macKeyboardBacklight.swift

//
//  macKeyboardBacklight.swift
//
//  Created by Wiliam Toader on 10.09.2021.
//  Solution suggested by user Alex293 on github issue https://github.com/pirate/mac-keyboard-brightness/issues/1

import Foundation
import IOKit
import AppKit

func up() -> Void {
    let code = NX_KEYTYPE_ILLUMINATION_UP
    let event1 = NSEvent.otherEvent(with: .systemDefined, location: NSPoint.zero, modifierFlags: NSEvent.ModifierFlags(rawValue: 0xa00), timestamp: 0, windowNumber: 0, context: nil, subtype: 8, data1: (Int((code << 16 as Int32) | (0xa << 8 as Int32))), data2: -1)
    event1?.cgEvent?.post(tap: .cghidEventTap)
    let event2 = NSEvent.otherEvent(with: .systemDefined, location: NSPoint.zero, modifierFlags: NSEvent.ModifierFlags(rawValue: 0xb00), timestamp: 0, windowNumber: 0, context: nil, subtype: 8, data1: (Int((code << 16 as Int32) | (0xb << 8 as Int32))), data2: -1)
    event2?.cgEvent?.post(tap: .cghidEventTap)
}

func down() -> Void {
    let code = NX_KEYTYPE_ILLUMINATION_DOWN
    let event1 = NSEvent.otherEvent(with: .systemDefined, location: NSPoint.zero, modifierFlags: NSEvent.ModifierFlags(rawValue: 0xa00), timestamp: 0, windowNumber: 0, context: nil, subtype: 8, data1: (Int((code << 16 as Int32) | (0xa << 8 as Int32))), data2: -1)
    event1?.cgEvent?.post(tap: .cghidEventTap)
    let event2 = NSEvent.otherEvent(with: .systemDefined, location: NSPoint.zero, modifierFlags: NSEvent.ModifierFlags(rawValue: 0xb00), timestamp: 0, windowNumber: 0, context: nil, subtype: 8, data1: (Int((code << 16 as Int32) | (0xb << 8 as Int32))), data2: -1)
    event2?.cgEvent?.post(tap: .cghidEventTap)
}

let cmdUp = CommandLine.arguments.firstIndex(where: {$0 == "-up"}) ?? 0
let cmdDown = CommandLine.arguments.firstIndex(where: {$0 == "-down"}) ?? 0

let nr = cmdUp > 0 ? cmdUp + 1 : (cmdDown > 0 ? cmdDown + 1 : 0)

for _ in 1...(Int(CommandLine.arguments[nr]) ?? 1) {
    if(cmdUp > 0) { up() }
    else if(cmdDown > 0) {down()}
}

if(CommandLine.arguments.count < 2) {
    print("A simple program to adjust keyboard backlight\n")
    print("Arguments:\n")
    print("-up\t<number>\t\tIncrements brightness by number of steps.\n")
    print("-down\t<number>\t\tDecrements brightness by number of steps.\n")
}