{ description = "niss's silly extra packages";

  outputs = all@{ self, nixpkgs, ... }:
  let
    inherit (nixpkgs.lib) genAttrs optionalAttrs systems;

    forAllSystems = genAttrs systems.flakeExposed;
    getCallPackage = system: nixpkgs.legacyPackages.${system}.callPackage;
    ifLinux64 = system: attrs: optionalAttrs (system == "x86_64-linux") attrs;

    linuxPackageNames =
      [ "basilisk" "firefox-esr-alias" "isabelle" "multi-ghc" ];
    fontNames =
      [ "constructium" "fairfax-hd" "kreative-square" "muller"
        "pragmatapro" "teranoptia" ];

    linuxAppNames = [ "basilisk" "isabelle" "firefox-esr-alias" ];
    linuxAppExes  = { "firefox-esr-alias" = "firefox-esr"; };

    packagesInDir = names: dir: call:
      genAttrs names (pkg: call ./${dir}/${pkg}.nix {});

    linuxOnly = packagesInDir linuxPackageNames "apps";
    fonts     = packagesInDir fontNames         "fonts";
    all = system: call: ifLinux64 system (linuxOnly call) // fonts call;

    makeApp = pkgs: name: {
      type    = "app";
      program = "${pkgs.${name}}/bin/${linuxAppExes.${name} or name}";
    };

    linuxApps = call: genAttrs linuxAppNames (makeApp (linuxOnly call));
  in {
    packages = forAllSystems (s: all s (getCallPackage s));
    apps     = forAllSystems (s: ifLinux64 s (linuxApps (getCallPackage s)));
    overlays = forAllSystems (s: final: prev: all s final.callPackage);
  };
}