+package org.argeo.api.acr.uuid;
+
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.net.UnknownHostException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.time.Duration;
+import java.time.temporal.Temporal;
+import java.util.Objects;
+import java.util.Random;
+import java.util.UUID;
+
+/**
+ * Implementation of the basic RFC4122 algorithms.
+ *
+ * @see https://datatracker.ietf.org/doc/html/rfc4122
+ */
+public abstract class AbstractUuidFactory implements UuidFactory {
+
+ /*
+ * TIME-BASED (version 1)
+ */
+
+ private final static long MOST_SIG_VERSION1 = (1l << 12);
+ private final static long LEAST_SIG_RFC4122_VARIANT = (1l << 63);
+
+ protected UUID newTimeUUID(long timestamp, long clockSequence, byte[] node, int offset) {
+ Objects.requireNonNull(node, "Node array cannot be null");
+ if (node.length < offset + 6)
+ throw new IllegalArgumentException("Node array must be at least 6 bytes long");
+
+ long mostSig = MOST_SIG_VERSION1 // base for version 1 UUID
+ | ((timestamp & 0xFFFFFFFFL) << 32) // time_low
+ | (((timestamp >> 32) & 0xFFFFL) << 16) // time_mid
+ | ((timestamp >> 48) & 0x0FFFL);// time_hi_and_version
+
+ long leastSig = LEAST_SIG_RFC4122_VARIANT // base for Leach–Salz UUID
+ | (((clockSequence & 0x3F00) >> 8) << 56) // clk_seq_hi_res
+ | ((clockSequence & 0xFF) << 48) // clk_seq_low
+ | (node[offset] & 0xFFL) //
+ | ((node[offset + 1] & 0xFFL) << 8) //
+ | ((node[offset + 2] & 0xFFL) << 16) //
+ | ((node[offset + 3] & 0xFFL) << 24) //
+ | ((node[offset + 4] & 0xFFL) << 32) //
+ | ((node[offset + 5] & 0xFFL) << 40); //
+ UUID uuid = new UUID(mostSig, leastSig);
+
+ // tests
+// assert uuid.node() == BitSet.valueOf(node).toLongArray()[0];
+ // assert uuid.node() == longFromBytes(node);
+ assert uuid.timestamp() == timestamp;
+ assert uuid.clockSequence() == clockSequence
+ : "uuid.clockSequence()=" + uuid.clockSequence() + " clockSequence=" + clockSequence;
+ assert uuid.version() == 1;
+ assert uuid.variant() == 2;
+ return uuid;
+ }
+
+ public UUID timeUUID(Temporal time, long clockSequence, byte[] node, int offset) {
+ // TODO add checks
+ Duration duration = Duration.between(TimeUuidState.GREGORIAN_START, time);
+ // Number of 100 ns intervals in one second: 1000000000 / 100 = 10000000
+ long timestamp = duration.getSeconds() * 10000000 + duration.getNano() / 100;
+ return newTimeUUID(timestamp, clockSequence, node, offset);
+ }
+
+ protected byte[] getHardwareAddress() {
+ InetAddress localHost;
+ try {
+ localHost = InetAddress.getLocalHost();
+ try {
+ NetworkInterface nic = NetworkInterface.getByInetAddress(localHost);
+ return nic.getHardwareAddress();
+ } catch (SocketException e) {
+ return null;
+ }
+ } catch (UnknownHostException e) {
+ return null;
+ }
+
+ }
+ /*
+ * NAME BASED (version 3 and 5)
+ */
+
+ protected UUID newNameUUIDv5(UUID namespace, byte[] name) {
+ Objects.requireNonNull(namespace, "Namespace cannot be null");
+ Objects.requireNonNull(name, "Name cannot be null");
+
+ byte[] bytes = sha1(toBytes(namespace), name);
+ bytes[6] &= 0x0f;
+ bytes[6] |= 0x50;// v5
+ bytes[8] &= 0x3f;
