import 'dart:async';

import 'package:contacts_plus_plus/apis/user_api.dart';
import 'package:contacts_plus_plus/client_holder.dart';
import 'package:contacts_plus_plus/clients/messaging_client.dart';
import 'package:contacts_plus_plus/models/friend.dart';
import 'package:contacts_plus_plus/models/personal_profile.dart';
import 'package:contacts_plus_plus/widgets/default_error_widget.dart';
import 'package:contacts_plus_plus/widgets/friends/expanding_input_fab.dart';
import 'package:contacts_plus_plus/widgets/friends/friend_list_tile.dart';
import 'package:contacts_plus_plus/widgets/my_profile_dialog.dart';
import 'package:contacts_plus_plus/widgets/settings_page.dart';
import 'package:contacts_plus_plus/widgets/friends/user_search.dart';
import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import 'package:provider/provider.dart';


class MenuItemDefinition {
  final String name;
  final IconData icon;
  final Function() onTap;

  const MenuItemDefinition({required this.name, required this.icon, required this.onTap});
}

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

  @override
  State<FriendsList> createState() => _FriendsListState();
}

class _FriendsListState extends State<FriendsList> {
  Future<PersonalProfile>? _userProfileFuture;
  Future<UserStatus>? _userStatusFuture;
  ClientHolder? _clientHolder;
  String _searchFilter = "";

  @override
  void didChangeDependencies() async {
    super.didChangeDependencies();
    final clientHolder = ClientHolder.of(context);
    if (_clientHolder != clientHolder) {
      _clientHolder = clientHolder;
      final apiClient = _clientHolder!.apiClient;
      _userProfileFuture = UserApi.getPersonalProfile(apiClient);
      _refreshUserStatus();
    }
  }

  void _refreshUserStatus() {
    final apiClient = _clientHolder!.apiClient;
    _userStatusFuture = UserApi.getUserStatus(apiClient, userId: apiClient.userId).then((value) async {
      if (value.onlineStatus == OnlineStatus.offline) {
        final newStatus = value.copyWith(
            onlineStatus: OnlineStatus.values[_clientHolder!.settingsClient.currentSettings.lastOnlineStatus
                .valueOrDefault]
        );
        await UserApi.setStatus(apiClient, status: newStatus);
        return newStatus;
      }
      return value;
    });
  }

  @override
  Widget build(BuildContext context) {
    final clientHolder = ClientHolder.of(context);
    return Scaffold(
      appBar: AppBar(
        title: const Text("Contacts++"),
        actions: [
          FutureBuilder(
              future: _userStatusFuture,
              builder: (context, snapshot) {
                if (snapshot.hasData) {
                  final userStatus = snapshot.data as UserStatus;
                  return PopupMenuButton<OnlineStatus>(
                      child: Row(
                        children: [
                          Padding(
                            padding: const EdgeInsets.only(right: 8.0),
                            child: Icon(Icons.circle, size: 16, color: userStatus.onlineStatus.color,),
                          ),
                          Text(toBeginningOfSentenceCase(userStatus.onlineStatus.name) ?? "Unknown"),
                        ],
                      ),
                      onSelected: (OnlineStatus onlineStatus) async {
                        try {
                          final newStatus = userStatus.copyWith(onlineStatus: onlineStatus);
                          setState(() {
                            _userStatusFuture = Future.value(newStatus.copyWith(lastStatusChange: DateTime.now()));
                          });
                          final settingsClient = ClientHolder
                              .of(context)
                              .settingsClient;
                          await UserApi.setStatus(clientHolder.apiClient, status: newStatus);
                          await settingsClient.changeSettings(
                              settingsClient.currentSettings.copyWith(lastOnlineStatus: onlineStatus.index));
                        } catch (e, s) {
                          FlutterError.reportError(FlutterErrorDetails(exception: e, stack: s));
                          ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text(
                              "Failed to set online-status.")));
                          setState(() {
                            _userStatusFuture = Future.value(userStatus);
                          });
                        }
                      },
                      itemBuilder: (BuildContext context) =>
                          OnlineStatus.values.where((element) =>
                          element == OnlineStatus.online
                              || element == OnlineStatus.invisible).map((item) =>
                              PopupMenuItem<OnlineStatus>(
                                value: item,
                                child: Row(
                                  mainAxisAlignment: MainAxisAlignment.start,
                                  children: [
                                    Icon(Icons.circle, size: 16, color: item.color,),
                                    const SizedBox(width: 8,),
                                    Text(toBeginningOfSentenceCase(item.name)!),
                                  ],
                                ),
                              ),
                          ).toList());
                } else if (snapshot.hasError) {
                  return TextButton.icon(
                    style: TextButton.styleFrom(
                        foregroundColor: Theme
                            .of(context)
                            .colorScheme
                            .onSurface,
                        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 2)
                    ),
                    onPressed: () {
                      setState(() {
                        _userStatusFuture = UserApi.getUserStatus(clientHolder.apiClient, userId: clientHolder.apiClient
                            .userId);
                      });

