import 'dart:async';

import 'package:adaptive_dialog/adaptive_dialog.dart';
import 'package:adaptive_page_layout/adaptive_page_layout.dart';
import 'package:famedlysdk/famedlysdk.dart';
import 'package:fluffychat/components/avatar.dart';
import 'package:fluffychat/components/default_app_bar_search_field.dart';
import 'package:future_loading_dialog/future_loading_dialog.dart';
import 'package:fluffychat/components/matrix.dart';
import 'package:flutter/material.dart';
import 'package:flutter_gen/gen_l10n/l10n.dart';

class DiscoverPage extends StatefulWidget {
  final String alias;

  const DiscoverPage({Key key, this.alias}) : super(key: key);
  @override
  _DiscoverPageState createState() => _DiscoverPageState();
}

class _DiscoverPageState extends State<DiscoverPage> {
  final ScrollController _scrollController = ScrollController();
  bool _scrolledToTop = true;
  Future<PublicRoomsResponse> _publicRoomsResponse;
  Timer _coolDown;
  String _server;
  String _genericSearchTerm;

  void _search(BuildContext context, String query) async {
    _coolDown?.cancel();
    _coolDown = Timer(
      Duration(milliseconds: 500),
      () => setState(() {
        _genericSearchTerm = query;
        _publicRoomsResponse = null;
      }),
    );
  }

  void _setServer(BuildContext context) async {
    final newServer = await showTextInputDialog(
        title: L10n.of(context).changeTheHomeserver,
        context: context,
        textFields: [
          DialogTextField(
            hintText: Matrix.of(context).client.homeserver.toString(),
            initialText: _server,
            keyboardType: TextInputType.url,
          )
        ]);
    if (newServer == null) return;
    setState(() {
      _server = newServer.single;
      _publicRoomsResponse = null;
    });
  }

  Future<String> _joinRoomAndWait(
    BuildContext context,
    String roomId,
    String alias,
  ) async {
    if (Matrix.of(context).client.getRoomById(roomId) != null) {
      return roomId;
    }
    final newRoomId = await Matrix.of(context)
        .client
        .joinRoomOrAlias(alias?.isNotEmpty ?? false ? alias : roomId);
    await Matrix.of(context)
        .client
        .onRoomUpdate
        .stream
        .firstWhere((r) => r.id == newRoomId);
    return newRoomId;
  }

  void _joinGroupAction(BuildContext context, PublicRoom room) async {
    if (await showOkCancelAlertDialog(
          context: context,
          okLabel: L10n.of(context).joinRoom,
          title: '${room.name} (${room.numJoinedMembers ?? 0})',
          message: room.topic ?? L10n.of(context).noDescription,
        ) ==
        OkCancelResult.cancel) {
      return;
    }
    final success = await showFutureLoadingDialog(
      context: context,
      future: () => _joinRoomAndWait(
        context,
        room.roomId,
        room.canonicalAlias ?? room.aliases.first,
      ),
    );
    if (success.error == null) {
      await AdaptivePageLayout.of(context)
          .pushNamedAndRemoveUntilIsFirst('/rooms/${success.result}');
    }
  }

  @override
  void initState() {
    _genericSearchTerm = widget.alias;
    _scrollController.addListener(() async {
      if (_scrollController.position.pixels > 0 && _scrolledToTop) {
        setState(() => _scrolledToTop = false);
      } else if (_scrollController.position.pixels == 0 && !_scrolledToTop) {
        setState(() => _scrolledToTop = true);
      }
    });
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    final server = _genericSearchTerm?.isValidMatrixId ?? false
        ? _genericSearchTerm.domain
        : _server;
    _publicRoomsResponse ??= Matrix.of(context)
        .client
        .searchPublicRooms(
          server: server,
          genericSearchTerm: _genericSearchTerm,
        )
        .catchError((error) {
      if (widget.alias == null) {
        throw error;
      }
      return PublicRoomsResponse.fromJson({
        'chunk': [],
      });
    }).then((PublicRoomsResponse res) {
      if (widget.alias != null &&
          !res.chunk.any((room) =>
              room.aliases.contains(widget.alias) ||
              room.canonicalAlias == widget.alias)) {
        // we have to tack on the original alias
        res.chunk.add(PublicRoom.fromJson(<String, dynamic>{
          'aliases': [widget.alias],
          'name': widget.alias,
        }));
      }
      return res;
    });
    return Scaffold(
      appBar: AppBar(
        leading: BackButton(),
        titleSpacing: 0,
        elevation: _scrolledToTop ? 0 : null,
        title: DefaultAppBarSearchField(
          onChanged: (text) => _search(context, text),
          hintText: L10n.of(context).searchForAChat,
          suffix: IconButton(
            icon: Icon(Icons.edit_outlined),
            onPressed: () => _setServer(context),
          ),
        ),
      ),
      body: FutureBuilder<PublicRoomsResponse>(
        future: _publicRoomsResponse,
        builder: (BuildContext context,
            AsyncSnapshot<PublicRoomsResponse> snapshot) {
          if (snapshot.hasError) {
            return Center(child: Text(snapshot.error.toString()));
          }
          if (snapshot.connectionState != ConnectionState.done) {
            return Center(child: CircularProgressIndicator());
          }
          final publicRoomsResponse = snapshot.data;
          if (publicRoomsResponse.chunk.isEmpty) {
            return Center(
              child: Text(
                'No public groups found...',
                textAlign: TextAlign.center,
              ),
            );
          }
          return GridView.builder(
            padding: EdgeInsets.all(12),
            gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
              crossAxisCount: 2,
              childAspectRatio: 1,
              crossAxisSpacing: 16,
              mainAxisSpacing: 16,
            ),
            controller: _scrollController,
            itemCount: publicRoomsResponse.chunk.length,
            itemBuilder: (BuildContext context, int i) => Material(
              elevation: 2,
              borderRadius: BorderRadius.circular(16),
              child: InkWell(
                onTap: () => _joinGroupAction(
                  context,
                  publicRoomsResponse.chunk[i],
                ),
                borderRadius: BorderRadius.circular(16),
                child: Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      Avatar(
                          Uri.parse(
                              publicRoomsResponse.chunk[i].avatarUrl ?? ''),
                          publicRoomsResponse.chunk[i].name),
                      Text(
                        publicRoomsResponse.chunk[i].name,
                        style: TextStyle(
                          fontSize: 16,
                          fontWeight: FontWeight.bold,
                        ),
                        maxLines: 1,
                        textAlign: TextAlign.center,
                      ),
                      Text(
                        L10n.of(context).countParticipants(
                            publicRoomsResponse.chunk[i].numJoinedMembers ?? 0),
                        style: TextStyle(fontSize: 10.5),
                        maxLines: 1,
                        textAlign: TextAlign.center,
                      ),
                      Text(
                        publicRoomsResponse.chunk[i].topic ??
                            L10n.of(context).noDescription,
                        maxLines: 4,
                        textAlign: TextAlign.center,
                      ),
                    ],
                  ),
                ),
              ),
            ),
          );
        },
      ),
    );
  }
}