// @dart=2.9

import 'dart:async';
import 'dart:io';
import 'dart:ui';

import 'package:flutter/material.dart';
import 'package:flutter/scheduler.dart';
import 'package:flutter/services.dart';
import 'package:logging/logging.dart';
import 'package:move_to_background/move_to_background.dart';
import 'package:photo_manager/photo_manager.dart';
import 'package:photos/core/configuration.dart';
import 'package:photos/core/event_bus.dart';
import 'package:photos/db/files_db.dart';
import 'package:photos/ente_theme_data.dart';
import 'package:photos/events/account_configured_event.dart';
import 'package:photos/events/backup_folders_updated_event.dart';
import 'package:photos/events/files_updated_event.dart';
import 'package:photos/events/force_reload_home_gallery_event.dart';
import 'package:photos/events/local_photos_updated_event.dart';
import 'package:photos/events/permission_granted_event.dart';
import 'package:photos/events/subscription_purchased_event.dart';
import 'package:photos/events/sync_status_update_event.dart';
import 'package:photos/events/tab_changed_event.dart';
import 'package:photos/events/trigger_logout_event.dart';
import 'package:photos/events/user_logged_out_event.dart';
import 'package:photos/models/file_load_result.dart';
import 'package:photos/models/gallery_type.dart';
import 'package:photos/models/selected_files.dart';
import 'package:photos/services/collections_service.dart';
import 'package:photos/services/ignored_files_service.dart';
import 'package:photos/services/local_sync_service.dart';
import 'package:photos/services/update_service.dart';
import 'package:photos/services/user_service.dart';
import 'package:photos/states/user_details_state.dart';
import 'package:photos/theme/ente_theme.dart';
import 'package:photos/ui/backup_folder_selection_page.dart';
import 'package:photos/ui/collections_gallery_widget.dart';
import 'package:photos/ui/common/bottom_shadow.dart';
import 'package:photos/ui/common/gradient_button.dart';
import 'package:photos/ui/create_collection_page.dart';
import 'package:photos/ui/extents_page_view.dart';
import 'package:photos/ui/grant_permissions_widget.dart';
import 'package:photos/ui/landing_page_widget.dart';
import 'package:photos/ui/loading_photos_widget.dart';
import 'package:photos/ui/memories_widget.dart';
import 'package:photos/ui/nav_bar.dart';
import 'package:photos/ui/settings/app_update_dialog.dart';
import 'package:photos/ui/settings_page.dart';
import 'package:photos/ui/shared_collections_gallery.dart';
import 'package:photos/ui/status_bar_widget.dart';
import 'package:photos/ui/viewer/gallery/gallery.dart';
import 'package:photos/ui/viewer/gallery/gallery_app_bar_widget.dart';
import 'package:photos/ui/viewer/gallery/gallery_footer_widget.dart';
import 'package:photos/ui/viewer/gallery/gallery_overlay_widget.dart';
import 'package:photos/utils/dialog_util.dart';
import 'package:photos/utils/navigation_util.dart';
import 'package:receive_sharing_intent/receive_sharing_intent.dart';
import 'package:uni_links/uni_links.dart';

class HomeWidget extends StatefulWidget {
  const HomeWidget({Key key}) : super(key: key);

  @override
  State<StatefulWidget> createState() => _HomeWidgetState();
}

class _HomeWidgetState extends State<HomeWidget> {
  static const _deviceFolderGalleryWidget = CollectionsGalleryWidget();
  static const _sharedCollectionGallery = SharedCollectionGallery();
  static final _settingsPage = SettingsPage(
    emailNotifier: UserService.instance.emailValueNotifier,
  );
  static const _headerWidget = HeaderWidget();

  final _logger = Logger("HomeWidgetState");
  final _selectedFiles = SelectedFiles();

  final PageController _pageController = PageController();
  int _selectedTabIndex = 0;
  Widget _headerWidgetWithSettingsButton;

