// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0

import { currentSizeKey } from '../constants';

/**
 * return the byte size of the string
 * @param str
 */
export function getByteLength(str: string): number {
	let ret = 0;
	ret = str.length;

	for (let i = str.length; i >= 0; i -= 1) {
		const charCode: number = str.charCodeAt(i);
		if (charCode > 0x7f && charCode <= 0x7ff) {
			ret += 1;
		} else if (charCode > 0x7ff && charCode <= 0xffff) {
			ret += 2;
		}
		// trail surrogate
		if (charCode >= 0xdc00 && charCode <= 0xdfff) {
			i -= 1;
		}
	}

	return ret;
}

/**
 * get current time
 */
export function getCurrentTime(): number {
	const currentTime = new Date();

	return currentTime.getTime();
}

/**
 * check if passed value is an integer
 */
export function isInteger(value?: number): boolean {
	if (Number.isInteger) {
		return Number.isInteger(value);
	}

	return (
		typeof value === 'number' && isFinite(value) && Math.floor(value) === value
	);
}

export const getCurrentSizeKey = (keyPrefix: string) =>
	`${keyPrefix}${currentSizeKey}`;