// SPDX-FileCopyrightText: 2019-Present Christian Kußowski
// SPDX-FileCopyrightText: 2019-Present Contributors to FluffyChat
//
// SPDX-License-Identifier: AGPL-3.0-or-later

import 'dart:async';

import 'package:material_ui/material_ui.dart';
import 'package:matrix/matrix.dart';
import 'package:tatchat/l10n/l10n.dart';
import 'package:tatchat/pages/chat_list/chat_list.dart';
import 'package:tatchat/pages/chat_list/mural_list_item.dart';
import 'package:tatchat/pages/chat_list/tabs/chat_tab_header.dart';
import 'package:tatchat/pages/chat_list/tabs/empty_tab_view.dart';
import 'package:tatchat/pages/chat_list/tabs/home_tab.dart';
import 'package:tatchat/utils/matrix_sdk_extensions/matrix_locals.dart';
import 'package:tatchat/utils/matrix_sdk_extensions/room_extension.dart';
import 'package:tatchat/utils/stream_extension.dart';
import 'package:tatchat/widgets/matrix.dart';

class MuralsTab extends StatefulWidget {
  final ChatListController controller;

  const MuralsTab(this.controller, {super.key});

  @override
  State<MuralsTab> createState() => _MuralsTabState();
}

class _MuralsTabState extends State<MuralsTab> {
  final TextEditingController _searchController = TextEditingController();
  final FocusNode _searchFocusNode = FocusNode();
  final Set<String> _loadingRooms = {};
  bool _isSearchMode = false;

  @override
  void dispose() {
    _searchController.dispose();
    _searchFocusNode.dispose();
    super.dispose();
  }

  /// Loads the missing state events (e.g. `m.room.topic` and `m.room.create`)
  /// of a mural room so that its description and creator are already visible in
  /// the list without having to open the mural first.
  Future<void> _loadMissingRoomState(Room room) async {
    final roomId = room.id;
    try {
      final stateEvents = await room.client.getRoomState(roomId);
      for (final state in stateEvents) {
        room.setState(StrippedStateEvent.fromJson(state.toJson()));
      }
      if (!mounted) return;
      setState(() {});
    } catch (_) {
      // State loading is best-effort, ignore failures (e.g. offline).
    } finally {
      _loadingRooms.remove(roomId);
    }
  }

  @override
  Widget build(BuildContext context) {
    final client = Matrix.of(context).client;
    final theme = Theme.of(context);
    final searchText = _searchController.text.trim().toLowerCase();
    return ChatTabScaffold(
      tab: HomeTab.murals,
      isSearchMode: _isSearchMode,
      onSearchPressed: () => setState(() => _isSearchMode = true),
      onSearchCancelled: () {
        setState(() {
          _isSearchMode = false;
          _searchController.clear();
        });
      },
      searchController: _searchController,
      searchFocusNode: _searchFocusNode,
      onSearchChanged: (_) => setState(() {}),
      controller: widget.controller,
      child: StreamBuilder(
        key: ValueKey(client.userID.toString()),
        stream: client.onSync.stream
            .where((s) => s.hasRoomUpdate)
            .rateLimit(const Duration(seconds: 1)),
        builder: (context, _) {
          final murals = client.rooms
              .where((room) => !room.isLeftOrBanned)
              .where((room) => room.isMural)
              .where(
                (room) =>
                    searchText.isEmpty ||
                    room
                        .getLocalizedDisplayname(MatrixLocals(L10n.of(context)))
                        .toLowerCase()
                        .contains(searchText),
              )
              .toList();
          return ColoredBox(
            color: theme.colorScheme.surface,
            child: CustomScrollView(
              slivers: [
                if (murals.isEmpty)
                  SliverFillRemaining(
                    hasScrollBody: false,
                    child: EmptyTabView(
                      icon: Icons.dashboard_outlined,
                      title: L10n.of(context).noMuralsFound,
                    ),
                  )
                else
                  SliverList.builder(
                    itemCount: murals.length,
                    itemBuilder: (context, i) {
                      final room = murals[i];
                      final roomId = room.id;
                      if ((room.topic.isEmpty || room.creatorUserIds.isEmpty) &&
                          !_loadingRooms.contains(roomId)) {
                        _loadingRooms.add(roomId);
                        unawaited(_loadMissingRoomState(room));
                      }
                      final creatorId = room.creatorUserIds.isEmpty
                          ? null
                          : room.creatorUserIds.first;
                      final creatorState = creatorId == null
                          ? null
                          : room.getState(EventTypes.RoomMember, creatorId);
                      final creatorDisplayName = creatorState?.content
                          .tryGet<String>('displayname');
                      return MuralListItem(
                        room,
                        key: Key('mural_list_item_$roomId'),
                        onTap: () => widget.controller.onChatTap(room),
                        onLongPress: (context) =>
                            widget.controller.chatContextAction(room, context),
                        activeChat: widget.controller.activeChat == room.id,
                        displayAvatar: Uri.tryParse(
                          creatorState?.content.tryGet<String>('avatar_url') ??
                              '',
                        ),
                        displayAvatarName: creatorDisplayName,
                        creatorName: creatorDisplayName ?? creatorId,
                        description: room.topic,
                      );
                    },
                  ),
              ],
            ),
          );
        },
      ),
    );
  }
}