//@dart=2.12

import 'dart:async';
import 'dart:io';

import 'package:flutter/material.dart';

import 'package:emoji_picker_flutter/emoji_picker_flutter.dart';
import 'package:flutter_gen/gen_l10n/l10n.dart';
import 'package:matrix/matrix.dart';
import 'package:path_provider/path_provider.dart';
import 'package:video_player/video_player.dart';
import 'package:vrouter/vrouter.dart';

import 'package:fluffychat/pages/story/story_view.dart';
import 'package:fluffychat/utils/matrix_sdk_extensions.dart/client_stories_extension.dart';
import 'package:fluffychat/utils/platform_infos.dart';
import 'package:fluffychat/utils/room_status_extension.dart';
import 'package:fluffychat/widgets/avatar.dart';
import 'package:fluffychat/widgets/matrix.dart';

class StoryPage extends StatefulWidget {
  const StoryPage({Key? key}) : super(key: key);

  @override
  StoryPageController createState() => StoryPageController();
}

class StoryPageController extends State<StoryPage> {
  int index = 0;
  int max = 0;
  Duration progress = Duration.zero;
  Timer? _progressTimer;
  bool loadingMode = false;

  final TextEditingController replyController = TextEditingController();
  final FocusNode replyFocus = FocusNode();

  final List<Event> events = [];

  Timeline? timeline;

  Event? get currentEvent => index < events.length ? events[index] : null;

  bool replyLoading = false;

  void replyEmojiAction() async {
    if (replyLoading) return;
    hold();
    await showModalBottomSheet(
      context: context,
      builder: (context) => EmojiPicker(
        onEmojiSelected: (c, e) {
          Navigator.of(context).pop();
          replyAction(e.emoji);
        },
      ),
    );
    unhold();
  }

  void replyAction([String? message]) async {
    message ??= replyController.text;
    setState(() {
      replyLoading = true;
    });
    try {
      final client = Matrix.of(context).client;
      final roomId = await client.startDirectChat(currentEvent!.senderId);
      await client.getRoomById(roomId)!.sendTextEvent(
            message,
            inReplyTo: currentEvent!,
          );
      replyController.clear();
      replyFocus.unfocus();
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(L10n.of(context)!.replyHasBeenSent),
        ),
      );
    } catch (e, s) {
      Logs().w('Unable to reply to story', e, s);
    } finally {
      setState(() {
        replyLoading = false;
      });
    }
  }

  List<User> get currentSeenByUsers {
    final timeline = this.timeline;
    final currentEvent = this.currentEvent;
    if (timeline == null || currentEvent == null) return [];
    return Matrix.of(context).client.getRoomById(roomId)?.getSeenByUsers(
              timeline,
              events,
              {},
              eventId: currentEvent.eventId,
            ) ??
        [];
  }

  void displaySeenByUsers() => showModalBottomSheet(
        context: context,
        builder: (context) => Scaffold(
          appBar: AppBar(
            title: Text(seenByUsersTitle),
          ),
          body: ListView.builder(
            itemCount: currentSeenByUsers.length,
            itemBuilder: (context, i) => ListTile(
              leading: Avatar(
                mxContent: currentSeenByUsers[i].avatarUrl,
                name: currentSeenByUsers[i].calcDisplayname(),
              ),
              title: Text(currentSeenByUsers[i].calcDisplayname()),
            ),
          ),
        ),
      );

  String get seenByUsersTitle {
    final seenByUsers = currentSeenByUsers;
    if (seenByUsers.isEmpty) return '';
    if (seenByUsers.length == 1) {
      return L10n.of(context)!.seenByUser(seenByUsers.single.calcDisplayname());
    }
    if (seenByUsers.length == 2) {
      return L10n.of(context)!.seenByUserAndUser(
        seenByUsers.first.calcDisplayname(),
        seenByUsers.last.calcDisplayname(),
      );
    }
    return L10n.of(context)!.seenByUserAndCountOthers(
      seenByUsers.single.calcDisplayname(),
      seenByUsers.length - 1,
    );
  }

  static const Duration _step = Duration(milliseconds: 50);
  static const Duration maxProgress = Duration(seconds: 5);

  void _restartTimer([bool reset = true]) {
    _progressTimer?.cancel();
    if (reset) progress = Duration.zero;
    _progressTimer = Timer.periodic(_step, (_) {
      if (!mounted) {
        _progressTimer?.cancel();
        return;
      }
      if (loadingMode) return;
      setState(() {
        progress = progress += _step;
      });
      if (progress > maxProgress) {
        skip();
      }
    });
  }

  bool get isOwnStory {
    final client = Matrix.of(context).client;
    final room = client.getRoomById(roomId);
    if (room == null) return false;
    return room.ownPowerLevel >= 100;
  }

  String get roomId => VRouter.of(context).pathParameters['roomid'] ?? '';

