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)
  })
}