import 'dart:async';

import 'package:example/localizations.dart';
import 'package:example/routes/routes.dart';
import 'package:example/search_text_field.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:stream_chat_flutter/stream_chat_flutter.dart';
import 'package:flutter_slidable/flutter_slidable.dart';

import 'channel_page.dart';
import 'chat_info_screen.dart';
import 'group_info_screen.dart';

class ChannelList extends StatefulWidget {
  @override
  _ChannelList createState() => _ChannelList();
}

class _ChannelList extends State<ChannelList> {
  ScrollController _scrollController = ScrollController();

  late StreamMessageSearchListController _messageSearchListController =
      StreamMessageSearchListController(
    client: StreamChat.of(context).client,
    filter: Filter.in_('members', [StreamChat.of(context).currentUser!.id]),
    limit: 5,
    searchQuery: '',
    sort: [
      SortOption(
        'created_at',
        direction: SortOption.ASC,
      ),
    ],
  );

  TextEditingController? _controller;

  bool _isSearchActive = false;

  Timer? _debounce;

  void _channelQueryListener() {
    if (_debounce?.isActive ?? false) _debounce!.cancel();
    _debounce = Timer(const Duration(milliseconds: 350), () {
      if (mounted) {
        _messageSearchListController.searchQuery = _controller!.text;
        setState(() {
          _isSearchActive = _controller!.text.isNotEmpty;
        });
        if (_isSearchActive) _messageSearchListController.doInitialLoad();
      }
    });
  }

  late final _channelListController = StreamChannelListController(
    client: StreamChat.of(context).client,
    filter: Filter.in_(
      'members',
      [StreamChat.of(context).currentUser!.id],
    ),
    presence: true,
    limit: 30,
  );

  @override
  void initState() {
    super.initState();
    _controller = TextEditingController()..addListener(_channelQueryListener);
  }

