From 8b9a01a0efc691239104330bc7fb4c797a614a83 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Sat, 25 Feb 2023 01:03:42 +0000
Subject: [PATCH] modules: system: nix: DRY inputs handling

---
 modules/system/nix/default.nix | 38 +++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/modules/system/nix/default.nix b/modules/system/nix/default.nix
index 056b5da..c8ce001 100644
--- a/modules/system/nix/default.nix
+++ b/modules/system/nix/default.nix
@@ -2,6 +2,21 @@
 { config, inputs, lib, options, pkgs, ... }:
 let
   cfg = config.my.system.nix;
+
+  channels = lib.my.merge [
+    {
+      # Allow me to use my custom package using `nix run self#pkg`
+      self = inputs.self;
+      # Add NUR to run some packages that are only present there
+      nur = inputs.nur;
+      # Use pinned nixpkgs when using `nix run pkgs#<whatever>`
+      pkgs = inputs.nixpkgs;
+    }
+    (lib.optionalAttrs cfg.overrideNixpkgs {
+      # ... And with `nix run nixpkgs#<whatever>`
+      nixpkgs = inputs.nixpkgs;
+    })
+  ];
 in
 {
   options.my.system.nix = with lib; {
@@ -40,16 +55,12 @@ in
     }
 
     (lib.mkIf cfg.addToRegistry {
-      nix.registry = {
-        # Allow me to use my custom package using `nix run self#pkg`
-        self.flake = inputs.self;
-        # Use pinned nixpkgs when using `nix run pkgs#<whatever>`
-        pkgs.flake = inputs.nixpkgs;
-        # ... And with `nix run nixpkgs#<whatever>`
-        nixpkgs.flake = lib.mkIf cfg.overrideNixpkgs inputs.nixpkgs;
-        # Add NUR to run some packages that are only present there
-        nur.flake = inputs.nur;
-      };
+      nix.registry =
+        let
+          makeEntry = v: { flake = v; };
+          makeEntries = lib.mapAttrs (lib.const makeEntry);
+        in
+        makeEntries channels;
     })
 
     (lib.mkIf cfg.linkInputs {
@@ -60,13 +71,6 @@ in
             value = { source = v.outPath; };
           };
           makeLinks = lib.mapAttrs' makeLink;
-          channels = {
-            self = inputs.self;
-            pkgs = inputs.nixpkgs;
-            nur = inputs.nur;
-          } // lib.optionalAttrs cfg.overrideNixpkgs {
-            nixpkgs = inputs.nixpkgs;
-          };
         in
         makeLinks channels;
     })