# Edit this configuration file to define what should be installed on
# your system.  Help is available in the configuration.nix(5) man page
# and in the NixOS manual (accessible by running ‘nixos-help’).
{
  config,
  pkgs,
  ...
}: {
  # Add Lix instead of Nix

  nixpkgs.overlays = [
    (final: prev: {
      inherit
        (prev.lixPackageSets.stable)
        nixpkgs-review
        nix-eval-jobs
        nix-fast-build
        colmena
        ;
    })
  ];

  nix.package = pkgs.lixPackageSets.stable.lix;

  imports = [
    # Include the results of the hardware scan.
    ./hardware-configuration.nix
  ];

  # Enable Rsymc
  services.rsync.enable = true;

  # Passwordless sudo for wheel group
  security.sudo.wheelNeedsPassword = false;

  # Hardware U2F support - Passwordless sudo with hardware key
  security.pam.u2f = {
    enable = true;
    settings = {
      authfile = "/etc/u2f_keys";
      cue = true;
      pinverification = 0; # No PIN verification
      userpresence = 1; # Require user presence (touch)
    };
  };

  # Add to your configuration.nix
  # Optimize builds
  nix.settings = {
    # Enable parallel building
    max-jobs = "auto";
    cores = 0; # Use all available cores

    # Optimize store operations
    auto-optimise-store = true;

    # Build settings
    sandbox = true;
    keep-outputs = true;
    keep-derivations = true;
  };

  # Enable distributed builds (optional, for your VM setup)
  nix.buildMachines = [];
  nix.distributedBuilds = false;

  # Optimize garbage collection
  nix.gc = {
    automatic = true;
    dates = "weekly";
    options = "--delete-older-than 30d";
  };

  # Increase build speed with tmpfs for builds (if you have enough RAM)
  # Comment out if low on memory
  systemd.services.nix-daemon.environment = {
    TMPDIR = "/tmp";
  };
  boot.tmp.useTmpfs = true;
  boot.tmp.tmpfsSize = "50%"; # Adjust based on your 62GB RAM

  # For image building specifically
  virtualisation.vmVariant = {
    virtualisation = {
      memorySize = 4096; # Adjust for build-vm
      cores = 2;
    };
  };

  # SSH Agent authentication
  security.pam.sshAgentAuth.enable = true;

  # Automatic upgrades
  system.autoUpgrade = {
    enable = true; # Set to true for automatic updates
    dates = "daily";
    allowReboot = false;
  };

  # Bootloader.
  boot.loader.systemd-boot.enable = true;
  boot.loader.efi.canTouchEfiVariables = true;

  # Enable Tailscale
  services.tailscale.enable = true;

  networking.hostName = "nixos-build-machine"; # Define your hostname.
  # networking.wireless.enable = true;  # Enables wireless support via wpa_supplicant.

  # Configure network proxy if necessary
  # networking.proxy.default = "http://user:password@proxy:port/";
  # networking.proxy.noProxy = "127.0.0.1,localhost,internal.domain";

  # Enable networking
  networking.networkmanager.enable = true;

  # Set your time zone.
  time.timeZone = "Europe/Copenhagen";

  # Select internationalisation properties.
  i18n.defaultLocale = "en_AU.UTF-8";

  i18n.extraLocaleSettings = {
    LC_ADDRESS = "en_AU.UTF-8";
    LC_IDENTIFICATION = "en_AU.UTF-8";
    LC_MEASUREMENT = "en_AU.UTF-8";
    LC_MONETARY = "en_AU.UTF-8";
    LC_NAME = "en_AU.UTF-8";
    LC_NUMERIC = "en_AU.UTF-8";
    LC_PAPER = "en_AU.UTF-8";
    LC_TELEPHONE = "en_AU.UTF-8";
    LC_TIME = "en_AU.UTF-8";
  };

  # Configure keymap in X11
  services.xserver.xkb = {
    layout = "au";
    variant = "";
  };

  # Define a user account. Don't forget to set a password with ‘passwd’.
  users.users.nixosbm = {
    isNormalUser = true;
    description = "NixOS Build Machine";
    extraGroups = ["networkmanager" "wheel"];
    packages = with pkgs; [];
  };

