import 'billing_models.dart';

/// Clean abstraction over store billing operations.
/// All platform-specific types (e.g. in_app_purchase / BillingClient) remain isolated behind this interface.
abstract class BillingService {
  /// Stream emitting real-time purchase updates from the store.
  Stream<List<StorePurchase>> get purchaseStream;

  /// Initializes the billing service and verifies connection to the store.
  Future<bool> initialize();

  /// Whether the store service (e.g. Google Play Billing) is currently available on the device.
  Future<bool> isAvailable();

  /// Queries the store for product details matching the catalog.
  Future<List<StoreProduct>> queryProducts();

  /// Initiates purchase flow for a product.
  Future<bool> launchPurchaseFlow(String productId);

  /// Restores prior purchases from the store (e.g. on reinstall or new device).
  Future<void> restorePurchases();

  /// Acknowledges / completes an eligible purchase transaction with the store.
  Future<void> completePurchase(StorePurchase purchase);

  /// Disposes listeners and resources.
  void dispose();
}