migrate constructSystem to lib/

migrates the bulk of constructSystem to lib/ and splits out the largest
chunks into individual functions (namely SOPS, home-manager, and user creation);

Signed-off-by: ahuston-0 <aliceghuston@gmail.com>

lib/default.nix

@@ -2,6 +2,8 @@
 {
   # create rad-dev namespace for lib
   rad-dev = rec {
+    systems = import ./systems.nix { inherit lib; };
+
     # any(), but checks if any value in the list is true
     #
     # args:

lib/systems.nix

@@ -0,0 +1,88 @@
+{ lib, ... }:
+
+rec {
+  genHostName = hostname: { config.networking.hostName = hostname; };
+
+  genHome =
+    {
+      inputs,
+      users,
+      src,
+      ...
+    }:
+    [ inputs.home-manager.nixosModules.home-manager ]
+    ++ (map (user: { home-manager.users.${user} = import (src + "/users/${user}/home.nix"); }) users);
+
+  genSops =
+    {
+      inputs,
+      users,
+      src,
+      ...
+    }:
+    [ inputs.sops-nix.nixosModules.sops ]
+    ++ (map (user: {
+      sops.secrets."${user}/user-password" = {
+        sopsFile = src + "/users/${user}/secrets.yaml";
+        neededForUsers = true;
+      };
+    }) users);
+
+  genUsers =
+    { users, src, ... }:
+    (map (
+      user:
+      {
+        config,
+        lib,
+        pkgs,
+        ...
+      }@args:
+      {
+        users.users.${user} = import (src + "/users/${user}") (args // { name = user; });
+      }
+    ) users);
+
+  genWrapper =
+    var: func: args:
+    lib.optionals var (func args);
+
+  nonX86 = {
+    config.nixpkgs = {
+      config.allowUnsupportedSystem = true;
+      buildPlatform = "x86_64-linux";
+    };
+  };
+
+  constructSystem =
+    {
+      hostname,
+      users,
+      inputs,
+      src,
+      home ? true,
+      iso ? [ ],
+      modules ? [ ],
+      server ? true,
+      sops ? true,
+      system ? "x86_64-linux",
+
+    }@args:
+
+    lib.nixosSystem {
+      inherit system;
+      specialArgs = inputs;
+      modules =
+        [
+          inputs.nixos-modules.nixosModule
+          (genHostName hostname)
+          (src + "/systems/${hostname}/hardware.nix")
+          (src + "/systems/${hostname}/configuration.nix")
+        ]
+        ++ modules
+        ++ (lib.rad-dev.fileList src "modules")
+        ++ genWrapper sops genSops args
+        ++ genWrapper home genHome args
+        ++ genWrapper true genUsers args;
+    };
+}