manifests/modules/lib.nix

{ pkgs }:
{
  appOptions = opts: with pkgs.lib; {
      enable = mkOption {
        type = types.bool;
        default = true;
        description = "Enable";
      };

      autoSync = mkOption {
        type = types.bool;
        default = true;
        description = "Auto sync";
      };

      prune = mkOption {
        type = types.bool;
        default = false;
        description = "Prune";
      };

      serverSideDiff = mkOption {
        type = types.bool;
        default = true;
        description = "Enable server-side diffing";
      };

      values = mkOption {
        type = types.attrsOf types.anything;
        default = {};
        description = "Values";
      };
    } // opts;

  appConfig = cfg: name: conf:
    with pkgs.lib;
    let
       app = conf // {
         createNamespace = true;

         compareOptions = {
           serverSideDiff = cfg.serverSideDiff;
          };

         syncPolicy = {
           syncOptions = {
             applyOutOfSyncOnly = true;
           };

           autoSync = mkIf cfg.autoSync {
             prune = cfg.prune;
             selfHeal = false;
           };
         };
       };

    in mkIf cfg.enable { applications.${name} = app; };
}