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

{
  # === T490-specific hardware configuration ===
  # Requires nixos-hardware flake input: nixos-hardware.nixosModules.lenovo-thinkpad-t490
  # The nixos-hardware module provides:
  #   - services.throttled (CPU throttling fix)
  #   - PulseAudio profile set (5 simultaneous sinks)
  #   - common/cpu/intel (VA-API drivers, microcode)

  # === Kernel parameters ===
  boot.kernelParams = [
    "mem_sleep_default=deep"       # prefer S3 deep sleep over s2idle
    "pcie_aspm=force"              # PCIe Active State Power Management
    "i915.enable_fbc=1"            # frame buffer compression (power saving)
    "i915.enable_psr=1"            # panel self-refresh (power saving)
    "i915.enable_rc6=7"            # maximum GPU render power saving
  ];

  boot.kernelModules = [ "thinkpad_acpi" ];
  boot.blacklistedKernelModules = [
    "iTCO_wdt"
    "iTCO_vendor_support"
  ];

  # === Display DPI ===
  services.xserver.dpi = 157;     # 14" 1920×1080 IPS = 157 DPI

  # === Firmware updates ===
  services.fwupd.enable = true;

  # === Fingerprint reader (Synaptics 06cb:00bd) ===
  # Requires firmware update via fwupd first
  services.fprintd.enable = true;

  # === TLP — ThinkPad power management ===
  # nixos-hardware thinkpad module provides base config; tune here
  services.tlp = {
    enable = true;
    settings = {
      CPU_SCALING_GOVERNOR_ON_AC = "performance";
      CPU_SCALING_GOVERNOR_ON_BAT = "powersave";
      CPU_ENERGY_PERF_POLICY_ON_AC = "balance_performance";
      CPU_ENERGY_PERF_POLICY_ON_BAT = "power";
      CPU_MAX_PERF_ON_AC = 100;
      CPU_MAX_PERF_ON_BAT = 40;      # cap at ~1.7 GHz on battery
      CPU_BOOST_ON_AC = 1;
      CPU_BOOST_ON_BAT = 0;           # disable turbo on battery
      START_CHARGE_THRESH_BAT0 = 40;  # battery health: start charging below 40%
      STOP_CHARGE_THRESH_BAT0 = 80;   # battery health: stop at 80%
      WIFI_PWR_ON_AC = "off";
      WIFI_PWR_ON_BAT = "on";
      RUNTIME_PM_ON_AC = "on";
      RUNTIME_PM_ON_BAT = "auto";
      USB_AUTOSUSPEND = 1;
      INTEL_GPU_MIN_FREQ_ON_AC = 300;
      INTEL_GPU_MAX_FREQ_ON_AC = 1100;
      INTEL_GPU_MIN_FREQ_ON_BAT = 300;
      INTEL_GPU_MAX_FREQ_ON_BAT = 600;
    };
  };

  # === powertop ===
  powerManagement.powertop.enable = true;

  # Skip thermald — conflicts with throttled (enabled by nixos-hardware)
  services.thermald.enable = false;

  # === zram swap (faster + saves NVMe writes) ===
  zramSwap = {
    enable = true;
    memoryPercent = 50;
  };

  # === Intel GPU — hardware video acceleration ===
  hardware.graphics = {
    enable = true;
    extraPackages = with pkgs; [
      intel-media-driver    # modern VA-API (iHD)
      intel-vaapi-driver    # legacy VA-API (i965)
      libvdpau-va-gl        # VDPAU → VA-API bridge
    ];
  };

  environment.sessionVariables = {
    LIBVA_DRIVER_NAME = "iHD";
    MOZ_ENABLE_WAYLAND = "1";
  };

  # === Suspend/resume: reload WiFi after wake ===
  powerManagement.powerUpCommands = ''
    ${pkgs.kmod}/bin/modprobe -r iwlmvm iwlwifi || true
    ${pkgs.kmod}/bin/modprobe iwlwifi || true
  '';

  # === Remote Nix builders (k3s cluster) ===
  nix.distributedBuilds = true;
  nix.buildMachines = [
    {
      hostName = "n97-mini";
      system = "x86_64-linux";
      maxJobs = 4;
      supportedFeatures = [
        "nixos-test"
        "benchmark"
        "big-parallel"
        "kvm"
      ];
      sshUser = "root";
      sshKey = "/root/.ssh/remote-build";
    }
    {
      hostName = "n97";
      system = "x86_64-linux";
      maxJobs = 4;
      supportedFeatures = [
        "nixos-test"
        "benchmark"
        "big-parallel"
        "kvm"
      ];
      sshUser = "root";
      sshKey = "/root/.ssh/remote-build";
    }
  ];

  # === Syncthing (Obsidian vault sync) ===
  services.syncthing = {
    enable = true;
    user = "sscoble";
    dataDir = "/home/sscoble/.syncthing";
    configDir = "/home/sscoble/.syncthing/config";
  };

  # === Tailscale (consistent cluster access from any network) ===
  services.tailscale.enable = true;

  # === NVMe tools ===
  environment.systemPackages = with pkgs; [ nvme-cli ];

  # === Touchpad & TrackPoint ===
  services.xserver.libinput = {
    enable = true;
    touchpad = {
      tapping = true;
      naturalScrolling = true;
      accelSpeed = "0.3";
      disableWhileTyping = true;
    };
  };

  # TrackPoint sensitivity
  services.udev.extraRules = ''
    ACTION=="add", SUBSYSTEM=="input", ATTR{name}=="*TrackPoint*", \
      ATTR{device/sensitivity}="200", ATTR{device/speed}="150"
  '';
}