import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:worldhopper/l10n/app_localizations.dart';
import 'package:worldhopper/config/constants.dart';
import 'package:worldhopper/models/downloaded_chapter.dart';
import 'package:worldhopper/models/downloaded_series.dart';
import 'package:worldhopper/providers/download_provider.dart';
import 'package:worldhopper/widgets/downloaded_chapter_card.dart';
import 'package:worldhopper/widgets/worldhopper_app_bar.dart';

/// Shows all chapters in a downloaded series
class DownloadedSeriesDetailScreen extends ConsumerWidget {
  final String seriesId;

  const DownloadedSeriesDetailScreen({
    super.key,
    required this.seriesId,
  });

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final l10n = AppLocalizations.of(context);
    final seriesAsync = ref.watch(downloadedSeriesListProvider);
    final chaptersAsync = ref.watch(downloadedChaptersProvider(seriesId));

    // Find the series from the list
    final series = seriesAsync.whenOrNull(
      data: (list) {
        for (final s in list) {
          if (s.id == seriesId) return s;
        }
        return null;
      },
    );

    final hasFailedChapters = chaptersAsync.whenOrNull(
          data: (chapters) =>
              chapters.any((c) => c.status == DownloadStatus.failed),
        ) ??
        false;

    return Scaffold(
      appBar: WorldhopperAppBar(
        title: Text(series?.title ?? l10n.downloadedSeriesDetailTitle),
        actions: [
          if (hasFailedChapters && series != null)
            IconButton(
              icon: const Icon(Icons.refresh),
              tooltip: l10n.downloadRetryAll,
              onPressed: () => _retryAllFailed(context, ref, series),
            ),
          IconButton(
            icon: const Icon(Icons.delete_outline),
            onPressed: () => _confirmDeleteSeries(context, ref, series),
          ),
        ],
      ),
      body: chaptersAsync.when(
        data: (chapters) => _buildChaptersList(context, ref, chapters, series),
        loading: () => const Center(child: CircularProgressIndicator()),
        error: (error, _) => Center(
          child: Text(l10n.libraryErrorLoading),
        ),
      ),
    );
  }

  Widget _buildChaptersList(
    BuildContext context,
    WidgetRef ref,
    List<DownloadedChapter> chapters,
    DownloadedSeries? series,
  ) {
    if (chapters.isEmpty) {
      return const Center(child: Text('No chapters'));
    }

    return ListView.builder(
      padding: const EdgeInsets.all(16),
      itemCount: chapters.length,
      itemBuilder: (context, index) {
        final chapter = chapters[index];
        return Padding(
          padding: const EdgeInsets.only(bottom: 8),
          child: DownloadedChapterCard(
            chapter: chapter,
            onTap: () => _openChapter(context, ref, chapter),
            onRetry: chapter.status == DownloadStatus.failed && series != null
                ? () => _retryChapter(context, ref, series, chapter)
                : null,
          ),
        );
      },
    );
  }

  void _openChapter(
    BuildContext context,
    WidgetRef ref,
    DownloadedChapter chapter,
  ) {
    final entry = chapter.toEntry();

    if (chapter.contentType == ChapterContentType.epub) {
      context.push(AppConstants.routeEpubReader, extra: {
        'entry': entry,
        'serverId': chapter.serverId,
        'localFilePath': chapter.filePath,
      });
    } else {
      context.push(AppConstants.routeReader, extra: {
        'entry': entry,
        'serverId': chapter.serverId,
        'initialPage': 0,
        'localContentPath': chapter.filePath,
      });
    }
  }

  Future<void> _retryChapter(
    BuildContext context,
    WidgetRef ref,
    DownloadedSeries series,
    DownloadedChapter chapter,
  ) async {
    final server = await ref.read(serverByIdProvider(series.serverId).future);
    if (server == null) {
      if (context.mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Server not found')),
        );
      }
      return;
    }

    await ref
        .read(downloadNotifierProvider.notifier)
        .retryChapter(server: server, chapter: chapter);
  }

  Future<void> _retryAllFailed(
    BuildContext context,
    WidgetRef ref,
    DownloadedSeries series,
  ) async {
    final server = await ref.read(serverByIdProvider(series.serverId).future);
    if (server == null) {
      if (context.mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Server not found')),
        );
      }
      return;
    }

    await ref
        .read(downloadNotifierProvider.notifier)
        .retryFailedChapters(server: server, seriesId: series.id);
  }

  Future<void> _confirmDeleteSeries(
    BuildContext context,
    WidgetRef ref,
    DownloadedSeries? series,
  ) async {
    if (series == null) return;
    final l10n = AppLocalizations.of(context);

    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: Text(l10n.downloadDeleteSeries),
        content: Text(l10n.downloadDeleteSeriesConfirmation(series.title)),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(context).pop(false),
            child: Text(l10n.commonCancel),
          ),
          FilledButton(
            onPressed: () => Navigator.of(context).pop(true),
            style: FilledButton.styleFrom(
              backgroundColor: Theme.of(context).colorScheme.error,
            ),
            child: Text(l10n.commonDelete),
          ),
        ],
      ),
    );

    if (confirmed == true && context.mounted) {
      await ref.read(downloadNotifierProvider.notifier).deleteSeries(series.id);
      if (context.mounted) {
        context.pop();
      }
    }
  }
}