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

with lib;

let
  cfg = config.sydnix.impermanence;
in {
  options = {
    sydnix.impermanence = {
      enable = mkOption {
        description = "Enable Impermanence";
        type = types.bool;
        default = false;
      };

      directories = mkOption {
        description = "";
        type = with types;
          listOf (coercedTo str (d: { directory = d; }) userDir);
        default = [];
      };

      files = mkOption {
        description = "";
        type = with types;
          listOf (coercedTo str (f: { file = f; }) userFile);
        default = [];
      };
    };
  };

  config = mkIf cfg.enable {
    systemd.services.erase-home-darlings =
      let service = {
            description = "Rollback home to a blank state on boot";
            wantedBy = [
              "multi-user.target"
            ];
            after = [
              "home.mount"
            ];
            path = [ pkgs.zfs pkgs.babashka ];
            # unitConfig.DefaultDependencies = "no";
            serviceConfig = {
              Type = "oneshot";
              RemainAfterExit = true;
              ExecStart =
                let script = ./erase-home-darlings.clj;
                in ''${pkgs.babashka}/bin/bb "${script}" 3'';
            };
            stopIfChanged = false;
            restartIfChanged = false;
          };
      in if config.boot.initrd.systemd.enable
         then service
         else throw "sydnix.impermanence currently requires config.boot.initrd.systemd.enable'!";
  };
}