import 'dart:convert';

import 'package:rental_income_tracker/models/app_settings.dart';
import 'package:rental_income_tracker/models/monthly_rent_record.dart';
import 'package:shared_preferences/shared_preferences.dart';

class StorageService {
  static const _settingsKey = 'app_settings';
  static const _recordsKey = 'monthly_records';

  Future<AppSettings> loadSettings() async {
    final prefs = await SharedPreferences.getInstance();
    final raw = prefs.getString(_settingsKey);
    if (raw == null || raw.isEmpty) {
      return AppSettings.defaults();
    }

    return AppSettings.fromJson(jsonDecode(raw) as Map<String, dynamic>);
  }

  Future<void> saveSettings(AppSettings settings) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString(_settingsKey, jsonEncode(settings.toJson()));
  }

  Future<Map<String, MonthlyRentRecord>> loadRecords() async {
    final prefs = await SharedPreferences.getInstance();
    final raw = prefs.getString(_recordsKey);
    if (raw == null || raw.isEmpty) {
      return <String, MonthlyRentRecord>{};
    }

    final decoded = jsonDecode(raw) as Map<String, dynamic>;
    return decoded.map((key, value) {
      return MapEntry(
        key,
        MonthlyRentRecord.fromJson(value as Map<String, dynamic>),
      );
    });
  }

  Future<void> saveRecords(Map<String, MonthlyRentRecord> records) async {
    final prefs = await SharedPreferences.getInstance();
    final encoded = records.map((key, value) => MapEntry(key, value.toJson()));
    await prefs.setString(_recordsKey, jsonEncode(encoded));
  }
}