/*
    * 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
    *
   *   http://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.maven.artifact.versioning;
  
  import java.util.StringTokenizer;
  
  /**
   * Default implementation of artifact versioning.
   *
   * @author <a href="mailto:brett@apache.org">Brett Porter</a>
   */
  public class DefaultArtifactVersion implements ArtifactVersion {
      private Integer majorVersion;
  
      private Integer minorVersion;
  
      private Integer incrementalVersion;
  
      private Integer buildNumber;
  
      private String qualifier;
  
      private ComparableVersion comparable;
  
      public DefaultArtifactVersion(String version) {
          parseVersion(version);
      }
  
      @Override
      public int hashCode() {
          return 11 + comparable.hashCode();
      }
  
      @Override
      public boolean equals(Object other) {
          if (this == other) {
              return true;
          }
  
          if (!(other instanceof ArtifactVersion)) {
              return false;
          }
  
          return compareTo((ArtifactVersion) other) == 0;
      }
  
      public int compareTo(ArtifactVersion otherVersion) {
          if (otherVersion instanceof DefaultArtifactVersion) {
              return this.comparable.compareTo(((DefaultArtifactVersion) otherVersion).comparable);
          } else {
              return compareTo(new DefaultArtifactVersion(otherVersion.toString()));
          }
      }
  
      public int getMajorVersion() {
          return majorVersion != null ? majorVersion : 0;
      }
  
      public int getMinorVersion() {
          return minorVersion != null ? minorVersion : 0;
      }
  
      public int getIncrementalVersion() {
          return incrementalVersion != null ? incrementalVersion : 0;
      }
  
      public int getBuildNumber() {
          return buildNumber != null ? buildNumber : 0;
      }
  
      public String getQualifier() {
          return qualifier;
      }
  
      public final void parseVersion(String version) {
          comparable = new ComparableVersion(version);
  
          int index = version.indexOf('-');
  
          String part1;
          String part2 = null;
  
          if (index < 0) {
             part1 = version;
         } else {
             part1 = version.substring(0, index);
             part2 = version.substring(index + 1);
         }
 
         if (part2 != null) {
             if (part2.length() == 1 || !part2.startsWith("0")) {
                 buildNumber = tryParseInt(part2);
                 if (buildNumber == null) {
                     qualifier = part2;
                 }
             } else {
                 qualifier = part2;
             }
         }
 
         if ((!part1.contains(".")) && !part1.startsWith("0")) {
             majorVersion = tryParseInt(part1);
             if (majorVersion == null) {
                 // qualifier is the whole version, including "-"
                 qualifier = version;
                 buildNumber = null;
             }
         } else {
             boolean fallback = false;
 
             StringTokenizer tok = new StringTokenizer(part1, ".");
             if (tok.hasMoreTokens()) {
                 majorVersion = getNextIntegerToken(tok);
                 if (majorVersion == null) {
                     fallback = true;
                 }
             } else {
                 fallback = true;
             }
             if (tok.hasMoreTokens()) {
                 minorVersion = getNextIntegerToken(tok);
                 if (minorVersion == null) {
                     fallback = true;
                 }
             }
             if (tok.hasMoreTokens()) {
                 incrementalVersion = getNextIntegerToken(tok);
                 if (incrementalVersion == null) {
                     fallback = true;
                 }
             }
             if (tok.hasMoreTokens()) {
                 qualifier = tok.nextToken();
                 fallback = isDigits(qualifier);
             }
 
             // string tokenizer won't detect these and ignores them
             if (part1.contains("..") || part1.startsWith(".") || part1.endsWith(".")) {
                 fallback = true;
             }
 
             if (fallback) {
                 // qualifier is the whole version, including "-"
                 qualifier = version;
                 majorVersion = null;
                 minorVersion = null;
                 incrementalVersion = null;
                 buildNumber = null;
             }
         }
     }
 
     private static boolean isDigits(String cs) {
         if (cs == null || cs.isEmpty()) {
             return false;
         }
         final int sz = cs.length();
         for (int i = 0; i < sz; i++) {
             if (!Character.isDigit(cs.charAt(i))) {
                 return false;
             }
         }
         return true;
     }
 
     private static Integer getNextIntegerToken(StringTokenizer tok) {
         String s = tok.nextToken();
         if ((s.length() > 1) && s.startsWith("0")) {
             return null;
         }
         return tryParseInt(s);
     }
 
     private static Integer tryParseInt(String s) {
         // for performance, check digits instead of relying later on catching NumberFormatException
         if (!isDigits(s)) {
             return null;
         }
 
         try {
             long longValue = Long.parseLong(s);
             if (longValue > Integer.MAX_VALUE) {
                 return null;
             }
             return (int) longValue;
         } catch (NumberFormatException e) {
             // should never happen since checked isDigits(s) before
             return null;
         }
     }
 
     @Override
     public String toString() {
         return comparable.toString();
     }
 }