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

{
  # Kernel configuration
  boot = {
    kernelPackages = pkgs.linuxPackages_zen;
    kernelParams =
      [ "zfs.zfs_arc_max=1073741824 zfs.zfs_arc_meta_limit_percent=90" ];
    kernelModules = [ "i915" "acpi_call" "kvm-intel" ];
    extraModulePackages = with config.boot.kernelPackages; [ acpi_call ];
    blacklistedKernelModules = [ "btusb" ];
    supportedFilesystems = [ "zfs" ];
    zfs.requestEncryptionCredentials = true;
    zfs.enableUnstable = true;
  };

  # Intel CPU tweaks
  hardware.cpu.intel.updateMicrocode =
    lib.mkDefault config.hardware.enableRedistributableFirmware;
  services.fwupd.enable = true;

  hardware.opengl.extraPackages = with pkgs; [
    vaapiIntel
    vaapiVdpau
    libvdpau-va-gl
  ];

  # Bootloader configuration
  boot.loader = {
    efi.canTouchEfiVariables = true;
    systemd-boot = {
      enable = true;
      configurationLimit = 50;
      editor = false;
    };
    timeout = 3;
  };

  # Run Nix garbage collector and enable flakes
  nix = {
    autoOptimiseStore = true;
    gc = {
      automatic = true;
      options = "--delete-older-than 7d";
      dates = "Tue 23:00";
    };
    extraOptions = ''
      keep-outputs = true
      keep-derivations = true
      gc-keep-outputs = true
      experimental-features = nix-command flakes
    '';
    package = pkgs.nixUnstable;
  };

  # Clean tmp directory on shutdown
  boot.cleanTmpDir = true;

  # Rotate logs after 7 days
  services.journald.extraConfig = "SystemMaxFiles=7";

  # Allow propietary software and build packages with Pulseaudio support
  nixpkgs.config = {
    allowUnfree = true;
    pulseaudio = true;
  };

  # Scrub zpool monthly
  services.zfs.autoScrub = {
    enable = true;
    interval = "monthly";
  };

  # Set timezone and synchronize NTP
  time.timeZone = "Europe/London";
  services.chrony.enable = true;

  # NixOS version
  system.stateVersion = "20.09";

  # Create coolneng user
  users.users.coolneng = {
    isNormalUser = true;
    home = "/home/coolneng";
    extraGroups = [ "wheel" "video" "audio" "libvirtd" "lp" ];
    shell = pkgs.fish;
  };

  # Set shell and SSH for root user
  users.users.root = {
    shell = pkgs.fish;
    openssh.authorizedKeys.keys = [''
      ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIBvnfIsxGZWh+tU7OI60Tw3CyT+q3ghoETfRyWsXhioZ coolneng@panacea
    ''];
  };

  # Auto-upgrade the system
  system.autoUpgrade = {
    enable = false;
    dates = "14:00";
  };

  # Specify secrets
  age.secrets = {
    soundcloud_api_key.file = secrets/soundcloud_api_key.age;
    wireguard.file = secrets/wireguard.age;
  };

  # Import other configuration modules
  imports = [
    ./modules/hardware-configuration.nix
    ./modules/software.nix
    ./modules/networking.nix
    ./modules/gui.nix
    ./modules/datasync.nix
    ./modules/audio.nix
    ./modules/development.nix
    ./modules/printing.nix
    ./modules/periodic.nix
    ./modules/power.nix
    ./modules/cachix.nix
    ./overlays/emacs.nix
  ];

}