import 'package:easy_localization/easy_localization.dart';
import 'package:flutter/material.dart';
import 'package:flutter_expandable_fab/flutter_expandable_fab.dart';
import 'package:gap/gap.dart';
import 'package:go_router/go_router.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:material_symbols_icons/symbols.dart';
import 'package:provider/provider.dart';
import 'package:responsive_framework/responsive_framework.dart';
import 'package:surface/providers/channel.dart';
import 'package:surface/providers/sn_network.dart';
import 'package:surface/providers/user_directory.dart';
import 'package:surface/providers/userinfo.dart';
import 'package:surface/screens/chat/room.dart';
import 'package:surface/types/chat.dart';
import 'package:surface/widgets/account/account_image.dart';
import 'package:surface/widgets/account/account_select.dart';
import 'package:surface/widgets/app_bar_leading.dart';
import 'package:surface/widgets/dialog.dart';
import 'package:surface/widgets/loading_indicator.dart';
import 'package:surface/widgets/navigation/app_background.dart';
import 'package:surface/widgets/navigation/app_scaffold.dart';
import 'package:surface/widgets/unauthorized_hint.dart';
import 'package:uuid/uuid.dart';

class ChatScreen extends StatefulWidget {
  const ChatScreen({super.key});

  @override
  State<ChatScreen> createState() => _ChatScreenState();
}

class _ChatScreenState extends State<ChatScreen> {
  final _fabKey = GlobalKey<ExpandableFabState>();

  bool _isBusy = true;

  List<SnChannel>? _channels;
  Map<int, SnChatMessage>? _lastMessages;
  Map<int, int>? _unreadCounts;

  Future<void> _fetchWhatsNew() async {
    final sn = context.read<SnNetworkProvider>();
    final resp = await sn.client.get('/cgi/im/whats-new');
    if (resp.data == null) return;
    final List<dynamic> out = resp.data;
    setState(() {
      _unreadCounts = {for (var v in out) v['channel_id']: v['count']};
    });
  }

  void _refreshChannels({bool noRemote = false}) {
    final ua = context.read<UserProvider>();
    if (!ua.isAuthorized) {
      setState(() => _isBusy = false);
      return;
    }

    final chan = context.read<ChatChannelProvider>();
    chan.fetchChannels(noRemote: noRemote).listen((channels) async {
      final lastMessages = await chan.getLastMessages(channels);
      _lastMessages = {for (final val in lastMessages) val.channelId: val};
      channels.sort((a, b) {
        if (_lastMessages!.containsKey(a.id) &&
            _lastMessages!.containsKey(b.id)) {
          return _lastMessages![b.id]!
              .createdAt
              .compareTo(_lastMessages![a.id]!.createdAt);
        }
        if (_lastMessages!.containsKey(a.id)) return -1;
        if (_lastMessages!.containsKey(b.id)) return 1;
        return 0;
      });

      if (!mounted) return;
      final ud = context.read<UserDirectoryProvider>();
      for (final channel in channels) {
        if (channel.type == 1) {
          await ud.listAccount(
            channel.members
                    ?.cast<SnChannelMember?>()
                    .map((ele) => ele?.accountId)
                    .where((ele) => ele != null)
                    .toSet() ??
                {},
          );
        }
      }

      if (mounted) setState(() => _channels = channels);
    })
      ..onError((err) {
        if (!mounted) return;
        context.showErrorDialog(err);
        setState(() => _isBusy = false);
      })
      ..onDone(() {
        if (!mounted) return;
        setState(() => _isBusy = false);
      });
  }

  void _newDirectMessage() async {
    final user = await showModalBottomSheet(
      context: context,
      builder: (context) =>
          AccountSelect(title: 'channelNewDirectMessage'.tr()),
    );
    if (user == null) return;
    if (!mounted) return;

    try {
      const uuid = Uuid();
      final sn = context.read<SnNetworkProvider>();
      final ua = context.read<UserProvider>();
      await sn.client.post('/cgi/im/channels/global/dm', data: {
        'alias': uuid.v4().replaceAll('-', '').substring(0, 12),
        'name': 'DM',
        'description':
            'A direct message channel between @${ua.user?.name} and @${user.name}',
        'related_user': user.id,
      });
      _fabKey.currentState!.toggle();
      _refreshChannels();
    } catch (err) {
      if (!mounted) return;
      context.showErrorDialog(err);
    }
  }

  SnChannel? _focusChannel;

