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

#zpool import -f rpool
#mount -t zfs rpool/local/root /mnt
#mkdir -p /mnt/{boot,nix,home,persist,var/lib,var/log}
#mount /dev/vda2 /mnt/boot
#mount -t zfs rpool/local/nix /mnt/nix
#mount -t zfs rpool/safe/home /mnt/home
#mount -t zfs rpool/safe/persist /mnt/persist
#mount -t zfs rpool/local/var/lib /mnt/var/lib
#mount -t zfs rpool/local/var/log /mnt/var/log
let
  impermanence = builtins.fetchTarball "https://github.com/nix-community/impermanence/archive/master.tar.gz";
in
{
  imports =
    [
      ./hardware-configuration.nix
      "${impermanence}/nixos.nix"
    ];

  # Enable ZFS support
  boot.supportedFilesystems = [ "zfs" ];
  boot.zfs.requestEncryptionCredentials = false;

  fileSystems = {
    "/persist" = {
      device = "rpool/safe/persist";
      fsType = "zfs";
      neededForBoot = true; # Only /persist needs to be marked as needed for boot
    };
  };

  # Import the existing ZFS pool from the second disk without formatting it
  boot.zfs.extraPools = [ "tank" ];
  boot.zfs.devNodes = "/dev/disk/by-path"; # This is neede for ZFS to find the pool at boot

  # Use GRUB with MBR for BIOS booting
  boot.loader.grub.enable = true;
  boot.loader.grub.device = "/dev/vda";
  boot.loader.grub.zfsSupport = true;
  boot.loader.grub.efiSupport = false;

  # Impermanence configuration
  # Set up impermanence - root filesystem will be reset on each boot
  boot.initrd.postResumeCommands = lib.mkAfter ''
    zfs rollback -r rpool/local/root@blank
  '';
  # /var/log and /var/lib ar persisted through zfs datasets, but not backed up.
  # Anything stored in /persist should get backed up.
  environment.persistence."/persist" = {
    hideMounts = true;
    directories = [
      "/root"
      "/etc/nixos"
      "/etc/ssh"
    ];
    files = [
      "/etc/machine-id"
      #"/etc/nix/id_rsa" # Needed?
    ];
  };
  # Files are not copied to /persist during install, so need to do so manually
  #rsync -azPH /mnt/root/ /mnt/persist/root
  #rsync -azPH /mnt/etc/nixos/ /mnt/persist/etc/nixos
  #rsync -azPH /mnt/etc/ssh/ /mnt/persist/etc/ssh
  #cp /mnt/etc/machine-id /mnt/persist/etc/machine-id

  # Swap configuration
  swapDevices = [ {
    device = "/dev/vda3"; 
    randomEncryption.enable = true;
  } ];

  # Basic system configuration
  networking.hostId = "5472a981"; # Required for ZFS
  networking.hostName = "cryochamber";

  # Enable networking
  networking.networkmanager.enable = true;

  # Set your time zone
  time.timeZone = "UTC";

  # Docker configuration
  virtualisation.docker = {
    enable = true;
    extraOptions = "--storage-driver=overlay2";
  };

  # System packages
  environment.systemPackages = with pkgs; [
    git
    vim
    wget
    curl
    htop
    zfs
    zsh
    tmux
    docker-compose
  ];

  # Define a user account
  users.users.hunner = {
    isNormalUser = true;
    extraGroups = [ "wheel" "docker" "networkmanager" ];
    initialPassword = "a";
    shell = pkgs.zsh;
  };

  programs.zsh.enable = true;
  services.openssh.enable = true;

  system.stateVersion = "24.11";
}