util: Check if Steam configuration files exist before marking as avai…

…lable (#356)

* util: Check if Steam configuration files exist before marking as available

* constants: Move valid Steam install check to is_valid_launcher_installation

* constants: Use os.path.join for building Steam install location paths

* constants: Don't use os.path.join when building Steam POSSIBLE_INSTALL_LOCATIONS

Fixes a strange recusion depth crash.

* comment cleanup

* comment cleanup 2 electric boogaloo

pupgui2/constants.py

@@ -23,20 +23,32 @@
 TEMP_DIR = os.path.join(os.getenv('XDG_CACHE_HOME'), 'tmp', 'pupgui2.a70200/') if os.path.exists(os.getenv('XDG_CACHE_HOME', '')) else '/tmp/pupgui2.a70200/'
 HOME_DIR = os.path.expanduser('~')
 
-# support different Steam root directories
-# valid install dir should have config.vdf and libraryfolders.vdf, to ensure it is not an unused folder with correct directory structure
-_POSSIBLE_STEAM_ROOTS = ['~/.local/share/Steam', '~/.steam/root', '~/.steam/steam', '~/.steam/debian-installation']
-_STEAM_ROOT = _POSSIBLE_STEAM_ROOTS[0]
-for steam_root in _POSSIBLE_STEAM_ROOTS:
-    ct_dir = os.path.join(os.path.expanduser(steam_root), 'config')
-    config_vdf = os.path.join(ct_dir, 'config.vdf')
-    libraryfolders_vdf = os.path.join(ct_dir, 'libraryfolders.vdf')
-    if os.path.exists(config_vdf) and os.path.exists(libraryfolders_vdf):
-        _STEAM_ROOT = steam_root
-        break
+# support different Steam root directories, building paths relative to HOME_DIR (i.e. /home/gaben/.local/share/Steam)
+# Use os.path.realpath to expand all _STEAM_ROOT paths
+_POSSIBLE_STEAM_ROOTS = [
+    os.path.realpath(os.path.join(HOME_DIR, _STEAM_ROOT)) for _STEAM_ROOT in ['.local/share/Steam', '.steam/root', '.steam/steam', '.steam/debian-installation']
+]
+
+# Remove duplicate paths while preserving order, as os.path.realpath may expand some symlinks to the real Steam root
+_POSSIBLE_STEAM_ROOTS = list(dict.fromkeys(_POSSIBLE_STEAM_ROOTS))
 
+# Steam can be installled in any of the locations at '_POSSIBLE_STEAM_ROOTS' - usually only one, and the others (if they exist) are typically symlinks,
+# i.e. '~/.steam/root' is usually a symlink to '~/.local/share/Steam'
+# These paths may still not be valid installations however, as they could be leftother paths from an old Steam installation without the data files we need ('config.vdf' and 'libraryfolders.vdf')
+# We catch this later on in util#is_valid_launcher_installation though
 POSSIBLE_INSTALL_LOCATIONS = [
-    {'install_dir': f'{_STEAM_ROOT}/compatibilitytools.d/', 'display_name': 'Steam', 'launcher': 'steam', 'type': 'native', 'icon': 'steam', 'vdf_dir': f'{_STEAM_ROOT}/config'},
+        {
+            'install_dir': f'{_STEAM_ROOT}/compatibilitytools.d/',
+            'display_name': 'Steam',
+            'launcher': 'steam',
+            'type': 'native',
+            'icon': 'steam',
+            'vdf_dir': f'{_STEAM_ROOT}/config'
+        } for _STEAM_ROOT in _POSSIBLE_STEAM_ROOTS if os.path.exists(_STEAM_ROOT)
+]
+
+# Possible install locations for all other launchers, ensuring Steam paths are at the top of the list
+POSSIBLE_INSTALL_LOCATIONS += [
     {'install_dir': '~/.var/app/com.valvesoftware.Steam/data/Steam/compatibilitytools.d/', 'display_name': 'Steam Flatpak', 'launcher': 'steam', 'type': 'flatpak', 'icon': 'steam', 'vdf_dir': '~/.var/app/com.valvesoftware.Steam/.local/share/Steam/config'},
     {'install_dir': '~/snap/steam/common/.steam/root/compatibilitytools.d/', 'display_name': 'Steam Snap', 'launcher': 'steam', 'type': 'snap', 'icon': 'steam', 'vdf_dir': '~/snap/steam/common/.steam/root/config'},
     {'install_dir': '~/.local/share/lutris/runners/wine/', 'display_name': 'Lutris', 'launcher': 'lutris', 'type': 'native', 'icon': 'lutris', 'config_dir': '~/.config/lutris'},

