content: /**
   * 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
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * 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.atlas.model.notification;
  
  import com.fasterxml.jackson.annotation.JsonAutoDetect;
  import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
  import com.fasterxml.jackson.annotation.JsonInclude;
  
  import javax.xml.bind.annotation.XmlAccessType;
  import javax.xml.bind.annotation.XmlAccessorType;
  import javax.xml.bind.annotation.XmlRootElement;
  
  import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.Arrays;
  
  import static com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility.NONE;
  import static com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility.PUBLIC_ONLY;
  
  /**
   * Represents the version of a notification message.
   */
  @JsonAutoDetect(getterVisibility = PUBLIC_ONLY, setterVisibility = PUBLIC_ONLY, fieldVisibility = NONE)
  @JsonInclude(JsonInclude.Include.NON_NULL)
  @JsonIgnoreProperties(ignoreUnknown = true)
  @XmlRootElement
  @XmlAccessorType(XmlAccessType.PROPERTY)
  public class MessageVersion implements Comparable<MessageVersion>, Serializable {
      private static final long serialVersionUID = 1L;
  
      /**
       * Used for message with no version (old format).
       */
      public static final MessageVersion NO_VERSION      = new MessageVersion("0");
      public static final MessageVersion VERSION_1       = new MessageVersion("1.0.0");
      public static final MessageVersion CURRENT_VERSION = VERSION_1;
  
      private String version;
  
      // ----- Constructors ----------------------------------------------------
      public MessageVersion() {
          this.version = CURRENT_VERSION.version;
      }
  
      /**
       * Create a message version.
       *
       * @param version  the version string
       */
      public MessageVersion(String version) {
          this.version = version;
  
          try {
              getVersionParts();
          } catch (NumberFormatException e) {
              throw new IllegalArgumentException(String.format("Invalid version string : %s.", version), e);
          }
      }
  
      public String getVersion() {
          return version;
      }
  
      public void setVersion(String version) {
          this.version = version;
      }
  
      // ----- Comparable ------------------------------------------------------
  
      @Override
      public int compareTo(MessageVersion that) {
          if (that == null) {
              return 1;
          }
  
          Integer[] thisParts = getVersionParts();
          Integer[] thatParts = that.getVersionParts();
  
          int length = Math.max(thisParts.length, thatParts.length);
  
          for (int i = 0; i < length; i++) {
              int comp = getVersionPart(thisParts, i) - getVersionPart(thatParts, i);
  
              if (comp != 0) {
                  return comp;
              }
          }
          return 0;
      }
  
      // ----- Object overrides ------------------------------------------------
  
      @Override
      public int hashCode() {
          return Arrays.hashCode(getVersionParts());
      }
  
      @Override
      public boolean equals(Object that) {
          if (this == that) {
              return true;
          } else if (that == null || getClass() != that.getClass()) {
              return false;
          }
  
          return compareTo((MessageVersion) that) == 0;
      }
  
      @Override
      public String toString() {
          return "MessageVersion[version=" + version + "]";
      }
  
      // ----- helper methods --------------------------------------------------
  
      /**
       * Get the version parts array by splitting the version string.
       * Strip the trailing zeros (i.e. '1.0.0' equals '1').
       *
       * @return the version parts array
       */
      public Integer[] getVersionParts() {
          String[]           sParts        = version.split("\\.");
          ArrayList<Integer> iParts        = new ArrayList<>();
          int                trailingZeros = 0;
  
          for (String sPart : sParts) {
              int iPart = Integer.parseInt(sPart);
  
              if (iPart == 0) {
                  ++trailingZeros;
              } else {
                  for (int i = 0; i < trailingZeros; ++i) {
                      iParts.add(0);
                  }
  
                  trailingZeros = 0;
  
                  iParts.add(iPart);
              }
          }
  
          return iParts.toArray(new Integer[iParts.size()]);
      }
  
      public Integer getVersionPart(Integer[] versionParts, int i) {
          return i < versionParts.length ? versionParts[i] : 0;
      }
  }
  