Specify waybar config in nix.

This is to facilitate having different waybar configs for each machine.

nix/configuration/roles/waybar/default.nix

@@ -6,6 +6,11 @@
 }:
 
 let
+  settings_format = pkgs.formats.json { };
+  waybar_config_json = settings_format.generate "config" config.me.waybar.config;
+  launch_waybar = pkgs.writeShellScript "launch_waybar" ''
+    exec waybar --config '${waybar_config_json}' --style '${./files/style.css}'
+  '';
   waybar_sway_config = pkgs.writeTextFile {
     name = "waybar.conf";
     text = ''
@@ -17,7 +22,7 @@ let
           position top
 
           font pango:Cascadia Mono, FontAwesome 10
-          swaybar_command waybar
+          swaybar_command ${launch_waybar}
 
           colors {
               statusline #ffffff
@@ -28,54 +33,39 @@ let
     '';
   };
 
-  waybar_available_memory =
-    (pkgs.writeScriptBin "waybar_custom_available_memory" (
+  patchScriptBin =
+    filename: contents:
+    ((pkgs.writeScriptBin filename contents).overrideAttrs (old: {
+      buildCommand = "${old.buildCommand}\n patchShebangs $out";
+    }));
+  waybar_available_memory = (
+    patchScriptBin "waybar_custom_available_memory" (
       builtins.readFile ./files/waybar_scripts/waybar_available_memory_linux.bash
-    )).overrideAttrs
-      (old: {
-        buildCommand = "${old.buildCommand}\n patchShebangs $out";
-
-      });
-  waybar_battery =
-    (pkgs.writeScriptBin "waybar_custom_battery" (
+    )
+  );
+  waybar_battery = (
+    patchScriptBin "waybar_custom_battery" (
       builtins.readFile ./files/waybar_scripts/waybar_battery_linux.bash
-    )).overrideAttrs
-      (old: {
-        buildCommand = "${old.buildCommand}\n patchShebangs $out";
-
-      });
-  waybar_clock =
-    (pkgs.writeScriptBin "waybar_custom_clock" (
+    )
+  );
+  waybar_clock = (
+    patchScriptBin "waybar_custom_clock" (
       builtins.readFile ./files/waybar_scripts/waybar_custom_clock.py
-    )).overrideAttrs
-      (old: {
-        buildCommand = "${old.buildCommand}\n patchShebangs $out";
-
-      });
-  waybar_night_mode =
-    (pkgs.writeScriptBin "waybar_night_mode" (
-      builtins.readFile ./files/waybar_scripts/waybar_night_mode.bash
-    )).overrideAttrs
-      (old: {
-        buildCommand = "${old.buildCommand}\n patchShebangs $out";
-
-      });
-  waybar_sound =
-    (pkgs.writeScriptBin "waybar_custom_sound" (
+    )
+  );
+  waybar_night_mode = (
+    patchScriptBin "waybar_night_mode" (builtins.readFile ./files/waybar_scripts/waybar_night_mode.bash)
+  );
+  waybar_sound = (
+    patchScriptBin "waybar_custom_sound" (
       builtins.readFile ./files/waybar_scripts/waybar_sound_linux.bash
-    )).overrideAttrs
-      (old: {
-        buildCommand = "${old.buildCommand}\n patchShebangs $out";
-
-      });
-  waybar_temperature =
-    (pkgs.writeScriptBin "waybar_custom_temperature" (
+    )
+  );
+  waybar_temperature = (
+    patchScriptBin "waybar_custom_temperature" (
       builtins.readFile ./files/waybar_scripts/waybar_temperature_linux.bash
-    )).overrideAttrs
-      (old: {
-        buildCommand = "${old.buildCommand}\n patchShebangs $out";
-
-      });
+    )
+  );
 in
 {
   imports = [ ];
@@ -87,22 +77,87 @@ in
       example = true;
       description = "Whether we want to install waybar.";
     };
+
+    waybar.config = lib.mkOption rec {
+      apply = lib.recursiveUpdate default;
+      inherit (settings_format) type;
+      default = {
+        # "height": 10, # Waybar height (to be removed for auto height)
+        "modules-left" = [
+          "sway/workspaces"
+          "sway/mode"
+        ];
+        "modules-center" = [ "sway/window" ];
+        "modules-right" = [
+          "custom/night_mode"
+          "custom/temperature"
+          "custom/sound"
+          "custom/available_memory"
+          "custom/battery"
+          "idle_inhibitor"
+          "custom/clock"
+          "tray"
+        ];
+        "sway/workspaces" = {
+          "disable-scroll" = true;
+        };
+        "sway/mode" = {
+          "format" = "<span style=\"italic\">{}</span>";
+        };
+        "sway/window" = {
+          "format" = "{title}";
+        };
+        "idle_inhibitor" = {
+          "format" = "{icon}";
+          "format-icons" = {
+            "activated" = "☕"; # ☕
+            "deactivated" = "💤"; # ☾☁⛾⛔⏾⌛⏳💤
+          };
+        };
+        "tray" = {
+          # "icon-size" = 21;
+          "spacing" = 10;
+        };
+        "custom/clock" = {
+          "exec" = "waybar_custom_clock";
+          "return-type" = "json";
+          "restart-interval" = 30;
+        };
+        "custom/battery" = {
+          "exec" = "waybar_custom_battery";
+          "return-type" = "json";
+          "restart-interval" = 30;
+        };
+        "custom/available_memory" = {
+          "exec" = "waybar_custom_available_memory";
+          "return-type" = "json";
+          "restart-interval" = 30;
+        };
+        "custom/sound" = {
+          "exec" = "waybar_custom_sound";
+          "return-type" = "json";
+          "restart-interval" = 30;
+        };
+        "custom/temperature" = {
+          "exec" = "waybar_custom_temperature";
+          "return-type" = "json";
+          "restart-interval" = 30;
+        };
+        "custom/night_mode" = {
+          "exec" = "waybar_night_mode";
+          "return-type" = "json";
+          "restart-interval" = 30;
+          "on-click" = "pkill -USR1 -f waybar_night_mode";
+        };
+      };
+      example = null;
+      description = "Waybar's config in nix form.";
+    };
   };
 
