# Do not modify this file!  It was generated by ‘nixos-generate-config’
# and may be overwritten by future invocations.  Please make changes
# to /etc/nixos/configuration.nix instead.
{ config, lib, pkgs, modulesPath, ... }:
let
  NIXBOOT = "/dev/disk/by-uuid/641A-6BDB";
  NIXROOT ="/dev/disk/by-uuid/ae94db42-ec46-4e2f-a98a-118359428a68"; 
  cryptroot = "/dev/disk/by-uuid/49f11bf1-d4b7-4188-9203-4d7a42569afa";

  USB_KEY = "/dev/disk/by-uuid/9985-EBD1";
in
{
  imports =
    [ (modulesPath + "/installer/scan/not-detected.nix")
    ];

  boot.initrd.availableKernelModules = [ "xhci_pci" "ahci" "usb_storage" "usbhid" "sd_mod" "sdhci_pci" "ehci_pci" "uas" ];
  boot.initrd.kernelModules = [ ];
  boot.kernelModules = [ "kvm-intel" ];
  boot.extraModulePackages = [ ];

  fileSystems."/boot" =
    { device = NIXBOOT;
      fsType = "vfat";
      options = [ "fmask=0077" "dmask=0077" ];
    };

  boot.initrd.luks.devices."cryptroot" = {
    device = NIXROOT;

    # Auto decrypt
    keyFile = USB_KEY;
    keyFileSize = 5000;
    keyFileOffset = 5443;

    tryEmptyPassphrase = true;
    fallbackToPassword = true;
    crypttabExtraOpts = [ "tries=2" ];
  };

  fileSystems."/" =
    { device = cryptroot;
      fsType = "btrfs";
      options = [ "subvol=@root" "compress=zstd" ];
    };

  fileSystems."/nix" =
    { device = cryptroot;
      fsType = "btrfs";
      options = [ "subvol=@nix" "compress=zstd" "noatime" ];
    };

  fileSystems."/persist" =
    { device = cryptroot;
      neededForBoot = true;
      fsType = "btrfs";
      options = [ "subvol=@persist" "compress=zstd" ];
    };

  fileSystems."/.swap" =
    { device = cryptroot;
      fsType = "btrfs";
      options = [ "subvol=@swap" "noatime" ];
    };

  fileSystems."/.snapshots" =
    { device = cryptroot;
      fsType = "btrfs";
      options = [ "subvol=@snapshots" "compress=zstd" "noatime"];
    };

  services.btrfs.autoScrub = {
    enable = true;
    # syntax as defined by https://www.freedesktop.org/software/systemd/man/systemd.time.html#Calendar%20Event s
    interval = "monthly";
    fileSystems = ["/"];
  };

  swapDevices = [{
    device = "/.swap/swapfile"; 
    size = 8*1024; # Creates an 8GB swap file 
  }];

  boot.initrd.postResumeCommands = lib.mkAfter ''
    mkdir /btrfs_tmp
    mount ${cryptroot} /btrfs_tmp
    if [[ -e /btrfs_tmp/@root ]]; then
        mkdir -p /btrfs_tmp/old_roots
        timestamp=$(date --date="@$(stat -c %Y /btrfs_tmp/@root)" "+%Y-%m-%-d_%H:%M:%S")
        mv /btrfs_tmp/@root "/btrfs_tmp/old_roots/$timestamp"
    fi

    delete_subvolume_recursively() {
        IFS=$'\n'
        for i in $(btrfs subvolume list -o "$1" | cut -f 9- -d ' '); do
            delete_subvolume_recursively "/btrfs_tmp/$i"
        done
        btrfs subvolume delete "$1"
    }

    for i in $(find /btrfs_tmp/old_roots/ -maxdepth 1 -mtime +30); do
        delete_subvolume_recursively "$i"
    done

    btrfs subvolume create /btrfs_tmp/@root
    umount /btrfs_tmp
  '';

  # Enables DHCP on each ethernet and wireless interface. In case of scripted networking
  # (the default) this is the recommended approach. When using systemd-networkd it's
  # still possible to use this option, but it's recommended to use it in conjunction
  # with explicit per-interface declarations with `networking.interfaces.<interface>.useDHCP`.
  networking.useDHCP = lib.mkDefault true;
  # networking.interfaces.enp1s0.useDHCP = lib.mkDefault true;
  # networking.interfaces.enp3s0.useDHCP = lib.mkDefault true;
  # networking.interfaces.wlp2s0.useDHCP = lib.mkDefault true;

  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
  hardware.cpu.intel.updateMicrocode = lib.mkDefault config.hardware.enableRedistributableFirmware;
}