{
  description = "A very basic flake";

  inputs = {
    deploy-rs = {
      url = "github:serokell/deploy-rs";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    image-builder.url = "git+https://git.asonix.dog/asonix/nixos-aarch64-images";
    nixpkgs.url = "github:nixos/nixpkgs/master";
    sops-nix = {
      url = "github:Mic92/sops-nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs = { self, deploy-rs, image-builder, nixpkgs, sops-nix }:
    let
      pkgs = import nixpkgs {
        system = "aarch64-linux";
      };

      btrbkPrimary = { subvolumes ? [ ] }: {
        snapshot_dir = "@snapshots";
        subvolume = builtins.foldl'
          (acc: subvol: acc // {
            ${subvol} = { };
          })
          { }
          subvolumes;
      };

      btrbkSecondary = { target-dir, subvolumes ? [ ] }: {
        target = "send-receive ${target-dir}";
        subvolume = builtins.foldl'
          (acc: subvol: acc // {
            ${subvol} = {
              snapshot_dir = "@snapshots";
              snapshot_preserve_min = "all";
              snapshot_create = "no";
            };
          })
          { }
          subvolumes;
      };

      nextcloudSubvolumes = [
        "@nc-config"
        "@nc-data"
        "@postgres"
        "@redis"
        "@gitea"
        "@gitea-conf"
        "@pihole"
        "@papermc"
        "@docker-cfg"
        "@garage"
        "@garage-config"
      ];

      postgresSubvolumes = [
        "postgres"
        "postgres-cfg"
      ];

      sharedModule = ({ config, ... }: {
        services.openssh.settings.PasswordAuthentication = false;

        # Use the extlinux boot loader. (NixOS wants to enable GRUB by default)
        boot.loader.grub.enable = false;
        # Enables the generation of /boot/extlinux/extlinux.conf
        boot.loader.generic-extlinux-compatible.enable = true;

        fileSystems."/" = {
          device = "/dev/disk/by-uuid/44444444-4444-4444-8888-888888888888";
          fsType = "ext4";
        };

        environment.systemPackages = with pkgs; [
          bottom
          btrbk
          cryptsetup
          htop
        ];

        sops = {
          age.keyFile = "/home/asonix/.config/sops/age/keys.txt";
          age.generateKey = true;
          secrets.private_key = {
            format = "yaml";
            sopsFile = ./secrets/btrbk.yaml;
          };
          secrets.btrfsKeyFile = {
            format = "binary";
            sopsFile = ./secrets/keyfile.bin;
          };
        };

        services.btrbk = {
          sshAccess = [
            {
              key = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHTqU3EvTgY5/e9m6YyQWypQPK58t9iPmPnPYAvnODGB asonix@lionheart";
              roles = [ "source" "info" "send" ];
            }
          ];
          extraPackages = with pkgs; [ xz ];
          instances.btrbk = {
            onCalendar = "hourly";
            settings = {
              transaction_log = "/var/log/btrbk.log";
              stream_buffer = "512m";
              snapshot_preserve_min = "2d";
              snapshot_preserve = "35d 20w 12m";
              target_preserve_min = "24h";
              target_preserve = "24h 7d";
              archive_preserve_min = "latest";
              archive_preserve = "12m 10y";
              ssh_user = "btrbk";
              ssh_identity = config.sops.secrets.private_key.path;
              backend_remote = "btrfs-progs-sudo";
            };
          };
        };
      });

      makeDockerConfig = { hostname, volume, baseModule, extraModules ? [ ] }: with image-builder.packages.aarch64-linux.modules; nixpkgs.lib.nixosSystem {
        system = "aarch64-linux";
        modules = [
          sops-nix.nixosModules.sops
          baseModule
          sharedModule
          userModule
          ({ config, ... }: {
            environment.systemPackages = with pkgs; [
              docker
              docker-compose
            ];

            networking.hostName = hostname;

            virtualisation.docker.enable = true;

            services.btrbk.instances.btrbk.settings.volume = volume;
          })
        ] ++ extraModules;
      };

