{config, inputs, lib, ...}:
let 
  cfg = config.malobeo.disks;
in
{
  imports = [inputs.disko.nixosModules.disko];
  options.malobeo.disks = {
    enable = lib.mkOption {
      type = lib.types.bool;
      default = false;
      description = "Enable disko disk creation";
    };
    hostId = lib.mkOption {
      type = lib.types.str;
      default = "";
      description = "Host ID for zfs disks, generate with 'head -c4 /dev/urandom | od -A none -t x4'";
    };
    encryption = lib.mkOption {
      type = lib.types.bool;
      default = true;
      description = "Allows encryption to be disabled for testing";
    };
    devNodes = lib.mkOption {
      type = lib.types.str;
      default = "/dev/disk/by-id/";
      description = ''
        where disks should be mounted from
        https://openzfs.github.io/openzfs-docs/Project%20and%20Community/FAQ.html#selecting-dev-names-when-creating-a-pool-linux
        use "/dev/disk/by-path/" for vm's
      '';
    };
    root = {
      disk0 = lib.mkOption {
        type = lib.types.str;
        default = "";
        description = "name ab /dev für root dateisystem";
      };
      disk1 = lib.mkOption {
        type = lib.types.str;
        default = "";
        description = "name ab /dev für eventuellen root mirror";
      };
      swap = lib.mkOption {
        type = lib.types.str;
        default = "8G";
        description = "size of swap partition (only disk0)";
      };
      reservation = lib.mkOption {
        type = lib.types.str;
        default = "20GiB";
        description = "zfs reservation";
      };
      mirror = lib.mkOption {
        type = lib.types.bool;
        default = false;
        description = "mirror zfs root pool";
      };
    };
    storage = {
      enable = lib.mkOption {
        type = lib.types.bool;
        default = false;
        description = "Enable storage pool";
      };
      disks = lib.mkOption {
        type = lib.types.listOf lib.types.str;
        default = [ ];
        description = "name ab /dev/ für storage pool";
        example = "ata-ST16000NE000-2RW103_ZL2P0YSZ";
      };
      reservation = lib.mkOption {
        type = lib.types.str;
        default = "20GiB";
        description = "zfs reservation";
      };
      mirror = lib.mkOption {
        type = lib.types.bool;
        default = false;
        description = "mirror zfs storage pool";
      };
    };
  };

  config = lib.mkIf cfg.enable {
    networking.hostId = cfg.hostId;
    disko.devices = {
      disk = lib.mkMerge [
        {
          ssd0 = lib.mkIf (cfg.root.disk0 != "") {
            type = "disk";
            device = "/dev/${cfg.root.disk0}";
            content = {
              type = "gpt";
              partitions = {
                ESP = {
                  size = "1024M";
                  type = "EF00";
                  content = {
                    type = "filesystem";
                    format = "vfat";
                    mountpoint = "/boot";
                    mountOptions = [ "umask=0077" ];
                  };
                };
                encryptedSwap = lib.mkIf cfg.encryption {
                  size = cfg.root.swap;
                  content =  {
                    type = "swap";
                    randomEncryption = true;
                  };
                };
                zfs = {
                  size = "100%";
                  content = {
                    type = "zfs";
                    pool = "zroot";
                  };
                };
              };
            };
          };
          ssd1 = lib.mkIf (cfg.root.disk1 != "") {
            type = "disk";
            device = "/dev/${cfg.root.disk1}";
            content = {
              type = "gpt";
              partitions = {
                zfs = {
                  size = "100%";
                  content = {
                    type = "zfs";
                    pool = "zroot";
                  };
                };
              };
            };
          };
        }
        (lib.mkIf cfg.storage.enable (
          lib.mkMerge (
            map (diskname: {
              "${diskname}" = {
                type = "disk";
                device = "/dev/${diskname}";
                content = {
                  type = "gpt";
                  partitions = {
                    zfs = {
                      size = "100%";
                      content = {
                        type = "zfs";
                        pool = "storage";
                      };
                    };
                  };
                };
              };
            }) cfg.storage.disks
          )
        ))
      ];