  // for receiving media files
  // ignore: unused_field
  StreamSubscription _intentDataStreamSubscription;
  List<SharedMediaFile> _sharedFiles;

  StreamSubscription<TabChangedEvent> _tabChangedEventSubscription;
  StreamSubscription<SubscriptionPurchasedEvent> _subscriptionPurchaseEvent;
  StreamSubscription<TriggerLogoutEvent> _triggerLogoutEvent;
  StreamSubscription<UserLoggedOutEvent> _loggedOutEvent;
  StreamSubscription<PermissionGrantedEvent> _permissionGrantedEvent;
  StreamSubscription<SyncStatusUpdate> _firstImportEvent;
  StreamSubscription<BackupFoldersUpdatedEvent> _backupFoldersUpdatedEvent;
  StreamSubscription<AccountConfiguredEvent> _accountConfiguredEvent;

  @override
  void initState() {
    _logger.info("Building initstate");
    _headerWidgetWithSettingsButton = Stack(
      children: const [
        _headerWidget,
      ],
    );
    _tabChangedEventSubscription =
        Bus.instance.on<TabChangedEvent>().listen((event) {
      if (event.source != TabChangedEventSource.pageView) {
        _selectedTabIndex = event.selectedIndex;
        _pageController.animateToPage(
          event.selectedIndex,
          duration: const Duration(milliseconds: 100),
          curve: Curves.easeIn,
        );
      }
    });
    _subscriptionPurchaseEvent =
        Bus.instance.on<SubscriptionPurchasedEvent>().listen((event) {
      setState(() {});
    });
    _accountConfiguredEvent =
        Bus.instance.on<AccountConfiguredEvent>().listen((event) {
      setState(() {});
    });
    _triggerLogoutEvent =
        Bus.instance.on<TriggerLogoutEvent>().listen((event) async {
      final AlertDialog alert = AlertDialog(
        title: const Text("Session expired"),
        content: const Text("Please login again"),
        actions: [
          TextButton(
            child: Text(
              "Ok",
              style: TextStyle(
                color: Theme.of(context).colorScheme.greenAlternative,
              ),
            ),
            onPressed: () async {
              Navigator.of(context, rootNavigator: true).pop('dialog');
              final dialog = createProgressDialog(context, "Logging out...");
              await dialog.show();
              await Configuration.instance.logout();
              await dialog.hide();
            },
          ),
        ],
      );

      showDialog(
        context: context,
        builder: (BuildContext context) {
          return alert;
        },
      );
    });
    _loggedOutEvent = Bus.instance.on<UserLoggedOutEvent>().listen((event) {
      _logger.info('logged out, selectTab index to 0');
      _selectedTabIndex = 0;
      if (mounted) {
        setState(() {});
      }
    });
    _permissionGrantedEvent =
        Bus.instance.on<PermissionGrantedEvent>().listen((event) async {
      if (mounted) {
        setState(() {});
      }
    });
    _firstImportEvent =
        Bus.instance.on<SyncStatusUpdate>().listen((event) async {
      if (mounted && event.status == SyncStatus.completedFirstGalleryImport) {
        Duration delayInRefresh = const Duration(milliseconds: 0);
        // Loading page will redirect to BackupFolderSelectionPage.
        // To avoid showing folder hook in middle during routing,
        // delay state refresh for home page
        if (!LocalSyncService.instance.hasGrantedLimitedPermissions()) {
          delayInRefresh = const Duration(milliseconds: 250);
        }
        Future.delayed(
          delayInRefresh,
          () => {
            if (mounted)
              {
                setState(
                  () {},
                )
              }
          },
        );
      }
    });
    _backupFoldersUpdatedEvent =
        Bus.instance.on<BackupFoldersUpdatedEvent>().listen((event) async {
      if (mounted) {
        setState(() {});
      }
    });
    _initDeepLinks();
    UpdateService.instance.shouldUpdate().then((shouldUpdate) {
      if (shouldUpdate) {
        Future.delayed(Duration.zero, () {
          showDialog(
            context: context,
            builder: (BuildContext context) {
              return AppUpdateDialog(
                UpdateService.instance.getLatestVersionInfo(),
              );
            },
            barrierColor: Colors.black.withOpacity(0.85),
          );
        });
      }
    });
    // For sharing images coming from outside the app while the app is in the memory
    _initMediaShareSubscription();
    super.initState();
  }

