import type { Args, GenericFn, GenericResolver } from "../HKT";
import type { Dec } from "../Num/Int/Dec";
import type { Nat } from "../Num/Nat";

/**
 * Repeat `T` for `N` times.
 *
 * Sig: `<N extends Nat, T>(n: N, x: T) => readonly [T, T, ...]`
 */
export type Repeat<N extends Nat, T> =
  N extends 0 ? readonly [] : readonly [T, ...Repeat<Dec<N>, T>];

interface Resolver extends GenericResolver<[Nat, unknown], readonly unknown[]> {
  on1_: ([n]: Args<this>) => [[unknown], Repeat<typeof n, unknown>];
  on_1: ([, x]: Args<this>) => [[Nat], readonly (typeof x)[]];
  on11: ([n, x]: Args<this>) => [[], Repeat<typeof n, typeof x>];
}

/**
 * [Fn] Repeat `T` for `N` times.
 *
 * Sig: `<N extends Nat, T>(n: N, x: T) => readonly [T, T, ...]`
 */
export interface RepeatFn extends GenericFn<Resolver> {
  def: ([n, x]: Args<this>) => Repeat<typeof n, typeof x>;
}