  @override
  void initState() {
    super.initState();
    _refreshChannels();
    _fetchWhatsNew();
  }

  void _onTapChannel(SnChannel channel) {
    final doExpand = ResponsiveBreakpoints.of(context).largerOrEqualTo(DESKTOP);

    if (doExpand) {
      setState(() => _focusChannel = channel);
      return;
    }
    GoRouter.of(context).pushNamed(
      'chatRoom',
      pathParameters: {
        'scope': channel.realm?.alias ?? 'global',
        'alias': channel.alias,
      },
    ).then((value) {
      if (mounted) {
        _unreadCounts?[channel.id] = 0;
        setState(() => _unreadCounts?[channel.id] = 0);
        _refreshChannels(noRemote: true);
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    final ud = context.read<UserDirectoryProvider>();
    final ua = context.read<UserProvider>();

    if (!ua.isAuthorized) {
      return AppScaffold(
        appBar: AppBar(
          leading: AutoAppBarLeading(),
          title: Text('screenChat').tr(),
        ),
        body: Center(
          child: UnauthorizedHint(),
        ),
      );
    }

    final doExpand = ResponsiveBreakpoints.of(context).largerOrEqualTo(DESKTOP);

    final chatList = AppScaffold(
      noBackground: doExpand,
      appBar: AppBar(
        leading: AutoAppBarLeading(),
        title: Text('screenChat').tr(),
      ),
      floatingActionButtonLocation: ExpandableFab.location,
      floatingActionButton: ExpandableFab(
        key: _fabKey,
        distance: 75,
        type: ExpandableFabType.up,
        childrenAnimation: ExpandableFabAnimation.none,
        overlayStyle: ExpandableFabOverlayStyle(
          color: Theme.of(context)
              .colorScheme
              .surface
              .withAlpha((255 * 0.5).round()),
        ),
        openButtonBuilder: RotateFloatingActionButtonBuilder(
          child: const Icon(Symbols.add, size: 28),
          fabSize: ExpandableFabSize.regular,
          foregroundColor:
              Theme.of(context).floatingActionButtonTheme.foregroundColor,
          backgroundColor:
              Theme.of(context).floatingActionButtonTheme.backgroundColor,
          shape: const CircleBorder(),
        ),
        closeButtonBuilder: DefaultFloatingActionButtonBuilder(
          child: const Icon(Symbols.close, size: 28),
          fabSize: ExpandableFabSize.regular,
          foregroundColor:
              Theme.of(context).floatingActionButtonTheme.foregroundColor,
          backgroundColor:
              Theme.of(context).floatingActionButtonTheme.backgroundColor,
          shape: const CircleBorder(),
        ),
        children: [
          Row(
            children: [
              Text('channelNewChannel').tr(),
              const Gap(20),
              FloatingActionButton(
                heroTag: null,
                tooltip: 'channelNewChannel'.tr(),
                onPressed: () {
                  _fabKey.currentState!.toggle();
                  GoRouter.of(context).pushNamed('chatManage').then((value) {
                    if (value != null && context.mounted) _refreshChannels();
                  });
                },
                child: const Icon(Symbols.chat_add_on),
              ),
            ],
          ),
          Row(
            children: [
              Text('channelNewDirectMessage').tr(),
              const Gap(20),
              FloatingActionButton(
                heroTag: null,
                tooltip: 'channelNewDirectMessage'.tr(),
                onPressed: _newDirectMessage,
                child: const Icon(Symbols.communication),
              ),
            ],
          ),
        ],
      ),
      body: Column(
        children: [
          LoadingIndicator(isActive: _isBusy),
          Expanded(
            child: MediaQuery.removePadding(
              context: context,
              removeTop: true,
              child: RefreshIndicator(
                onRefresh: () => Future.wait([
                  Future.sync(() => _refreshChannels()),
                  _fetchWhatsNew(),
                ]),
                child: ListView.builder(
                  itemCount: _channels?.length ?? 0,
                  itemBuilder: (context, idx) {
                    final channel = _channels![idx];
                    final lastMessage = _lastMessages?[channel.id];

                    if (channel.type == 1) {
                      final otherMember =
                          channel.members?.cast<SnChannelMember?>().firstWhere(
                                (ele) => ele?.accountId != ua.user?.id,
                                orElse: () => null,
                              );

