{ inputs
, lib
, ...
}:

{
  imports = [
    inputs.disko.nixosModules.disko
  ];
  
  # !!! DANGER !!!
  # You have to carefully configure your partitions here.
  boot.initrd.postDeviceCommands = lib.mkAfter ''
    mkdir /btrfs_tmp
    mount /dev/disk/by-label/nixos /btrfs_tmp
    
    if [[ -e /btrfs_tmp/root ]]; then
        mkdir -p /btrfs_tmp/roots.old
        timestamp=$(date --date="@$(stat -c %Y /btrfs_tmp/root)" "+%Y-%m-%-d_%H:%M:%S")
        mv /btrfs_tmp/root "/btrfs_tmp/roots.old/$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 $(find /btrfs_tmp/roots.old/ -maxdepth 1 -mtime +7); do
        delete_subvolume_recursively "$i"
    done

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

  disko.devices = {
    disk = {
      main = {
        type = "disk";
        device = "/dev/sda";
        content = {
          type = "gpt";
          partitions = {
            boot = {
              name = "boot";
              size = "1M";
              type = "EF02";
              priority = 1;
            };
            esp = {
              name = "ESP";
              end = "512M";
              type = "EF00";
              content = {
                type = "filesystem";
                format = "vfat";
                mountpoint = "/boot";
                mountOptions = [ "umask=0077" ];
              };
            };
            root = {
              size = "100%";
              content = {
                type = "btrfs";
                extraArgs = [ "-L" "nixos" "-f" ]; # Override existing partition
                # Subvolumes must set a mountpoint in order to be mounted,
                # unless their parent is mounted
                subvolumes = {
                  "/root" = {
                    mountpoint = "/";
                    mountOptions = [ "subvol=root" "compress=zstd" "noatime" ];
                  };
                  "/home" = {
                    mountpoint = "/home";
                    mountOptions = [ "subvol=home" "compress=zstd" "noatime" ];
                  };
                  "/nix" = {
                    mountpoint = "/nix";
                    mountOptions = [ "subvol=nix" "compress=zstd" "noatime" ];
                  };
                  "/persist" = {
                    mountpoint = "/persist";
                    mountOptions = [ "subvol=persist" "compress=zstd" "noatime" ];
                  };
                  "/var-lib" = {
                    mountpoint = "/var/lib";
                    mountOptions = [ "subvol=var-lib" "compress=zstd" "noatime" ];
                  };
                  "/var-log" = {
                    mountpoint = "/var/log";
                    mountOptions = [ "subvol=var-log" "compress=zstd" "noatime" ];
                  };
                  "/var-tmp" = {
                    mountpoint = "/var/tmp";
                    mountOptions = [ "subvol=var-tmp" "compress=zstd" "noatime" ];
                  };
                  "/swap" = {
                    mountpoint = "/.swap";
                    swap.swapfile.size = "4G";
                  };
                };
              };
            };
          };
        };
      };
    };
  };

  fileSystems = {
    # /, /nix/, /nix/store, /var, /var/log, /var/lib, /var/lib/nixos, /etc, /usr
    # are all automatically mounted marked as needed for boot.

    "/boot".neededForBoot = true;
    
    "/persist".neededForBoot = true;

    # Possibly not required
    "/home".neededForBoot = true;
  };
}