From c9ee01f65e4ba81425620c37d4159b9c8d58c8ba Mon Sep 17 00:00:00 2001
From: Natsu Kagami <nki@nkagami.me>
Date: Mon, 4 Jul 2022 15:41:04 -0400
Subject: [PATCH] Modernizing overlay

---
 darwin/brew.nix          | 17 +--------------
 darwin/configuration.nix |  5 +----
 flake.nix                | 46 +++++++++++++++++++++++-----------------
 overlay.nix              | 26 +++++++++++------------
 4 files changed, 41 insertions(+), 53 deletions(-)

diff --git a/darwin/brew.nix b/darwin/brew.nix
index ed74b78..9260844 100644
--- a/darwin/brew.nix
+++ b/darwin/brew.nix
@@ -16,27 +16,12 @@ with lib;
   ];
 
   homebrew.brews = [
-    # Base libraries
-    "coreutils"
-
-    # Compilers and Language Interpreters
-    "elm"
-    "llvm"
-    "luajit-openresty"
-    "node"
-    "perl"
-    "ruby@2.7"
-
     # CLI tools
     "pinentry-mac" # UI for Pin Entry on gpg Mac
 
     # U2F
     "pam-u2f"
-  ] ++ (optionals (pkgs.system == "aarch64-darwin") [
-    # Because python on Nix is a bit abababa
-    "python@3.9"
-    "scipy"
-  ]);
+  ];
 
   homebrew.casks = [
     "anki"
diff --git a/darwin/configuration.nix b/darwin/configuration.nix
index 54c9ab9..4de1593 100644
--- a/darwin/configuration.nix
+++ b/darwin/configuration.nix
@@ -16,7 +16,7 @@
 
   # Auto upgrade nix package and the daemon service.
   # services.nix-daemon.enable = true;
-  nix.package = pkgs.nixUnstable;
+  nix.package = pkgs.nixFlakes;
 
   # Create /etc/bashrc that loads the nix-darwin environment.
   programs.zsh.enable = true; # default shell on catalina
@@ -25,9 +25,6 @@
   ## Networking related settings
   networking.hostName = "nki-macbook";
 
-  ## Programs
-  nixpkgs.config.allowUnfree = true;
-
   environment.variables = {
     EDITOR = ""; # don't set it by default
 
diff --git a/flake.nix b/flake.nix
index 1cbe510..2fb8bba 100644
--- a/flake.nix
+++ b/flake.nix
@@ -29,10 +29,13 @@
 
   outputs = { self, darwin, nixpkgs, nixpkgs-unstable, home-manager, deploy-rs, sops-nix, nur, ... }@inputs:
     let
-      overlayForSystem = import ./overlay.nix inputs;
+      overlays = import ./overlay.nix inputs;
 
-      nixpkgsAsRegistry = { ... }: {
-        nix.registry.nixpkgs.flake = nixpkgs;
+      pkgs = system: import nixpkgs { inherit system overlays; };
+      pkgs-unstable = system: import nixpkgs-unstable { inherit system overlays; };
+
+      nixpkgsAsRegistry_ = stable: { ... }: {
+        nix.registry.nixpkgs.flake = stable;
         nix.registry.nixpkgs-unstable.flake = nixpkgs-unstable;
         nix.nixPath = [
           "nixpkgs=${nixpkgs}"
@@ -40,6 +43,17 @@
           "/nix/var/nix/profiles/per-user/root/channels"
         ];
       };
+      nixpkgsAsRegistry = nixpkgsAsRegistry_ nixpkgs;
+
+      haskellDotNix = { ... }: {
+        # Binary Cache for Haskell.nix  
+        nix.binaryCachePublicKeys = [
+          "hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ="
+        ];
+        nix.binaryCaches = [
+          "https://cache.iog.io"
+        ];
+      };
 
