feat: add CLI with start/stop/status commands

Made-with: Cursor

src/cursor_flasher/cli.py

@@ -0,0 +1,103 @@
+"""CLI for starting/stopping the cursor-flasher daemon."""
+import argparse
+import os
+import signal
+import sys
+from pathlib import Path
+
+from cursor_flasher.daemon import run_daemon
+
+PID_FILE = Path.home() / ".cursor-flasher" / "daemon.pid"
+
+
+def _write_pid() -> None:
+    PID_FILE.parent.mkdir(parents=True, exist_ok=True)
+    PID_FILE.write_text(str(os.getpid()))
+
+
+def _read_pid() -> int | None:
+    if not PID_FILE.exists():
+        return None
+    try:
+        pid = int(PID_FILE.read_text().strip())
+        os.kill(pid, 0)
+        return pid
+    except (ValueError, ProcessLookupError, PermissionError):
+        PID_FILE.unlink(missing_ok=True)
+        return None
+
+
+def _remove_pid() -> None:
+    PID_FILE.unlink(missing_ok=True)
+
+
+def cmd_start(args: argparse.Namespace) -> None:
+    existing = _read_pid()
+    if existing is not None:
+        print(f"Daemon already running (PID {existing})")
+        sys.exit(1)
+
+    if args.foreground:
+        _write_pid()
+        try:
+            run_daemon()
+        finally:
+            _remove_pid()
+    else:
+        pid = os.fork()
+        if pid > 0:
+            print(f"Daemon started (PID {pid})")
+            return
+        os.setsid()
+        _write_pid()
+        try:
+            run_daemon()
+        finally:
+            _remove_pid()
+
+
+def cmd_stop(args: argparse.Namespace) -> None:
+    pid = _read_pid()
+    if pid is None:
+        print("Daemon is not running")
+        sys.exit(1)
+
+    os.kill(pid, signal.SIGTERM)
+    _remove_pid()
+    print(f"Daemon stopped (PID {pid})")
+
+
+def cmd_status(args: argparse.Namespace) -> None:
+    pid = _read_pid()
+    if pid is None:
+        print("Daemon is not running")
+    else:
+        print(f"Daemon is running (PID {pid})")
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        prog="cursor-flasher",
+        description="Flash the Cursor window when the AI agent is waiting for input",
+    )
+    sub = parser.add_subparsers(dest="command")
+
+    start_parser = sub.add_parser("start", help="Start the daemon")
+    start_parser.add_argument(
+        "--foreground", "-f", action="store_true",
+        help="Run in the foreground (don't daemonize)",
+    )
+    start_parser.set_defaults(func=cmd_start)
+
+    stop_parser = sub.add_parser("stop", help="Stop the daemon")
+    stop_parser.set_defaults(func=cmd_stop)
+
+    status_parser = sub.add_parser("status", help="Check daemon status")
+    status_parser.set_defaults(func=cmd_status)
+
+    args = parser.parse_args()
+    if not hasattr(args, "func"):
+        parser.print_help()
+        sys.exit(1)
+
+    args.func(args)