  Future<VideoPlayerController> loadVideoController(Event event) async {
    final matrixFile = await event.downloadAndDecryptAttachment();
    final tmpDirectory = await getTemporaryDirectory();
    final file = File(tmpDirectory.path + matrixFile.name);
    final videoPlayerController = VideoPlayerController.file(file)
      ..setLooping(true);
    await videoPlayerController.initialize();
    videoPlayerController.play();
    return videoPlayerController;
  }

  void skip() {
    if (index + 1 >= max) {
      VRouter.of(context).to('/rooms');
      return;
    }
    setState(() {
      index++;
    });
    _restartTimer();
    maybeSetReadMarker();
  }

  DateTime _holdedAt = DateTime.fromMicrosecondsSinceEpoch(0);

  bool isHold = false;

  void hold([_]) {
    _holdedAt = DateTime.now();
    if (loadingMode) return;
    _progressTimer?.cancel();
    setState(() {
      isHold = true;
    });
  }

  void unhold([_]) {
    isHold = false;
    if (DateTime.now().millisecondsSinceEpoch -
            _holdedAt.millisecondsSinceEpoch <
        200) {
      skip();
      return;
    }
    _restartTimer(false);
  }

  void loadingModeOn() => _setLoadingMode(true);
  void loadingModeOff() => _setLoadingMode(false);

  final Map<String, Future<MatrixFile>> _fileCache = {};

  Future<MatrixFile> downloadAndDecryptAttachment(
      Event event, bool getThumbnail) async {
    return _fileCache[event.eventId] ??=
        event.downloadAndDecryptAttachment(getThumbnail: getThumbnail);
  }

  void _setLoadingMode(bool mode) => loadingMode != mode
      ? WidgetsBinding.instance?.addPostFrameCallback((_) {
          setState(() {
            loadingMode = mode;
          });
        })
      : null;

  Uri? get avatar => Matrix.of(context)
      .client
      .getRoomById(roomId)
      ?.getState(EventTypes.RoomCreate)
      ?.sender
      .avatarUrl;

  String get title =>
      Matrix.of(context)
          .client
          .getRoomById(roomId)
          ?.getState(EventTypes.RoomCreate)
          ?.sender
          .calcDisplayname() ??
      'Story not found';

  Future<void>? loadStory;

  Future<void> _loadStory() async {
    try {
      final client = Matrix.of(context).client;
      await client.roomsLoading;
      await client.accountDataLoading;
      final room = client.getRoomById(roomId);
      if (room == null) return;
      if (room.membership != Membership.join) {
        final joinedFuture = room.client.onSync.stream
            .where((u) => u.rooms?.join?.containsKey(room.id) ?? false)
            .first;
        await room.join();
        await joinedFuture;
      }
      final timeline = this.timeline = await room.getTimeline();
      timeline.requestKeys();
      var events =
          timeline.events.where((e) => e.type == EventTypes.Message).toList();

      final hasOutdatedEvents = events.removeOutdatedEvents();

      // Request history if possible
      if (!hasOutdatedEvents &&
          timeline.events.first.type != EventTypes.RoomCreate &&
          events.length < 30) {
        try {
          await timeline
              .requestHistory(historyCount: 100)
              .timeout(const Duration(seconds: 5));
          events = timeline.events
              .where((e) => e.type == EventTypes.Message)
              .toList();
          events.removeOutdatedEvents();
        } catch (e, s) {
          Logs().d('Unable to request history in stories', e, s);
        }
      }

      max = events.length;
      if (events.isNotEmpty) {
        _restartTimer();
      }

      // Preload images and videos
      events
          .where((event) => {MessageTypes.Image, MessageTypes.Video}
              .contains(event.messageType))
          .forEach((event) => downloadAndDecryptAttachment(
              event,
              event.messageType == MessageTypes.Video &&
                  PlatformInfos.isMobile));

      // Reverse list
      this.events.clear();
      this.events.addAll(events.reversed.toList());

      // Set start position
      if (this.events.isNotEmpty) {
        final receiptId = room.roomAccountData['m.receipt']?.content
            .tryGetMap<String, dynamic>(room.client.userID!)
            ?.tryGet<String>('event_id');
        index = this.events.indexWhere((event) => event.eventId == receiptId);
        index++;
        if (index >= this.events.length) index = 0;
      }
      maybeSetReadMarker();
    } catch (e, s) {
      Logs().e('Unable to load story', e, s);
    }
    return;
  }

  void maybeSetReadMarker() {
    final currentEvent = this.currentEvent;
    if (currentEvent == null) return;
    final room = currentEvent.room;
    if (!currentSeenByUsers.any((u) => u.id == u.room.client.userID)) {
      room.setReadMarker(
        currentEvent.eventId,
        mRead: currentEvent.eventId,
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    loadStory ??= _loadStory();
    return StoryView(this);
  }
}

extension on List<Event> {
  bool removeOutdatedEvents() {
    final outdatedIndex = indexWhere((event) =>
        DateTime.now().difference(event.originServerTs).inHours >
        ClientStoriesExtension.lifeTimeInHours);
    if (outdatedIndex != -1) {
      removeRange(outdatedIndex, length);
      return true;
    }
    return false;
  }
}