import type { Primitive } from "#/engine/lib/Primitive.ts";

export type Cache<T> = {
	clear(): void;
	delete(key: unknown): boolean;
	get(key: unknown): T | undefined;
	has(key: unknown): boolean;
	set(key: unknown, value: T): unknown;
};

export function withCache<T, U extends (...args: Parameters<U>) => T>(
	fn: U,
	cache: Cache<T>,
): (key: unknown, ...args: Parameters<U>) => T {
	return (key, ...args) => {
		if (cache.has(key)) {
			return cache.get(key) as T;
		}

		const value = fn(...args);
		cache.set(key, value);

		return value;
	};
}

export function memoize<T, U extends Primitive>(
	fn: (arg: U) => T,
): [(arg: U) => T, Cache<T>] {
	const cache = new Map<Primitive, T>();
	const callback = withCache(fn, cache);

	return [
		(arg) => {
			return callback(arg, arg);
		},
		cache,
	];
}