Script to pair/unpair magic mouse and keyboard

magic_switch.py

#!/usr/bin/env python3
"""
Magic Switch
Script to pair/unpair magic mouse and keyboard 

Usage:
* Save somewhere in $PATH as `magic-switch`
* Whenever switching magic devices between laptops:
  * Run `magic-switch off` on the currently connected one
  * Then `magic-switch on` in the new one
"""
import argparse
import subprocess
import urllib.request
import sys
from pathlib import Path
from time import sleep

GIST_URL = "https://gist.githubusercontent.com/fopina/71345e937195d88f98899420f147d8b5/raw/magic_switch.py"
CONFIG_DIR = Path.home() / ".config" / "magic-switch"
CONFIG_FILE = CONFIG_DIR / "devices.txt"


def run_command(command):
    """Runs a shell command and prints output."""
    try:
        result = subprocess.run(command, capture_output=True, text=True, check=True).stdout.strip()
        if result:
            print(result)
        return 0
    except subprocess.CalledProcessError as e:
        print(f"Error: {e.stderr.strip()}")
        return e.returncode


def print_notify(message, notify=False):
    print(message)
    if notify:
        run_command(['osascript', '-e', f'display notification "{message}" with title "magic-switch"'])


def get_device_ids():
    """Reads device IDs from the config file."""
    if not CONFIG_FILE.exists():
        print(f"Error: Device list not found. Create {CONFIG_FILE} and add one device ID per line.")
        sys.exit(1)
    
    return [line.strip() for line in CONFIG_FILE.read_text().splitlines() if line.strip() and line.strip()[0] != '#']


def bluetooth_on(retries=0, force_connect=False, notify=False):
    """Unpairs and then pairs all devices from the config file."""
    devices = get_device_ids()
    
    for device in devices:
        print(f"Unpairing {device}...")
        run_command(["blueutil", "--unpair", device])
    
    for device in devices:
        for _t in range(retries + 1):
            print(f"Pairing {device}...")
            c = run_command(["blueutil", "--pair", device])
            if c == 0:
                break
        if c == 0:
            print_notify(f"Paired {device}...", notify=notify)
            if force_connect:
                sleep(1)
                run_command(["blueutil", "--connect", device])
        else:
            print_notify(f"FAILED to pair {device} ({c})...", notify=notify)


def bluetooth_off(notify=False):
    """Unpairs all devices from the config file."""
    devices = get_device_ids()
    
    for device in devices:
        print(f"Unpairing {device}...")
        c = run_command(["blueutil", "--unpair", device])
        if c == 0:
            print_notify(f"Unpaired {device}...", notify=notify)
        else:
            print_notify(f"FAILED to unpair {device}...", notify=notify)


def update_script():
    """Checks for updates and replaces the script if confirmed."""
    print("Checking for updates...")

    try:
        with urllib.request.urlopen(GIST_URL) as response:
            latest_content = response.read().decode("utf-8")
    except Exception as e:
        print(f"Error: Failed to fetch latest script from Gist ({e})")
        sys.exit(1)

    script_path = Path(__file__)
    current_content = script_path.read_text(encoding="utf-8")

    if current_content.strip() == latest_content.strip():
        print("The script is already up to date.")
        return

    print("A new version is available. Do you want to update? (y/N): ", end="")
    choice = input().strip().lower()
    
    if choice == "y":
        script_path.write_text(latest_content, encoding="utf-8")
        print("Script updated successfully! Restarting...")
        sys.exit(0)  # Exit cleanly (user can restart manually)
    else:
        print("Update canceled.")


def ensure_config_file():
    """Ensures the configuration directory and file exist."""
    CONFIG_DIR.mkdir(parents=True, exist_ok=True)
    if not CONFIG_FILE.exists():
        CONFIG_FILE.write_text("# Add one device ID per line\n", encoding="utf-8")
        print(f"Created config file at {CONFIG_FILE}. Please add your device IDs.")


def main():
    parser = argparse.ArgumentParser(description="Control Bluetooth devices using blueutil.")
    parser.add_argument('--notify', action='store_true', help='Show notification after connecting or disconnecting devices')
    subparsers = parser.add_subparsers(dest="command", required=True)

    on_cmd = subparsers.add_parser("on", help="Unpair and re-pair all devices.")
    on_cmd.add_argument('--retries', '-r', type=int, default=0, help="Number of pairing retries, as it sometimes fails for no good reason.")
    on_cmd.add_argument('--connect', '-c', action="store_true", help="Force connect after pairing, as it sometimes does not connect automatically.")
    subparsers.add_parser("off", help="Unpair all devices.")
    subparsers.add_parser("update", help="Check for script updates.")

    args = parser.parse_args()

    ensure_config_file()

    if args.command == "on":
        bluetooth_on(retries=args.retries, force_connect=args.connect, notify=args.notify)
    elif args.command == "off":
        bluetooth_off(notify=args.notify)
    elif args.command == "update":
        update_script()


if __name__ == "__main__":
    main()