import 'package:flutter/foundation.dart';

import '../models/note.dart';
import '../services/note_service.dart';

enum BackupStatus { idle, loading, success, error }

class NoteViewModel extends ChangeNotifier {
  final NoteService _service;

  NoteViewModel({required NoteService service}) : _service = service;

  List<Note> _notes = [];
  bool _isLoading = false;
  String? _error;
  BackupStatus _backupStatus = BackupStatus.idle;

  // ── Getters ────────────────────────────────────────────────
  List<Note> get notes => _notes;
  bool get isLoading => _isLoading;
  String? get error => _error;
  BackupStatus get backupStatus => _backupStatus;

  // ── Notes CRUD ─────────────────────────────────────────────
  Future<void> loadNotes() async {
    _setLoading(true);
    try {
      _notes = await _service.getAllNotes();
      _error = null;
    } catch (e) {
      _error = 'Failed to load notes: $e';
    } finally {
      _setLoading(false);
    }
  }

  Future<Note> createNote() async {
    final note = await _service.createNote();
    _notes.insert(0, note);
    notifyListeners();
    return note;
  }

  Future<void> updateNote(Note note) async {
    final updated = await _service.updateNote(note);
    final index = _notes.indexWhere((n) => n.id == updated.id);
    if (index != -1) {
      _notes[index] = updated;
      notifyListeners();
    }
  }

  Future<void> deleteNote(String id) async {
    await _service.deleteNote(id);
    _notes.removeWhere((n) => n.id == id);
    notifyListeners();
  }

  // ── Backup ─────────────────────────────────────────────────
  Future<void> backup() async {
    _setBackupStatus(BackupStatus.loading);
    try {
      await _service.triggerBackup();
      _setBackupStatus(BackupStatus.success);
    } catch (e) {
      _error = e.toString();
      _setBackupStatus(BackupStatus.error);
    }
  }

  Future<void> restore() async {
    _setBackupStatus(BackupStatus.loading);
    try {
      await _service.triggerRestore();
      await loadNotes();
      _setBackupStatus(BackupStatus.success);
    } catch (e) {
      _error = e.toString();
      _setBackupStatus(BackupStatus.error);
    }
  }

  // ── Helpers ────────────────────────────────────────────────
  void _setLoading(bool value) {
    _isLoading = value;
    notifyListeners();
  }

  void _setBackupStatus(BackupStatus status) {
    _backupStatus = status;
    notifyListeners();
  }
}