From f7548cccda82477b731dee31032a861573f5be3d Mon Sep 17 00:00:00 2001
From: "Hugo Cartigny (BlueskyFR)" <hugo.cartigny@gmail.com>
Date: Sat, 1 Mar 2025 20:33:31 +0100
Subject: [PATCH] nixos/light: add minBrightness option

Make the minimum brightness level configurable instead of using an arbitrary value of 0.1.
---
 nixos/modules/programs/light.nix | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/nixos/modules/programs/light.nix b/nixos/modules/programs/light.nix
index f86aeeb390a7..406b9f105c10 100644
--- a/nixos/modules/programs/light.nix
+++ b/nixos/modules/programs/light.nix
@@ -49,6 +49,15 @@ in
           '';
         };
 
+        minBrightness = lib.mkOption {
+          type = lib.types.numbers.between 0 100;
+          default = 0.1;
+          description = ''
+            The minimum authorized brightness value, e.g. to avoid the
+            display going dark.
+          '';
+        };
+
       };
 
     };
@@ -63,13 +72,14 @@ in
         let
           light = "${pkgs.light}/bin/light";
           step = builtins.toString cfg.brightnessKeys.step;
+          minBrightness = builtins.toString cfg.brightnessKeys.minBrightness;
         in
         [
           {
             keys = [ 224 ];
             events = [ "key" ];
-            # Use minimum brightness 0.1 so the display won't go totally black.
-            command = "${light} -N 0.1 && ${light} -U ${step}";
+            # -N is used to ensure that value >= minBrightness
+            command = "${light} -N ${minBrightness} && ${light} -U ${step}";
           }
           {
             keys = [ 225 ];