import 'dart:convert';
import 'dart:typed_data';

import 'package:cloud_functions/cloud_functions.dart';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../household/data/household_providers.dart';

/// Ergebnis der Standort-Analyse (Cloud Function analyzeLocation).
class LocationAnalysisResult {
  const LocationAnalysisResult({
    required this.lightCategory,
    required this.description,
  });

  final String lightCategory;
  final String description;
}

class LocationAnalysisService {
  LocationAnalysisService(
    this._functionsGetter,
    this._storage,
    this._householdIdGetter,
  );

  // Lazy, damit Widget-Tests ohne initialisiertes Firebase auskommen —
  // FirebaseFunctions.instanceFor wirft sonst schon beim Erzeugen.
  final FirebaseFunctions Function() _functionsGetter;
  final FirebaseStorage _storage;
  final String? Function() _householdIdGetter;

  /// Lädt das Stellplatz-Foto in den Haushalts-Ordner in Storage und
  /// liefert die URL.
  Future<String> uploadPhoto(Uint8List imageBytes) async {
    final householdId = _householdIdGetter();
    if (householdId == null) {
      throw StateError('Kein Haushalt geladen – Aktion nicht möglich.');
    }
    final ref = _storage.ref(
      'households/$householdId/location-photos/'
      '${DateTime.now().millisecondsSinceEpoch}.jpg',
    );
    await ref.putData(
      imageBytes,
      SettableMetadata(contentType: 'image/jpeg'),
    );
    return ref.getDownloadURL();
  }

  /// Schickt das Foto an die Cloud Function (Claude) – dauert einige Sekunden.
  Future<LocationAnalysisResult> analyze(Uint8List imageBytes) async {
    final callable = _functionsGetter().httpsCallable('analyzeLocation');
    final response = await callable.call<Map<String, dynamic>>({
      'imageBase64': base64Encode(imageBytes),
    });
    final data = response.data;
    return LocationAnalysisResult(
      lightCategory: data['lightCategory'] as String? ?? '',
      description: data['description'] as String? ?? '',
    );
  }
}

final locationAnalysisServiceProvider =
    Provider<LocationAnalysisService>((ref) {
  return LocationAnalysisService(
    () => FirebaseFunctions.instanceFor(region: 'europe-west3'),
    FirebaseStorage.instance,
    () => ref.read(householdIdProvider).value,
  );
});