zsh: Automatically set color scheme at init

users/simon/modules/zsh/default.nix

@@ -1,4 +1,4 @@
-{ lib, pkgs, ... }:
+{ lib, nixosConfig, pkgs, ... }:
 let
   dircolors-solarized = pkgs.fetchFromGitHub {
     owner = "seebi";
@@ -8,6 +8,14 @@ let
 
     meta.license = lib.licenses.mit;
   };
+
+  # automatically set color scheme based on sun with dynamic-colors
+  dcauto =
+    let
+      latitude = (toString nixosConfig.location.latitude) + (if nixosConfig.location.latitude > 0 then "N" else "S");
+      longitude = (toString nixosConfig.location.longitude) + (if nixosConfig.location.longitude > 0 then "E" else "W");
+    in
+    "${pkgs.sunwait}/bin/sunwait poll civil ${latitude} ${longitude} | grep -qE '^DAY$' && dynamic-colors switch solarized-light || dynamic-colors switch solarized-dark";
 in
 {
   programs = {
@@ -53,6 +61,7 @@ in
       ];
       shellAliases = {
         cp = "cp --reflink=auto"; # TODO: remove with coreutils > 8.32
+        dcauto = dcauto;
         dcsd = "dynamic-colors switch solarized-dark";
         dcsl = "dynamic-colors switch solarized-light";
         exa = "exa --git --binary";
@@ -66,6 +75,10 @@ in
         vim = "nvim";
         vimdiff = "nvim -d";
       };
+      initExtraFirst = ''
+        # automatic color scheme
+        ${dcauto}
+      '';
       initExtra = lib.mkMerge [
         (lib.mkBefore ''
           prompt off # collides with starship