import { useMemo } from "react";
import { SelectOption, SelectOptionsByCategory } from "../shared/types";

interface UseTransformSelectOptionsBase<T> {
  isCreatable: boolean | undefined;
  creatableOption: T;
}

interface TransformBasic<T> extends UseTransformSelectOptionsBase<T> {
  optionsDisplay: "basic" | undefined;
  options: T[];
}

interface TransformCategories<T extends SelectOption>
  extends UseTransformSelectOptionsBase<T> {
  optionsDisplay: "categories";
  options: SelectOptionsByCategory<T>[];
}

type UseTransformSelectOptionsProps<T extends SelectOption> =
  | TransformBasic<T>
  | TransformCategories<T>;

export function useTransformSelectOptions<T extends SelectOption>({
  isCreatable,
  creatableOption,
  ...props
}: UseTransformSelectOptionsProps<T>): T[] {
  return useMemo(() => {
    let optionsWithoutCreatable: T[];
    if (props.optionsDisplay === "categories") {
      optionsWithoutCreatable = props.options.reduce<T[]>((acc, cur) => {
        return acc.concat(cur.options);
      }, []);
    } else {
      // "basic" optionsDisplay
      optionsWithoutCreatable = props.options;
    }
    return isCreatable
      ? [creatableOption, ...optionsWithoutCreatable]
      : optionsWithoutCreatable;
  }, [props.options, props.optionsDisplay, isCreatable, creatableOption]);
}