/*!
 * V4Fire Core
 * https://github.com/V4Fire/Core
 *
 * Released under the MIT license
 * https://github.com/V4Fire/Core/blob/master/LICENSE
 */

/**
 * [[include:core/uuid/README.md]]
 * @packageDocumentation
 */

import { IS_NODE } from 'core/env';
import { separatorIndices } from 'core/uuid/const';

/**
 * Generates a UUIDv4 buffer and returns it
 */
export function generate(): Uint8Array {
	if (IS_NODE) {
		//#if node_js

		// eslint-disable-next-line @typescript-eslint/no-var-requires, import/no-nodejs-modules
		const crypto = require('crypto');

		const uuid = crypto.randomBytes(16);

		// eslint-disable-next-line no-bitwise
		uuid[6] = uuid[6] & 0x0f | 0x40;

		// eslint-disable-next-line no-bitwise
		uuid[8] = uuid[8] & 0x3f | 0x80;

		const
			{toString} = uuid;

		uuid.toString = (...args) => {
			if (args.length === 0) {
				return serialize(uuid);
			}

			return toString.apply(uuid, args);
		};

		return uuid;

		//#endif
	}

	const tmpUrl = URL.createObjectURL(new Blob());
	URL.revokeObjectURL(tmpUrl);

	let uuidStr = tmpUrl.toString();
	uuidStr = uuidStr.split(/[:/]/g).pop()!.toLowerCase();

	const uuid = parse(uuidStr);
	uuid.toString = () => uuidStr;

	return uuid;
}

/**
 * Converts the specified binary UUID to a string and returns it
 * @param uuid
 */
export function serialize(uuid: Uint8Array): string {
	let
		res = '';

	for (let i = 0; i < uuid.length; ++i) {
		let
			chunk = uuid[i].toString(16);

		if (chunk.length < 2) {
			chunk = `0${chunk}`;
		}

		res += chunk + (separatorIndices[i] === true ? '-' : '');
	}

	return res;
}

/**
 * Converts the specified UUID string to a binary sequence and returns it
 * @param uuid
 */
export function parse(uuid: string): Uint8Array {
	const
		arr = new Uint8Array(16);

	for (let i = 0, byteIndex = 0; i < uuid.length; i++) {
		if (uuid[i] === '-') {
			continue;
		}

		arr[byteIndex++] = parseInt(uuid[i] + uuid[++i], 16);
	}

	return arr;
}