import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:logging/logging.dart';
import 'package:result_monad/result_monad.dart';

import '../controls/async_value_widget.dart';
import '../controls/login_aware_cached_network_image.dart';
import '../controls/padding.dart';
import '../controls/standard_appbar.dart';
import '../controls/status_and_refresh_button.dart';
import '../globals.dart';
import '../models/auth/profile.dart';
import '../models/visibility.dart';
import '../riverpod_controllers/account_services.dart';
import '../riverpod_controllers/gallery_services.dart';
import '../serializers/friendica/image_entry_friendica_extensions.dart';
import '../utils/snackbar_builder.dart';
import 'media_viewer_screen.dart';

class GalleryScreen extends ConsumerWidget {
  static final _logger = Logger('$GalleryScreen');
  final String galleryName;

  const GalleryScreen({super.key, required this.galleryName});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    _logger.finer('Building $galleryName');
    final profile = ref.watch(activeProfileProvider);
    final loading = switch (ref.watch(galleryProvider(profile, galleryName))) {
      AsyncData() => false,
      _ => true,
    };
    return Scaffold(
      appBar: StandardAppBar.build(context, galleryName, actions: [
        StatusAndRefreshButton(
          executing: loading,
          refreshFunction: () async => ref
              .read(galleryImagesProvider(profile, galleryName).notifier)
              .updateGalleryImages(
                withNextPage: false,
                nextPageOnly: false,
              ),
          busyColor: Theme.of(context).appBarTheme.foregroundColor,
        ),
      ]),
      body: _GalleryScreenBody(
        profile: profile,
        galleryName: galleryName,
      ),
    );
  }
}

class _GalleryScreenBody extends ConsumerWidget {
  static const thumbnailDimension = 350.0;
  static final _logger = Logger('$_GalleryScreenBody');
  final Profile profile;
  final String galleryName;

  const _GalleryScreenBody({required this.profile, required this.galleryName});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    _logger.finer('Building');

    return AsyncValueWidget(ref.watch(galleryProvider(profile, galleryName)),
        valueBuilder: (context, ref, galleriesResult) {
      return galleriesResult.fold(
        onSuccess: (gallery) => buildBody(context, ref, gallery.count),
        onError: (error) => buildErrorBody(error.message),
      );
    });
  }

  Widget buildErrorBody(String error) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          Text('Error getting images for gallery: $error'),
        ],
      ),
    );
  }

  Widget buildBody(
    BuildContext context,
    WidgetRef ref,
    int expectedPhotoCount,
  ) {
    return AsyncValueWidget(
        ref.watch(galleryImagesProvider(profile, galleryName)),
        loadingBuilder: (_, __) => const Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                crossAxisAlignment: CrossAxisAlignment.center,
                children: [
                  Text('Loading images'),
                  VerticalPadding(),
                  CircularProgressIndicator(),
                ],
              ),
            ),
        valueBuilder: (context, ref, galleryImagesResult) {
          return galleryImagesResult.fold(
            onSuccess: (images) {
              final attachments =
                  images.map((i) => i.toMediaAttachment()).toList();
              if (images.isEmpty) {
                return const Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    crossAxisAlignment: CrossAxisAlignment.center,
                    children: [
                      Text('No images'),
                    ],
                  ),
                );
              }

              return GridView.builder(
                  itemCount: images.length,
                  padding: const EdgeInsets.all(5.0),
                  gridDelegate: const SliverGridDelegateWithMaxCrossAxisExtent(
                      maxCrossAxisExtent: thumbnailDimension),
                  itemBuilder: (context, index) {
                    final image = images[index];
                    if (images.length < expectedPhotoCount &&
                        index == images.length - 1) {
                      ref
                          .read(galleryImagesProvider(profile, galleryName)
                              .notifier)
                          .updateGalleryImages(
                            withNextPage: true,
                            nextPageOnly: true,
                          );
                    }
                    return Padding(
                      padding: const EdgeInsets.all(2.0),
                      child: GestureDetector(
                        onTap: () {
                          Navigator.push(context,
                              MaterialPageRoute(builder: (context) {
                            return MediaViewerScreen(
                              attachments: attachments,
                              initialIndex: index,
                            );
                          }));
                        },
                        child: Card(
                          child: Stack(
                            children: [
                              LoginAwareCachedNetworkImage(
                                width: thumbnailDimension,
                                height: thumbnailDimension,
                                imageUrl: image.thumbnailUrl,
                              ),
                              Positioned(
                                top: 5.0,
                                right: 5.0,
                                child: Row(
                                  children: [
                                    Card(
                                      color: Theme.of(context)
                                          .scaffoldBackgroundColor
                                          .withValues(alpha: 0.7),
                                      child: IconButton(
                                        onPressed: () => context.push(
                                          '/gallery/edit/$galleryName/image/${image.id}',
                                        ),
                                        icon: const Icon(Icons.edit),
                                      ),
                                    ),
                                    Card(
                                      color: Theme.of(context)
                                          .scaffoldBackgroundColor
                                          .withValues(alpha: 0.7),
                                      child: IconButton(
                                        onPressed: () async {
                                          final confirm = await showYesNoDialog(
                                              context, 'Delete image?');
                                          if (confirm != true) {
                                            return;
                                          }
                                          await ref
                                              .read(galleryImagesProvider(
                                                      profile, galleryName)
                                                  .notifier)
                                              .deleteImage(image)
                                              .withError((error) {
                                            if (context.mounted) {
                                              buildSnackbar(context,
                                                  'Error deleting image: $error');
                                            }
                                          });
                                        },
                                        icon: const Icon(Icons.delete),
                                      ),
                                    ),
                                  ],
                                ),
                              ),
                              if (image.description.isNotEmpty)
                                Positioned(
                                  bottom: 5.0,
                                  left: 5.0,
                                  child: ElevatedButton(
                                    onPressed: () async => await showInfoDialog(
                                      context,
                                      image.description,
                                    ),
                                    style: ElevatedButton.styleFrom(
                                        backgroundColor: Theme.of(context)
                                            .scaffoldBackgroundColor
                                            .withValues(alpha: 0.7)),
                                    child: const Text('ALT'),
                                  ),
                                ),
                              Positioned(
                                bottom: 5.0,
                                right: 5.0,
                                child: Card(
                                  color: Theme.of(context)
                                      .scaffoldBackgroundColor
                                      .withValues(alpha: 0.7),
                                  child: Icon(image.visibility.type ==
                                          VisibilityType.public
                                      ? Icons.public
                                      : Icons.lock),
                                ),
                              ),
                            ],
                          ),
                        ),
                      ),
                    );
                  });
            },
            onError: (error) => buildErrorBody(error.message),
          );
        });
  }
}