This class is used to check the connectivity a MAC OSX project

ReachabilityManager.swift

extension Notification.Name{
    static let internetIsBack = Notification.Name(rawValue: "internetIsBack")
}

class ReachabilityManager:NSObject {
    private var monitor: NWPathMonitor?
    private var queue = DispatchQueue.global(qos: .background)
    private var isConnected: Bool = false  // To store the current network status

    static let shared:ReachabilityManager = ReachabilityManager()// Singleton instance for global access
    
    override init() {
        super.init()
        startMonitoring()  // Automatically start monitoring when NetworkManager is initialized
    }

    // Start monitoring the network connection
    func startMonitoring() {
        monitor = NWPathMonitor()
        monitor?.start(queue: queue)
        
        monitor?.pathUpdateHandler = { [weak self] path in
            guard let self = self else { return }
            
            if path.status == .satisfied {
                self.isConnected = true
                print("Connected to the network.")
                NotificationCenter.default.post(name: .internetIsBack, object: nil)
            } else {
                self.isConnected = false
                print("No network connection.")
            }
        }
    }
    
    // Stop monitoring the network connection
    func stopMonitoring() {
        monitor?.cancel()
        monitor = nil
    }
    
    // Method to check if the network is currently available
    func isNetworkReachable() -> Bool {
        return isConnected
    }
    
    // Method to show an alert when network is not available
    func showNetworkError(){
       let alert = NSAlert()
        alert.messageText = "Network Unavailable"
        alert.informativeText = "It seems you are not connected to the internet. Please check your connection."
        alert.alertStyle = .warning
        alert.addButton(withTitle: "OK")
        
        if let window = NSApplication.shared.windows.first {
            alert.beginSheetModal(for: window) { response in
                // Handle response if necessary
            }
        } else {
            alert.runModal()  // Use runModal if no window is present
        }
    }
}