add nix derivation to build catppuccin userstyles

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1712791164,
-        "narHash": "sha256-3sbWO1mbpWsLepZGbWaMovSO7ndZeFqDSdX0hZ9nVyw=",
+        "lastModified": 1713537308,
+        "narHash": "sha256-XtTSSIB2DA6tOv+l0FhvfDMiyCmhoRbNB+0SeInZkbk=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "1042fd8b148a9105f3c0aca3a6177fd1d9360ba5",
+        "rev": "5c24cf2f0a12ad855f444c30b2421d044120c66f",
         "type": "github"
       },
       "original": {

flake.nix

@@ -23,7 +23,7 @@
           config._module.args = {
             inherit inputs;
             inherit pkgs system;
-            inherit (pkgs) lib stdenv;
+            inherit (pkgs) lib stdenv stdenvNoCC;
           };
 
           # Local user nix env

nix/default.nix

@@ -3,5 +3,6 @@
   imports = [
     ./cgnix
     ./mcdev.nix
+    ./userstyles.nix
   ];
 }

nix/userstyles.nix

@@ -0,0 +1,38 @@
+# Module that provides an output for a stylus import file with catppuccin themes.
+{ pkgs, stdenvNoCC, ... }:
+let
+  flavor = "mocha";
+  accent-color = "red";
+in 
+{
+  packages.userstyles = stdenvNoCC.mkDerivation {
+    name = "userstyles.json";
+    src = pkgs.fetchurl {
+      url = "https://github.com/catppuccin/userstyles/releases/download/all-userstyles-export/import.json";
+      hash = "sha256-eYU9Y95au9mI3muS4+1QJt31W7s2zVmurdKbQ1dU+pk=";
+    };
+
+    dontUnpack = true;
+
+    # TODO: use better language
+    realBuilder = "${pkgs.deno}/bin/deno";
+    args = [
+      "run"
+      "-A"
+      (pkgs.writeText "build.js" ''
+        const json = await import(Deno.env.get("src"), { with: { type: "json" } });
+        const processed = json.default.map(theme => {
+          if (theme.usercssData?.vars?.accentColor?.default)
+            theme.usercssData.vars.accentColor.default = "${accent-color}";
+
+          if (theme.usercssData?.vars?.darkFlavor?.default)
+            theme.usercssData.vars.darkFlavor.default = "${flavor}";
+
+            return theme;
+        });
+
+        Deno.writeTextFileSync(Deno.env.get("out"), JSON.stringify(processed));
+      '')
+    ];
+  };
+}