   config = lib.mkIf (config.me.waybar.enable && config.me.graphical) {
     environment.systemPackages = with pkgs; [
       waybar
-      waybar_available_memory
-      waybar_battery
-      waybar_clock
-      waybar_night_mode
-      waybar_sound
-      waybar_temperature
-      python3 # for clock TODO python should not be in the system packages, maybe switch to a venv? ref https://nixos.wiki/wiki/Python
-      bc # for temperature and sound
-      jq # for memory, battery, sound, night mode, and temperature
-      upower # for battery
-      wlsunset # for night mode
     ];
 
     me.swayIncludes = [
@@ -111,13 +166,31 @@ in
 
     services.upower.enable = true; # for battery
 
-    me.install.user.talexander.file = {
-      ".config/waybar/config" = {
-        source = ./files/waybar_config.json;
-      };
-      ".config/waybar/style.css" = {
-        source = ./files/style.css;
-      };
-    };
+    nixpkgs.overlays = [
+      (final: prev: {
+        waybar = pkgs.symlinkJoin {
+          name = prev.waybar.name;
+          paths = [ prev.waybar ];
+          buildInputs = [ pkgs.makeWrapper ];
+          postBuild = ''
+            wrapProgram $out/bin/waybar --prefix PATH : ${
+              lib.makeBinPath [
+                waybar_available_memory
+                waybar_battery
+                waybar_clock
+                waybar_night_mode
+                waybar_sound
+                waybar_temperature
+                final.python3 # for clock TODO python should not be in the system packages, maybe switch to a venv? ref https://nixos.wiki/wiki/Python
+                final.bc # for temperature and sound
+                final.jq # for memory, battery, sound, night mode, and temperature
+                final.upower # for battery
+                final.wlsunset # for night mode
+              ]
+            }
+          '';
+        };
+      })
+    ];
   };
 }