[desktop] Add steam sleep inhibitor

Adds sleep inhibitor based on whether or not Steam is actively streaming
a remote session

roles/desktop/default.nix

@@ -20,5 +20,6 @@ with lib;
     ./kde.nix
     ./programs.nix
     ./sddm.nix
+    ./steam-sleep-inhibitor.nix
   ];
 }

roles/desktop/steam-sleep-inhibitor.nix

@@ -0,0 +1,116 @@
+{ lib, config, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.roles.desktop;
+  
+  steamSleepInhibitor = pkgs.writeShellScript "steam-sleep-inhibitor" ''
+    #!/usr/bin/env bash
+    
+    # Steam log path - adjust if different
+    STEAM_LOG="$HOME/.local/share/Steam/logs/streaming_log.txt"
+    FALLBACK_LOG="$HOME/.steam/steam/logs/streaming_log.txt"
+    
+    # Find Steam log file
+    if [[ -f "$STEAM_LOG" ]]; then
+      LOG_FILE="$STEAM_LOG"
+    elif [[ -f "$FALLBACK_LOG" ]]; then
+      LOG_FILE="$FALLBACK_LOG"
+    else
+      # Monitor Steam process for streaming activity
+      LOG_FILE=""
+    fi
+    
+    INHIBITOR_PID=""
+    MONITORING=false
+    
+    cleanup() {
+      if [[ -n "$INHIBITOR_PID" ]]; then
+        echo "Stopping sleep inhibitor (PID: $INHIBITOR_PID)"
+        kill "$INHIBITOR_PID" 2>/dev/null
+      fi
+      exit 0
+    }
+    
+    start_inhibitor() {
+      if [[ -z "$INHIBITOR_PID" ]]; then
+        echo "Starting sleep inhibitor for Steam Remote Play session"
+        ${pkgs.systemd}/bin/systemd-inhibit \
+          --what=sleep \
+          --who="Steam Remote Play" \
+          --why="Active streaming session detected" \
+          --mode=block \
+          sleep infinity &
+        INHIBITOR_PID=$!
+      fi
+    }
+    
+    stop_inhibitor() {
+      if [[ -n "$INHIBITOR_PID" ]]; then
+        echo "Stopping sleep inhibitor - streaming session ended"
+        kill "$INHIBITOR_PID" 2>/dev/null
+        INHIBITOR_PID=""
+      fi
+    }
+    
+    # Check if Steam Remote Play is active by looking for streaming processes
+    check_streaming_active() {
+      # Check for Steam streaming processes
+      if pgrep -f "streaming_client" >/dev/null || \
+         pgrep -f "steamremoteplay" >/dev/null || \
+         ${pkgs.procps}/bin/pgrep -f "Remote Play" >/dev/null; then
+        return 0
+      fi
+      
+      # Check for active network connections on Steam streaming ports
+      if ${pkgs.nettools}/bin/netstat -an 2>/dev/null | grep -E ":(27036|27037)" | grep ESTABLISHED >/dev/null; then
+        return 0
+      fi
+      
+      return 1
+    }
+    
+    trap cleanup EXIT INT TERM
+    
+    echo "Steam sleep inhibitor monitoring started"
+    
+    while true; do
+      if check_streaming_active; then
+        if [[ "$MONITORING" == "false" ]]; then
+          MONITORING=true
+          start_inhibitor
+        fi
+      else
+        if [[ "$MONITORING" == "true" ]]; then
+          MONITORING=false
+          stop_inhibitor
+        fi
+      fi
+      
+      sleep 10
+    done
+  '';
+in
+{
+  config = mkIf (cfg.enable && cfg.kde && cfg.gaming) {
+    # Steam streaming sleep inhibitor service
+    systemd.user.services.steam-sleep-inhibitor = {
+      description = "Steam Remote Play Sleep Inhibitor";
+      wantedBy = [ "default.target" ];
+      after = [ "graphical-session.target" ];
+      
+      serviceConfig = {
+        Type = "simple";
+        ExecStart = "${steamSleepInhibitor}";
+        Restart = "always";
+        RestartSec = "5";
+      };
+    };
+
+    # Steam-specific environment variables to prevent sleep interference
+    environment.sessionVariables = {
+      SDL_VIDEO_ALLOW_SCREENSAVER = "1";
+    };
+  };
+}