{ pkgs, lib, ... }:

{
  boot.initrd.postDeviceCommands = lib.mkAfter ''
    mkdir /btrfs_tmp
    mount /dev/root_vg/root /btrfs_tmp

    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"
    }

    delete_subvolume_recursively "/btrfs_tmp/root"

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

  fileSystems."/persist".neededForBoot = true;
  environment.persistence."/persist/system" = {
    hideMounts = true;
    directories = [
      "/var/log"
      "/var/lib/bluetooth"
      "/var/lib/nixos"
      "/var/lib/libvirt"
      "/var/lib/systemd/coredump"
      "/etc/NetworkManager/system-connections"
      "/var/lib/docker"
    ];
    files = [
      "/etc/machine-id"
      { file = "/var/keys/secret_file"; parentDirectory = { mode = "u=rwx,g=,o="; }; }
    ];
  };
}