+ bytes[8] |= 0x80;// variant 1
+ UUID result = fromBytes(bytes, 0);
+ return result;
+ }
+
+ protected UUID newNameUUIDv3(UUID namespace, byte[] name) {
+ Objects.requireNonNull(namespace, "Namespace cannot be null");
+ Objects.requireNonNull(name, "Name cannot be null");
+
+ byte[] arr = new byte[name.length + 16];
+ copyBytes(namespace, arr, 0);
+ System.arraycopy(name, 0, arr, 16, name.length);
+ return UUID.nameUUIDFromBytes(arr);
+ }
+
+ /*
+ * RANDOM v4
+ */
+ protected UUID newRandomUUID(Random random) {
+ byte[] arr = new byte[16];
+ random.nextBytes(arr);
+ arr[6] &= 0x0f;
+ arr[6] |= 0x40;// v4
+ arr[8] &= 0x3f;
+ arr[8] |= 0x80;// variant 1
+ return fromBytes(arr);
+ }
+
+ /*
+ * DIGEST UTILITIES
+ */
+
+ private final static String MD5 = "MD5";
+ private final static String SHA1 = "SHA1";
+
+ protected byte[] sha1(byte[]... bytes) {
+ MessageDigest digest = getSha1Digest();
+ for (byte[] arr : bytes)
+ digest.update(arr);
+ byte[] checksum = digest.digest();
+ return checksum;
+ }
+
+ protected byte[] md5(byte[]... bytes) {
+ MessageDigest digest = getMd5Digest();
+ for (byte[] arr : bytes)
+ digest.update(arr);
+ byte[] checksum = digest.digest();
+ return checksum;
+ }
+
+ protected MessageDigest getSha1Digest() {
+ return getDigest(SHA1);
+ }
+
+ protected MessageDigest getMd5Digest() {
+ return getDigest(MD5);
+ }
+
+ private MessageDigest getDigest(String name) {
+ try {
+ return MessageDigest.getInstance(name);
+ } catch (NoSuchAlgorithmException e) {
+ throw new UnsupportedOperationException(name + " digest is not avalaible", e);
+ }
+ }
+
+ /*
+ * UTILITIES
+ */
+ /**
+ * Convert bytes to an UUID. Byte array must not be null and be exactly of
+ * length 16.
+ */
+ protected UUID fromBytes(byte[] data) {
+ Objects.requireNonNull(data, "Byte array must not be null");
+ if (data.length != 16)
+ throw new IllegalArgumentException("Byte array as length " + data.length);
+ return fromBytes(data, 0);
+ }
+
+ /**
+ * Convert bytes to an UUID, starting to read the array at this offset.
+ */
+ protected UUID fromBytes(byte[] data, int offset) {
+ Objects.requireNonNull(data, "Byte array cannot be null");
+ long msb = 0;
+ long lsb = 0;
+ for (int i = offset; i < 8 + offset; i++)
+ msb = (msb << 8) | (data[i] & 0xff);
+ for (int i = 8 + offset; i < 16 + offset; i++)
+ lsb = (lsb << 8) | (data[i] & 0xff);
+ return new UUID(msb, lsb);
+ }
+
+ protected long longFromBytes(byte[] data) {
+ long msb = 0;
+ for (int i = 0; i < data.length; i++)
+ msb = (msb << 8) | (data[i] & 0xff);
+ return msb;
+ }
+
+ protected byte[] toBytes(UUID uuid) {
+ Objects.requireNonNull(uuid, "UUID cannot be null");
+ long msb = uuid.getMostSignificantBits();
+ long lsb = uuid.getLeastSignificantBits();
+ return toBytes(msb, lsb);
+ }
+
+ protected void copyBytes(UUID uuid, byte[] arr, int offset) {
+ Objects.requireNonNull(uuid, "UUID cannot be null");
+ long msb = uuid.getMostSignificantBits();
+ long lsb = uuid.getLeastSignificantBits();
+ copyBytes(msb, lsb, arr, offset);
+ }
+
+ /**
+ * Converts an UUID hex representation without '-' to the standard form (with
+ * '-').