       enableOsuStable = { lib, ... }: {
         imports = [ inputs.nix-gaming.nixosModules.pipewireLowLatency ];
@@ -63,31 +77,26 @@
     in
     {
       # MacBook configuration: nix-darwin + home-manager
-      darwinConfigurations."nki-macbook" = darwin.lib.darwinSystem {
+      darwinConfigurations."nki-macbook" = darwin.lib.darwinSystem rec {
         system = "aarch64-darwin";
+        pkgs = pkgs-unstable system;
         modules = [
           ./darwin/configuration.nix
           # Set nix path
-          ({ ... }: {
-            nix.nixPath = [
-              "nixpkgs=${nixpkgs-unstable}"
-              "nixpkgs-unstable=${nixpkgs-unstable}"
-              "/nix/var/nix/profiles/per-user/root/channels"
-              "\$HOME/.nix-defexpr/channels"
-            ];
-          })
+          haskellDotNix
+          (nixpkgsAsRegistry_ nixpkgs-unstable)
           home-manager.darwinModules.home-manager
           {
             home-manager.useGlobalPkgs = true;
             home-manager.useUserPackages = true;
             home-manager.users.nki = import ./home/macbook-home.nix;
           }
-          (overlayForSystem "aarch64-darwin")
         ];
       };
 
       # Home configuration
-      nixosConfigurations."nki-home" = nixpkgs.lib.nixosSystem {
+      nixosConfigurations."nki-home" = nixpkgs.lib.nixosSystem rec {
+        pkgs = pkgs system;
         system = "x86_64-linux";
         modules = [
           ./modules/my-tinc
@@ -102,11 +111,11 @@
             home-manager.users.nki = import ./home/kagami-pc-home.nix;
           }
           inputs.secrets.nixosModules.x86_64-linux.common
-          (overlayForSystem "x86_64-linux")
         ];
       };
       # x1c1 configuration
-      nixosConfigurations."nki-x1c1" = nixpkgs.lib.nixosSystem {
+      nixosConfigurations."nki-x1c1" = nixpkgs.lib.nixosSystem rec {
+        pkgs = pkgs system;
         system = "x86_64-linux";
         modules = [
           ./modules/my-tinc
@@ -119,12 +128,12 @@
             home-manager.useUserPackages = true;
             home-manager.users.nki = import ./home/nki-x1c1.nix;
           }
-          (overlayForSystem "x86_64-linux")
         ];
       };
 
       # DigitalOcean node
-      nixosConfigurations."nki-personal-do" = nixpkgs.lib.nixosSystem {
+      nixosConfigurations."nki-personal-do" = nixpkgs.lib.nixosSystem rec {
+        pkgs = pkgs system;
         system = "x86_64-linux";
         modules = [
           ./modules/my-tinc
@@ -132,7 +141,6 @@
           sops-nix.nixosModules.sops
           ./nki-personal-do/configuration.nix
           inputs.secrets.nixosModules.x86_64-linux.nki-personal-do
-          (overlayForSystem "x86_64-linux")
         ];
       };
       deploy.nodes."nki-personal-do" = {
diff --git a/overlay.nix b/overlay.nix
index 0169c56..464df46 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -1,28 +1,26 @@
-{ nixpkgs, nixpkgs-unstable, nur, ... }@inputs: system:
+{ nixpkgs, nixpkgs-unstable, nur, ... }@inputs:
 let
   overlay-unstable = final: prev: {
     unstable = import nixpkgs-unstable { config.allowUnfree = true; system = prev.system; };
     unfree = import nixpkgs { config.allowUnfree = true; system = prev.system; };
-    x86 = import nixpkgs-unstable { system = "${system}"; config.allowUnsupportedSystem = true; };
+    x86 = import nixpkgs-unstable { system = prev.system; config.allowUnsupportedSystem = true; };
   };
   overlay-needs-unstable = final: prev: {
     # override some packages that needs unstable that cannot be changed in the setup.
     nix-direnv = prev.unstable.nix-direnv;
   };
   overlay-imported = final: prev: {
-    rnix-lsp = inputs.rnix-lsp.defaultPackage."${system}";
+    rnix-lsp = inputs.rnix-lsp.defaultPackage."${prev.system}";
   };
 in
-{
-  nixpkgs.overlays = [
-    (import ./overlays/openrazer)
-    overlay-unstable
-    overlay-needs-unstable
-    overlay-imported
-    nur.overlay
+[
+  (import ./overlays/openrazer)
+  overlay-unstable
+  overlay-needs-unstable
+  overlay-imported
+  nur.overlay
 
-    # Bug fixes
-    (import ./overlays/bugfixes/delta)
-  ]; # we assign the overlay created before to the overlays of nixpkgs.
-}
+  # Bug fixes
+  (import ./overlays/bugfixes/delta)
+] # we assign the overlay created before to the overlays of nixpkgs.