Gaming/retroarch: update retroarch library automatically

roles/gaming/programs/retroarch.nix

@@ -51,6 +51,28 @@
       "d /%h/.local/share/retroarch/saves"
       "d /%h/.local/share/retroarch/states"
     ];
+    systemd.user.paths = {
+      snes-roms = {
+        Unit.Description = "Monitor SNES rom path for changes";
+        Path = {
+          PathChanged = "/%h/Games/SNES";
+          Unit = "update-retroarch-library.service";
+        };
+        Install.WantedBy = ["default.target"];
+      };
+    };
+    systemd.user.services.update-retroarch-library = {
+      Service = {
+        Type = "oneshot";
+        ExecStart = pkgs.writeShellScript "scan-snes-games" ''
+          ${pkgs.libnotify}/bin/notify-send -a RetroArch \
+            -i retroarch \
+            "SNES games changed!" \
+            "Scanning $TRIGGER_PATH..."
+          ${pkgs.retroarch}/bin/retroarch --scan "/home/toast/Games/SNES"
+        '';
+      };
+    };
   };
 
   # Sync saves and some other stuff