Windows support

Service.py

@@ -1,11 +1,22 @@
-"""SaraSortd's systemd user unit: status, start/stop/restart, autostart, and
-its journal. SaraSortd's own log files are read from its LogDir."""
+"""SaraSortd as a background service: status, start/stop/restart, autostart,
+and its journal. SaraSortd's own log files are read from its LogDir.
 
+Linux: its systemd user unit (systemctl / journalctl).
+Windows: SaraSuite's stand-in for a systemd service, used the same way here:
+- it runs windowless as `pythonw.exe ServiceRun.py SaraSortd SaraSortd.py`
+  from SaraSortd's config folder, and ServiceRun.py records its PID in
+  %LOCALAPPDATA%\\SaraSuite\\Services\\SaraSortd.pid (that's how "running" is told);
+- autostart is a shortcut to that command in the Startup folder.
+Unit is the systemd unit on Linux and the service name ("SaraSortd") on Windows.
+"""
+
+import re
 import subprocess
 from dataclasses import dataclass
+from datetime import datetime
 from pathlib import Path
 
-from Core import ChildEnvironment
+from Core import ChildEnvironment, ConfigHome, DataHome, IsWindows, LoadConfig
 
 
 @dataclass
@@ -22,11 +33,98 @@ class ServiceStatus:
         return self.Active in ("active", "activating", "reloading")
 
 
+_NoWindow = getattr(subprocess, "CREATE_NO_WINDOW", 0)
+
+
 def _Run(Arguments: list[str], Timeout: int = 15) -> subprocess.CompletedProcess:
-    return subprocess.run(Arguments, capture_output=True, text=True, timeout=Timeout, env=ChildEnvironment())
+    return subprocess.run(Arguments, capture_output=True, text=True, timeout=Timeout, env=ChildEnvironment(),
+                          creationflags=_NoWindow)
+
+
+# --- Windows ------------------------------------------------------------------------------
+
+
+def _PidFile(Name: str) -> Path:
+    return DataHome / "SaraSuite" / "Services" / f"{Name}.pid"
+
+
+def _StartupLink(Name: str) -> Path:
+    return ConfigHome / "Microsoft" / "Windows" / "Start Menu" / "Programs" / "Startup" / f"{Name}.lnk"
+
+
+def _WindowsCommand() -> tuple[Path, list[str], Path]:
+    """(pythonw.exe, its arguments, working folder), from SaraSuite's install layout."""
+    Config = LoadConfig()
+    AppDir = Path(Config.SortdAppDir).expanduser()
+    ProgramDir = AppDir.parent
+    PythonW = ProgramDir / ".venv" / "Scripts" / "pythonw.exe"
+    Arguments = ["-X", "utf8", str(ProgramDir / "ServiceRun.py"), Config.ServiceName, str(Config.SortdScriptPath)]
+    return PythonW, Arguments, Path(Config.SortdConfigDir).expanduser()
+
+
+def _WindowsPid(Name: str) -> str:
+    try:
+        Pid = int(_PidFile(Name).read_text().strip())
+        Output = _Run(["tasklist", "/FI", f"PID eq {Pid}", "/NH", "/FO", "CSV"]).stdout
+    except (OSError, ValueError, subprocess.SubprocessError):
+        return ""
+    return str(Pid) if re.search(rf'"{Pid}"', Output) else ""
+
+
+def _WindowsStatus(Name: str) -> ServiceStatus:
+    PythonW, Arguments, _Folder = _WindowsCommand()
+    Pid = _WindowsPid(Name)
+    Since = ""
+    if Pid:
+        Since = datetime.fromtimestamp(_PidFile(Name).stat().st_mtime).strftime("%Y-%m-%d %H:%M:%S")
+    return ServiceStatus(
+        Active="active" if Pid else "inactive",
+        Sub="running" if Pid else "dead",
+        Enabled="enabled" if _StartupLink(Name).exists() else "disabled",
+        Pid=Pid,
+        Since=Since,
+        Found=PythonW.is_file() and Path(Arguments[2]).is_file(),
+    )
+
+
+def _WindowsControl(Name: str, Action: str) -> str:
+    PythonW, Arguments, Folder = _WindowsCommand()
+    try:
+        if Action in ("stop", "restart"):
+            Pid = _WindowsPid(Name)
+            if Pid:
+                _Run(["taskkill", "/PID", Pid, "/T", "/F"])
+            _PidFile(Name).unlink(missing_ok=True)
+        if Action in ("start", "restart"):
+            if _WindowsPid(Name):
+                return ""
+            Folder.mkdir(parents=True, exist_ok=True)
+            subprocess.Popen(
+                [str(PythonW), *Arguments], cwd=str(Folder), env=ChildEnvironment(), close_fds=True,
+                stdin=subprocess.DEVNULL, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
+                creationflags=getattr(subprocess, "DETACHED_PROCESS", 0) | _NoWindow,
+            )
+        elif Action == "enable":
+            import pylnk3
+
+            Link = _StartupLink(Name)
+            Link.parent.mkdir(parents=True, exist_ok=True)
+            Quoted = " ".join(f'"{Item}"' if " " in Item or "\\" in Item else Item for Item in Arguments)
+            pylnk3.for_file(str(PythonW), str(Link), arguments=Quoted, work_dir=str(Folder),
+                            description=f"{Name} (background service)")
+        elif Action == "disable":
+            _StartupLink(Name).unlink(missing_ok=True)
+    except (OSError, subprocess.SubprocessError) as Error:
+        return str(Error)
+    return ""
+
+
+# --- Both -----------------------------------------------------------------------------------
 
 
 def Status(Unit: str) -> ServiceStatus:
+    if IsWindows:
+        return _WindowsStatus(Unit)
     try:
         Result = _Run(["systemctl", "--user", "show", Unit,
                        "-p", "LoadState,ActiveState,SubState,UnitFileState,MainPID,ActiveEnterTimestamp"])
@@ -45,6 +143,8 @@ def Status(Unit: str) -> ServiceStatus:
 
 def Control(Unit: str, Action: str) -> str:
     """Action: start, stop, restart, enable, disable. Returns "" or an error."""
+    if IsWindows:
+        return _WindowsControl(Unit, Action)
     try:
         Result = _Run(["systemctl", "--user", Action, Unit])
     except (OSError, subprocess.SubprocessError) as Error:
@@ -60,6 +160,9 @@ def RestartIfRunning(Unit: str) -> str:
 
 
 def Journal(Unit: str, Lines: int) -> list[str]:
+    if IsWindows:
+        return ["Windows has no systemd journal. SaraSortd's own log files (the other log source) "
+                "have everything it does."]
     try:
         Result = _Run(["journalctl", "--user", "-u", Unit, "-n", str(Lines), "--no-pager", "-o", "short-iso"])
     except (OSError, subprocess.SubprocessError) as Error: