frostfs-sdk-java/models/src/main/java/info/frostfs/sdk/UuidExtension.java

package info.frostfs.sdk;

import java.nio.ByteBuffer;
import java.util.UUID;

import static java.util.Objects.isNull;

public class UuidExtension {
    private static final int UUID_BYTE_ARRAY_LENGTH = 16;
    private static final String ERROR_WRONG_UUID_SIZE = "Uuid byte array length must be " + UUID_BYTE_ARRAY_LENGTH;
    private static final String ERROR_UUID_MISSING = "Uuid is not present";

    private UuidExtension() {
    }

    public static UUID asUuid(byte[] bytes) {
        if (isNull(bytes) || bytes.length != UUID_BYTE_ARRAY_LENGTH) {
            throw new IllegalArgumentException(ERROR_WRONG_UUID_SIZE);
        }

        ByteBuffer bb = ByteBuffer.wrap(bytes);
        long firstLong = bb.getLong();
        long secondLong = bb.getLong();
        return new UUID(firstLong, secondLong);
    }

    public static byte[] asBytes(UUID uuid) {
        if (isNull(uuid)) {
            throw new IllegalArgumentException(ERROR_UUID_MISSING);
        }

        ByteBuffer bb = ByteBuffer.allocate(UUID_BYTE_ARRAY_LENGTH);
        bb.putLong(uuid.getMostSignificantBits());
        bb.putLong(uuid.getLeastSignificantBits());
        return bb.array();
    }
}