pupgui2/steamutil.py

@@ -791,4 +791,21 @@ def determine_most_recent_steam_user(steam_users: List[SteamUser]) -> SteamUser:
         return steam_users[0]
 
     print('Warning: No Steam users found. Returning None')
-    return None
+    return None
+
+
+def is_valid_steam_install(steam_path) -> bool:
+
+    """
+    Return whether required Steam data files actually exist to determine if 'steam_path' is a valid Steam installation.
+    Return Type: bool
+    """
+
+    ct_dir = os.path.join(os.path.expanduser(steam_path), 'config')
+
+    config_vdf = os.path.join(ct_dir, 'config.vdf')
+    libraryfolders_vdf = os.path.join(ct_dir, 'libraryfolders.vdf')
+
+    is_valid_steam_install = os.path.exists(config_vdf) and os.path.exists(libraryfolders_vdf)
+
+    return is_valid_steam_install

pupgui2/util.py

@@ -23,7 +23,7 @@
 from pupgui2.constants import AWACY_GAME_LIST_URL, LOCAL_AWACY_GAME_LIST
 from pupgui2.constants import GITHUB_API, GITLAB_API, GITLAB_API_RATELIMIT_TEXT
 from pupgui2.datastructures import BasicCompatTool, CTType, Launcher, SteamApp, LutrisGame, HeroicGame
-from pupgui2.steamutil import remove_steamtinkerlaunch
+from pupgui2.steamutil import remove_steamtinkerlaunch, is_valid_steam_install
 
 
 def create_msgbox(
@@ -196,6 +196,25 @@ def create_compatibilitytools_folder() -> None:
                 print(f'Error trying to create compatibility tools folder {str(install_dir)}: {str(e)}')
 
 
+def is_valid_launcher_installation(loc) -> bool:
+
+    """
+    Check whether a launcher installation is actually valid based on per-launcher criteria
+    Return Type: bool
+    """
+
+    install_dir = os.path.expanduser(loc['install_dir'])
+
+    # Right now we only check to make sure regular Steam (not Flatpak or Snap) has config.vdf and libraryfolders.vdf
+    # because Steam can leave behind its directory structure when uninstalled, but not these files.
+    #
+    # In future we could expand this to other Steam flavours and other launchers.
+    if loc['display_name'] == 'Steam':  # This seems to get called many times, why?
+        return is_valid_steam_install(os.path.realpath(os.path.join(install_dir, '..')))
+
+    return os.path.exists(install_dir)  # Default to path check for all other launchers
+
+
 def available_install_directories() -> List[str]:
     """
     List available install directories
@@ -204,10 +223,11 @@ def available_install_directories() -> List[str]:
     available_dirs = []
     for loc in POSSIBLE_INSTALL_LOCATIONS:
         install_dir = os.path.expanduser(loc['install_dir'])
-        if os.path.exists(install_dir):
+        # only add unique paths to available_dirs
+        if is_valid_launcher_installation(loc) and not install_dir in available_dirs:
             available_dirs.append(install_dir)
     install_dir = config_custom_install_location().get('install_dir')
-    if install_dir and os.path.exists(install_dir):
+    if install_dir and os.path.exists(install_dir) and not install_dir in available_dirs:
         available_dirs.append(install_dir)
     return available_dirs