fixup(buildClan): split up the inner-module into: {forSystem, forName}

I am preparing this such that we can move the forName modules into the
defaults for the deferred module outputs and the forSystem modules are
added later and only for the 'configsPerSystem' where we actually need
the system modules

lib/build-clan/inner-module.nix

@@ -1,61 +0,0 @@
-{
-  system,
-  name,
-  pkgs,
-  clanConfiguration,
-}:
-{
-  _class,
-  lib,
-  ...
-}:
-let
-  inherit (clanConfiguration) directory machines pkgsForSystem;
-  inherit (clanConfiguration.clanInternals) inventoryClass;
-in
-{
-  imports = [
-    {
-      imports = builtins.filter builtins.pathExists (
-        [
-          "${directory}/machines/${name}/configuration.nix"
-        ]
-        ++ lib.optionals (_class == "nixos") [
-          "${directory}/machines/${name}/hardware-configuration.nix"
-          "${directory}/machines/${name}/disko.nix"
-        ]
-      );
-    }
-    (lib.optionalAttrs (_class == "nixos") {
-      imports = (inventoryClass.machines.${name}.machineImports or [ ]);
-
-      config = {
-        clan.core.settings = {
-          inherit (clanConfiguration.inventory.meta) name icon;
-
-          inherit directory;
-          machine = {
-            inherit name;
-          };
-        };
-        # Inherited from clan wide settings
-        # TODO: remove these
-      };
-    })
-    (
-      {
-        networking.hostName = lib.mkDefault name;
-
-        # For vars we need to override the system so we run vars
-        # generators on the machine that runs `clan vars generate`. If a
-        # users is using the `pkgsForSystem`, we don't set
-        # nixpkgs.hostPlatform it would conflict with the `nixpkgs.pkgs`
-        # option.
-        nixpkgs.hostPlatform = lib.mkIf (system != null && (pkgsForSystem system) != null) (
-          lib.mkForce system
-        );
-      }
-      // lib.optionalAttrs (pkgs != null) { nixpkgs.pkgs = lib.mkForce pkgs; }
-    )
-  ];
-}

lib/build-clan/machineModules/forName.nix

@@ -0,0 +1,28 @@
+{
+  name,
+  directory,
+}:
+{
+  _class,
+  lib,
+  ...
+}:
+{
+  imports = [
+    {
+      imports = builtins.filter builtins.pathExists (
+        [
+          "${directory}/machines/${name}/configuration.nix"
+        ]
+        ++ lib.optionals (_class == "nixos") [
+          "${directory}/machines/${name}/hardware-configuration.nix"
+          "${directory}/machines/${name}/disko.nix"
+        ]
+      );
+    }
+    # TODO: move into nixos modules
+    ({
+      networking.hostName = lib.mkDefault name;
+    })
+  ];
+}

lib/build-clan/machineModules/forSystem.nix

@@ -0,0 +1,26 @@
+{
+  pkgs,
+  pkgsForSystem,
+  system,
+}:
+{
+  lib,
+  ...
+}:
+{
+  imports = [
+    (
+      {
+        # For vars we need to override the system so we run vars
+        # generators on the machine that runs `clan vars generate`. If a
+        # users is using the `pkgsForSystem`, we don't set
+        # nixpkgs.hostPlatform it would conflict with the `nixpkgs.pkgs`
+        # option.
+        nixpkgs.hostPlatform = lib.mkIf (system != null && (pkgsForSystem system) != null) (
+          lib.mkForce system
+        );
+      }
+      // lib.optionalAttrs (pkgs != null) { nixpkgs.pkgs = lib.mkForce pkgs; }
+    )
+  ];
+}

lib/build-clan/module.nix

@@ -59,17 +59,25 @@ let
       nixpkgs.lib.nixosSystem {
         modules =
           let
-            innerModule = lib.modules.importApply ./inner-module.nix {
+            innerModule = lib.modules.importApply ./machineModules/forSystem.nix {
               inherit
-                system
-                name
                 pkgs
+                pkgsForSystem
+                system
                 ;
-              clanConfiguration = config;
             };
+            staticModules = (
+              lib.modules.importApply ./machineModules/forName.nix {
+                inherit
+                  name
+                  directory
+                  ;
+              }
+            );
           in
           [
             (config.outputs.moduleForMachine.${name} or { })
+            staticModules
             innerModule
             {
               config.clan.core.module = innerModule;
@@ -90,13 +98,24 @@ let
       nix-darwin.lib.darwinSystem {
         modules = [
           (config.outputs.moduleForMachine.${name} or { })
-          (lib.modules.importApply ./inner-module.nix {
+          # We split the modules to reduce the number of dependencies
+          # This module only depends on the machine name
+          # and the directory
+          (lib.modules.importApply ./machineModules/forName.nix {
             inherit
-              system
               name
-              pkgs
+              directory
+              ;
+          })
+          # This module depends on the system and pkgs
+          # It contains optional logic to override 'nixpkgs.pkgs' and 'nixpkgs.hostPlatform'
+          # and other 'system' related logic
+          (lib.modules.importApply ./machineModules/forSystem.nix {
+            inherit
+              pkgs
+              pkgsForSystem
+              system
               ;
-            clanConfiguration = config;
           })
         ];
 
@@ -170,7 +189,26 @@ in
         # See: 'staticModules' in the moduleForMachine option
         # This is only necessary because clan.machines doesn't include all machines
         # There can other sources: i.e. inventory
-        (lib.mapAttrs (_: _: { }) config.inventory.machines)
+        (lib.mapAttrs (
+          name: v:
+          (
+            { _class, ... }:
+            {
+              imports = (v.machineImports or [ ]);
+              config = lib.optionalAttrs (_class == "nixos") {
+                clan.core.settings = {
+                  inherit (config.inventory.meta) name icon;
+
+                  inherit directory;
+                  machine = {
+                    inherit name;
+                  };
+                };
+              };
+
+            }
+          )
+        ) inventoryClass.machines)
 
         # The user can define some machine config here
         # i.e. 'clan.machines.jon = ...'