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

import '../../../l10n/generated/app_localizations.dart';
import '../../household/data/household_providers.dart';
import '../../household/domain/household.dart';
import '../../plants/data/plant_fit_service.dart';
import '../../plants/data/plants_provider.dart';
import '../../plants/domain/plant.dart';
import '../data/location_analysis_service.dart';
import '../data/locations_provider.dart';
import '../domain/plant_location.dart';

class LocationDetailScreen extends ConsumerWidget {
  const LocationDetailScreen({super.key, required this.locationId});

  final String locationId;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final l10n = AppLocalizations.of(context);
    final location = ref.watch(locationByIdProvider(locationId));

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

    final plants = (ref.watch(plantsProvider).value ?? const [])
        .where((plant) => plant.locationId == locationId)
        .toList();
    final canEdit = ref.watch(myRoleProvider) == HouseholdRole.member;

    return Scaffold(
      appBar: AppBar(title: Text(location.name)),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          _LocationPhotoSection(location: location, canEdit: canEdit),
          const Divider(height: 32),
          Text(
            l10n.locationAssignedPlants,
            style: Theme.of(context).textTheme.titleMedium,
          ),
          const SizedBox(height: 8),
          if (plants.isEmpty)
            Text(
              l10n.locationNoPlantsAssigned,
              style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                    color: Theme.of(context).colorScheme.onSurfaceVariant,
                  ),
            )
          else
            for (final plant in plants) ...[
              _PlantFitTile(plant: plant, location: location),
              const Divider(height: 24),
            ],
        ],
      ),
    );
  }
}

/// Foto vom Stellplatz aufnehmen und von Claude die Lichtverhältnisse
/// einschätzen lassen (V3). Nur volle Mitglieder dürfen das auslösen.
class _LocationPhotoSection extends ConsumerStatefulWidget {
  const _LocationPhotoSection({required this.location, required this.canEdit});

  final PlantLocation location;
  final bool canEdit;

  @override
  ConsumerState<_LocationPhotoSection> createState() =>
      _LocationPhotoSectionState();
}

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

  Future<void> _pickAndAnalyze(ImageSource source) async {
    final l10n = AppLocalizations.of(context);
    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(locationAnalysisServiceProvider);
      final photoUrl = await service.uploadPhoto(bytes);
      final result = await service.analyze(bytes);
      await ref.read(locationRepositoryProvider).updateAnalysis(
            widget.location.id,
            photoUrl: photoUrl,
            lightCategory: result.lightCategory,
            lightAssessment: result.description,
          );
    } on FirebaseFunctionsException catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context)
        ..hideCurrentSnackBar()
        ..showSnackBar(
            SnackBar(content: Text(e.message ?? l10n.locationAnalysisFailed)));
    } catch (_) {
      if (!mounted) return;
      ScaffoldMessenger.of(context)
        ..hideCurrentSnackBar()
        ..showSnackBar(SnackBar(content: Text(l10n.locationAnalysisFailed)));
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context);
    final theme = Theme.of(context);
    final location = widget.location;

    Widget preview;
    if (location.photoUrl != null) {
      preview = Image.network(location.photoUrl!, fit: BoxFit.cover);
    } else {
      preview = Container(
        color: theme.colorScheme.surfaceContainerHighest,
        child: Icon(
          Icons.place,
          size: 64,
          color: theme.colorScheme.onSurfaceVariant,
        ),
      );
    }

