{ config, pkgs, lib, ... }:
with builtins // lib;
let
  cfg = config.koreader;
in {
  options.koreader = {
    enable = mkEnableOption "KOReader";

    package = mkPackageOption pkgs "kobo-koreader" {};

    _createdFiles = mkOption {
      type = types.package;
      internal = true;
      readOnly = true;
      default = pkgs.buildEnv {
        name = "koreader-files-created";
        paths = mapAttrsToList (_: v: v._package) cfg.file;
        extraPrefix = cfg.devicePath;
      };
    };

    finalPackage = mkOption {
      type = types.package;
      internal = true;
      readOnly = true;
      default = pkgs.mergePaths {
        name = "koreader-package";
        paths = [
          (pkgs.linkFarm "koreader" [{
            name = removePrefix "/" cfg.devicePath;
            path = cfg.package.out;
          }])
          cfg._createdFiles
          cfg.package.KoboRoot
        ];
      };
    };

    path = mkOption {
      type = types.str;
      readOnly = true;
      internal = true;
      default = ".adds/koreader";
    };

    devicePath = mkOption {
      type = types.str;
      readOnly = true;
      internal = true;
      default = "/mnt/onboard/${cfg.path}";
    };

    file = mkOption {
      default = {};
      type = types.attrsOf (types.submodule (pkgs.callPackage ../lib/file-type.nix {}));
      apply = filterAttrs (_: v: v.enable);
    };

    nickel = {
      enable = mkEnableOption "Add NickelMenu entry" // { default = ! config.kfmon.enable; };
    };
  };

  config = mkMerge [
    {
      info.koreader = cfg.enable;
    }
    (mkIf cfg.enable {
      koboroot.include = singleton cfg.finalPackage;

      nickel.menu.item = mkIf cfg.nickel.enable {
        koreader = singleton {
          location = "main";
          label = "KOReader";
          action = "cmd_spawn";
          arg = [
            "quiet"
            "exec ${cfg.devicePath}/koreader.sh"
          ];
        };
      };

      kfmon.configs.koreader.watch = {
        filename = "/mnt/onboard/icons/koreader.png";
        action = "${cfg.devicePath}/koreader.sh";
        label = "KOReader";
        hidden = 0;
        block_spawns = 1;
        do_db_update = 0;
        db_title = "KOReader";
        db_author = "KOReader Devs";
        db_comment = "An eBook reader application";
      };
    })
  ];
}