Add arch to hosts, share host config with flake.

lib/fudo/hosts.nix

@@ -149,7 +149,6 @@ let
       arch = mkOption {
         type = str;
         description = "System architecture of the system.";
-        default = "x86_64-linux";
       };
 
       android-dev = mkEnableOption "Enable ADB on the host.";

lib/hosts.nix

@@ -0,0 +1,16 @@
+{ lib, ... }:
+
+with lib;
+{
+  base-host-config = host-path: let
+    hostname-from-file = filename: builtins.replaceStrings [".nix"] [""] filename;
+
+    is-nix-file = filename: type: (builtins.match ".+\.nix$" filename) != null;
+    is-regular-file = filename: type: type == "regular" || type == "link";
+
+    host-files = attrNames (filterAttrs is-nix-file (filterAttrs is-regular-file (builtins.readDir host-path)));
+    hosts = map hostname-from-file host-files;
+
+    load-host-file = hostname: import (./. + "/hosts/${hostname}.nix");
+  in genAttrs hosts (hostname: load-host-file hostname);
+}

lib/system.nix

@@ -1,4 +1,4 @@
-{ config, lib, ... }:
+{ lib, ... }:
 
 with lib;
 let