import 'package:shared_preferences/shared_preferences.dart';

/// 记录上一次使用的 USB 摄像头，插拔后优先重连。
class UsbCameraPrefs {
  static const String _lastDeviceIdKey = 'usb_camera_last_device_id';
  static const String _lastResolutionKey = 'usb_camera_last_resolution';

  static Future<String?> getLastDeviceId() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getString(_lastDeviceIdKey);
  }

  static Future<void> setLastDeviceId(String? id) async {
    final prefs = await SharedPreferences.getInstance();
    if (id == null) {
      await prefs.remove(_lastDeviceIdKey);
      return;
    }
    await prefs.setString(_lastDeviceIdKey, id);
  }

  static Future<String?> getLastResolution() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getString(_lastResolutionKey);
  }

  static Future<void> setLastResolution(String? resolution) async {
    final prefs = await SharedPreferences.getInstance();
    if (resolution == null) {
      await prefs.remove(_lastResolutionKey);
      return;
    }
    await prefs.setString(_lastResolutionKey, resolution);
  }
}