/**
 * Copyright (c) 2010-2023 Contributors to the openHAB project
 *
 * See the NOTICE file(s) distributed with this work for additional
 * information.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0
 *
 * SPDX-License-Identifier: EPL-2.0
 */
package org.openhab.binding.folderwatcher.internal.api.util;

import java.util.Locale;

import org.eclipse.jdt.annotation.NonNullByDefault;

/**
 * The {@link BinaryUtils} class contains methods for binary interactions.
 * <p>
 * Based on offical AWS example {@see https://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-examples-using-sdks.html}
 * 
 * @author Alexandr Salamatov - Initial contribution
 */
@NonNullByDefault
public class BinaryUtils {
    public static String toHex(byte[] data) {
        StringBuilder sb = new StringBuilder(data.length * 2);
        for (int i = 0; i < data.length; i++) {
            String hex = Integer.toHexString(data[i]);
            if (hex.length() == 1) {
                sb.append("0");
            } else if (hex.length() == 8) {
                hex = hex.substring(6);
            }
            sb.append(hex);
        }
        return sb.toString().toLowerCase(Locale.getDefault());
    }

    public static byte[] fromHex(String hexData) {
        byte[] result = new byte[(hexData.length() + 1) / 2];
        String hexNumber = null;
        int stringOffset = 0;
        int byteOffset = 0;
        while (stringOffset < hexData.length()) {
            hexNumber = hexData.substring(stringOffset, stringOffset + 2);
            stringOffset += 2;
            result[byteOffset++] = (byte) Integer.parseInt(hexNumber, 16);
        }
        return result;
    }
}
