/*
    * 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.plugins.gpg;
  
  import java.util.Arrays;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  /**
   * Represents the semver value of GPG.
   * This is in most cases the first line of <code>gpg --version</code>
   *
   *
   * @author Robert Scholte
   * @since 3.0.0
   */
  public class GpgVersion implements Comparable<GpgVersion> {
  
      private static final Pattern VERSION_PATTERN = Pattern.compile("(\\d+\\.)+(\\d+)");
  
      private final int[] versionSegments;
  
      private GpgVersion(int... versionSegments) {
          this.versionSegments = versionSegments;
      }
  
      public static GpgVersion parse(String rawVersion) {
          final Matcher versionMatcher = VERSION_PATTERN.matcher(rawVersion);
          if (!versionMatcher.find()) {
              throw new IllegalArgumentException("Can't parse version of " + rawVersion);
          }
  
          final String[] rawVersionSegments = versionMatcher.group(0).split("\\.");
  
          final int[] versionSegments = new int[rawVersionSegments.length];
          for (int index = 0; index < rawVersionSegments.length; index++) {
              versionSegments[index] = Integer.parseInt(rawVersionSegments[index]);
          }
  
          return new GpgVersion(versionSegments);
      }
  
      @Override
      public int compareTo(GpgVersion other) {
          final int[] thisSegments = versionSegments;
          final int[] otherSegments = other.versionSegments;
  
          int minSegments = Math.min(thisSegments.length, otherSegments.length);
  
          for (int index = 0; index < minSegments; index++) {
              int compareValue = Integer.compare(thisSegments[index], otherSegments[index]);
  
              if (compareValue != 0) {
                  return compareValue;
              }
          }
  
          return (thisSegments.length - otherSegments.length);
      }
  
      /**
       * Verify if this version is before some other version
       *
       * @param other the version to compare with
       * @return {@code true} is this is less than {@code other}, otherwise {@code false}
       */
      public boolean isBefore(GpgVersion other) {
          return this.compareTo(other) < 0;
      }
  
      /**
       * Verify if this version is at least some other version
       *
       * @param other the version to compare with
       * @return  {@code true}  is this is greater than or equal to {@code other}, otherwise {@code false}
       */
      public boolean isAtLeast(GpgVersion other) {
          return this.compareTo(other) >= 0;
      }
  
      @Override
      public String toString() {
          if (versionSegments.length == 0) {
             return "";
         }
 
         final StringBuilder versionStringBuilder = new StringBuilder();
         versionStringBuilder.append(versionSegments[0]);
 
         for (int index = 1; index < versionSegments.length; index++) {
             versionStringBuilder.append('.').append(versionSegments[index]);
         }
 
         return versionStringBuilder.toString();
     }
 
     @Override
     public boolean equals(final Object other) {
         if (this == other) {
             return true;
         }
 
         if (!(other instanceof GpgVersion)) {
             return false;
         }
 
         final GpgVersion that = (GpgVersion) other;
 
         return compareTo(that) == 0;
     }
 
     @Override
     public int hashCode() {
         return Arrays.hashCode(versionSegments);
     }
 }