  # Remote builder server setup
  users.users.nixremote = {
    isNormalUser = true;
    description = "Nix Remote Builder";
    home = "/home/nixremote";
    createHome = true;

    # Lock the user account (no login shell)
    shell = pkgs.shadow;

    # SSH key for remote builds
    openssh.authorizedKeys.keys = [
      # Add the public key from your client machines here
      # Example: "ssh-ed25519 AAAAC3... root@client-machine"
    ];
  };

  systemd.tmpfiles.rules = [
    "z /home/nixremote 0555 nixremote nixremote - -"
    "z /home/nixremote/.ssh 0555 nixremote nixremote - -"
  ];

  # Allow unfree packages
  nixpkgs.config.allowUnfree = true;

  # List packages installed in system profile. To search, run:
  # $ nix search wget
  environment.systemPackages = with pkgs; [
    #  vim # Do not forget to add an editor to edit configuration.nix! The Nano editor is also installed by default.
    wget
    fastfetch
    hyfetch
    helix
  ];

  # Some programs need SUID wrappers, can be configured further or are
  # started in user sessions.
  # programs.mtr.enable = true;
  programs.gnupg.agent = {
    enable = true;
    enableSSHSupport = true;
  };

  # List services that you want to enable:

  # Enable the OpenSSH daemon.
  services.openssh.enable = true;

  # Open ports in the firewall.
  # networking.firewall.allowedTCPPorts = [ ... ];
  # networking.firewall.allowedUDPPorts = [ ... ];
  # Or disable the firewall altogether.
  # networking.firewall.enable = false;

  # Attach the system to the IPFire network:  set a static IP on the Proxmox bridge (ens18)
  # Adjust `ens18` and the address below to your environment.
  networking.interfaces.ens18.ipv4.addresses = [
    {
      address = "10.1.1.3";
      #dns = "10.1.1.2";
      prefixLength = 24;
    }
  ];
  networking.defaultGateway = "10.1.1.1";
  environment.etc."resolv.conf".text = ''
    nameserver 10.1.1.2
  '';

  # This value determines the NixOS release from which the default
  # settings for stateful data, like file locations and database versions
  # on your system were taken. It‘s perfectly fine and recommended to leave
  # this value at the release version of the first install of this system.
  # Before changing this value read the documentation for this option
  # (e.g. man configuration.nix or on https://nixos.org/nixos/options.html).
  system.stateVersion = "25.11"; # Did you read the comment?

  # THE FOLLOWING CODE BLOCK IS FOR COPYING TO OTHER CONFIGURATIONS, NOT FOR THIS FILE
  #  nix.distributedBuilds = true;
  #  nix.buildMachines = [
  #    {
  #      hostName = "nixos-build-machine";
  #      system = "x86_64-linux";
  #      sshUser = "nixremote";
  #      sshKey = "/root/.ssh/nixremote";
  #      maxJobs = 4;
  #      speedFactor = 2;
  #          supportedFeatures = [ "nixos-test" "benchmark" "big-parallel" "kvm" ];
  #    }
  #  ];
  #
  # Generate SSH key for remote building
  #systemd.services.generate-nixremote-key = {
  #  description = "Generate SSH key for remote Nix builds";
  #  wantedBy = [ "multi-user.target" ];
  #  serviceConfig = {
  #    Type = "oneshot";
  #    RemainAfterExit = true;
  #  };
  #  script = ''
  #    if [ ! -f /root/.ssh/nixremote ]; then
  #      ${pkgs.openssh}/bin/ssh-keygen -t ed25519 -f /root/.ssh/nixremote -N "" -C "nix-remote-builder"
  #    fi
  #  '';
  #};
  #
  #programs.ssh.extraConfig = ''
  #  Host nixos-build-machine
  #    HostName 192.168.1.175
  #    IdentitiesOnly yes
  #    IdentityFile /root/.ssh/nixremote
  #    User nixremoteStrictHostKeyChecking accept-new
  #'';
  #
  # Manual step required: After rebuilding the client, copy /root/.ssh/nixremote.pub
  # from the client to the build machine's users.users.nixremote.openssh.authorizedKeys.keys list,
  # then rebuild the build machine.
  # i.e on the client: run "cat /root.ssh/nixremote.pub"
  # and copy the output to the build machine's configuration.nix
}