From 44a7bb72efdb9bfb69db8bfca876497cadec4f2d Mon Sep 17 00:00:00 2001
From: Alexander Heldt <me@alexanderheldt.se>
Date: Sat, 7 Feb 2026 10:08:21 +0100
Subject: [PATCH] pinwheel: Add dynamic hyprland monitor hotplug handler

---
 hosts/pinwheel/modules/hyprland/default.nix | 82 ++++++++++++++++++---
 1 file changed, 71 insertions(+), 11 deletions(-)

diff --git a/hosts/pinwheel/modules/hyprland/default.nix b/hosts/pinwheel/modules/hyprland/default.nix
index 7fd3263..a364124 100644
--- a/hosts/pinwheel/modules/hyprland/default.nix
+++ b/hosts/pinwheel/modules/hyprland/default.nix
@@ -7,6 +7,59 @@
 }:
 let
   enabled = config.mod.hyprland.enable;
+
+  monitorScript = pkgs.writeShellScript "hyprland-monitor-handler" ''
+    INTERNAL="eDP-1"
+    EXTERNAL_MONITORS="HDMI-A-1 DP-3"
+    HYPRCTL="${pkgs.hyprland}/bin/hyprctl"
+    JQ="${pkgs.jq}/bin/jq"
+
+    get_active_external() {
+      # Return the first connected external monitor
+      for mon in $EXTERNAL_MONITORS; do
+        if $HYPRCTL monitors -j | $JQ -e ".[] | select(.name == \"$mon\")" > /dev/null 2>&1; then
+          echo "$mon"
+          return 0
+        fi
+      done
+      return 1
+    }
+
+    bind_workspaces() {
+      local external
+
+      if external=$(get_active_external); then
+        # External monitor connected: 1-5 on external, 6-10 on internal
+        for ws in 1 2 3 4 5; do
+          $HYPRCTL keyword workspace "$ws, monitor:$external, default:true"
+        done
+        for ws in 6 7 8 9 10; do
+          $HYPRCTL keyword workspace "$ws, monitor:$INTERNAL, default:true"
+        done
+      else
+        # No external monitor: all workspaces on internal
+        for ws in 1 2 3 4 5 6 7 8 9 10; do
+          $HYPRCTL keyword workspace "$ws, monitor:$INTERNAL, default:true"
+        done
+      fi
+    }
+
+    handle_event() {
+      case $1 in
+        monitoradded*|monitorremoved*)
+          sleep 0.5  # Give monitor time to initialize
+          bind_workspaces
+          ;;
+      esac
+    }
+
+    # Bind workspaces on startup
+    bind_workspaces
+
+    ${pkgs.socat}/bin/socat -U - UNIX-CONNECT:"$XDG_RUNTIME_DIR/hypr/$HYPRLAND_INSTANCE_SIGNATURE/.socket2.sock" | while read -r line; do
+      handle_event "$line"
+    done
+  '';
 in
 {
   options = {
@@ -41,17 +94,7 @@ in
 
           monitor=eDP-1, 1920x1200, auto-center-down, 1
           monitor=HDMI-A-1, 2560x1440@100, auto-center-up, 1
-
-          workspace = 1, monitor:HDMI-A-1
-          workspace = 2, monitor:HDMI-A-1
-          workspace = 3, monitor:HDMI-A-1
-          workspace = 4, monitor:HDMI-A-1
-          workspace = 5, monitor:HDMI-A-1
-          workspace = 6, monitor:eDP-1
-          workspace = 7, monitor:eDP-1
-          workspace = 8, monitor:eDP-1
-          workspace = 9, monitor:eDP-1
-          workspace = 10, monitor:eDP-1
+          monitor=DP-3, 2560x1440@60, auto-center-up, 1
 
           workspace = w[tv1], gapsout:0, gapsin:0
           workspace = f[1], gapsout:0, gapsin:0
@@ -171,6 +214,23 @@ in
         pkgs.wdisplays
         pkgs.bc
       ];
+
+      systemd.user.services.hyprland-monitors = {
+        Unit = {
+          Description = "Hyprland monitor hotplug handler";
+          PartOf = [ "graphical-session.target" ];
+          After = [ "graphical-session.target" ];
+        };
+        Service = {
+          Type = "simple";
+          ExecStart = "${monitorScript}";
+          Restart = "on-failure";
+          RestartSec = 5;
+        };
+        Install = {
+          WantedBy = [ "graphical-session.target" ];
+        };
+      };
     };
 
     # To start electron apps like `chromium` with wayland support