/*
	Spacebar: A FOSS re-implementation and extension of the Discord.com backend.
	Copyright (C) 2025 Spacebar and Spacebar Contributors
	
	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Affero General Public License as published
	by the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.
	
	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Affero General Public License for more details.
	
	You should have received a copy of the GNU Affero General Public License
	along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

declare global {
	interface Array<T> {
		containsAll(target: T[]): boolean;
		partition(filter: (elem: T) => boolean): [T[], T[]];
		single(filter: (elem: T) => boolean): T | null;
		forEachAsync(callback: (elem: T, index: number, array: T[]) => Promise<void>): Promise<void>;
	}
}

export function containsAll<T>(arr: T[], target: T[]) {
	return target.every((v) => arr.includes(v));
}

/* https://stackoverflow.com/a/50636286 */
export function partition<T>(array: T[], filter: (elem: T) => boolean): [T[], T[]] {
	const pass: T[] = [],
		fail: T[] = [];
	array.forEach((e) => (filter(e) ? pass : fail).push(e));
	return [pass, fail];
}

export function single<T>(array: T[], filter: (elem: T) => boolean): T | null {
	const results = array.filter(filter);
	if (results.length > 1) throw new Error("Array contains more than one matching element");
	if (results.length === 0) return null;
	return results[0];
}

export async function forEachAsync<T>(array: T[], callback: (elem: T, index: number, array: T[]) => Promise<void>): Promise<void> {
	await Promise.all(array.map(callback));
}

// register extensions
if (!Array.prototype.containsAll)
	Array.prototype.containsAll = function <T>(this: T[], target: T[]) {
		return containsAll(this, target);
	};
if (!Array.prototype.partition)
	Array.prototype.partition = function <T>(this: T[], filter: (elem: T) => boolean) {
		return partition(this, filter);
	};
if (!Array.prototype.single)
	Array.prototype.single = function <T>(this: T[], filter: (elem: T) => boolean) {
		return single(this, filter);
	};
if (!Array.prototype.forEachAsync)
	Array.prototype.forEachAsync = function <T>(this: T[], callback: (elem: T, index: number, array: T[]) => Promise<void>) {
		return forEachAsync(this, callback);
	};