloc) async {
    bloc.add(const PublishEventStarted());
    await bloc.stream.firstWhere((state) => state is PublishStateReady);
    bloc.add(
      const PublishEventRequested(
        slug: 'japanese',
        notes: 'First lessons.',
        subtree: ['japanese'],
      ),
    );
    return await bloc.stream.firstWhere(
      (state) => state is PublishStateReady && !state.publishing,
    ) as PublishStateReady;
  }

  /// A card in Japanese, edited on another device on [parents]' heads to
  /// [content].
  Future<String> editedElsewhere(
    CardContent mine,
    CardContent theirs,
  ) async {
    final id = await cards.create('japanese', card('猫', 'cat'));
    final created = (await cards.cardsOf('japanese')).single;
    await cards.save(created, mine);
    cardGateway.receiveRemoteRevision(
      id: 'rev-elsewhere',
      cardId: id,
      parents: created.heads,
      payload: encodeCardPayload(theirs),
    );
    return id;
  }

  test('reads the publication with the profile', () async {
    final publisher = bloc()..add(const PublishEventStarted());

    final ready = await publisher.stream.firstWhere(
      (state) => state is PublishStateReady,
    ) as PublishStateReady;

    expect(ready.publication, isNull);
    expect(ready.profile!.handle, 'raisondetredev');
    await publisher.close();
  });

  test('syncs before publishing: the instance builds the release from what '
      'it holds', () async {
    final publisher = bloc();

    final ready = await publish(publisher);

    expect(ready.outcome, PublishOutcome.published);
    expect(ready.publication!.latest!.version, 1);
    expect(calls, ['sync']);
    expect(publishing.publishes.single.notes, 'First lessons.');
    await publisher.close();
  });

  test('changes from two devices that merge are saved merged, and '
      'publishing tries again', () async {
    final id = await editedElsewhere(card('ねこ', 'cat'), card('猫', 'a cat'));
    publishing.refusals.add(
      PublishRefused(PublishProblem.conflicts, items: [id]),
    );
    final publisher = bloc();

    final ready = await publish(publisher);

    expect(ready.outcome, PublishOutcome.published);
    expect(publishing.publishes, hasLength(2));
    expect(cardGateway.written.last.parents, hasLength(2));
    expect((await cards.cardsOf('japanese')).single.heads, hasLength(1));
    expect(calls, ['sync', 'sync']);
    await publisher.close();
  });

  test('changes that differ on the same side are left to the person, '
      'named', () async {
    final id = await editedElsewhere(card('猫', 'a cat'), card('猫', 'the cat'));
    final written = cardGateway.written.length;
    publishing.refusals.add(
      PublishRefused(PublishProblem.conflicts, items: [id]),
    );
    final publisher = bloc();

    final ready = await publish(publisher);

    expect(ready.problem, PublishProblem.conflicts);
    expect(ready.unsettled, [
      UnsettledItem(
        kind: UnsettledKind.card,
        id: id,
        studysetId: 'japanese',
        title: '猫',
      ),
    ]);
    expect(publishing.publishes, hasLength(1));
    expect(cardGateway.written, hasLength(written));
    await publisher.close();
  });

  test('a refusal says why; an instance out of reach, that nothing was '
      'published', () async {
    publishing.refusals.add(PublishRefused(PublishProblem.nothingChanged));
    final publisher = bloc();

    expect((await publish(publisher)).problem, PublishProblem.nothingChanged);

    publishing.fail = Exception('offline');
    publisher.add(
      const PublishEventRequested(slug: 'japanese', notes: '', subtree: []),
    );
    final failed = await publisher.stream.firstWhere(
      (state) => state is PublishStateReady && !state.publishing,
    ) as PublishStateReady;
    expect(failed.outcome, PublishOutcome.failed);
    expect(failed.publication, isNull);
    await publisher.close();
  });

  group('A name from a title', () {
    test('is lower-case letters and digits with hyphens between', () {
      expect(slugFrom('Japanese'), 'japanese');
      expect(slugFrom('  N5 — Kanji & Kana! '), 'n5-kanji-kana');
      expect(slugFrom('Japanisch für Anfänger'), 'japanisch-fuer-anfaenger');
      expect(slugFrom('Café crème'), 'cafe-creme');
    });

    test('is empty for a title without Latin letters or digits', () {
      expect(slugFrom('日本語'), '');
    });

    test('is at most 50 characters, never ending in a hyphen', () {
      final slug = slugFrom('${'a' * 49} b');
      expect(slug, 'a' * 49);
    });
  });
}