Modularize nixos and home-manager packages

modules/programs/flatpak.nix

@@ -0,0 +1,31 @@
+{ lib, config, options, pkgs, ... }: {
+  options.mods.flatpak = {
+    enable = lib.mkOption {
+      default = true;
+      example = false;
+      type = lib.types.bool;
+      description = "Enables the flatpak package manager";
+    };
+    additional_packages = lib.mkOption {
+      default = [ ];
+      example = [ ];
+      type = with lib.types; listOf str;
+      description = "Flatpak packages";
+    };
+  };
+  config = lib.mkIf config.mods.flatpak.enable
+    (lib.optionalAttrs (options?services.flatpak.remote)
+      {
+        services.flatpak.remotes = lib.mkOptionDefault [{
+          name = "flathub-stable";
+          location = "https://dl.flathub.org/repo/flathub.flatpakrepo";
+        }];
+        services.flatpak.uninstallUnmanaged = true;
+      } // lib.optionalAttrs (options?services.flatpak.packages) {
+      services.flatpak.packages = [
+        # fallback if necessary, but generally avoided as nix is superior :)
+        # default flatseal installation since flatpak permissions are totally not a broken idea 
+        "com.github.tchx84.Flatseal"
+      ] ++ config.mods.flatpak.additional_packages;
+    });
+}