From 08bfaa4e88e80af6ca0e94444ffbb754dc6b030e Mon Sep 17 00:00:00 2001
From: Sridhar Ratnakumar <srid@srid.ca>
Date: Sat, 3 Dec 2022 21:57:30 -0500
Subject: [PATCH] Isolate common nix into lib.nix

---
 activate.nix           | 32 ----------------
 flake.nix              | 11 +++---
 home/default.nix       | 28 --------------
 lib.nix                | 87 ++++++++++++++++++++++++++++++++++++++++++
 nix-darwin/default.nix | 10 +----
 nixos/default.nix      | 10 -----
 6 files changed, 93 insertions(+), 85 deletions(-)
 delete mode 100644 activate.nix
 create mode 100644 lib.nix

diff --git a/activate.nix b/activate.nix
deleted file mode 100644
index 54f6143..0000000
--- a/activate.nix
+++ /dev/null
@@ -1,32 +0,0 @@
-# A rough flake-parts module for activating the system
-#
-# TODO: Replace with deploy-rs or (new) nixinate
-{ self, inputs, ... }:
-{
-  perSystem = { system, pkgs, lib, ... }: {
-    apps.default =
-      let
-        # Create a flake app that wraps the given bash CLI.
-        bashCmdApp = name: cmd: {
-          type = "app";
-          program =
-            (pkgs.writeShellApplication {
-              inherit name;
-              text = ''
-                set -x
-                ${cmd}
-              '';
-            }) + "/bin/${name}";
-        };
-      in
-      if system == "aarch64-darwin" then
-        bashCmdApp "darwin" ''
-          ${self.darwinConfigurations.default.system}/sw/bin/darwin-rebuild \
-            switch --flake ${self}#default
-        ''
-      else
-        bashCmdApp "linux" ''
-          ${lib.getExe pkgs.nixos-rebuild} --use-remote-sudo switch -j auto
-        '';
-  };
-}
diff --git a/flake.nix b/flake.nix
index 68b70e3..e6525c2 100644
--- a/flake.nix
+++ b/flake.nix
@@ -33,11 +33,11 @@
     inputs.flake-parts.lib.mkFlake { inherit (inputs) self; } {
       systems = [ "x86_64-linux" "aarch64-darwin" ];
       imports = [
+        ./lib.nix
         ./config.nix
         ./home
         ./nixos
         ./nix-darwin
-        ./activate.nix
       ];
 
       people = {
@@ -68,11 +68,9 @@
             ];
           };
         };
-        # Configurations for my only[^1] macOS machine (using nix-darwin)
-        #
-        # [^1]: This is why attr key is 'default'.
+        # Configurations for my (only) macOS machine (using nix-darwin)
         darwinConfigurations = {
-          default = self.lib-darwin.mkMacosSystem {
+          default = self.lib.mkMacosSystem {
             imports = [
               self.darwinModules.default # Defined in nix-darwin/default.nix
               ./systems/darwin.nix
@@ -81,11 +79,12 @@
         };
       };
 
