import 'dart:io';

import 'package:flutter_test/flutter_test.dart';
import 'package:halkyon_app/halkyon_app.dart';
import 'package:halkyon_app/testing.dart';
import 'package:material_ui/material_ui.dart';
import 'package:path/path.dart' as p;

void main() {
  final files = {
    '0.18.0.en.txt': '- Eighteen\n',
    '0.19.0.en.txt': '- Nineteen, first\n- Nineteen, second\n',
    '0.19.0.de.txt': '- Neunzehn\n',
    '0.20.0.en.txt': '- Twenty\n\n',
    '0.21.0.en.txt': '- Not out yet\n',
    'notes.txt': '- Not a release\n',
  };

  /// [releases] as lists, which compare by their contents.
  List<Object> flat(Iterable<ReleaseChanges?> releases) => [
    for (final release in releases) [release?.version, release?.changes],
  ];

  WhatsNew whatsNew(MemoryWhatsNewStore store, {String version = '0.20.0'}) =>
      WhatsNew(MemoryWhatsNewSource(files), store, version: version);

  group('unseen', () {
    test('after an update, every release since the one shown last, newest '
        'first, and they count as seen', () async {
      final store = MemoryWhatsNewStore(seen: '0.18.0');

      final releases = await whatsNew(
        store,
      ).unseen(language: 'en', usedBefore: true);

      expect(flat(releases), [
        [
          '0.20.0',
          ['Twenty'],
        ],
        [
          '0.19.0',
          ['Nineteen, first', 'Nineteen, second'],
        ],
      ]);
      expect(store.seen, '0.20.0');
    });

    test(
      'in the language asked for where there is one, else English',
      () async {
        final releases = await whatsNew(
          MemoryWhatsNewStore(seen: '0.18.0'),
        ).unseen(language: 'de', usedBefore: true);

        expect(flat(releases), [
          [
            '0.20.0',
            ['Twenty'],
          ],
          [
            '0.19.0',
            ['Neunzehn'],
          ],
        ]);
      },
    );

    test('nothing once seen', () async {
      final store = MemoryWhatsNewStore(seen: '0.18.0');
      await whatsNew(store).unseen(language: 'en', usedBefore: true);

      expect(
        await whatsNew(store).unseen(language: 'en', usedBefore: true),
        isEmpty,
      );
    });

    test('nothing on a fresh install, which counts as seen', () async {
      final store = MemoryWhatsNewStore();

      expect(
        await whatsNew(store).unseen(language: 'en', usedBefore: false),
        isEmpty,
      );
      expect(store.seen, '0.20.0');
    });

    test('a device used before the app showed what is new gets the version '
        'that runs alone', () async {
      final releases = await whatsNew(
        MemoryWhatsNewStore(),
      ).unseen(language: 'en', usedBefore: true);

      expect(flat(releases), [
        [
          '0.20.0',
          ['Twenty'],
        ],
      ]);
    });

    test('nothing after going back to an older version, which counts as seen '
        'from then', () async {
      final store = MemoryWhatsNewStore(seen: '0.21.0');

      expect(
        await whatsNew(store).unseen(language: 'en', usedBefore: true),
        isEmpty,
      );
      expect(store.seen, '0.20.0');
    });

    test('nothing for a version without a release number, such as a '
        "development build's", () async {
      final store = MemoryWhatsNewStore(seen: '0.18.0');

      expect(
        await whatsNew(
          store,
          version: 'dev',
        ).unseen(language: 'en', usedBefore: true),
        isEmpty,
      );
      expect(store.seen, '0.18.0');
    });
  });

  test("current is the running version's changes, null without", () async {
    expect(
      flat([await whatsNew(MemoryWhatsNewStore()).current(language: 'de')]),
      [
        [
          '0.20.0',
          ['Twenty'],
        ],
      ],
    );
    expect(
      await whatsNew(
        MemoryWhatsNewStore(),
        version: '0.17.0',
      ).current(language: 'en'),
      isNull,
    );
  });

  test("changesOf takes the lines starting with '- '", () {
    expect(changesOf('Intro\n- One\n  - Two  \n\n-Three\n'), ['One', 'Two']);
  });

  group('FileWhatsNewStore', () {
    late Directory folder;

    setUp(() => folder = Directory.systemTemp.createTempSync('whats_new'));
    tearDown(() => folder.deleteSync(recursive: true));

    test('keeps the version shown last; none before', () async {
      final file = File(p.join(folder.path, 'whats_new.json'));

      expect(await FileWhatsNewStore(file).read(), isNull);
      await FileWhatsNewStore(file).write('0.20.0');

      expect(await FileWhatsNewStore(file).read(), '0.20.0');
    });

    test('reads nothing from a broken file', () async {
      final file = File(p.join(folder.path, 'whats_new.json'))
        ..writeAsStringSync('{');

      expect(await FileWhatsNewStore(file).read(), isNull);
    });
  });

  group('widgets', () {
    Future<MemoryWhatsNewStore> show(
      WidgetTester tester, {
      required String? seen,
      Widget child = const WhatsNewOnUpdate(child: Text('Tabs')),
    }) async {
      final store = MemoryWhatsNewStore(seen: seen);
      await tester.pumpWidget(
        WhatsNewScope(
          whatsNew: whatsNew(store),
          usedBefore: true,
          child: testApp(Scaffold(body: child)),
        ),
      );
      await tester.pumpAndSettle();
      return store;
    }

    testWidgets('after an update, the sheet lists each release since', (
      tester,
    ) async {
      await show(tester, seen: '0.18.0');

      expect(find.text("What's new"), findsOneWidget);
      expect(find.text('Version 0.20.0'), findsOneWidget);
      expect(find.text('Twenty'), findsOneWidget);
      expect(find.text('Version 0.19.0'), findsOneWidget);
      expect(find.text('Nineteen, second'), findsOneWidget);
      expect(
        tester.getTopLeft(find.text('Version 0.20.0')).dy,
        lessThan(tester.getTopLeft(find.text('Version 0.19.0')).dy),
      );
    });

    testWidgets('once seen, no sheet', (tester) async {
      await show(tester, seen: '0.20.0');

      expect(find.text("What's new"), findsNothing);
      expect(find.text('Tabs'), findsOneWidget);
    });

    testWidgets("Settings' tile shows the running version's changes", (
      tester,
    ) async {
      await show(tester, seen: '0.20.0', child: const WhatsNewTile());

      expect(find.text('Version 0.20.0'), findsOneWidget);
      await tester.tap(find.text("What's new"));
      await tester.pumpAndSettle();

      expect(find.text('Twenty'), findsOneWidget);
    });

    testWidgets('without a scope, neither the sheet nor the tile', (
      tester,
    ) async {
      await tester.pumpWidget(
        testApp(
          const Scaffold(
            body: WhatsNewOnUpdate(child: WhatsNewTile()),
          ),
        ),
      );
      await tester.pumpAndSettle();

      expect(find.text("What's new"), findsNothing);
    });
  });
}