  @override
  void dispose() {
    _tabChangedEventSubscription.cancel();
    _subscriptionPurchaseEvent.cancel();
    _triggerLogoutEvent.cancel();
    _loggedOutEvent.cancel();
    _permissionGrantedEvent.cancel();
    _firstImportEvent.cancel();
    _backupFoldersUpdatedEvent.cancel();
    _accountConfiguredEvent.cancel();
    _intentDataStreamSubscription?.cancel();
    super.dispose();
  }

  void _initMediaShareSubscription() {
    _intentDataStreamSubscription =
        ReceiveSharingIntent.getMediaStream().listen(
      (List<SharedMediaFile> value) {
        setState(() {
          _sharedFiles = value;
        });
      },
      onError: (err) {
        _logger.severe("getIntentDataStream error: $err");
      },
    );
    // For sharing images coming from outside the app while the app is closed
    ReceiveSharingIntent.getInitialMedia().then((List<SharedMediaFile> value) {
      setState(() {
        _sharedFiles = value;
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    _logger.info("Building home_Widget with tab $_selectedTabIndex");
    bool isSettingsOpen = false;
    final enableDrawer = LocalSyncService.instance.hasCompletedFirstImport();

    return UserDetailsStateWidget(
      child: WillPopScope(
        child: Scaffold(
          drawerScrimColor: getEnteColorScheme(context).strokeFainter,
          drawerEnableOpenDragGesture:
              false, //using a hack instead of enabling this as enabling this will create other problems
          drawer: enableDrawer
              ? ConstrainedBox(
                  constraints: const BoxConstraints(maxWidth: 428),
                  child: Drawer(
                    width: double.infinity,
                    child: _settingsPage,
                  ),
                )
              : null,
          onDrawerChanged: (isOpened) => isSettingsOpen = isOpened,
          body: SafeArea(
            bottom: false,
            child: Builder(
              builder: (context) {
                return _getBody(context);
              },
            ),
          ),
          resizeToAvoidBottomInset: false,
        ),
        onWillPop: () async {
          if (_selectedTabIndex == 0) {
            if (isSettingsOpen) {
              Navigator.pop(context);
              return false;
            }
            if (Platform.isAndroid) {
              MoveToBackground.moveTaskToBack();
              return false;
            } else {
              return true;
            }
          } else {
            Bus.instance
                .fire(TabChangedEvent(0, TabChangedEventSource.backButton));
            return false;
          }
        },
      ),
    );
  }

  Widget _getBody(BuildContext context) {
    if (!Configuration.instance.hasConfiguredAccount()) {
      _closeDrawerIfOpen(context);
      return const LandingPageWidget();
    }
    if (!LocalSyncService.instance.hasGrantedPermissions()) {
      return const GrantPermissionsWidget();
    }
    if (!LocalSyncService.instance.hasCompletedFirstImport()) {
      return const LoadingPhotosWidget();
    }
    if (_sharedFiles != null && _sharedFiles.isNotEmpty) {
      ReceiveSharingIntent.reset();
      return CreateCollectionPage(null, _sharedFiles);
    }
    final isBottomInsetPresent = MediaQuery.of(context).viewPadding.bottom != 0;