-      perSystem = { pkgs, ... }: {
+      perSystem = { pkgs, config, ... }: {
         devShells.default = pkgs.mkShell {
           buildInputs = [ pkgs.nixpkgs-fmt ];
         };
         formatter = pkgs.nixpkgs-fmt;
+        apps.default = config.apps.activate;
       };
     };
 }
diff --git a/home/default.nix b/home/default.nix
index 2baede9..7b940e5 100644
--- a/home/default.nix
+++ b/home/default.nix
@@ -33,33 +33,5 @@
         ];
       };
     };
-    nixosModules.home-manager = {
-      imports = [
-        inputs.home-manager.nixosModules.home-manager
-        ({
-          home-manager.useGlobalPkgs = true;
-          home-manager.useUserPackages = true;
-          home-manager.extraSpecialArgs = {
-            inherit inputs;
-            system = "x86_64-linux";
-            flake = { inherit config; };
-          };
-        })
-      ];
-    };
-    darwinModules.home-manager = {
-      imports = [
-        inputs.home-manager.darwinModules.home-manager
-        ({
-          home-manager.useGlobalPkgs = true;
-          home-manager.useUserPackages = true;
-          home-manager.extraSpecialArgs = {
-            inherit inputs;
-            system = "aarch64-darwin";
-            flake = { inherit config; };
-          };
-        })
-      ];
-    };
   };
 }
diff --git a/lib.nix b/lib.nix
new file mode 100644
index 0000000..8838dd0
--- /dev/null
+++ b/lib.nix
@@ -0,0 +1,87 @@
+# Support code for this repo. This module could be made its own external repo.
+{ self, inputs, config, ... }:
+{
+  flake = {
+    # Linux home-manager module
+    nixosModules.home-manager = {
+      imports = [
+        inputs.home-manager.nixosModules.home-manager
+        ({
+          home-manager.useGlobalPkgs = true;
+          home-manager.useUserPackages = true;
+          home-manager.extraSpecialArgs = {
+            inherit inputs;
+            system = "x86_64-linux";
+            flake = { inherit config; };
+          };
+        })
+      ];
+    };
+    # macOS home-manager module
+    darwinModules.home-manager = {
+      imports = [
+        inputs.home-manager.darwinModules.home-manager
+        ({
+          home-manager.useGlobalPkgs = true;
+          home-manager.useUserPackages = true;
+          home-manager.extraSpecialArgs = {
+            inherit inputs;
+            system = "aarch64-darwin";
+            flake = { inherit config; };
+          };
+        })
+      ];
+    };
+    lib = {
+      mkLinuxSystem = mod: inputs.nixpkgs.lib.nixosSystem rec {
+        system = "x86_64-linux";
+        # Arguments to pass to all modules.
+        specialArgs = {
+          inherit system inputs;
+          flake = { inherit config; };
+        };
+        modules = [ mod ];
+      };
+
+      mkMacosSystem = mod: inputs.darwin.lib.darwinSystem rec {
+        system = "aarch64-darwin";
+        specialArgs = {
+          inherit inputs system;
+          flake = { inherit config; };
+          rosettaPkgs = import inputs.nixpkgs { system = "x86_64-darwin"; };
+        };
+        modules = [ mod ];
+      };
+    };
+  };
+
+  perSystem = { system, pkgs, lib, ... }: {
+    # A rough app for activating the system locally.
+    #
+    # TODO: Replace with deploy-rs or (new) nixinate
+    apps.activate =
+      let
+        # Create a flake app that wraps the given bash CLI.
+        bashCmdApp = name: cmd: {
+          type = "app";
+          program =
+            (pkgs.writeShellApplication {
+              inherit name;
+              text = ''
+                set -x
+                ${cmd}
+              '';
+            }) + "/bin/${name}";
+        };
+      in
+      if system == "aarch64-darwin" then
+        bashCmdApp "darwin" ''
+          ${self.darwinConfigurations.default.system}/sw/bin/darwin-rebuild \
+            switch --flake ${self}#default
+        ''
+      else
+        bashCmdApp "linux" ''
+          ${lib.getExe pkgs.nixos-rebuild} --use-remote-sudo switch -j auto
+        '';
+  };
+}
diff --git a/nix-darwin/default.nix b/nix-darwin/default.nix
index df7be80..96bd955 100644
--- a/nix-darwin/default.nix
+++ b/nix-darwin/default.nix
@@ -18,14 +18,6 @@
         ../nixos/caches
       ];
     };
-    lib-darwin.mkMacosSystem = mod: inputs.darwin.lib.darwinSystem rec {
-      system = "aarch64-darwin";
-      specialArgs = {
-        inherit inputs system;
-        flake = { inherit config; };
-        rosettaPkgs = import inputs.nixpkgs { system = "x86_64-darwin"; };
-      };
-      modules = [ mod ];
-    };
+
   };
 }
diff --git a/nixos/default.nix b/nixos/default.nix
index c4d1325..319ec7a 100644
--- a/nixos/default.nix
+++ b/nixos/default.nix
@@ -30,15 +30,5 @@ in
         ./current-location.nix
       ];
     };
-
-    lib.mkLinuxSystem = mod: inputs.nixpkgs.lib.nixosSystem rec {
-      system = "x86_64-linux";
-      # Arguments to pass to all modules.
-      specialArgs = {
-        inherit system inputs;
-        flake = { inherit config; };
-      };
-      modules = [ mod ];
-    };
   };
 }