import { Tuple } from '../../primitive/Tuple';
import { Includes } from '../Includes';
import { MatchReadonly } from '../MatchReadonly';
import { Push } from '../Push';
/**
 *
 * Type to remove duplicate elements from an array and keep only unique elements
 *
 * 튜플에서 중복된 요소를 제거하고 유니크한 요소만 남기는 타입
 *
 * @param T Tuple to remove duplicates from / 중복 제거할 튜플
 *
 * @returns Array with unique elements / 유니크한 요소만 남은 배열
 *
 * @example
 * type cases = [
 *   Expect<Equal<Unique<[1, 1, 2, 2, 3, 3]>, [1, 2, 3]>>,
 *   Expect<Equal<Unique<[1, 2, 3]>, [1, 2, 3]>>,
 *   Expect<Equal<Unique<[string, number, 1, "a", 1, string, 2, "a"]>, [string, number, 1, "a", 2]>>,
 * ]
 *
 * @link https://www.utilscript.site/docs/usage-array/unique
 *
 */
export type Unique<T extends Tuple, R extends Tuple = []> = T extends readonly [
    infer Current,
    ...infer Rest
] ? Includes<R, Current> extends true ? Unique<MatchReadonly<T, Rest>, R> : Unique<MatchReadonly<T, Rest>, Push<R, Current>> : MatchReadonly<T, R>;