import 'package:cloud_functions/cloud_functions.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:image_picker/image_picker.dart';
import 'package:intl/intl.dart';

import '../../../core/router/app_router.dart';
import '../../../l10n/generated/app_localizations.dart';
import '../../household/data/household_providers.dart';
import '../../household/domain/household.dart';
import '../../locations/data/locations_provider.dart';
import '../data/plant_diagnosis_service.dart';
import '../data/plants_provider.dart';
import '../domain/plant.dart';

class PlantDetailScreen extends ConsumerWidget {
  const PlantDetailScreen({super.key, required this.plantId});

  final String plantId;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final l10n = AppLocalizations.of(context);
    final plant = ref.watch(plantByIdProvider(plantId));

    if (plant == null) {
      // Pflanze wurde gelöscht, während der Screen offen war.
      return Scaffold(appBar: AppBar(), body: const SizedBox.shrink());
    }

    final location = ref.watch(locationByIdProvider(plant.locationId));
    final locale = Localizations.localeOf(context).toString();
    final dateFormat = DateFormat('d. MMMM y', locale);
    String formatDate(DateTime? date) =>
        date != null ? dateFormat.format(date) : l10n.never;

    final canEdit = ref.watch(myRoleProvider) == HouseholdRole.member;

    return Scaffold(
      appBar: AppBar(
        title: Text(plant.nickname),
        actions: [
          if (canEdit) ...[
          IconButton(
            icon: const Icon(Icons.edit),
            tooltip: l10n.plantDetailTitle,
            onPressed: () => context.push(AppRoutes.plantEdit, extra: plant),
          ),
          IconButton(
            icon: const Icon(Icons.delete_outline),
            tooltip: l10n.delete,
            onPressed: () async {
              final confirmed = await showDialog<bool>(
                context: context,
                builder: (dialogContext) => AlertDialog(
                  title: Text(l10n.deletePlantQuestion(plant.nickname)),
                  actions: [
                    TextButton(
                      onPressed: () => Navigator.pop(dialogContext, false),
                      child: Text(l10n.cancel),
                    ),
                    FilledButton(
                      onPressed: () => Navigator.pop(dialogContext, true),
                      child: Text(l10n.delete),
                    ),
                  ],
                ),
              );
              if (confirmed == true && context.mounted) {
                ref.read(plantRepositoryProvider).removePlant(plant.id);
                context.pop();
              }
            },
          ),
          ],
        ],
      ),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          if (plant.photoUrl != null) ...[
            ClipRRect(
              borderRadius: BorderRadius.circular(16),
              child: Image.network(
                plant.photoUrl!,
                height: 220,
                fit: BoxFit.cover,
              ),
            ),
            const SizedBox(height: 16),
          ],
          _InfoTile(
            icon: Icons.local_florist,
            label: l10n.speciesLabel,
            value: plant.species,
          ),
          _InfoTile(
            icon: Icons.place,
            label: l10n.locationLabel,
            value: location?.name ?? l10n.locationNone,
          ),
          const Divider(height: 32),
          _InfoTile(
            icon: Icons.water_drop,
            label: l10n.wateringEvery(plant.wateringIntervalDays),
            value: l10n.lastWatered(formatDate(plant.lastWatered)) +
                (plant.lastWateredBy != null
                    ? l10n.doneBy(plant.lastWateredBy!)
                    : ''),
          ),
          _InfoTile(
            icon: Icons.compost,
            label: l10n.fertilizingEvery(plant.fertilizingIntervalDays),
            value: l10n.lastFertilized(formatDate(plant.lastFertilized)) +
                (plant.lastFertilizedBy != null
                    ? l10n.doneBy(plant.lastFertilizedBy!)
                    : ''),
          ),
          if (plant.description.isNotEmpty) ...[
            const Divider(height: 32),
            Text(
              plant.description,
              style: Theme.of(context).textTheme.bodyLarge,
            ),
          ],
          if (plant.careNotes.isNotEmpty) ...[
            const SizedBox(height: 12),
            Card(
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Row(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Icon(
                      Icons.tips_and_updates,
                      color: Theme.of(context).colorScheme.primary,
                    ),
                    const SizedBox(width: 12),
                    Expanded(
                      child: Text(
                        plant.careNotes,
                        style: Theme.of(context).textTheme.bodyLarge,
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ],
          const Divider(height: 32),
          _DiagnosisSection(plant: plant),
          _DiagnosisHistory(plant: plant),
        ],
      ),
    );
  }
}

