{ config, lib, pkgs, ... }:

{
  hardware.graphics = {
    enable = true;
    enable32Bit = true;
  };

  # --- Hybrid graphics: AMD Radeon 680M (iGPU, drives the internal panel)
  # + NVIDIA RTX 4050 Max-Q (dGPU, offload-only) — ASUS TUF Gaming A15
  # FA507NU. Bus IDs come straight from `lspci` on this machine, not
  # guessed: 01:00.0 (NVIDIA) -> PCI:1:0:0, 35:00.0 (AMD) -> PCI:53:0:0
  # (the PCI: form is decimal, 0x35 = 53).
  services.xserver.videoDrivers = [ "nvidia" ];

  hardware.nvidia = {
    modesetting.enable = true;

    # Open GPU kernel modules — fine on Turing or newer, and this Ada
    # Lovelace RTX 4050 is well within support.
    open = true;
    nvidiaSettings = true;
    package = config.boot.kernelPackages.nvidiaPackages.stable;

    # Preserves video memory across suspend/resume, which is what fixes the
    # classic NVIDIA-laptop "black screen after lid close" hang.
    powerManagement.enable = true;

    # Runtime PM, i.e. letting the dGPU drop to D3cold when idle, is left
    # off on purpose: supergfxd below already power-cycles the dGPU when you
    # switch to Integrated mode, and driving both power paths at once is the
    # usual source of resume hangs on TUF laptops. If you want to try it:
    #   powerManagement.finegrained = true;

    # PRIME render offload: the AMD iGPU drives the display at all times
    # (much better battery life than keeping the dGPU powered on), and the
    # NVIDIA GPU only spins up on demand for a specific process — run
    # anything with `nvidia-offload <command>` (generated by
    # enableOffloadCmd) to route it through the RTX 4050, e.g. games or
    # Blender's Cycles renderer.
    prime = {
      offload = {
        enable = true;
        enableOffloadCmd = true;
      };
      amdgpuBusId = "PCI:53:0:0";
      nvidiaBusId = "PCI:1:0:0";
    };
  };

  # ASUS laptop control: keyboard backlight/fan curves/battery charge limit
  # (asusctl) and dGPU power-state switching between Integrated/Hybrid modes
  # (supergfxctl) — the two standard asus-linux.org daemons for ROG/TUF
  # laptops, both packaged directly in nixpkgs.
  services.asusd.enable = true;
  services.supergfxd.enable = true;

  hardware.opentabletdriver.enable = true;
  hardware.uinput.enable = true;
  boot.kernelModules = [ "uinput" "v4l2loopback" ];

  # Virtual webcam device so ffmpeg (fed by the GoPro's stream) can appear
  # as a normal camera to apps like Discord. exclusive_caps=1 is required
  # for Chromium/WebRTC-based apps to recognize it as a real capture device.
  boot.extraModulePackages = [ config.boot.kernelPackages.v4l2loopback ];
  boot.extraModprobeConfig = ''
    options v4l2loopback devices=1 video_nr=10 card_label="GoPro Webcam" exclusive_caps=1
    # DualSense/PS4 pads pair over Bluetooth then drop instantly; broken
    # ERTM in many adapters. Disabling it is the standard fix.
    options bluetooth disable_ertm=1
  '';

  hardware.bluetooth = {
    enable = true;
    powerOnBoot = true;
    settings = {
      General = {
        Experimental = true;      # Battery level of connected devices
        FastConnectable = true;   # Faster reconnects, more power draw
      };
      Policy = {
        AutoEnable = true;
      };
    };
  };
  # No blueman here: Plasma brings its own Bluetooth stack (bluedevil), and
  # running the GTK applet alongside it just gives you two tray icons
  # fighting over the same adapter. The desktop repo still has it enabled,
  # left over from the Budgie days.

  # Blog V4 needs the rtlsdrblog fork of librtlsdr, which is what
  # pkgs.rtl-sdr already is here. Also blacklists the DVB-T drivers.
  hardware.rtl-sdr.enable = true;

  # I2C bus, for DDC/CI brightness on an external monitor over HDMI/USB-C
  # via ddcutil. The internal panel goes through the kernel backlight class
  # instead — brightness-ctl picks whichever applies, see
  # modules/scripts/brightness-ctl.sh.
  hardware.i2c.enable = true;

  services.udev.extraRules = ''
    # ddcutil without root (i2c group, see modules/users.nix)
    SUBSYSTEM=="i2c-dev", GROUP="i2c", MODE="0660"
  '';

  # No OpenRGB: that's the desktop's motherboard/RAM lighting. The keyboard
  # backlight on this machine is asusd's job (`asusctl aura`).

  services.printing.enable = true;
}