"""Runs a SaraSuite program as a background service on Windows, the stand-in
for a systemd --user service. Started windowless with pythonw.exe, both at
login (by the program's shortcut in the Startup folder) and when SaraSuite
or the program's own GUI (e.g. SaraSort for SaraSortd) starts it:

    pythonw.exe ServiceRun.py <Name> <Script>       (in the service's working folder)

It records its PID in %LOCALAPPDATA%\\SaraSuite\\Services\\<Name>.pid, so
anything can tell whether the service runs, and stop it (taskkill), without
a Windows service and without admin rights. Installed next to each program
that has a Windows service (Programs/<Name>/Manifest.toml, [[Services]]).
"""

import os
import runpy
import sys
from pathlib import Path


def Main() -> None:
    Name, Script = sys.argv[1], Path(sys.argv[2])
    LocalAppData = Path(os.environ.get("LOCALAPPDATA") or Path.home() / "AppData" / "Local")
    PidFile = LocalAppData / "SaraSuite" / "Services" / f"{Name}.pid"
    PidFile.parent.mkdir(parents=True, exist_ok=True)
    PidFile.write_text(str(os.getpid()))
    try:
        sys.argv = [str(Script)]
        sys.path.insert(0, str(Script.parent))
        runpy.run_path(str(Script), run_name="__main__")
    finally:
        # Only remove it if it's still ours (a newer start may have replaced it).
        try:
            if PidFile.read_text().strip() == str(os.getpid()):
                PidFile.unlink()
        except OSError:
            pass


if __name__ == "__main__":
    Main()