fix!: improve nix flake

.gitignore

@@ -385,3 +385,6 @@ svg-inkscape/
 .xamples
 algotex-ctan.zip
 algotex.tds.zip
+
+# nix
+result

flake.nix

@@ -1,59 +1,97 @@
 {
   description = "AlgoTeX flake";
 
-  outputs = { self, nixpkgs, }:
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixpkgs-unstable";
+    tuda-pdf = {
+      url = "https://www.tu-darmstadt.de/media/medien_stabsstelle_km/services/medien_cd/das_bild_der_tu_darmstadt.pdf";
+      flake = false;
+    };
+  };
+
+  outputs =
+    {
+      self,
+      nixpkgs,
+      tuda-pdf,
+    }:
     let
-      system = "x86_64-linux";
-      pkgs = import nixpkgs { inherit system; };
-      algotex = with pkgs;
-        stdenvNoCC.mkDerivation (finalAttrs: {
-          name = "algotex";
-          src = fetchFromGitHub {
-            owner = "tudalgo";
-            repo = "AlgoTeX";
-            rev = "5f0d8bd394bba5b04eef0d11614b3cadd315f1c8";
-            hash = "sha256-hpuPeK1xj62xveMBh8X1NvRKgtRTSUBZk5eOPixxIpY=";
-          };
-          passthru = {
-            pkgs = [ finalAttrs.finalPackage ];
-            tlType = "run";
-            tlDeps = with texlive; [ latex ];
-          };
-          buildInputs = [ librsvg ];
-          installPhase = ''
-            mkdir -p $out/tex/latex/algotex
-            cp -t $out/tex/latex/algotex/ $src/tex/*
-            cp $out/tex/latex/algotex/FOPBot.sty $out/tex/latex/algotex/fopbot.sty
-
-            mkdir -p $out/tex/latex/local
-            rsvg-convert -f pdf -o $out/tex/latex/local/tuda_logo.pdf ${
-              builtins.fetchurl {
-                url =
-                  "https://upload.wikimedia.org/wikipedia/de/2/24/TU_Darmstadt_Logo.svg";
-                sha256 =
-                  "sha256:0wb2ygg0wzd2ajdzv847xp1qxkx4m1j64p1gdrq4r05klbrddbwl";
-              }
-            }
-          '';
-        });
-      patched-latex = with pkgs.texlive;
-        combine {
-          inherit scheme-full;
-          inherit algotex;
-        };
-    in {
-      devShells.${system}.default = with pkgs;
-        mkShell {
+      systems = [
+        "aarch64-darwin"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "x86_64-linux"
+      ];
+      forAllSystems = nixpkgs.lib.genAttrs systems;
+      allPkgs = forAllSystems (system: import nixpkgs { inherit system; });
+    in
+    {
+      # minimal example shell for using algotex
+      devShells = forAllSystems (
+        system:
+        let
+          inherit (allPkgs.${system}) pkgs;
+        in
+        pkgs.mkShell {
           buildInputs = [
-            python311Packages.pygments
-            patched-latex
-            pre-commit
-            python310Packages.editorconfig
+            pkgs.python313Packages.pygments
+            self.packages.${system}.latex_with_algotex
           ];
-          shellHook = ''
-            pre-commit install
-          '';
-        };
-      packages.${system}.default = patched-latex;
+        }
+      );
+
+      packages = forAllSystems (
+        system:
+        let
+          inherit (allPkgs.${system}) pkgs;
+        in
+        {
+          # algotex and logo only
+          algotex = pkgs.stdenvNoCC.mkDerivation (finalAttrs: {
+            name = "algotex";
+            src = ./.;
+            passthru = {
+              pkgs = [ finalAttrs.finalPackage ];
+              tlType = "run";
+              tlDeps = with pkgs.texlive; [ latex ];
+            };
+            nativeBuildInputs = with pkgs; [
+              inkscape
+              librsvg
+            ];
+            installPhase = ''
+              runHook preInstall
+
+              # copy algotex files
+              algotex_path=$out/tex/latex/algotex
+              mkdir -p $algotex_path
+              cp $src/tex/* $algotex_path/
+
+              # build tuda logo
+              logo_path=$out/tex/latex/local
+              mkdir -p $logo_path
+              cp ${tuda-pdf} tuda.pdf
+
+              # see https://github.com/tudalgo/AlgoTeX/commit/ce0e2c032d3067070ef07bd8c84520f8209e1997
+              inkscape tuda.pdf --export-filename=p1_i.svg --export-dpi=3000 --pages=1
+              sed -i 's/icc-color([^)]*)//g' p1_i.svg
+              sed -i 's/#000000/#1d1d1bff/g' p1_i.svg
+              rsvg-convert -f pdf -o $logo_path/tuda_logo.pdf p1_i.svg --export-id=g20
+
+              runHook postInstall
+            '';
+            dontConfigure = true;
+            dontBuild = true;
+          });
+
+          # full texlive distribution with algotex and the logo file
+          latex_with_algotex = pkgs.texlive.combine {
+            inherit (pkgs.texlive) scheme-full;
+            inherit (self.packages.${system}) algotex;
+          };
+
+          default = self.packages.${system}.latex_with_algotex;
+        }
+      );
     };
 }