import 'package:flutter/rendering.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:halkyon_learn_flutter/src/core/video/media_players.dart';
import 'package:halkyon_learn_flutter/src/core/video/subtitles.dart';
import 'package:halkyon_learn_flutter/src/feature/jellyfin/data/jellyfin_gateway.dart';
import 'package:http/http.dart' as http;
import 'package:integration_test/integration_test.dart';
import 'package:material_ui/material_ui.dart';

// The video player for real (ExoPlayer on Android, libmpv on Linux and
// Windows), streaming from a Jellyfin server, which `flutter test` can't:
// on a device or the desktop,
//
//   flutter test integration_test/jellyfin_player_test.dart -d <device> \
//     --dart-define=JELLYFIN_URL=https://jellyfin.example.org \
//     --dart-define=JELLYFIN_USER=<name> \
//     --dart-define=JELLYFIN_PASSWORD=<password>
//
// with a server holding at least one episode, film or video with text
// subtitles, reached over HTTPS as the app reaches it (Android refuses plain
// HTTP to it). A Linux build needs libmpv-dev.
const _url = String.fromEnvironment('JELLYFIN_URL');
const _user = String.fromEnvironment('JELLYFIN_USER');
const _password = String.fromEnvironment('JELLYFIN_PASSWORD');

void main() {
  // Frames as the app draws them, as the picture is checked.
  IntegrationTestWidgetsFlutterBinding.ensureInitialized().framePolicy =
      LiveTestWidgetsFlutterBindingFramePolicy.fullyLive;

  testWidgets('streams a video with subtitles from the server and plays it', (
    tester,
  ) async {
    final client = http.Client();
    addTearDown(client.close);
    final gateway = HttpJellyfinGateway(
      client,
      device: (id: 'device-check', name: 'Device check', version: '0'),
    );
    final found = await tester.runAsync(() async {
      final server = await gateway.server(Uri.parse(_url));
      final account = await gateway.signIn(server, _user, _password);
      final videos = await gateway.search(account, '');
      final libraries = await gateway.libraries(account);
      // Down the first library to its first video.
      var items = [...videos, ...libraries];
      for (var depth = 0; depth < 4; depth++) {
        final video = items.where((item) => item.kind.isVideo).firstOrNull;
        if (video != null) {
          final playback = await gateway.playback(account, video.id);
          final track = playback.subtitles
              .where((track) => track.isText)
              .firstOrNull;
          final cues = track == null
              ? const <SubtitleCue>[]
              : parseSubtitles(
                  await gateway.subtitles(account, playback, track),
                );
          return (account: account, playback: playback, cues: cues);
        }
        items = items.isEmpty
            ? items
            : await gateway.children(account, items.first.id);
      }
      return null;
    });
    expect(found, isNotNull, reason: 'No video found on $_url');
    final (:account, :playback, :cues) = found!;
    expect(cues, isNotEmpty, reason: 'The video has no text subtitles');

    final players = PlatformMediaPlayers();
    expect(players.available, isTrue);
    // From the middle, where a picture is unlikely to be one colour.
    final video = (await tester.runAsync(
      () => players.open(
        gateway.streamOf(account, playback),
        headers: gateway.headersOf(account),
        start: (playback.runTime ?? Duration.zero) ~/ 2,
      ),
    ))!;
    addTearDown(() => tester.runAsync(video.dispose));
    final picture = GlobalKey();
    await tester.pumpWidget(
      MaterialApp(
        home: Scaffold(
          body: Center(
            child: RepaintBoundary(
              key: picture,
              child: SizedBox(width: 640, height: 360, child: video.view()),
            ),
          ),
        ),
      ),
    );

    await tester.runAsync(() async {
      await video.play();
      await Future<void>.delayed(const Duration(seconds: 4));
    });
    await tester.pump();

    final state = video.state.value;
    expect(state.error, isNull);
    expect(state.duration, greaterThan(Duration.zero));
    expect(state.position, greaterThan(const Duration(seconds: 1)));
    // The picture is drawn, not only the sound played: a frame isn't one
    // flat colour.
    final boundary =
        picture.currentContext!.findRenderObject()! as RenderRepaintBoundary;
    final frame = (await tester.runAsync(() async {
      final image = await boundary.toImage();
      return (await image.toByteData())!;
    }))!;
    final lightness = [
      for (var i = 0; i < frame.lengthInBytes; i += 4)
        frame.getUint8(i) + frame.getUint8(i + 1) + frame.getUint8(i + 2),
    ];
    final mean = lightness.reduce((a, b) => a + b) / lightness.length;
    final spread =
        lightness.map((value) => (value - mean).abs()).reduce((a, b) => a + b) /
        lightness.length;
    expect(spread, greaterThan(4), reason: 'The picture is one flat colour');

    await tester.runAsync(() => video.seekTo(cues.first.start));
    await tester.runAsync(
      () => Future<void>.delayed(const Duration(milliseconds: 500)),
    );
    expect(
      cueAt(cues, video.state.value.position + const Duration(milliseconds: 1)),
      isNotNull,
    );
  });
}