const generateUuid = (function () {
    // use `randomUUID` if possible
    if (typeof crypto.randomUUID === 'function') {
        // see https://developer.mozilla.org/en-US/docs/Web/API/Window/crypto
        // > Although crypto is available on all windows, the returned Crypto object only has one
        // > usable feature in insecure contexts: the getRandomValues() method.
        // > In general, you should use this API only in secure contexts.
        return crypto.randomUUID.bind(crypto);
    }
    // prep-work
    const _data = new Uint8Array(16);
    const _hex = [];
    for (let i = 0; i < 256; i++) {
        _hex.push(i.toString(16).padStart(2, '0'));
    }
    return function generateUuid() {
        // get data
        crypto.getRandomValues(_data);
        // set version bits
        _data[6] = (_data[6] & 0x0f) | 0x40;
        _data[8] = (_data[8] & 0x3f) | 0x80;
        // print as string
        let i = 0;
        let result = '';
        result += _hex[_data[i++]];
        result += _hex[_data[i++]];
        result += _hex[_data[i++]];
        result += _hex[_data[i++]];
        result += '-';
        result += _hex[_data[i++]];
        result += _hex[_data[i++]];
        result += '-';
        result += _hex[_data[i++]];
        result += _hex[_data[i++]];
        result += '-';
        result += _hex[_data[i++]];
        result += _hex[_data[i++]];
        result += '-';
        result += _hex[_data[i++]];
        result += _hex[_data[i++]];
        result += _hex[_data[i++]];
        result += _hex[_data[i++]];
        result += _hex[_data[i++]];
        result += _hex[_data[i++]];
        return result;
    };
})();
/** Namespace should be 3 letter. */
function prefixedUuid(namespace) {
    return `${namespace}-${generateUuid()}`;
}

export { generateUuid, prefixedUuid };