{ lib, config, ... }:
with lib;
let
  cfg = config.cluster.mounts;

  options =
    [ "soft" "defaults" "vers=4.2" ] ++
    (if cfg.automount.enable then [ "x-systemd.automount" ] else []);

  users =
    if cfg.users then {
      "/users" = {
          device = "/ceph/volumes/nfs/home";
          options = [ "bind"  ];
      };
    } else {};

  opt =
    if cfg.opt then {
      "/opt/bin" = {
          device = "/ceph/volumes/nfs/opt/bin";
          options = [ "bind" ];
      };
      "/opt/sif" = {
          device = "/ceph/volumes/nfs/opt/sif";
          options = [ "bind" ];
      };
    } else {};

  data =
      if cfg.ceph then {
        "/data" = {
          device = "/ceph";
          options = [ "bind" ];
        };
      } else {};

  work =
      if cfg.work then {
        "/work" = {
          device = if cfg.rdma.enable then "10.1.6.210:/work" else "172.16.239.210:/work";
          fsType = "nfs4";
          options =  options ++ (if cfg.rdma.enable then [ "rdma" ] else []);
        };
    } else {};

  ceph  =
    if cfg.ceph then {
        "/ceph" = {
          device = "oceanbox@.data=/";
          fsType = "ceph";
          options = [
            "mon_addr=172.16.239.211/172.16.239.212/172.16.239.213:6789"
            "_netdev"
            "x-systemd.automount"
          ];
        };
      } else {};

  fileSystems = users // opt // data // work // ceph;

  automount = mountpoint:
      if cfg.automount.enable && builtins.hasAttr mountpoint fileSystems then
        [{
          wantedBy = [ "multi-user.target" ];
          automountConfig = {
            TimeoutIdleSec = "600";
          };
          where = mountpoint;
        }]
      else [];

  automounts =
      [] ++
      automount "/work" ++
      automount "/opt" ++
      automount "/backup" ++
      automount "/data";

  cephConf =
   if cfg.ceph then {
      "ceph/ceph.conf" = {
        text = ''
          [global]
          mon_host = 172.16.239.211:6789,172.16.239.212:6789,172.16.239.213:6789
          log file = /tmp/ceph-$pid.log
          [client.oceanbox]
          key = AQDb7sZokwnUAxAANjnzxX0p+W/FUtSYryuyqg==
          [client.rbd]
          key = replaceme
        '';
        mode = "0660";
        group = "admin";
      };
    } else {};

in
{
  options.cluster.mounts = {
    rdma.enable = mkEnableOption "Enable NFS over RDMA";
    automount.enable = mkEnableOption "Enable NFS automounting";
    users = mkEnableOption "Enable /users";
    opt = mkEnableOption "Enable /opt";
    data = mkEnableOption "Enable /data";
    work = mkEnableOption "Enable /work";
    ceph = mkEnableOption "Enable /ceph";
  };

  config = {
    fileSystems = fileSystems;
    environment.etc = cephConf;
    systemd.automounts = automounts;
    boot.kernelModules = [ "rbd" ];
  };
}