CoastalCommitsPastes/client/lib/generate-uuid.ts

export default function generateUUID() {
	if (typeof crypto === "object") {
		if (typeof crypto.randomUUID === "function") {
			// https://developer.mozilla.org/en-US/docs/Web/API/Crypto/randomUUID
			return crypto.randomUUID()
		}
		if (
			typeof crypto.getRandomValues === "function" &&
			typeof Uint8Array === "function"
		) {
			// https://stackoverflow.com/questions/105034/how-to-create-a-guid-uuid
			const callback = (c: string) => {
				const num = Number(c)
				return (
					num ^
					(crypto.getRandomValues(new Uint8Array(1))[0] & (15 >> (num / 4)))
				).toString(16)
			}
			return "10000000-1000-4000-8000-100000000000".replace(/[018]/g, callback)
		}
	}
	let timestamp = new Date().getTime()
	let perforNow =
		(typeof performance !== "undefined" &&
			performance.now &&
			performance.now() * 1000) ||
		0
	return "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx".replace(/[xy]/g, (c) => {
		let random = Math.random() * 16
		if (timestamp > 0) {
			random = (timestamp + random) % 16 | 0
			timestamp = Math.floor(timestamp / 16)
		} else {
			random = (perforNow + random) % 16 | 0
			perforNow = Math.floor(perforNow / 16)
		}
		return (c === "x" ? random : (random & 0x3) | 0x8).toString(16)
	})
}