Add FUSE external mapping support, BG3/Oblivion Remastered fixes, fomod-plus and NaK integration

FUSE VFS now deploys non-data-dir mod mappings (Paks, OBSE, UE4SS, etc.)
via real symlinks and injects file-level data-dir mappings (plugins.txt,
loadorder.txt) into the VFS tree. Fixes game launches for Oblivion
Remastered (Root Builder path resolution, script extender support) and
BG3 (Wine prefix documents directory, file mapper symlinks on Linux).

Vendors mo2-fomod-plus plugin and NaK crate for FOMOD installer and
game finder/runtime support.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 92 insertions, 5 deletions

diff --git a/libs/basic_games/games/baldursgate3/pak_parser.py b/libs/basic_games/games/baldursgate3/pak_parser.py
index 18598a9..4ebc83c 100644
--- a/libs/basic_games/games/baldursgate3/pak_parser.py
+++ b/libs/basic_games/games/baldursgate3/pak_parser.py
@@ -1,6 +1,9 @@
+from __future__ import annotations
+
 import configparser
 import hashlib
 import os
+import platform
 import re
 import shutil
 import subprocess
@@ -38,7 +41,39 @@ class BG3PakParser:
 
     @cached_property
     def _divine_command(self):
-        return f"{self._utils.tools_dir / 'Divine.exe'} -g bg3 -l info"
+        divine_exe = self._utils.tools_dir / "Divine.exe"
+        if platform.system() != "Windows":
+            wine = self._find_proton_wine()
+            if wine:
+                return f'"{wine}" "{divine_exe}" -g bg3 -l info'
+            qWarning(
+                "BG3: could not find Proton/Wine to run Divine.exe. "
+                "Ensure a Proton version is configured in Settings > Proton."
+            )
+        return f'"{divine_exe}" -g bg3 -l info'
+
+    def _find_proton_wine(self) -> str | None:
+        """Locate the wine binary from the configured Proton installation."""
+        try:
+            config_dir = os.environ.get(
+                "XDG_CONFIG_HOME", os.path.join(Path.home(), ".config")
+            )
+            cfg_path = os.path.join(config_dir, "fluorine", "config.json")
+            if not os.path.isfile(cfg_path):
+                return None
+            import json as _json
+            with open(cfg_path, "r") as f:
+                cfg = _json.load(f)
+            proton_path = cfg.get("proton_path", "")
+            if not proton_path:
+                return None
+            for subdir in ("files/bin/wine", "dist/bin/wine"):
+                candidate = os.path.join(proton_path, subdir)
+                if os.path.isfile(candidate):
+                    return candidate
+        except Exception as e:
+            qDebug(f"BG3: failed to read Fluorine config for Proton wine: {e}")
+        return None
 
     @cached_property
     def _folder_pattern(self):
@@ -198,18 +233,70 @@ class BG3PakParser:
             qWarning(traceback.format_exc())
             return ""
 
+    @staticmethod
+    def _to_wine_path(path: str) -> str:
+        """Convert a Linux absolute path to a Wine Z: drive path."""
+        if path.startswith("/"):
+            return "Z:" + path.replace("/", "\\")
+        return path
+
     def run_divine(
         self, action: str, source: Path | str
     ) -> subprocess.CompletedProcess[str]:
-        command = f'{self._divine_command} -a {action} -s "{source}"'
-        result = subprocess.run(
-            command,
-            creationflags=subprocess.CREATE_NO_WINDOW,
+        if platform.system() != "Windows":
+            # Divine.exe is a .NET Windows app — it needs Windows-style paths.
+            # Wine maps Z:\ to the Linux root, so /home/... becomes Z:\home\...
+            wine_source = self._to_wine_path(str(source))
+            wine_action = re.sub(
+                r'"(/[^"]*)"',
+                lambda m: '"' + self._to_wine_path(m.group(1)) + '"',
+                action,
+            )
+            command = f'{self._divine_command} -a {wine_action} -s "{wine_source}"'
+        else:
+            command = f'{self._divine_command} -a {action} -s "{source}"'
+        kwargs: dict = dict(
             check=False,
             stdout=subprocess.PIPE,
             stderr=subprocess.PIPE,
             text=True,
         )
+        if platform.system() == "Windows":
+            kwargs["creationflags"] = subprocess.CREATE_NO_WINDOW
+            kwargs["shell"] = True
+            result = subprocess.run(command, **kwargs)
+        else:
+            # Set WINEPREFIX so Proton's wine uses the game's prefix.
+            wine_prefix = ""
+            try:
+                config_dir = os.environ.get(
+                    "XDG_CONFIG_HOME", os.path.join(Path.home(), ".config")
+                )
+                cfg_path = os.path.join(config_dir, "fluorine", "config.json")
+                if os.path.isfile(cfg_path):
+                    import json as _json
+                    with open(cfg_path, "r") as f:
+                        cfg = _json.load(f)
+                    wine_prefix = cfg.get("prefix_path", "")
+            except Exception:
+                pass
+
+            if os.path.exists("/.flatpak-info"):
+                # In Flatpak, host wine binaries can't execute directly
+                # (missing host libraries). Use flatpak-spawn to run on host.
+                spawn_cmd = ["flatpak-spawn", "--host"]
+                if wine_prefix:
+                    spawn_cmd.append(f"--env=WINEPREFIX={wine_prefix}")
+                spawn_cmd.extend(["bash", "-c", command])
+                result = subprocess.run(spawn_cmd, **kwargs)
+            else:
+                env = os.environ.copy()
+                if wine_prefix:
+                    env["WINEPREFIX"] = wine_prefix
+                kwargs["env"] = env
+                kwargs["shell"] = True
+                result = subprocess.run(command, **kwargs)
+
         if result.returncode:
             qWarning(
                 f"{command.replace(str(Path.home()), '~', 1).replace(str(Path.home()), '$HOME')}"