      zpool = {
        zroot = {
          type = "zpool";
          mode = lib.mkIf cfg.root.mirror "mirror";
          # Workaround: cannot import 'zroot': I/O error in disko tests
          options.cachefile = "none";
          rootFsOptions = {
            mountpoint = "none";
            xattr = "sa";         # für microvm virtiofs mount
            acltype = "posixacl"; # für microvm virtiofs mount 
            compression = "zstd";
            "com.sun:auto-snapshot" = "false";
          };

          datasets = {
            encrypted = {
              type = "zfs_fs";
              options = {
                mountpoint = "none";
                encryption = lib.mkIf cfg.encryption "aes-256-gcm";
                keyformat = lib.mkIf cfg.encryption "passphrase";
                keylocation = lib.mkIf cfg.encryption "file:///tmp/secret.key";
              };
              # use this to read the key during boot
              postCreateHook = lib.mkIf cfg.encryption ''
                zfs set keylocation="prompt" zroot/encrypted;
              '';
            };
            "encrypted/root" = {
              type = "zfs_fs";
              mountpoint = "/";
              options.mountpoint = "legacy";
            };
            "encrypted/var" = {
              type = "zfs_fs";
              mountpoint = "/var";
              options.mountpoint = "legacy";
            };
            "encrypted/etc" = {
              type = "zfs_fs";
              mountpoint = "/etc";
              options.mountpoint = "legacy";
            };
            "encrypted/home" = {
              type = "zfs_fs";
              mountpoint = "/home";
              options.mountpoint = "legacy";
            };
            "encrypted/nix" = {
              type = "zfs_fs";
              mountpoint = "/nix";
              options.mountpoint = "legacy";
            };
            reserved = {
              # for cow delete if pool is full
              options = {
                canmount = "off";
                mountpoint = "none";
                reservation = "${cfg.root.reservation}";
              };
              type = "zfs_fs";
            };
          };
        };

        storage = lib.mkIf cfg.storage.enable {
          type = "zpool";
          mode = lib.mkIf (cfg.storage.mirror) "mirror";
          rootFsOptions = { 
            mountpoint = "none";
            xattr = "sa";         # für microvm virtiofs mount
            acltype = "posixacl"; # für microvm virtiofs mount 
          };
          datasets = {
            encrypted = {
              type = "zfs_fs";
              options = {
                mountpoint = "none";
                encryption = lib.mkIf cfg.encryption "aes-256-gcm";
                keyformat = lib.mkIf cfg.encryption "passphrase";
                keylocation = lib.mkIf cfg.encryption "file:///tmp/secret.key";
              };
              # use this to read the key during boot
              postCreateHook = lib.mkIf cfg.encryption ''
                zfs set keylocation="prompt" storage/encrypted;
              '';
            };
            "encrypted/data" = {
              type = "zfs_fs";
              mountpoint = "/data";
              options.mountpoint = "legacy";
            };
            "encrypted/data/microvms" = {
              type = "zfs_fs";
              mountpoint = "/data/microvms";
              options.mountpoint = "legacy";
            };
            reserved = {
              # for cow delete if pool is full
              options = {
                canmount = "off";
                mountpoint = "none";
                reservation = "${cfg.storage.reservation}";
              };
              type = "zfs_fs";
            };
          };
        };
      };
    };

    boot.zfs.devNodes = lib.mkDefault cfg.devNodes;

    fileSystems."/".neededForBoot = true;
    fileSystems."/etc".neededForBoot = true;
    fileSystems."/boot".neededForBoot = true;
    fileSystems."/var".neededForBoot = true;
    fileSystems."/home".neededForBoot = true;
    fileSystems."/nix".neededForBoot = true;
  };
}