+ */
+ public String compactToStd(String compact) {
+ if (compact.length() != 32)
+ throw new IllegalArgumentException(
+ "Compact UUID '" + compact + "' has length " + compact.length() + " and not 32.");
+ StringBuilder sb = new StringBuilder(36);
+ for (int i = 0; i < 32; i++) {
+ if (i == 8 || i == 12 || i == 16 || i == 20)
+ sb.append('-');
+ sb.append(compact.charAt(i));
+ }
+ String std = sb.toString();
+ assert std.length() == 36;
+ assert UUID.fromString(std).toString().equals(std);
+ return std;
+ }
+
+ /**
+ * Converts an UUID hex representation without '-' to an {@link UUID}.
+ */
+ public UUID fromCompact(String compact) {
+ return UUID.fromString(compactToStd(compact));
+ }
+
+ /** To a 32 characters hex string without '-'. */
+ public String toCompact(UUID uuid) {
+ return toHexString(toBytes(uuid));
+ }
+
+ final protected static char[] hexArray = "0123456789abcdef".toCharArray();
+
+ /** Convert two longs to a byte array with length 16. */
+ protected byte[] toBytes(long long1, long long2) {
+ byte[] result = new byte[16];
+ for (int i = 0; i < 8; i++)
+ result[i] = (byte) ((long1 >> ((7 - i) * 8)) & 0xff);
+ for (int i = 8; i < 16; i++)
+ result[i] = (byte) ((long2 >> ((15 - i) * 8)) & 0xff);
+ return result;
+ }
+
+ protected void copyBytes(long long1, long long2, byte[] arr, int offset) {
+ assert arr.length >= 16 + offset;
+ for (int i = offset; i < 8 + offset; i++)
+ arr[i] = (byte) ((long1 >> ((7 - i) * 8)) & 0xff);
+ for (int i = 8 + offset; i < 16 + offset; i++)
+ arr[i] = (byte) ((long2 >> ((15 - i) * 8)) & 0xff);
+ }
+
+ /** Converts a byte array to an hex String. */
+ protected String toHexString(byte[] bytes) {
+ char[] hexChars = new char[bytes.length * 2];
+ for (int j = 0; j < bytes.length; j++) {
+ int v = bytes[j] & 0xFF;
+ hexChars[j * 2] = hexArray[v >>> 4];
+ hexChars[j * 2 + 1] = hexArray[v & 0x0F];
+ }
+ return new String(hexChars);
+ }
+
+ protected byte[] toNodeId(byte[] source, int offset) {
+ if (source == null)
+ return null;
+ if (offset < 0 || offset + 6 > source.length)
+ throw new ArrayIndexOutOfBoundsException(offset);
+ byte[] nodeId = new byte[6];
+ System.arraycopy(source, offset, nodeId, 0, 6);
+ return nodeId;
+ }
+
+ /*
+ * STATIC UTILITIES
+ */
+ /**
+ * Converts an UUID to a binary string (list of 0 and 1), with a separator to
+ * make it more readable.
+ */
+ public static String toBinaryString(UUID uuid, int charsPerSegment, char separator) {
+ String binaryString = toBinaryString(uuid);
+ StringBuilder sb = new StringBuilder(128 + (128 / charsPerSegment));
+ for (int i = 0; i < binaryString.length(); i++) {
+ if (i != 0 && i % charsPerSegment == 0)
+ sb.append(separator);
+ sb.append(binaryString.charAt(i));
+ }
+ return sb.toString();
+ }
+
+ /** Converts an UUID to a binary string (list of 0 and 1). */
+ public static String toBinaryString(UUID uuid) {
+ String most = zeroTo64Chars(Long.toBinaryString(uuid.getMostSignificantBits()));
+ String least = zeroTo64Chars(Long.toBinaryString(uuid.getLeastSignificantBits()));
+ String binaryString = most + least;
+ assert binaryString.length() == 128;
+ return binaryString;
+ }
+
+ private static String zeroTo64Chars(String str) {
+ assert str.length() <= 64;
+ if (str.length() < 64) {
+ StringBuilder sb = new StringBuilder(64);
+ for (int i = 0; i < 64 - str.length(); i++)
+ sb.append('0');
+ sb.append(str);
+ return sb.toString();
+ } else
+ return str;
+ }
+
+}