/// Zeigt das Diagnose-Ergebnis als scrollbares Bottom-Sheet — sowohl für
/// eine frische Untersuchung als auch für Einträge aus der Historie
/// ([createdAt] gesetzt).
Future<void> _showDiagnosisSheet(
  BuildContext context, {
  required DiagnosisResult result,
  required String plantNickname,
  DateTime? createdAt,
}) {
  final l10n = AppLocalizations.of(context);
  final locale = Localizations.localeOf(context).toString();
  return showModalBottomSheet<void>(
    context: context,
    isScrollControlled: true,
    builder: (sheetContext) {
      final theme = Theme.of(sheetContext);
      final healthyColor = theme.brightness == Brightness.dark
          ? Colors.green.shade300
          : Colors.green.shade700;
      return DraggableScrollableSheet(
        expand: false,
        initialChildSize: 0.6,
        maxChildSize: 0.95,
        builder: (context, scrollController) => ListView(
          controller: scrollController,
          padding: const EdgeInsets.all(24),
          children: [
            if (!result.matchesSpecies) ...[
              Container(
                padding: const EdgeInsets.all(12),
                decoration: BoxDecoration(
                  color: theme.colorScheme.errorContainer,
                  borderRadius: BorderRadius.circular(12),
                ),
                child: Row(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Icon(
                      Icons.swap_horiz,
                      color: theme.colorScheme.onErrorContainer,
                    ),
                    const SizedBox(width: 12),
                    Expanded(
                      child: Text(
                        l10n.diagnosisSpeciesMismatch(plantNickname),
                        style: theme.textTheme.bodyMedium?.copyWith(
                          color: theme.colorScheme.onErrorContainer,
                        ),
                      ),
                    ),
                  ],
                ),
              ),
              const SizedBox(height: 16),
            ],
            Row(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Icon(
                  result.healthy
                      ? Icons.check_circle
                      : Icons.warning_amber_rounded,
                  size: 32,
                  color:
                      result.healthy ? healthyColor : theme.colorScheme.error,
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: Text(
                    result.summary,
                    style: theme.textTheme.titleLarge,
                  ),
                ),
              ],
            ),
            if (createdAt != null) ...[
              const SizedBox(height: 8),
              Text(
                l10n.diagnosisDate(
                  DateFormat('d. MMMM y, HH:mm', locale).format(createdAt),
                ),
                style: theme.textTheme.bodySmall?.copyWith(
                  color: theme.colorScheme.onSurfaceVariant,
                ),
              ),
            ],
            if (result.details.isNotEmpty) ...[
              const SizedBox(height: 16),
              Text(result.details, style: theme.textTheme.bodyLarge),
            ],
            if (result.treatment.isNotEmpty) ...[
              const SizedBox(height: 20),
              Text(
                l10n.diagnosisTreatmentTitle,
                style: theme.textTheme.titleMedium,
              ),
              const SizedBox(height: 4),
              Text(result.treatment, style: theme.textTheme.bodyLarge),
            ],
            if (result.prevention.isNotEmpty) ...[
              const SizedBox(height: 20),
              Text(
                l10n.diagnosisPreventionTitle,
                style: theme.textTheme.titleMedium,
              ),
              const SizedBox(height: 4),
              Text(result.prevention, style: theme.textTheme.bodyLarge),
            ],
            const SizedBox(height: 16),
            Text(
              l10n.diagnosisDisclaimer,
              style: theme.textTheme.bodySmall?.copyWith(
                color: theme.colorScheme.onSurfaceVariant,
              ),
            ),
          ],
        ),
      );
    },
  );
}

/// Liste der gespeicherten Untersuchungen dieser Pflanze (neueste zuerst).
class _DiagnosisHistory extends ConsumerWidget {
  const _DiagnosisHistory({required this.plant});

  final Plant plant;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final l10n = AppLocalizations.of(context);
    final theme = Theme.of(context);
    final entries = ref.watch(plantDiagnosesProvider(plant.id)).value ?? [];
    if (entries.isEmpty) return const SizedBox.shrink();

    final canEdit = ref.watch(myRoleProvider) == HouseholdRole.member;
    final locale = Localizations.localeOf(context).toString();
    final dateFormat = DateFormat('d. MMMM y, HH:mm', locale);
    final healthyColor = theme.brightness == Brightness.dark
        ? Colors.green.shade300
        : Colors.green.shade700;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        const SizedBox(height: 24),
        Text(l10n.diagnosisHistoryTitle, style: theme.textTheme.titleMedium),
        for (final entry in entries)
          ListTile(
            contentPadding: EdgeInsets.zero,
            leading: Icon(
              entry.result.healthy
                  ? Icons.check_circle
                  : Icons.warning_amber_rounded,
              color: entry.result.healthy
                  ? healthyColor
                  : theme.colorScheme.error,
            ),
            title: Text(
              entry.result.summary,
              maxLines: 2,
              overflow: TextOverflow.ellipsis,
            ),
            subtitle: entry.createdAt != null
                ? Text(dateFormat.format(entry.createdAt!))
                : null,
            trailing: canEdit
                ? IconButton(
                    icon: const Icon(Icons.delete_outline),
                    tooltip: l10n.delete,
                    onPressed: () => _confirmDelete(context, ref, entry),
                  )
                : null,
            onTap: () => _showDiagnosisSheet(
              context,
              result: entry.result,
              plantNickname: plant.nickname,
              createdAt: entry.createdAt,
            ),
          ),
      ],
    );
  }

