add(jellyfin): immersion mode

immersion turns off all other monitor. great for movies

apps/jellyfin/immersion.nix

@@ -0,0 +1,44 @@
+{
+  config,
+  pkgs,
+  ...
+}: let
+  # Dynamically turns off all unfocused monitors, and restores them on toggle
+  toggleImmersive = pkgs.writeShellScriptBin "toggle-immersive" ''
+    STATE_FILE="$XDG_RUNTIME_DIR/hypr_immersive_mode"
+
+    if [ -f "$STATE_FILE" ]; then
+      # 1. Restore: Reloading Hyprland snaps monitors back to your declared Nix defaults
+      hyprctl reload
+      rm "$STATE_FILE"
+      ${pkgs.libnotify}/bin/notify-send -u low "Immersive Mode" "Deactivated — Displays restored."
+    else
+      # 2. Activate: Mark state and dynamically disable all non-focused monitors
+      touch "$STATE_FILE"
+
+      # Use jq to find every monitor that does NOT currently have focus
+      for mon in $(${pkgs.hyprland}/bin/hyprctl monitors -j | ${pkgs.jq}/bin/jq -r '.[] | select(.focused == false) | .name'); do
+        ${pkgs.hyprland}/bin/hyprctl keyword monitor "$mon, disable"
+      done
+
+      # OPTIONAL: Remove borders and gaps for a true cinema experience
+      # ${pkgs.hyprland}/bin/hyprctl keyword general:gaps_in 0
+      # ${pkgs.hyprland}/bin/hyprctl keyword general:gaps_out 0
+      # ${pkgs.hyprland}/bin/hyprctl keyword general:border_size 0
+      # ${pkgs.hyprland}/bin/hyprctl keyword decoration:rounding 0
+
+      ${pkgs.libnotify}/bin/notify-send -u low "Immersive Mode" "Activated — Focused display only."
+    fi
+  '';
+in {
+  wayland.windowManager.hyprland = {
+    enable = true;
+
+    settings = {
+      # Bind to your preferred combo (e.g., Super + Alt + M)
+      bind = [
+        "$mod ALT, M, exec, ${toggleImmersive}/bin/toggle-immersive"
+      ];
+    };
+  };
+}