import Foundation

/// Throttles Darwin notification posting to at most once per 0.5 seconds.
/// Prevents flooding the main app with hundreds of "new traffic" notifications.
public final class NotificationThrottle: @unchecked Sendable {
    public static let shared = NotificationThrottle()

    private let lock = NSLock()
    private var pending = false
    private let interval: TimeInterval = 0.5

    private init() {}

    public func throttle() {
        lock.lock()
        if pending {
            lock.unlock()
            ProxyLogger.ipc.debug("NotificationThrottle: suppressed newTraffic while pending")
            return
        }
        pending = true
        lock.unlock()

        DispatchQueue.global().asyncAfter(deadline: .now() + interval) { [weak self] in
            self?.lock.lock()
            self?.pending = false
            self?.lock.unlock()
            ProxyLogger.ipc.debug("NotificationThrottle: emitting throttled newTraffic")
            IPCManager.shared.post(.newTrafficCaptured)
        }
    }
}