import type { Show, Show$GetConstruct, Show$GetTypeClass } from ".";
import type { Args, Call1W, Fn } from "../../HKT";
import type { IsUnion } from "../../Union/IsUnion";
import type { ToList } from "../../Union/ToList";
import type { And, AssertStr, IsAny, Not, Or } from "../../helpers";

type _ShowUnion<TS> =
  TS extends [infer S extends Show] ? Show_<S>
  : TS extends [infer H extends Show, ...infer R] ?
    // @ts-ignore - Type instantiation is excessively deep and possibly infinite.
    `${Show_<H>} | ${_ShowUnion<R>}`
  : never;

/**
 * Convert a `Show` instance to a string.
 *
 * Sig: `(s: Show) => string`
 */
type Show_<S extends Show> = AssertStr<
  IsAny<S> extends true ? string
  : And<IsUnion<S>, Or<IsUnion<Show$GetTypeClass<S>>, Not<IsUnion<Show$GetConstruct<S>>>>> extends (
    true
  ) ?
    _ShowUnion<ToList<S>>
  : Call1W<Show$GetTypeClass<S>["Show"], S> extends infer U extends string ? U
  : never
>;
export type { Show_ as Show };

/**
 * [Fn] Convert a `Show` instance to a string.
 *
 * Sig: `(s: Show) => string`
 */
export default interface ShowFn extends Fn<[Show], string> {
  def: ([s]: Args<this>) => Show_<typeof s>;
}