    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        ClipRRect(
          borderRadius: BorderRadius.circular(16),
          child: SizedBox(
            height: 180,
            child: Stack(
              fit: StackFit.expand,
              children: [
                preview,
                if (_busy)
                  Container(
                    color: Colors.black45,
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        const CircularProgressIndicator(color: Colors.white),
                        const SizedBox(height: 12),
                        Text(
                          l10n.locationAnalyzing,
                          style: const TextStyle(color: Colors.white),
                        ),
                      ],
                    ),
                  ),
              ],
            ),
          ),
        ),
        const SizedBox(height: 12),
        if (widget.canEdit)
          Row(
            children: [
              Expanded(
                child: FilledButton.tonalIcon(
                  onPressed:
                      _busy ? null : () => _pickAndAnalyze(ImageSource.camera),
                  icon: const Icon(Icons.photo_camera),
                  label: Text(l10n.takePhoto),
                ),
              ),
              const SizedBox(width: 12),
              Expanded(
                child: FilledButton.tonalIcon(
                  onPressed: _busy
                      ? null
                      : () => _pickAndAnalyze(ImageSource.gallery),
                  icon: const Icon(Icons.photo_library),
                  label: Text(l10n.fromGallery),
                ),
              ),
            ],
          ),
        const SizedBox(height: 12),
        if (location.lightCategory != null) ...[
          Chip(label: Text(location.lightCategory!)),
          if (location.lightAssessment != null) ...[
            const SizedBox(height: 8),
            Text(
              location.lightAssessment!,
              style: theme.textTheme.bodyMedium,
            ),
          ],
        ] else
          Text(
            l10n.locationAnalysisEmpty,
            style: theme.textTheme.bodyMedium
                ?.copyWith(color: theme.colorScheme.onSurfaceVariant),
          ),
      ],
    );
  }
}

/// Eine zugeordnete Pflanze mit ihrer Eignungs-Bewertung (auf Abruf) oder
/// einem Button, um sie anzustoßen. Für alle Rollen nutzbar (informativ),
/// setzt aber eine bereits analysierte Standort-Analyse voraus.
class _PlantFitTile extends ConsumerStatefulWidget {
  const _PlantFitTile({required this.plant, required this.location});

  final Plant plant;
  final PlantLocation location;

  @override
  ConsumerState<_PlantFitTile> createState() => _PlantFitTileState();
}

class _PlantFitTileState extends ConsumerState<_PlantFitTile> {
  bool _busy = false;

  Future<void> _check() async {
    final l10n = AppLocalizations.of(context);
    setState(() => _busy = true);
    try {
      final result = await ref.read(plantFitServiceProvider).assessFit(
            plant: widget.plant,
            location: widget.location,
          );
      await ref.read(plantRepositoryProvider).saveFitAssessment(
            widget.plant.id,
            stars: result.stars,
            reasoning: result.reasoning,
            locationId: widget.location.id,
          );
    } on FirebaseFunctionsException catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context)
        ..hideCurrentSnackBar()
        ..showSnackBar(SnackBar(content: Text(e.message ?? l10n.fitCheckFailed)));
    } catch (_) {
      if (!mounted) return;
      ScaffoldMessenger.of(context)
        ..hideCurrentSnackBar()
        ..showSnackBar(SnackBar(content: Text(l10n.fitCheckFailed)));
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context);
    final theme = Theme.of(context);
    final plant = widget.plant;
    final canAnalyze = widget.location.lightCategory != null;
    final stale = isFitStale(plant, widget.location);

    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(plant.nickname, style: theme.textTheme.titleMedium),
                if (plant.fitStars != null && !stale) ...[
                  const SizedBox(height: 2),
                  Text(
                    '★' * plant.fitStars! + '☆' * (5 - plant.fitStars!),
                    style: theme.textTheme.bodyLarge,
                  ),
                  if (plant.fitReasoning != null)
                    Text(
                      plant.fitReasoning!,
                      style: theme.textTheme.bodySmall?.copyWith(
                        color: theme.colorScheme.onSurfaceVariant,
                      ),
                    ),
                ] else if (plant.fitStars != null && stale) ...[
                  const SizedBox(height: 2),
                  Text(
                    l10n.fitCheckStale,
                    style: theme.textTheme.bodySmall?.copyWith(
                      color: theme.colorScheme.onSurfaceVariant,
                    ),
                  ),
                ],
              ],
            ),
          ),
          const SizedBox(width: 12),
          OutlinedButton.icon(
            onPressed: _busy || !canAnalyze ? null : _check,
            icon: _busy
                ? const SizedBox(
                    height: 16,
                    width: 16,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  )
                : const Icon(Icons.star_outline, size: 18),
            label: Text(
              _busy
                  ? l10n.fitChecking
                  : !canAnalyze
                      ? l10n.fitCheckNeedsAnalysis
                      : l10n.fitCheckButton,
            ),
          ),
        ],
      ),
    );
  }
}