code: /*
   * Copyright (c) 2019 the Eclipse Milo Authors
   *
   * This program and the accompanying materials are made
   * available under the terms of the Eclipse Public License 2.0
   * which is available at https://www.eclipse.org/legal/epl-2.0/
   *
   * SPDX-License-Identifier: EPL-2.0
   */
  
  package org.eclipse.milo.opcua.stack.core.types.builtin.unsigned;
  
  import java.math.BigInteger;
  
  import org.jetbrains.annotations.NotNull;
  
  /**
   * The <code>unsigned long</code> type
   *
   * @author Lukas Eder
   * @author Jens Nerche
   * @author Ivan Sokolov
   */
  public final class ULong extends UNumber implements Comparable<ULong> {
  
      /**
       * Generated UID
       */
      private static final long serialVersionUID = -6821055240959745390L;
  
      /**
       * A constant holding the minimum value an <code>unsigned long</code> can
       * have, 0.
       */
      public static final BigInteger MIN_VALUE = BigInteger.ZERO;
      /**
       * A constant holding the maximum value an <code>unsigned long</code> can
       * have, 2<sup>64</sup>-1.
       */
      public static final BigInteger MAX_VALUE = new BigInteger("18446744073709551615");
  
      /**
       * A constant holding the maximum value + 1 an <code>signed long</code> can
       * have, 2<sup>63</sup>.
       */
      public static final BigInteger MAX_VALUE_LONG = new BigInteger("9223372036854775808");
  
      /**
       * A constant holding the minimum value an <code>unsigned long</code> can
       * have as ULong, 0.
       */
      public static final ULong MIN = valueOf(MIN_VALUE.longValue());
  
      /**
       * A constant holding the maximum value + 1 an <code>signed long</code> can
       * have as ULong, 2<sup>63</sup>.
       */
      public static final ULong MAX = valueOf(MAX_VALUE);
  
      /**
       * The value modelling the content of this <code>unsigned long</code>
       */
      private final long value;
  
      /**
       * Create an <code>unsigned long</code>
       *
       * @throws NumberFormatException If <code>value</code> does not contain a
       *                               parsable <code>unsigned long</code>.
       */
      public static ULong valueOf(String value) throws NumberFormatException {
          return new ULong(value);
      }
  
      /**
       * Create an <code>unsigned long</code> by masking it with
       * <code>0xFFFFFFFFFFFFFFFF</code> i.e. <code>(long) -1</code> becomes
       * <code>(uint) 18446744073709551615</code>
       */
      public static ULong valueOf(long value) {
          return new ULong(value);
      }
  
      /**
       * Create an <code>unsigned long</code>
       *
       * @throws NumberFormatException If <code>value</code> is not in the range
       *                               of an <code>unsigned long</code>
       */
      public static ULong valueOf(BigInteger value) throws NumberFormatException {
          return new ULong(value);
      }
  
      public static int compare(long x, long y) {
          x += Long.MIN_VALUE;
          y += Long.MIN_VALUE;
          return (x < y) ? -1 : ((x == y) ? 0 : 1);
      }
  
      /**
       * Create an <code>unsigned long</code>
       *
       * @throws NumberFormatException If <code>value</code> is not in the range
       *                               of an <code>unsigned long</code>
       */
      private ULong(BigInteger value) throws NumberFormatException {
          if (value.compareTo(MIN_VALUE) < 0 || value.compareTo(MAX_VALUE) > 0) {
              throw new NumberFormatException();
          } else {
              this.value = value.longValue();
          }
      }
  
      /**
       * Create an <code>unsigned long</code> by masking it with
       * <code>0xFFFFFFFFFFFFFFFF</code> i.e. <code>(long) -1</code> becomes
       * <code>(uint) 18446744073709551615</code>
       */
      private ULong(long value) {
          this.value = value;
      }
  
      /**
       * Create an <code>unsigned long</code>
       *
       * @throws NumberFormatException If <code>value</code> does not contain a
       *                               parsable <code>unsigned long</code>.
       */
      private ULong(String value) throws NumberFormatException {
          if (value == null) {
              throw new NumberFormatException("null");
          }
  
          int length = value.length();
  
          if (length == 0) {
              throw new NumberFormatException("Empty input string");
          }
  
          if (value.charAt(0) == '-') {
              throw new NumberFormatException(
                  String.format("Illegal leading minus sign on unsigned string %s", value));
          }
  
          if (length <= 18) {
              this.value = Long.parseLong(value, 10);
              return;
          }
  
          final long first = Long.parseLong(value.substring(0, length - 1), 10);
          final int second = Character.digit(value.charAt(length - 1), 10);
          if (second < 0) {
              throw new NumberFormatException("Bad digit at end of " + value);
          }
          long result = first * 10 + second;
          if (compare(result, first) < 0) {
              throw new NumberFormatException(
                  String.format("String value %s exceeds range of unsigned long", value));
          }
  
          this.value = result;
      }
  
      @Override
      public int intValue() {
          return (int) value;
      }
  
      @Override
      public long longValue() {
          return value;
      }
  
      @Override
      public float floatValue() {
          if (value < 0) {
              return ((float) (value & Long.MAX_VALUE)) + Long.MAX_VALUE;
          } else {
              return value;
          }
      }
  
      @Override
      public double doubleValue() {
          if (value < 0) {
              return ((double) (value & Long.MAX_VALUE)) + Long.MAX_VALUE;
          } else {
              return value;
          }
      }
  
      @Override
      public int hashCode() {
          return Long.valueOf(value).hashCode();
      }
  
      @Override
      public boolean equals(Object obj) {
          if (obj instanceof ULong) {
              return value == ((ULong) obj).value;
          }
  
          return false;
      }
  
      @Override
      public String toString() {
          if (value >= 0) {
              return Long.toString(value);
          } else {
              return BigInteger.valueOf(value & Long.MAX_VALUE).add(MAX_VALUE_LONG).toString();
          }
      }
  
      @Override
      public int compareTo(@NotNull ULong o) {
          return compare(value, o.value);
      }
  
      public ULong add(ULong val) throws NumberFormatException {
          if (value < 0 && val.value < 0) {
              throw new NumberFormatException();
          }
          final long result = value + val.value;
          if ((value < 0 || val.value < 0) && result >= 0) {
              throw new NumberFormatException();
          }
          return valueOf(result);
      }
  
      public ULong add(int val) throws NumberFormatException {
          return add((long) val);
      }
  
      public ULong add(long val) throws NumberFormatException {
          if (val < 0) {
              return subtract(Math.abs(val));
          }
          final long result = value + val;
          if (value < 0 && result >= 0) {
              throw new NumberFormatException();
          }
          return valueOf(result);
      }
  
      public ULong subtract(final ULong val) {
          if (this.compareTo(val) < 0) {
              throw new NumberFormatException();
          }
          final long result = value - val.value;
          if (value < 0 && result >= 0) {
              throw new NumberFormatException();
          }
          return valueOf(result);
      }
  
      public ULong subtract(final int val) {
          return subtract((long) val);
      }
  
      public ULong subtract(final long val) {
          if (val < 0) {
              return add(-val);
          }
          if (compare(value, val) < 0) {
              throw new NumberFormatException();
          }
          final long result = value - val;
          if (value < 0 && result >= 0) {
              throw new NumberFormatException();
          }
          return valueOf(result);
      }
  }
  