  Future<void> _confirmDelete(
    BuildContext context,
    WidgetRef ref,
    PlantDiagnosisEntry entry,
  ) async {
    final l10n = AppLocalizations.of(context);
    final locale = Localizations.localeOf(context).toString();
    final dateText = entry.createdAt != null
        ? DateFormat('d. MMMM y', locale).format(entry.createdAt!)
        : '';
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: Text(l10n.deleteDiagnosisQuestion(dateText)),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(dialogContext, false),
            child: Text(l10n.cancel),
          ),
          FilledButton(
            onPressed: () => Navigator.pop(dialogContext, true),
            child: Text(l10n.delete),
          ),
        ],
      ),
    );
    if (confirmed == true) {
      await ref
          .read(plantDiagnosisServiceProvider)
          .deleteDiagnosis(plant.id, entry.id);
    }
  }
}

/// Krankheits-Check (V3): Foto aufnehmen → Claude beurteilt den Zustand
/// und gibt Behandlungstipps. Auch für Sitter nutzbar (nur lesend).
class _DiagnosisSection extends ConsumerStatefulWidget {
  const _DiagnosisSection({required this.plant});

  final Plant plant;

  @override
  ConsumerState<_DiagnosisSection> createState() => _DiagnosisSectionState();
}

class _DiagnosisSectionState extends ConsumerState<_DiagnosisSection> {
  final _picker = ImagePicker();
  bool _busy = false;

  Future<void> _start() async {
    final l10n = AppLocalizations.of(context);
    final source = await showModalBottomSheet<ImageSource>(
      context: context,
      builder: (sheetContext) => SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            ListTile(
              leading: const Icon(Icons.photo_camera),
              title: Text(l10n.takePhoto),
              onTap: () => Navigator.pop(sheetContext, ImageSource.camera),
            ),
            ListTile(
              leading: const Icon(Icons.photo_library),
              title: Text(l10n.fromGallery),
              onTap: () => Navigator.pop(sheetContext, ImageSource.gallery),
            ),
          ],
        ),
      ),
    );
    if (source == null || !mounted) return;

    final picked = await _picker.pickImage(
      source: source,
      maxWidth: 1280,
      imageQuality: 80,
    );
    if (picked == null || !mounted) return;
    final bytes = await picked.readAsBytes();

    setState(() => _busy = true);
    try {
      final service = ref.read(plantDiagnosisServiceProvider);
      final result = await service.diagnose(
        bytes,
        speciesHint: widget.plant.species,
      );
      // In der Historie ablegen — ein Speicherfehler soll die Anzeige des
      // Ergebnisses aber nicht verhindern.
      try {
        await service.saveDiagnosis(widget.plant.id, result);
      } catch (error) {
        debugPrint('Untersuchung speichern fehlgeschlagen: $error');
      }
      if (!mounted) return;
      await _showDiagnosisSheet(
        context,
        result: result,
        plantNickname: widget.plant.nickname,
      );
    } on FirebaseFunctionsException catch (e) {
      if (!mounted) return;
      // Die Function liefert deutsche Meldungen (z. B. „keine Pflanze
      // erkannt") – die zeigen wir direkt an.
      ScaffoldMessenger.of(context)
        ..hideCurrentSnackBar()
        ..showSnackBar(SnackBar(
          content: Text(e.message ?? l10n.diagnosisFailed),
        ));
    } catch (_) {
      if (!mounted) return;
      ScaffoldMessenger.of(context)
        ..hideCurrentSnackBar()
        ..showSnackBar(SnackBar(content: Text(l10n.diagnosisFailed)));
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }


  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context);
    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        OutlinedButton.icon(
          onPressed: _busy ? null : _start,
          icon: _busy
              ? const SizedBox(
                  height: 20,
                  width: 20,
                  child: CircularProgressIndicator(strokeWidth: 2),
                )
              : const Icon(Icons.health_and_safety_outlined),
          label: Text(_busy ? l10n.diagnosing : l10n.diagnoseButton),
        ),
        const SizedBox(height: 4),
        Text(
          l10n.diagnoseHint,
          style: Theme.of(context).textTheme.bodySmall?.copyWith(
                color: Theme.of(context).colorScheme.onSurfaceVariant,
              ),
          textAlign: TextAlign.center,
        ),
      ],
    );
  }
}

class _InfoTile extends StatelessWidget {
  const _InfoTile({
    required this.icon,
    required this.label,
    required this.value,
  });

  final IconData icon;
  final String label;
  final String value;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 8),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Icon(icon, color: theme.colorScheme.primary),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(label, style: theme.textTheme.titleMedium),
                const SizedBox(height: 2),
                Text(
                  value,
                  style: theme.textTheme.bodyMedium?.copyWith(
                    color: theme.colorScheme.onSurfaceVariant,
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}