  @override
  void dispose() {
    _controller?.removeListener(_channelQueryListener);
    _controller?.dispose();
    _scrollController.dispose();
    _channelListController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () async {
        if (_isSearchActive) {
          _controller!.clear();
          setState(() => _isSearchActive = false);
          return false;
        }
        return true;
      },
      child: NotificationListener<ScrollUpdateNotification>(
        onNotification: (ScrollNotification scrollInfo) {
          if (_scrollController.position.userScrollDirection ==
              ScrollDirection.reverse) {
            FocusScope.of(context).unfocus();
          }
          return true;
        },
        child: NestedScrollView(
          controller: _scrollController,
          floatHeaderSlivers: false,
          headerSliverBuilder: (_, __) => [
            SliverToBoxAdapter(
              child: SearchTextField(
                controller: _controller,
                showCloseButton: _isSearchActive,
                hintText: AppLocalizations.of(context).search,
              ),
            ),
          ],
          body: _isSearchActive
              ? StreamMessageSearchListView(
                  controller: _messageSearchListController,
                  emptyBuilder: (_) {
                    return LayoutBuilder(
                      builder: (context, viewportConstraints) {
                        return SingleChildScrollView(
                          physics: AlwaysScrollableScrollPhysics(),
                          child: ConstrainedBox(
                            constraints: BoxConstraints(
                              minHeight: viewportConstraints.maxHeight,
                            ),
                            child: Center(
                              child: Column(
                                children: [
                                  Padding(
                                    padding: const EdgeInsets.all(24),
                                    child: StreamSvgIcon.search(
                                      size: 96,
                                      color: Colors.grey,
                                    ),
                                  ),
                                  Text(
                                    AppLocalizations.of(context).noResults,
                                  ),
                                ],
                              ),
                            ),
                          ),
                        );
                      },
                    );
                  },
                  itemBuilder: (
                    context,
                    messageResponses,
                    index,
                    defaultWidget,
                  ) {
                    return defaultWidget.copyWith(
                      onTap: () async {
                        final messageResponse = messageResponses[index];
                        FocusScope.of(context).requestFocus(FocusNode());
                        final client = StreamChat.of(context).client;
                        final message = messageResponse.message;
                        final channel = client.channel(
                          messageResponse.channel!.type,
                          id: messageResponse.channel!.id,
                        );
                        if (channel.state == null) {
                          await channel.watch();
                        }
                        Navigator.pushNamed(
                          context,
                          Routes.CHANNEL_PAGE,
                          arguments: ChannelPageArgs(
                            channel: channel,
                            initialMessage: message,
                          ),
                        );
                      },
                    );
                  },
                )
              : SlidableAutoCloseBehavior(
                  closeWhenOpened: true,
                  child: RefreshIndicator(
                    onRefresh: _channelListController.refresh,
                    child: StreamChannelListView(
                      controller: _channelListController,
                      itemBuilder: (context, channels, index, defaultWidget) {
                        final chatTheme = StreamChatTheme.of(context);
                        final backgroundColor = chatTheme.colorTheme.inputBg;
                        final channel = channels[index];
                        final canDeleteChannel = channel.ownCapabilities
                            .contains(PermissionType.deleteChannel);
                        return Slidable(
                          groupTag: 'channels-actions',
                          endActionPane: ActionPane(
                            extentRatio: canDeleteChannel ? 0.40 : 0.20,
                            motion: const BehindMotion(),
                            children: [
                              CustomSlidableAction(
                                child: Icon(Icons.more_horiz),
                                backgroundColor: backgroundColor,
                                onPressed: (_) {
                                  showChannelInfoModalBottomSheet(
                                    context: context,
                                    channel: channel,
                                    onViewInfoTap: () {
                                      Navigator.pop(context);
                                      Navigator.push(
                                        context,
                                        MaterialPageRoute(
                                          builder: (context) {
                                            final isOneToOne =
                                                channel.memberCount == 2 &&
                                                    channel.isDistinct;
                                            return StreamChannel(
                                              channel: channel,
                                              child: isOneToOne
                                                  ? ChatInfoScreen(
                                                      messageTheme: chatTheme
                                                          .ownMessageTheme,
                                                      user: channel
                                                          .state!.members
                                                          .where((m) =>
                                                              m.userId !=
                                                              channel
                                                                  .client
                                                                  .state
                                                                  .currentUser!
                                                                  .id)
                                                          .first
                                                          .user,
                                                    )
                                                  : GroupInfoScreen(
                                                      messageTheme: chatTheme
                                                          .ownMessageTheme,
                                                    ),
                                            );
                                          },
                                        ),
                                      );
                                    },
                                  );
                                },
                              ),
                              if (canDeleteChannel)
                                CustomSlidableAction(
                                  backgroundColor: backgroundColor,
                                  child: StreamSvgIcon.delete(
                                    color: chatTheme.colorTheme.accentError,
                                  ),
                                  onPressed: (_) async {
                                    final res = await showConfirmationDialog(
                                      context,
                                      title: 'Delete Conversation',
                                      question:
                                          'Are you sure you want to delete this conversation?',
                                      okText: 'Delete',
                                      cancelText: 'Cancel',
                                      icon: StreamSvgIcon.delete(
                                        color: chatTheme.colorTheme.accentError,
                                      ),
                                    );
                                    if (res == true) {
                                      await _channelListController
                                          .deleteChannel(channel);
                                    }
                                  },
                                ),
                            ],
                          ),
                          child: defaultWidget,
                        );
                      },
                      onChannelTap: (channel) {
                        Navigator.pushNamed(
                          context,
                          Routes.CHANNEL_PAGE,
                          arguments: ChannelPageArgs(
                            channel: channel,
                          ),
                        );
                      },
                      emptyBuilder: (_) {
                        return Center(
                          child: Padding(
                            padding: const EdgeInsets.all(8),
                            child: StreamScrollViewEmptyWidget(
                              emptyIcon: StreamSvgIcon.message(
                                size: 148,
                                color: StreamChatTheme.of(context)
                                    .colorTheme
                                    .disabled,
                              ),
                              emptyTitle: TextButton(
                                onPressed: () {
                                  Navigator.pushNamed(
                                    context,
                                    Routes.NEW_CHAT,
                                  );
                                },
                                child: Text(
                                  'Start a chat',
                                  style: StreamChatTheme.of(context)
                                      .textTheme
                                      .bodyBold
                                      .copyWith(
                                        color: StreamChatTheme.of(context)
                                            .colorTheme
                                            .accentPrimary,
                                      ),
                                ),
                              ),
                            ),
                          ),
                        );
                      },
                    ),
                  ),
                ),
        ),
      ),
    );
  }
}