/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache License, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License.  You may obtain a copy of the License at
    *
    *      https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.commons.validator.util;
  
  import java.io.Serializable;
  
  /**
   * Represents a collection of 64 boolean (on/off) flags.  Individual flags
   * are represented by powers of 2.  For example,<br>
   * Flag 1 = 1<br>
   * Flag 2 = 2<br>
   * Flag 3 = 4<br>
   * Flag 4 = 8<br><br>
   * or using shift operator to make numbering easier:<br>
   * Flag 1 = 1 &lt;&lt; 0<br>
   * Flag 2 = 1 &lt;&lt; 1<br>
   * Flag 3 = 1 &lt;&lt; 2<br>
   * Flag 4 = 1 &lt;&lt; 3<br>
   *
   * <p>
   * There cannot be a flag with a value of 3 because that represents Flag 1
   * and Flag 2 both being on/true.
   * </p>
   */
  public class Flags implements Serializable, Cloneable {
  
      private static final long serialVersionUID = 8481587558770237995L;
  
      /**
       * Represents the current flag state.
       */
      private long flags;
  
      /**
       * Create a new Flags object.
       */
      public Flags() {
      }
  
      /**
       * Initialize a new Flags object with the given flags.
       *
       * @param flags collection of boolean flags to represent.
       */
      public Flags(final long flags) {
          this.flags = flags;
      }
  
      /**
       * Turn off all flags.  This is a synonym for {@code turnOffAll()}.
       *
       * @since 1.1.1
       */
      public void clear() {
          flags = 0;
      }
  
      /**
       * Clone this Flags object.
       *
       * @return a copy of this object.
       * @see Object#clone()
       */
      @Override
      public Object clone() {
          try {
              return super.clone();
          } catch (final CloneNotSupportedException e) {
              throw new UnsupportedOperationException("Couldn't clone Flags object.", e);
          }
      }
  
      /**
       * Tests if two Flags objects are in the same state.
       *
       * @param obj object being tested
       * @see Object#equals(Object)
       * @return whether the objects are equal.
       */
      @Override
      public boolean equals(final Object obj) {
          if (this == obj) {
              return true;
          }
          if (!(obj instanceof Flags)) {
             return false;
         }
         final Flags other = (Flags) obj;
         return flags == other.flags;
     }
 
     /**
      * Returns the current flags.
      *
      * @return collection of boolean flags represented.
      */
     public long getFlags() {
         return flags;
     }
 
     /**
      * The hash code is based on the current state of the flags.
      *
      * @see Object#hashCode()
      * @return the hash code for this object.
      */
     @Override
     public int hashCode() {
         return (int) flags;
     }
 
     /**
      * Tests whether the given flag is off. If the flag is not a power of 2
      * (for example, 3) this tests whether the combination of flags is off.
      *
      * @param flag Flag value to check.
      * @return whether the specified flag value is off.
      */
     public boolean isOff(final long flag) {
         return (flags & flag) == 0;
     }
 
     /**
      * Tests whether the given flag is on. If the flag is not a power of 2
      * (for example, 3) this tests whether the combination of flags is on.
      *
      * @param flag Flag value to check.
      * @return whether the specified flag value is on.
      */
     public boolean isOn(final long flag) {
         return (flags & flag) == flag;
     }
 
     /**
      * Returns a 64 length String with the first flag on the right and the
      * 64th flag on the left. A 1 indicates the flag is on, a 0 means it's
      * off.
      *
      * @return string representation of this object.
      */
     @Override
     public String toString() {
         final StringBuilder bin = new StringBuilder(Long.toBinaryString(flags));
         for (int i = 64 - bin.length(); i > 0; i--) { // CHECKSTYLE IGNORE MagicNumber
             bin.insert(0, "0");
         }
         return bin.toString();
     }
 
     /**
      * Turns off the given flag. If the flag is not a power of 2 (for example, 3) this
      * turns off multiple flags.
      *
      * @param flag Flag value to turn off.
      */
     public void turnOff(final long flag) {
         flags &= ~flag;
     }
 
     /**
      * Turn off all flags.
      */
     public void turnOffAll() {
         flags = 0;
     }
 
     /**
      * Turns on the given flag. If the flag is not a power of 2 (for example, 3) this
      * turns on multiple flags.
      *
      * @param flag Flag value to turn on.
      */
     public void turnOn(final long flag) {
         flags |= flag;
     }
 
     /**
      * Turn on all 64 flags.
      */
     public void turnOnAll() {
         flags = 0xFFFFFFFFFFFFFFFFL;
     }
 
 }