sendou.ink/app/modules/tournament-map-list-generator/utils.ts

// https://stackoverflow.com/a/68523152

function cyrb128(str: string) {
	let h1 = 1779033703;
	let h2 = 3144134277;
	let h3 = 1013904242;
	let h4 = 2773480762;
	// biome-ignore lint/suspicious/noImplicitAnyLet: biome migration
	for (let i = 0, k; i < str.length; i++) {
		k = str.charCodeAt(i);
		h1 = h2 ^ Math.imul(h1 ^ k, 597399067);
		h2 = h3 ^ Math.imul(h2 ^ k, 2869860233);
		h3 = h4 ^ Math.imul(h3 ^ k, 951274213);
		h4 = h1 ^ Math.imul(h4 ^ k, 2716044179);
	}
	h1 = Math.imul(h3 ^ (h1 >>> 18), 597399067);
	h2 = Math.imul(h4 ^ (h2 >>> 22), 2869860233);
	h3 = Math.imul(h1 ^ (h3 >>> 17), 951274213);
	h4 = Math.imul(h2 ^ (h4 >>> 19), 2716044179);
	return [
		(h1 ^ h2 ^ h3 ^ h4) >>> 0,
		(h2 ^ h1) >>> 0,
		(h3 ^ h1) >>> 0,
		(h4 ^ h1) >>> 0,
	];
}

function mulberry32(a: number) {
	return () => {
		// biome-ignore lint/suspicious/noAssignInExpressions: biome migration
		// biome-ignore lint/style/noParameterAssign: biome migration
		let t = (a += 0x6d2b79f5);
		t = Math.imul(t ^ (t >>> 15), t | 1);
		t ^= t + Math.imul(t ^ (t >>> 7), t | 61);
		return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
	};
}

export const seededRandom = (seed: string) => {
	const rng = mulberry32(cyrb128(seed)[0]);

	const rnd = (lo: number, hi?: number, defaultHi = 1) => {
		if (hi === undefined) {
			// biome-ignore lint/style/noParameterAssign: biome migration
			hi = lo === undefined ? defaultHi : lo;
			// biome-ignore lint/style/noParameterAssign: biome migration
			lo = 0;
		}

		return rng() * (hi - lo) + lo;
	};

	const rndInt = (lo: number, hi?: number) => Math.floor(rnd(lo, hi, 2));

	const shuffle = <T>(o: T[]) => {
		const a = o.slice();

		for (let i = a.length - 1; i > 0; i--) {
			const j = rndInt(i + 1);
			const x = a[i];
			a[i] = a[j]!;
			a[j] = x!;
		}

		return a;
	};

	return { rnd, rndInt, shuffle };
};