      makeNextcloudConfig = { hostname, volume }: with image-builder.packages.aarch64-linux.modules; makeDockerConfig {
        inherit hostname;
        inherit volume;
        baseModule = rockPro64v2;
        extraModules = [
          ({ config, ... }: {
            environment.etc.crypttab = {
              enable = true;
              text = ''
                cryptdrive1 /dev/sda1 ${config.sops.secrets.btrfsKeyFile.path} luks
                cryptdrive2 /dev/sdb1 ${config.sops.secrets.btrfsKeyFile.path} luks
                cryptdrive3 /dev/sdc1 ${config.sops.secrets.btrfsKeyFile.path} luks
              '';
            };

            fileSystems."/btrfs/hdd" = {
              device = "/dev/mapper/cryptdrive1";
              fsType = "btrfs";
              options = [ "defaults" "compress=zstd" "rw" ];
            };
          })
        ];
      };

      deployer = { hostname, configuration }: {
        hostname = hostname;
        profiles.system = {
          sshUser = "asonix";
          user = "root";
          magicRollback = false;
          sshOpts = [
            "-i"
            "/home/asonix/.ssh/kube-rsa"
            "-t"
          ];
          path = deploy-rs.lib.aarch64-linux.activate.nixos configuration;
        };
      };
    in
    {
      nixosConfigurations = with image-builder.packages.aarch64-linux.modules; {
        nextcloud1 = makeNextcloudConfig {
          hostname = "nextcloud1";
          volume = {
            # "ssh://192.168.20.28/btrfs/hdd" = btrbkSecondary {
            #   target-dir = "/btrfs/hdd/@snapshots";
            #   subvolumes = nextcloudSubvolumes;
            # };
            "/btrfs/hdd" = btrbkPrimary {
              subvolumes = nextcloudSubvolumes;
            };
          };
        };

        nextcloud2 = makeNextcloudConfig {
          hostname = "nextcloud2";
          volume = {
            "ssh://192.168.20.21/btrfs/hdd" = btrbkSecondary {
              target-dir = "/btrfs/hdd/@snapshots";
              subvolumes = nextcloudSubvolumes;
            };
            # "/btrfs/hdd" = btrbkPrimary {
            #   subvolumes = nextcloudSubvolumes;
            # };
          };
        };

        redtail1 = makeDockerConfig {
          hostname = "redtail1";
          volume = {
            "ssh://192.168.20.24/btrfs/ssd" = btrbkSecondary {
              target-dir = "/btrfs/ssd/@snapshots";
              subvolumes = postgresSubvolumes;
            };
            # "/btrfs/ssd" = btrbkPrimary {
            #   subvolumes = postgresSubvolumes;
            # };
          };
          baseModule = rock64;
        };

        redtail2 = makeDockerConfig {
          hostname = "redtail2";
          volume = {
            # "ssh://192.168.20.23/btrfs/ssd" = btrbkSecondary {
            #   target-dir = "/btrfs/ssd/@snapshots";
            #   subvolumes = postgresSubvolumes;
            # };
            "/btrfs/ssd" = btrbkPrimary {
              subvolumes = postgresSubvolumes;
            };
          };
          baseModule = rock64;
        };

        whitestorm1 = makeDockerConfig {
          hostname = "whitestorm1";
          volume = {
            # "ssh://192.168.20.11/btrfs/ssd" = btrbkSecondary {
            #   target-dir = "/btrfs/ssd/@snapshots";
            #   subvolumes = postgresSubvolumes;
            # };
            "/btrfs/ssd" = btrbkPrimary {
              subvolumes = postgresSubvolumes;
            };
          };
          baseModule = rock64;
        };

        whitestorm2 = makeDockerConfig {
          hostname = "whitestorm2";
          volume = {
            "ssh://192.168.20.26/btrfs/ssd" = btrbkSecondary {
              target-dir = "/btrfs/ssd/@snapshots";
              subvolumes = postgresSubvolumes;
            };
            # "/btrfs/ssd" = btrbkPrimary {
            #   subvolumes = postgresSubvolumes;
            # };
          };
          baseModule = rock64;
        };
      };

      deploy.nodes.nextcloud2 = deployer {
        hostname = "192.168.20.28";
        configuration = self.nixosConfigurations.nextcloud2;
      };
    };
}