Self-updates and program list from the repo

SelfUpdate.py

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+"""SaraSuite updating itself from its Gitea releases.
+
+Packaging/Release.py publishes a release (tag v<AppVersion>) with the
+AppImage attached. Here SaraSuite asks Gitea for the latest release, and if
+it's newer than AppVersion and SaraSuite runs as an AppImage, downloads it
+next to the running one and renames it into place (allowed while it's
+running), then restarts into it. The AppImage keeps its path, so its app
+menu entry keeps working.
+"""
+
+import os
+import subprocess
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Callable, Optional
+from urllib.parse import urlsplit
+
+from Core import AppName, AppVersion, ChildEnvironment, LoadConfig
+from Sources import GetBytes, GetJson, SourceError
+
+AssetName = f"{AppName}-x86_64.AppImage"
+
+
+@dataclass
+class Release:
+    Version: str
+    AssetUrl: str  # empty if the release has no AppImage attached
+
+
+def RunningAppImage() -> Optional[Path]:
+    Value = os.environ.get("APPIMAGE", "")
+    return Path(Value) if Value else None
+
+
+def _VersionTuple(Version: str) -> tuple[int, ...]:
+    Parts = []
+    for Part in Version.strip().lstrip("vV").split("."):
+        Digits = "".join(Char for Char in Part if Char.isdigit())
+        Parts.append(int(Digits) if Digits else 0)
+    return tuple(Parts)
+
+
+def IsNewer(Version: str) -> bool:
+    return _VersionTuple(Version) > _VersionTuple(AppVersion)
+
+
+def LatestRelease() -> Optional[Release]:
+    """The latest published release, or None if there's none or the git host
+    can't be reached. GitHost looks like https://host/owner; the API lives at
+    https://host/api/v1."""
+    Parts = urlsplit(LoadConfig().GitHost.rstrip("/"))
+    Owner = Parts.path.strip("/").split("/")[-1]
+    Url = f"{Parts.scheme}://{Parts.netloc}/api/v1/repos/{Owner}/{AppName}/releases/latest"
+    try:
+        Data = GetJson(Url)
+    except SourceError:
+        return None
+    Asset = next((Item for Item in Data.get("assets", []) if Item.get("name") == AssetName), None)
+    return Release(Data.get("tag_name", ""), Asset.get("browser_download_url", "") if Asset else "")
+
+
+def Install(Latest: Release, Log: Callable[[str], None]) -> Path:
+    """Replace the running AppImage with Latest's. Raises OSError/SourceError."""
+    Target = RunningAppImage()
+    if Target is None:
+        raise OSError("SaraSuite isn't running as an AppImage, so it can't replace itself.")
+    if not Latest.AssetUrl:
+        raise OSError(f"Release {Latest.Version} has no {AssetName} attached.")
+    Log(f"== Updating {AppName} {AppVersion} -> {Latest.Version.lstrip('v')}")
+    Log(f"Downloading {Latest.AssetUrl}")
+    Data = GetBytes(Latest.AssetUrl)
+    if not Data.startswith(b"\x7fELF"):
+        raise OSError("The download isn't an AppImage; leaving the current one alone.")
+    # Same folder, so the rename is atomic; renaming over a running AppImage
+    # is fine (overwriting it in place isn't: "Text file busy").
+    Temporary = Target.with_name(Target.name + ".new")
+    Temporary.write_bytes(Data)
+    Temporary.chmod(0o755)
+    Temporary.replace(Target)
+    Log(f"== {AppName} updated; it's the new version from the next start")
+    return Target
+
+
+def Restart() -> None:
+    """Start the (new) AppImage; the caller then closes this one."""
+    Target = RunningAppImage()
+    if Target is None:
+        return
+    Environment = ChildEnvironment()
+    for Key in ("APPIMAGE", "APPDIR", "ARGV0", "OWD"):  # the new AppImage sets its own
+        Environment.pop(Key, None)
+    subprocess.Popen([str(Target)], env=Environment, start_new_session=True,
+                     stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)