xmobar: write configuration in haskell

nix/configurations/vanadium/home/xmobar.nix

@@ -1,50 +1,26 @@
-{
-  programs.xmobar = {
-    enable = true;
-    # XMobar's config file is not a segment of valid Haskell source code -- it is instead a DSL
-    # Note how `Run` handles its arguments properly without parens?
-    #
-    # Also xmobar wants GHC if we use it as a library, and I'm lazy, you probably want to keep it this way.
-    extraConfig = ''
-      Config { overrideRedirect = False
-             , font             = "Iosevka 13"
-             , bgColor          = "#000000"
-             , fgColor          = "#FFFFFF"
-             , position = BottomH 30
-             , commands = [ Run Date "%a %d %H:%M:%S" "date" 10
-                          , Run Com "tomorrow"
-                              [ "--target", "2025-08-14"
-                              , "--target", "2025-08-21"
-                              ] "" 3600
-                          , Run Battery
-                              [ "-t", "<left> (<timeleft>"
-                              , "-H", "70"
-                              , "-L", "20"
-                              , "-h", "green"
-                              , "-n", "orange"
-                              , "-l", "red"
-                              , "--"
-                              , "-P"
-                              , "-A", "20"
-                              , "-a", "notify-send -u critical \"Battery Low\" \"Please charge your battery\""
-                              ]
-                              60
-                          , Run Com "powerprofilesctl" [ "get" ] "" 60
-                          , Run XMonadLog
-                          , Run
-                              Weather "LFRN"
-                              [ "-t", "<station>: <tempC>C"
-                              , "-L","10", "-H", "25"
-                              , "--normal", "white"
-                              , "--high", "orange"
-                              , "--low", "blue"
-                              ]
-                              9000
-                          ]
-             , sepChar  = "%"
-             , alignSep = "}{"
-             , template = " %XMonadLog% }{ %LFRN% | %battery%, %powerprofilesctl%) | %date%, j%tomorrow% "
-             }
-    '';
+{pkgs, ...}: {
+  home.packages = let
+    wrapped-xmobar = pkgs.symlinkJoin {
+      name = "xmobar";
+      paths = with pkgs; [
+        # Xmobar wants ghc
+        (haskellPackages.ghcWithPackages (self: [
+          self.xmobar
+        ]))
+        # The executable
+        xmobar
+      ];
+    };
+  in [
+    wrapped-xmobar
+  ];
+
+  xdg.configFile = {
+    "xmobar" = {
+      # Xmobar uses the directory to compile too,
+      # Linking the entire folder directly would make the directory not writable
+      recursive = true;
+      source = "${./xmobar}";
+    };
   };
 }