{config, pkgs, lib, ...}:
let
  cfg = config.services.glauth;
  settingsFormat = pkgs.formats.toml {};
in

with lib;

{
  options = {
    services.glauth = {
      enable = mkOption {
        default = false;
        type = with types; bool;
        description = ''
          Enable the glauth system service
        '';
      };

      package = mkPackageOption pkgs "glauth" { };

      dataDir = mkOption {
        type = types.path;
        default = "/var/lib/glauth";
      };

      user = mkOption {
        default = "glauth";
        type = types.str;
        description = ''
          Name of the user.
        '';
      };

      group = mkOption {
        default = "glauth";
        type = types.str;
        description = ''
          Name of the group.
        '';
      };

      settings = mkOption {
        type = settingsFormat.type;
        default = {};
        description = ''
          Configuration for glauth.cfg, see
          <link xlink:href="https://github.com/glauth/glauth/blob/master/v2/sample-simple.cfg"
          for supported settings.
        '';
      };

    };
  };

  config = mkIf cfg.enable {
    # Add user for glauth
    users.users."${cfg.user}" = {
      isSystemUser = true;
      group = cfg.group;
      home = cfg.dataDir;
    };
    users.groups."${cfg.group}" = {};

    # Add systemd service
    systemd.services.glauth = {
      wantedBy = [ "multi-user.target" ];
      after = [ "network.target" ];
      description = "Start a glauth server.";
      serviceConfig = {
        Type = "exec";
        User = "${cfg.user}";
        Group = "${cfg.group}";
        ExecStart = ''${cfg.package}/bin/glauth -c ${settingsFormat.generate "glauth.cfg" cfg.settings}'';
        StateDirectory = mkIf (cfg.dataDir == "/var/lib/glauth") [ "glauth" ];
      };
    };
  };
}