package org.apache.maven.plugin.invoker;
   
   /*
    * 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.
   */
  
  import org.apache.maven.project.MavenProject;
  import org.codehaus.plexus.util.Os;
  import org.codehaus.plexus.util.StringUtils;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Properties;
  
  /**
   * Provides utility methods for selecting build jobs based on environmental conditions.
   *
   * @author Benjamin Bentmann
   */
  class SelectorUtils
  {
  
      static void parseList( String list, Collection includes, Collection excludes )
      {
          String[] tokens = ( list != null ) ? StringUtils.split( list, "," ) : new String[0];
  
          for ( int i = 0; i < tokens.length; i++ )
          {
              String token = tokens[i].trim();
  
              if ( token.startsWith( "!" ) )
              {
                  excludes.add( token.substring( 1 ) );
              }
              else
              {
                  includes.add( token );
              }
          }
      }
  
      static boolean isOsFamily( String osSpec )
      {
          List includes = new ArrayList();
          List excludes = new ArrayList();
          parseList( osSpec, includes, excludes );
  
          return isOsFamily( includes, true ) && !isOsFamily( excludes, false );
      }
  
      static boolean isOsFamily( List families, boolean defaultMatch )
      {
          if ( families != null && !families.isEmpty() )
          {
              for ( Iterator it = families.iterator(); it.hasNext(); )
              {
                  String family = (String) it.next();
  
                  if ( Os.isFamily( family ) )
                  {
                      return true;
                  }
              }
  
              return false;
          }
          else
          {
              return defaultMatch;
          }
      }
  
      /**
       * Retrieves the current Maven version.
       * @return The current Maven version.
       */
      static String getMavenVersion()
      {
          try
          {
              // This relies on the fact that MavenProject is the in core classloader
              // and that the core classloader is for the maven-core artifact
             // and that should have a pom.properties file
             // if this ever changes, we will have to revisit this code.
             Properties properties = new Properties();
             properties.load( MavenProject.class.getClassLoader().getResourceAsStream(
                 "META-INF/maven/org.apache.maven/maven-core/pom.properties" ) );
             return StringUtils.trim( properties.getProperty( "version" ) );
         }
         catch ( Exception e )
         {
             return null;
         }
     }
 
     static boolean isMavenVersion( String mavenSpec )
     {
         List includes = new ArrayList();
         List excludes = new ArrayList();
         parseList( mavenSpec, includes, excludes );
 
         List mavenVersionList = parseVersion( getMavenVersion() );
 
         return isJreVersion( mavenVersionList, includes, true ) && !isJreVersion( mavenVersionList, excludes, false );
     }
 
     static boolean isJreVersion( String jreSpec )
     {
         List includes = new ArrayList();
         List excludes = new ArrayList();
         parseList( jreSpec, includes, excludes );
 
         List jreVersion = parseVersion( System.getProperty( "java.version", "" ) );
 
         return isJreVersion( jreVersion, includes, true ) && !isJreVersion( jreVersion, excludes, false );
     }
 
     static boolean isJreVersion( List jreVersion, List versionPatterns, boolean defaultMatch )
     {
         if ( versionPatterns != null && !versionPatterns.isEmpty() )
         {
             for ( Iterator it = versionPatterns.iterator(); it.hasNext(); )
             {
                 String versionPattern = (String) it.next();
 
                 if ( isJreVersion( jreVersion, versionPattern ) )
                 {
                     return true;
                 }
             }
 
             return false;
         }
         else
         {
             return defaultMatch;
         }
     }
 
     static boolean isJreVersion( List jreVersion, String versionPattern )
     {
         List checkVersion = parseVersion( versionPattern );
 
         if ( versionPattern.endsWith( "+" ) )
         {
             // 1.5+ <=> [1.5,)
             return compareVersions( jreVersion, checkVersion ) >= 0;
         }
         else if ( versionPattern.endsWith( "-" ) )
         {
             // 1.5- <=> (,1.5)
             return compareVersions( jreVersion, checkVersion ) < 0;
         }
         else
         {
             // 1.5 <=> [1.5,1.6)
             return checkVersion.size() <= jreVersion.size() && checkVersion.equals(
                 jreVersion.subList( 0, checkVersion.size() ) );
         }
     }
 
     static List parseVersion( String version )
     {
         version = version.replaceAll( "[^0-9]", "." );
 
         String[] tokens = StringUtils.split( version, "." );
 
         List numbers = new ArrayList();
 
         for ( int i = 0; i < tokens.length; i++ )
         {
             numbers.add( Integer.valueOf( tokens[i] ) );
         }
 
         return numbers;
     }
 
     static int compareVersions( List version1, List version2 )
     {
         for ( Iterator it1 = version1.iterator(), it2 = version2.iterator(); ; )
         {
             if ( !it1.hasNext() )
             {
                 return it2.hasNext() ? -1 : 0;
             }
             if ( !it2.hasNext() )
             {
                 return it1.hasNext() ? 1 : 0;
             }
 
             Integer num1 = (Integer) it1.next();
             Integer num2 = (Integer) it2.next();
 
             int rel = num1.compareTo( num2 );
             if ( rel != 0 )
             {
                 return rel;
             }
         }
     }
 
 }