Keep mac awake with native Caffeinate

caffeinate_mac.swift

#!/usr/bin/swift

// This script adds an icon in the macOS menu bar that controls the active status of caffeinate.

import AppKit

// The AppDelegate class manages the application's lifecycle and UI.
class AppDelegate: NSObject, NSApplicationDelegate {
    
    // UI Elements
    private var statusItem: NSStatusItem!
    private var menu: NSMenu!
    private var toggleMenuItem: NSMenuItem!
    
    // State Management for the caffeinate process
    private var caffeinateProcess: Process?

    // This method is called once the app has finished launching.
    func applicationDidFinishLaunching(_ aNotification: Notification) {
        
        // 1. Create the status bar item.
        statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.squareLength)
        
        // 2. Create the dropdown menu.
        menu = NSMenu()
        
        // 3. Create the menu item that will toggle caffeinate.
        // We give it a target (self) and an action (the function to call when clicked).
        toggleMenuItem = NSMenuItem(
            title: "Deactivate Caffeinate", // Initial state is active
            action: #selector(toggleCaffeinate),
            keyEquivalent: ""
        )
        menu.addItem(toggleMenuItem)
        
        // Add a separator for visual clarity.
        menu.addItem(NSMenuItem.separator())
        
        // Add the standard "Quit" option.
        menu.addItem(
            withTitle: "Quit",
            action: #selector(NSApplication.terminate(_:)),
            keyEquivalent: "q"
        )
        
        // Assign the menu to our status bar item.
        statusItem.menu = menu
        
        // 4. Start caffeinate by default on launch.
        startCaffeinate()
        
        // 5. Set the initial UI state.
        updateUI()
    }
    
    // This is the function called by our toggle menu item.
    @objc func toggleCaffeinate() {
        if caffeinateProcess == nil {
            // If the process isn't running, start it.
            startCaffeinate()
        } else {
            // If the process is running, stop it.
            stopCaffeinate()
        }
        // After any state change, update the icon and menu text.
        updateUI()
    }

    // Starts the /usr/bin/caffeinate command.
    private func startCaffeinate() {
        // Ensure we don't start a second process by mistake.
        guard caffeinateProcess == nil else { return }
        
        caffeinateProcess = Process()
        caffeinateProcess?.executableURL = URL(fileURLWithPath: "/usr/bin/caffeinate")
        // The "-d" argument prevents the display from sleeping.
        // You could use "-i" to prevent system idle sleep.
        caffeinateProcess?.arguments = ["-d"]
        
        do {
            try caffeinateProcess?.run()
        } catch {
            print("Error starting caffeinate: \(error)")
            caffeinateProcess = nil // Reset if it fails
        }
    }

    // Stops the running caffeinate process.
    private func stopCaffeinate() {
        caffeinateProcess?.terminate() // Sends a standard termination signal.
        caffeinateProcess = nil      // Set to nil to reflect its stopped state.
    }
    
    // Updates the status bar icon and menu item text based on the current state.
    private func updateUI() {
        if caffeinateProcess != nil {
            // Caffeinate is RUNNING
            statusItem.button?.title = "⚡️"
            toggleMenuItem.title = "Deactivate Caffeinate"
        } else {
            // Caffeinate is STOPPED
            statusItem.button?.title = "💤"
            toggleMenuItem.title = "Activate Caffeinate"
        }
    }
    
    // This function is called just before the application quits.
    func applicationWillTerminate(_ aNotification: Notification) {
        // CRITICAL: Ensure we kill the caffeinate process when the app exits.
        // This prevents leaving a "zombie" process running in the background.
        print("Quitting and cleaning up caffeinate process...")
        stopCaffeinate()
    }
}

// --- Application Boilerplate ---
// This code sets up and runs the application.
let app = NSApplication.shared
let delegate = AppDelegate()
app.delegate = delegate
app.run()