Add startup application picker

config/dot/quickshell/scripts/panama-default-apps

@@ -37,8 +37,8 @@ def xdg_data_roots() -> list[Path]:
     return [data_home, *(Path(item) for item in data_dirs.split(":") if item)]
 
 
-def discovered_desktop_ids() -> set[str]:
-    desktop_ids: set[str] = set()
+def discovered_desktop_files() -> dict[str, Path]:
+    desktop_files: dict[str, Path] = {}
     for root in xdg_data_roots():
         applications = root / "applications"
         if not applications.is_dir():
@@ -47,8 +47,12 @@ def discovered_desktop_ids() -> set[str]:
             if not path.is_file():
                 continue
             relative = path.relative_to(applications)
-            desktop_ids.add("-".join(relative.parts))
-    return desktop_ids
+            desktop_files.setdefault("-".join(relative.parts), path)
+    return desktop_files
+
+
+def discovered_desktop_ids() -> set[str]:
+    return set(discovered_desktop_files())
 
 
 def require_desktop_id(desktop_id: str, *, discovered: set[str]) -> None:
@@ -184,12 +188,7 @@ def set_default(role: str, desktop_id: str) -> None:
     run(command)
 
 
-def update_hidden(path: Path, *, hidden: bool) -> None:
-    try:
-        original = path.read_text(encoding="utf-8")
-    except (OSError, UnicodeError) as error:
-        raise BoundaryError("That autostart entry could not be read.") from error
-
+def with_hidden(original: str, *, hidden: bool) -> str:
     lines = original.splitlines()
     output: list[str] = []
     section = ""
@@ -216,24 +215,63 @@ def update_hidden(path: Path, *, hidden: bool) -> None:
         raise BoundaryError("That autostart entry is not a desktop file.")
     if not wrote_hidden:
         output.append(f"Hidden={'true' if hidden else 'false'}")
+    return "\n".join(output) + "\n"
 
-    mode = path.stat().st_mode
+
+def write_atomic(path: Path, text: str, *, mode: int) -> None:
+    temporary_path: Path | None = None
     try:
         with tempfile.NamedTemporaryFile(
             "w", encoding="utf-8", dir=path.parent, prefix=f".{path.name}.", delete=False
         ) as temporary:
-            temporary.write("\n".join(output) + "\n")
+            temporary.write(text)
             temporary.flush()
             os.fsync(temporary.fileno())
             temporary_path = Path(temporary.name)
         temporary_path.chmod(mode)
         os.replace(temporary_path, path)
     except OSError as error:
-        if "temporary_path" in locals():
+        if temporary_path is not None:
             temporary_path.unlink(missing_ok=True)
         raise BoundaryError("That autostart entry could not be updated.") from error
 
 
+def update_hidden(path: Path, *, hidden: bool) -> None:
+    try:
+        original = path.read_text(encoding="utf-8")
+    except (OSError, UnicodeError) as error:
+        raise BoundaryError("That autostart entry could not be read.") from error
+
+    mode = path.stat().st_mode
+    write_atomic(path, with_hidden(original, hidden=hidden), mode=mode)
+
+
+def add_autostart(desktop_id: str) -> None:
+    desktop_files = discovered_desktop_files()
+    require_desktop_id(desktop_id, discovered=set(desktop_files))
+    source = desktop_files[desktop_id]
+    directory = autostart_directory()
+    try:
+        directory.mkdir(parents=True, exist_ok=True)
+    except OSError as error:
+        raise BoundaryError("The user autostart directory could not be created.") from error
+
+    target = directory / desktop_id
+    if target.is_symlink():
+        raise BoundaryError("That autostart entry is not available.")
+    if target.exists():
+        if not target.is_file():
+            raise BoundaryError("That autostart entry is not available.")
+        update_hidden(target, hidden=False)
+        return
+
+    try:
+        original = source.read_text(encoding="utf-8")
+    except (OSError, UnicodeError) as error:
+        raise BoundaryError("That application could not be read.") from error
+    write_atomic(target, with_hidden(original, hidden=False), mode=0o644)
+
+
 def set_autostart(desktop_id: str, enabled_text: str) -> None:
     if enabled_text not in {"true", "false"}:
         raise BoundaryError("Autostart state must be true or false.")
@@ -260,10 +298,12 @@ def main(arguments: list[str]) -> int:
             set_default(arguments[1], arguments[2])
         elif len(arguments) == 3 and arguments[0] == "set-autostart":
             set_autostart(arguments[1], arguments[2])
+        elif len(arguments) == 2 and arguments[0] == "add-autostart":
+            add_autostart(arguments[1])
         else:
             raise BoundaryError(
                 "Usage: panama-default-apps snapshot | set-default ROLE DESKTOP_ID | "
-                "set-autostart DESKTOP_ID true|false"
+                "set-autostart DESKTOP_ID true|false | add-autostart DESKTOP_ID"
             )
     except BoundaryError as error:
         print(str(error), file=sys.stderr)