{ options
, lib
, config
, pkgs
, ...
}:

/*

Urbit Harbor is a supervisor for Urbit ships on the local machine. It does no
orchestration, it just manages systemd services.

Setup process:

    <running as user "urbit-harbor">
    dir=/var/urbit/harbor
    urbit -c $dir/zod -k $dir/zod.key -x          # one-time setup
    <create $dir/zod.service from some template>
    systemctl --user enable $dir/zod.service      # nees fullpath
    systemctl --user start zod.service


Service Template:

    [Service]
    ExecStart=urbit -tq /var/urbit/harbor/zod  # maybe want -d?
    ExecStartPre=mkdir -p /var/urbit/harbor/zod

    [Unit]
    Description=zod

    [Install]
    WantedBy=multi-user.target


TODO:
    - use systemd.resource-control to limit memory/CPU for ships
      - Urbit.Cloud controller will set different limits by reading/editing the
      ini file, and change price to customer
    - figure out what firewall stuff i need to do
*/

let
  cfg = config.services.urbit-harbor;
in {
  options.services.urbitharbor = {
    enable = lib.mkEnableOption "Enable urbit-harbor";

    dataDir = lib.mkOption {
      type = lib.types.path;
      default = "/var/urbit/harbor";
      description = "Where to store piers";
    };

    ships = lib.mkOption {
      type = lib.types.listOf lib.types.str;
      description = "List of @p's to start up, without the leading ~";
    };

    package = lib.mkOption {
      type = lib.types.package;
      default = pkgs.urbit-harbor;
      description = "The urbit-harbor package to use";
    };

    urbitPackage = lib.mkOption {
      type = lib.types.package;
      default = pkgs.urbit;
      description = "The urbit package to use";
    };

    user = lib.mkOption {
      type = lib.types.user;
      default = "urbit-harbor";
      description = "User to run as";
    };
  };

  config = lib.mkIf cfg.enable {
    systemd.services.urbit-harbor = {
      path = [ cfg.package cfg.urbitPackage ];
      wantedBy = [ "multi-user.target" ];
      preStart = ''
        mkdir -p ${cfg.dataDir}
      '';
      script = "${cfg.package}/bin/urbit-harbor ${cfg.dataDir}";
      description = "Urbit harbor";
      serviceConfig = {
        User = cfg.user;
        Type = "simple";
        Restart = "always";
        RestartSec = "3";
      };
    };

  };

}