    final bool showBackupFolderHook =
        !Configuration.instance.hasSelectedAnyBackupFolder() &&
            !LocalSyncService.instance.hasGrantedLimitedPermissions() &&
            CollectionsService.instance.getActiveCollections().isEmpty;
    return Stack(
      children: [
        Builder(
          builder: (context) {
            return ExtentsPageView(
              onPageChanged: (page) {
                Bus.instance.fire(
                  TabChangedEvent(
                    page,
                    TabChangedEventSource.pageView,
                  ),
                );
              },
              controller: _pageController,
              openDrawer: Scaffold.of(context).openDrawer,
              physics: const BouncingScrollPhysics(),
              children: [
                showBackupFolderHook
                    ? _getBackupFolderSelectionHook()
                    : _getMainGalleryWidget(),
                _deviceFolderGalleryWidget,
                _sharedCollectionGallery,
              ],
            );
          },
        ),
        const Align(
          alignment: Alignment.bottomCenter,
          child: BottomShadowWidget(),
        ),
        Align(
          alignment: Alignment.bottomCenter,
          child: Padding(
            padding: EdgeInsets.only(bottom: isBottomInsetPresent ? 32 : 8),
            child: HomeBottomNavigationBar(
              _selectedFiles,
              selectedTabIndex: _selectedTabIndex,
            ),
          ),
        ),
        Align(
          alignment: Alignment.bottomCenter,
          child: GalleryOverlayWidget(GalleryType.homepage, _selectedFiles),
        ),
      ],
    );
  }

  void _closeDrawerIfOpen(BuildContext context) {
    Scaffold.of(context).isDrawerOpen
        ? SchedulerBinding.instance.addPostFrameCallback((timeStamp) {
            Scaffold.of(context).closeDrawer();
          })
        : null;
  }

  Future<bool> _initDeepLinks() async {
    // Platform messages may fail, so we use a try/catch PlatformException.
    try {
      final String initialLink = await getInitialLink();
      // Parse the link and warn the user, if it is not correct,
      // but keep in mind it could be `null`.
      if (initialLink != null) {
        _logger.info("Initial link received: " + initialLink);
        _getCredentials(context, initialLink);
        return true;
      } else {
        _logger.info("No initial link received.");
      }
    } on PlatformException {
      // Handle exception by warning the user their action did not succeed
      // return?
      _logger.severe("PlatformException thrown while getting initial link");
    }

    // Attach a listener to the stream
    linkStream.listen(
      (String link) {
        _logger.info("Link received: " + link);
        _getCredentials(context, link);
      },
      onError: (err) {
        _logger.severe(err);
      },
    );
    return false;
  }

  void _getCredentials(BuildContext context, String link) {
    if (Configuration.instance.hasConfiguredAccount()) {
      return;
    }
    final ott = Uri.parse(link).queryParameters["ott"];
    UserService.instance.verifyEmail(context, ott);
  }

  Widget _getMainGalleryWidget() {
    Widget header;
    if (_selectedFiles.files.isEmpty) {
      header = _headerWidgetWithSettingsButton;
    } else {
      header = _headerWidget;
    }
    final gallery = Gallery(
      asyncLoader: (creationStartTime, creationEndTime, {limit, asc}) async {
        final ownerID = Configuration.instance.getUserID();
        final hasSelectedAllForBackup =
            Configuration.instance.hasSelectedAllFoldersForBackup();
        final archivedCollectionIds =
            CollectionsService.instance.getArchivedCollections();
        FileLoadResult result;
        if (hasSelectedAllForBackup) {
          result = await FilesDB.instance.getAllLocalAndUploadedFiles(
            creationStartTime,
            creationEndTime,
            ownerID,
            limit: limit,
            asc: asc,
            ignoredCollectionIDs: archivedCollectionIds,
          );
        } else {
          result = await FilesDB.instance.getAllPendingOrUploadedFiles(
            creationStartTime,
            creationEndTime,
            ownerID,
            limit: limit,
            asc: asc,
            ignoredCollectionIDs: archivedCollectionIds,
          );
        }

