SOURCE

function cached(callback) {
    let value, isCalled = false;
    return function () {
        if (!isCalled) {
            value = callback.apply(this, arguments);
            isCalled = true;
        }
        return value;
    }
}
function generateUUID() {
    let d = new Date().getTime();
    const seconds = timestamp() - 946656000;
    console.log(seconds)
    let daysStr = Math.floor(seconds / 86400).toString(16);
    let uuid = ('xxxx-yxxx-' + daysStr + '-8xxx-yx').replace(/[xy]/g, function (c) {
        let r = (d + Math.random() * 16) % 16 | 0;
        d = Math.floor(d / 16);
        let v = (c === 'x' ? r : (r & 0x3 | 0x8));
        return v.toString(16);
    });
    let sum = 0;
    const splits = uuid.split('-');
    for (let i = 0; i < splits.length; i++) {
        sum += parseInt(splits[i], 16);
    }

    return (uuid + (sum % 256).toString(16)).toUpperCase();
}
const getClientID = cached(function () {
    const STORAGE_KEY = "uuid";
    let uuid = '';
    if (!uuid) {
        uuid = generateUUID();
        console.log(1,uuid)
        // setStorageSync(STORAGE_KEY, uuid);
    }
    return uuid;
})
function timestamp(time = undefined) {
    return Math.floor(((time ? new Date(time) : new Date) - 0) / 1000);
}
console.log(getClientID())