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

with lib;

let
  cfg = config.sydnix.impermanence;
in {
  options = {
    sydnix.impermanence = {
      enable = mkEnableOption "impermanence";

      mutableDotfiles = {
        enable = mkEnableOption "dotfiles under impermanence";

        # storeAt = mkOption {
        #   default = "dots/config";
        #   type = types.str;
        #   # type = with types;
        #   #   addCheck
        #   #     path
        #   #     (x: cfg.mutableDotfiles.enable
        #   #         -> ! (elem x cfg.mutableDotfiles.directories));
        # };

        files = mkOption {
          default = [];
          # FIXME: Inaccurate type.
          type = with types;
            listOf anything;
        };

        directories = mkOption {
          default = [];
          # FIXME: Inaccurate type.
          type = with types;
            listOf anything;
        };
      };

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

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

  config = mkIf cfg.enable {
    home.persistence = {
      "/persist/home/${config.home.username}" = {
        allowOther = true;
        directories = cfg.directories;
        files = cfg.files;
      };
    } // (if ! cfg.mutableDotfiles.enable
          then {}
          else {
            "/persist/dots/users/${config.home.username}/dots/" = {
              removePrefixDirectory = true;
              directories = cfg.mutableDotfiles.directories;
              files = cfg.mutableDotfiles.files;
              allowOther = true;
            };
    });

  };
}