        // hide ignored files from home page UI
        final ignoredIDs = await IgnoredFilesService.instance.ignoredIDs;
        result.files.removeWhere(
          (f) =>
              f.uploadedFileID == null &&
              IgnoredFilesService.instance.shouldSkipUpload(ignoredIDs, f),
        );
        return result;
      },
      reloadEvent: Bus.instance.on<LocalPhotosUpdatedEvent>(),
      removalEventTypes: const {
        EventType.deletedFromRemote,
        EventType.deletedFromEverywhere,
        EventType.archived,
      },
      forceReloadEvents: [
        Bus.instance.on<BackupFoldersUpdatedEvent>(),
        Bus.instance.on<ForceReloadHomeGalleryEvent>(),
      ],
      tagPrefix: "home_gallery",
      selectedFiles: _selectedFiles,
      header: header,
      footer: const GalleryFooterWidget(),
    );
    return Stack(
      children: [
        Container(
          child: gallery,
        ),
        HomePageAppBar(_selectedFiles),
      ],
    );
  }

  Widget _getBackupFolderSelectionHook() {
    return Column(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        _headerWidgetWithSettingsButton,
        Padding(
          padding: const EdgeInsets.only(top: 64),
          child: Image.asset(
            "assets/onboarding_safe.png",
            height: 206,
          ),
        ),
        Text(
          'No photos are being backed up right now',
          style: Theme.of(context)
              .textTheme
              .caption
              .copyWith(fontFamily: 'Inter-Medium', fontSize: 16),
        ),
        Center(
          child: Material(
            type: MaterialType.transparency,
            child: Container(
              width: double.infinity,
              height: 64,
              padding: const EdgeInsets.fromLTRB(20, 0, 20, 0),
              child: GradientButton(
                onTap: () async {
                  if (LocalSyncService.instance
                      .hasGrantedLimitedPermissions()) {
                    PhotoManager.presentLimited();
                  } else {
                    routeToPage(
                      context,
                      const BackupFolderSelectionPage(
                        buttonText: "Start backup",
                      ),
                    );
                  }
                },
                text: "Start backup",
              ),
            ),
          ),
        ),
        const Padding(padding: EdgeInsets.all(50)),
      ],
    );
  }
}

class HomePageAppBar extends StatefulWidget {
  const HomePageAppBar(
    this.selectedFiles, {
    Key key,
  }) : super(key: key);

  final SelectedFiles selectedFiles;

  @override
  State<HomePageAppBar> createState() => _HomePageAppBarState();
}

class _HomePageAppBarState extends State<HomePageAppBar> {
  @override
  void initState() {
    super.initState();
    widget.selectedFiles.addListener(() {
      setState(() {});
    });
  }

  @override
  Widget build(BuildContext context) {
    final appBar = SizedBox(
      height: 60,
      child: GalleryAppBarWidget(
        GalleryType.homepage,
        null,
        widget.selectedFiles,
      ),
    );
    if (widget.selectedFiles.files.isEmpty) {
      return IgnorePointer(child: appBar);
    } else {
      return appBar;
    }
  }
}

class HomeBottomNavigationBar extends StatefulWidget {
  const HomeBottomNavigationBar(
    this.selectedFiles, {
    this.selectedTabIndex,
    Key key,
  }) : super(key: key);

  final SelectedFiles selectedFiles;
  final int selectedTabIndex;

  @override
  State<HomeBottomNavigationBar> createState() =>
      _HomeBottomNavigationBarState();
}

class _HomeBottomNavigationBarState extends State<HomeBottomNavigationBar> {
  StreamSubscription<TabChangedEvent> _tabChangedEventSubscription;
  int currentTabIndex = 0;

  @override
  void initState() {
    super.initState();
    currentTabIndex = widget.selectedTabIndex;
    widget.selectedFiles.addListener(() {
      setState(() {});
    });
    _tabChangedEventSubscription =
        Bus.instance.on<TabChangedEvent>().listen((event) {
      if (event.source != TabChangedEventSource.tabBar) {
        debugPrint('index changed to ${event.selectedIndex}');
        if (mounted) {
          setState(() {
            currentTabIndex = event.selectedIndex;
          });
        }
      }
    });
  }