                      return ListTile(
                        title: Row(
                          children: [
                            Expanded(
                              child: Text(ud
                                      .getAccountFromCache(
                                          otherMember?.accountId)
                                      ?.nick ??
                                  channel.name),
                            ),
                            const Gap(8),
                            if (_unreadCounts?[channel.id] != null &&
                                _unreadCounts![channel.id]! > 0)
                              Badge(
                                label: Text('${_unreadCounts![channel.id]}'),
                              ),
                          ],
                        ),
                        subtitle: lastMessage != null
                            ? Row(
                                children: [
                                  Expanded(
                                    child: Text(
                                      lastMessage.body['text'] ??
                                          'Unable preview',
                                      maxLines: 1,
                                      overflow: TextOverflow.ellipsis,
                                    ),
                                  ),
                                  const Gap(4),
                                  Text(
                                    DateFormat(
                                      lastMessage.createdAt.toLocal().day ==
                                              DateTime.now().day
                                          ? 'HH:mm'
                                          : lastMessage.createdAt
                                                      .toLocal()
                                                      .year ==
                                                  DateTime.now().year
                                              ? 'MM/dd'
                                              : 'yy/MM/dd',
                                    ).format(lastMessage.createdAt.toLocal()),
                                    style: GoogleFonts.robotoMono(
                                      fontSize: 12,
                                    ),
                                  ),
                                ],
                              )
                            : Text(
                                channel.description,
                                maxLines: 1,
                                overflow: TextOverflow.ellipsis,
                              ),
                        contentPadding:
                            const EdgeInsets.symmetric(horizontal: 16),
                        leading: AccountImage(
                          content: ud
                              .getAccountFromCache(otherMember?.accountId)
                              ?.avatar,
                        ),
                        onTap: () {
                          _onTapChannel(channel);
                        },
                      );
                    }

                    return ListTile(
                      title: Row(
                        children: [
                          Expanded(child: Text(channel.name)),
                          const Gap(8),
                          if (_unreadCounts?[channel.id] != null &&
                              _unreadCounts![channel.id]! > 0)
                            Badge(
                              label: Text('${_unreadCounts![channel.id]}'),
                            ),
                        ],
                      ),
                      subtitle: lastMessage != null
                          ? Row(
                              children: [
                                Badge(
                                  label: Text(ud
                                          .getAccountFromCache(
                                              lastMessage.sender.accountId)
                                          ?.nick ??
                                      'unknown'.tr()),
                                  backgroundColor:
                                      Theme.of(context).colorScheme.primary,
                                  textColor:
                                      Theme.of(context).colorScheme.onPrimary,
                                ),
                                const Gap(6),
                                Expanded(
                                  child: Text(
                                    lastMessage.body['text'] ??
                                        'Unable preview',
                                    maxLines: 1,
                                    overflow: TextOverflow.ellipsis,
                                  ),
                                ),
                                const Gap(4),
                                Text(
                                  DateFormat(
                                    lastMessage.createdAt.toLocal().day ==
                                            DateTime.now().day
                                        ? 'HH:mm'
                                        : lastMessage.createdAt
                                                    .toLocal()
                                                    .year ==
                                                DateTime.now().year
                                            ? 'MM/dd'
                                            : 'yy/MM/dd',
                                  ).format(lastMessage.createdAt.toLocal()),
                                  style: GoogleFonts.robotoMono(
                                    fontSize: 12,
                                  ),
                                ),
                              ],
                            )
                          : Text(
                              channel.description,
                              maxLines: 1,
                              overflow: TextOverflow.ellipsis,
                            ),
                      contentPadding:
                          const EdgeInsets.symmetric(horizontal: 16),
                      leading: AccountImage(
                        content: channel.realm?.avatar,
                        fallbackWidget: const Icon(Symbols.chat, size: 20),
                      ),
                      onTap: () {
                        if (doExpand) {
                          _unreadCounts?[channel.id] = 0;
                          setState(() => _focusChannel = channel);
                          return;
                        }
                        _onTapChannel(channel);
                      },
                    );
                  },
                ),
              ),
            ),
          ),
        ],
      ),
    );

    if (doExpand) {
      return AppBackground(
        isRoot: true,
        child: Row(
          children: [
            SizedBox(width: 340, child: chatList),
            const VerticalDivider(width: 1),
            if (_focusChannel != null)
              Expanded(
                child: ChatRoomScreen(
                  key: ValueKey(_focusChannel!.id),
                  scope: _focusChannel!.realm?.alias ?? 'global',
                  alias: _focusChannel!.alias,
                ),
              ),
          ],
        ),
      );
    }

    return chatList;
  }
}