                    },
                    icon: const Icon(Icons.warning),
                    label: const Text("Retry"),
                  );
                } else {
                  return TextButton.icon(
                    style: TextButton.styleFrom(
                      disabledForegroundColor: Theme
                          .of(context)
                          .colorScheme
                          .onSurface,
                    ),
                    onPressed: null,
                    icon: Container(
                      width: 16,
                      height: 16,
                      margin: const EdgeInsets.only(right: 4),
                      child: CircularProgressIndicator(
                        strokeWidth: 2,
                        color: Theme
                            .of(context)
                            .colorScheme
                            .onSurface,
                      ),
                    ),
                    label: const Text("Loading"),
                  );
                }
              }
          ),
          Padding(
            padding: const EdgeInsets.only(left: 4, right: 4),
            child: PopupMenuButton<MenuItemDefinition>(
              icon: const Icon(Icons.more_vert),
              onSelected: (MenuItemDefinition itemDef) async {
                await itemDef.onTap();
              },
              itemBuilder: (BuildContext context) =>
                  [
                    MenuItemDefinition(
                      name: "Settings",
                      icon: Icons.settings,
                      onTap: () async {
                        await Navigator.of(context).push(MaterialPageRoute(builder: (context) => const SettingsPage()));
                      },
                    ),
                    MenuItemDefinition(
                      name: "Find Users",
                      icon: Icons.person_add,
                      onTap: () async {
                        final mClient = Provider.of<MessagingClient>(context, listen: false);
                        await Navigator.of(context).push(
                          MaterialPageRoute(
                            builder: (context) =>
                                ChangeNotifierProvider<MessagingClient>.value(
                                  value: mClient,
                                  child: const UserSearch(),
                                ),
                          ),
                        );
                      },
                    ),
                    MenuItemDefinition(
                      name: "My Profile",
                      icon: Icons.person,
                      onTap: () async {
                        await showDialog(
                          context: context,
                          builder: (context) {
                            return FutureBuilder(
                                future: _userProfileFuture,
                                builder: (context, snapshot) {
                                  if (snapshot.hasData) {
                                    final profile = snapshot.data as PersonalProfile;
                                    return MyProfileDialog(profile: profile);
                                  } else if (snapshot.hasError) {
                                    return DefaultErrorWidget(
                                      title: "Failed to load personal profile.",
                                      onRetry: () {
                                        setState(() {
                                          _userProfileFuture = UserApi.getPersonalProfile(ClientHolder
                                              .of(context)
                                              .apiClient);
                                        });
                                      },
                                    );
                                  } else {
                                    return const Center(child: CircularProgressIndicator(),);
                                  }
                                }
                            );
                          },
                        );
                      },
                    ),
                  ].map((item) =>
                      PopupMenuItem<MenuItemDefinition>(
                        value: item,
                        child: Row(
                          mainAxisAlignment: MainAxisAlignment.spaceBetween,
                          children: [
                            Text(item.name),
                            Icon(item.icon),
                          ],
                        ),
                      ),
                  ).toList(),
            ),
          )
        ],
      ),
      body: Stack(
        alignment: Alignment.topCenter,
        children: [
          Consumer<MessagingClient>(
              builder: (context, mClient, _) {
                if (mClient.initStatus == null) {
                  return const LinearProgressIndicator();
                } else if (mClient.initStatus!.isNotEmpty) {
                  return Column(
                    children: [
                      Expanded(
                          child: DefaultErrorWidget(
                            message: mClient.initStatus,
                            onRetry: () async {
                              mClient.resetStatus();
                              mClient.refreshFriendsListWithErrorHandler();
                            },
                          ),
                      ),
                    ],
                  );
                } else {
                  var friends = List.from(mClient.cachedFriends); // Explicit copy.
                  if (_searchFilter.isNotEmpty) {
                    friends = friends.where((element) =>
                        element.username.toLowerCase().contains(_searchFilter.toLowerCase())).toList();
                    friends.sort((a, b) => a.username.length.compareTo(b.username.length));
                  }
                  return ListView.builder(
                    itemCount: friends.length,
                    itemBuilder: (context, index) {
                      final friend = friends[index];
                      final unreads = mClient.getUnreadsForFriend(friend);
                      return FriendListTile(
                        friend: friend,
                        unreads: unreads.length,
                      );
                    },
                  );
                }
              }
          ),
          Align(
            alignment: Alignment.bottomCenter,
            child: ExpandingInputFab(
              onInputChanged: (String text) {
                setState(() {
                  _searchFilter = text;
                });
              },
              onExpansionChanged: (expanded) {
                if (!expanded) {
                  setState(() {
                    _searchFilter = "";
                  });
                }
              },
            ),
          ),
        ],
      ),
    );
  }
}