  @override
  void dispose() {
    _tabChangedEventSubscription.cancel();
    super.dispose();
  }

  void _onTabChange(int index) {
    Bus.instance.fire(
      TabChangedEvent(
        index,
        TabChangedEventSource.tabBar,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final bool filesAreSelected = widget.selectedFiles.files.isNotEmpty;
    return AnimatedContainer(
      duration: const Duration(milliseconds: 300),
      curve: Curves.easeInOut,
      height: filesAreSelected ? 0 : 56,
      child: AnimatedOpacity(
        duration: const Duration(milliseconds: 100),
        opacity: filesAreSelected ? 0.0 : 1.0,
        curve: Curves.easeIn,
        child: IgnorePointer(
          ignoring: filesAreSelected,
          child: ListView(
            physics: const NeverScrollableScrollPhysics(),
            children: [
              Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  ClipRRect(
                    borderRadius: BorderRadius.circular(32),
                    child: Container(
                      alignment: Alignment.bottomCenter,
                      height: 56,
                      child: ClipRect(
                        child: BackdropFilter(
                          filter: ImageFilter.blur(sigmaX: 96, sigmaY: 96),
                          child: GNav(
                            curve: Curves.easeOutExpo,
                            backgroundColor:
                                getEnteColorScheme(context).fillMuted,
                            mainAxisAlignment: MainAxisAlignment.center,
                            rippleColor: Colors.white.withOpacity(0.1),
                            activeColor: Theme.of(context)
                                .colorScheme
                                .gNavBarActiveColor,
                            iconSize: 24,
                            padding: const EdgeInsets.fromLTRB(16, 8, 16, 8),
                            duration: const Duration(milliseconds: 200),
                            gap: 0,
                            tabBorderRadius: 24,
                            tabBackgroundColor: Theme.of(context)
                                .colorScheme
                                .gNavBarActiveColor,
                            haptic: false,
                            tabs: [
                              GButton(
                                margin: const EdgeInsets.fromLTRB(12, 8, 6, 8),
                                icon: Icons.home,
                                iconColor:
                                    Theme.of(context).colorScheme.gNavIconColor,
                                iconActiveColor: Theme.of(context)
                                    .colorScheme
                                    .gNavActiveIconColor,
                                text: '',
                                onPressed: () {
                                  _onTabChange(
                                    0,
                                  ); // To take care of occasional missing events
                                },
                              ),
                              GButton(
                                margin: const EdgeInsets.fromLTRB(6, 8, 6, 8),
                                icon: Icons.photo_library,
                                iconColor:
                                    Theme.of(context).colorScheme.gNavIconColor,
                                iconActiveColor: Theme.of(context)
                                    .colorScheme
                                    .gNavActiveIconColor,
                                text: '',
                                onPressed: () {
                                  _onTabChange(
                                    1,
                                  ); // To take care of occasional missing events
                                },
                              ),
                              GButton(
                                margin: const EdgeInsets.fromLTRB(6, 8, 12, 8),
                                icon: Icons.folder_shared,
                                iconColor:
                                    Theme.of(context).colorScheme.gNavIconColor,
                                iconActiveColor: Theme.of(context)
                                    .colorScheme
                                    .gNavActiveIconColor,
                                text: '',
                                onPressed: () {
                                  _onTabChange(
                                    2,
                                  ); // To take care of occasional missing events
                                },
                              ),
                            ],
                            selectedIndex: currentTabIndex,
                            onTabChange: _onTabChange,
                          ),
                        ),
                      ),
                    ),
                  ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class HeaderWidget extends StatelessWidget {
  static const _memoriesWidget = MemoriesWidget();
  static const _statusBarWidget = StatusBarWidget();

  const HeaderWidget({
    Key key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    Logger("Header").info("Building header widget");
    const list = [
      _statusBarWidget,
      _memoriesWidget,
    ];
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: list,
    );
  }
}