import Dependencies
import DependenciesMacros

/// The app-side transport seam used by ``NotificationsFeature``.
///
/// Authentication, stable installation identity, and provider-specific transport are installed by
/// the host. This client registers the current device token, replaces the mounted feature tree's
/// desired subscriptions, and exposes incoming signals for that installation.
@DependencyClient
public struct NotificationsClient: Sendable {
    public var registerDestination: @Sendable (
        _ destination: Push.Destination
    ) async throws -> Void
    public var replaceSubscriptions: @Sendable (
        _ subscriptions: Set<NotificationSubscription>
    ) async throws -> Void
    public var synchronize: @Sendable () async throws -> Void
    public var signals: @Sendable () async -> AsyncStream<NotificationSignal> = {
        AsyncStream { $0.finish() }
    }
}

extension NotificationsClient: TestDependencyKey {
    public static var testValue: Self {
        Self(
            registerDestination: { _ in },
            replaceSubscriptions: { _ in },
            synchronize: {},
            signals: { AsyncStream { $0.finish() } }
        )
    }
}

extension DependencyValues {
    public var notificationsClient: NotificationsClient {
        get { self[NotificationsClient.self] }
        set { self[NotificationsClient.self] = newValue }
    }
}