stepmania: simplify the wrapping

hosts/common/programs/stepmania.nix

@@ -1,6 +1,5 @@
 # configuration:
-# - things like calibration data live in ~/.local/share/stepmania/Save/Preferences.ini
-#   or try ~/.stepmania-5.1 if that fails
+# - things like calibration data live in ~/.stepmania-5.1/Save/Preferences.ini
 # - GlobalOffsetSeconds = difference between audio and video delay.
 #   Hit F6 twice in-game to being auto calibration
 #   Usually the result will be negative (i.e. the higher the latency of the pad, the more negative the offset)
@@ -14,7 +13,7 @@
 #   - https://fitupyourstyle.com/
 #     allows search by difficulty
 # - dl packs from <https://stepmaniaonline.net>
-{ config, lib, pkgs, ... }:
+{ lib, pkgs, ... }:
 {
   sane.programs.stepmania = {
     buildCost = 1;
@@ -24,15 +23,13 @@
         pkgs.makeWrapper
       ];
     } ''
-      # stepmania expects the current working directory to be the same directory where all its data resides.
-      # so we create such a directory, and a wrapper which `cd`s into it before launch
+      # stepmania search assets in ~/.stepmania-5.1, followed by the current working directory.
+      # therefore, create a wrapper which cd's to the directory holding all the builtin assets before launching the program.
+      # TODO: this can be simplified and included into nixpkgs' stepmania package
       mkdir -p $out/share/stepmania
-      for shipDir in Announcers BackgroundEffects BackgroundTransitions BGAnimations Characters Data Docs NoteSkins Scripts Themes; do
+      for shipDir in Announcers BackgroundEffects BackgroundTransitions BGAnimations Cache Characters Courses Data Docs NoteSkins Save Scripts Songs Themes; do
         ln -s ${pkgs.stepmania}/stepmania-5.1/$shipDir $out/share/stepmania/$shipDir
       done
-      for userDir in Cache Courses Save Songs; do
-        ln -s /home/${config.sane.defaultUser}/.local/share/stepmania/$userDir $out/share/stepmania/$userDir
-      done
 
       makeWrapper ${lib.getExe pkgs.stepmania} $out/share/stepmania/stepmania \
         --run "cd $out/share/stepmania"
@@ -51,14 +48,17 @@
       "/dev/input"
       "/sys/class/input"
     ];
+    sandbox.extraHomePaths = [
+      ".stepmania-5.1"
+    ];
 
     persist.byStore.plaintext = [
-      ".local/share/stepmania/Cache"  #< otherwise gotta index all the songs every launch
-      ".local/share/stepmania/Save"
+      ".stepmania-5.1/Cache"  #< otherwise gotta index all the songs every launch
+      ".stepmania-5.1/Save"
     ];
 
     # TODO: setup ~/.local/share/stepmania/Themes
-    fs.".local/share/stepmania/Courses".symlink.target = "/mnt/servo/media/games/stepmania/Courses";
-    fs.".local/share/stepmania/Songs".symlink.target = "/mnt/servo/media/games/stepmania/Songs";
+    fs.".stepmania-5.1/Courses".symlink.target = "/mnt/servo/media/games/stepmania/Courses";
+    fs.".stepmania-5.1/Songs".symlink.target = "/mnt/servo/media/games/stepmania/Songs";
   };
 }