//////////////////////////////////////////////////////////////////////////////
   // Clirr: compares two versions of a java library for binary compatibility
   // Copyright (C) 2003 - 2005  Lars Kühne
   //
   // This library is free software; you can redistribute it and/or
   // modify it under the terms of the GNU Lesser General Public
   // License as published by the Free Software Foundation; either
   // version 2.1 of the License, or (at your option) any later version.
   //
  // This library is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  //////////////////////////////////////////////////////////////////////////////
  package net.sf.clirr.core;
  
  import org.apache.bcel.classfile.JavaClass;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  
  /***
   * Given a JavaClass object, determines whether or not it is "selected",
   * based on its class or package. This is used to select subsets of the
   * classes available in a classpath for comparison or testing purposes.
   *
   * @author Simon Kitching
   */
  public final class ClassSelector implements ClassFilter
  {
      /*** Class for implementing an enumeration. */
      public static final class Mode
      {
          private Mode()
          {
          }
      }
  
      /*** positive selection. */
      public static final Mode MODE_IF = new Mode();
      /*** negative selection. */
      public static final Mode MODE_UNLESS = new Mode();
  
      private Mode mode;
  
      privateong> ArrayList packages = new ArrayList();
      privateong> ArrayList packageTrees = new ArrayList();
      private ArrayList classes = new ArrayList();
  
      /***
       * Create a selector.
       * <p>
       * When mode is MODE_IF then a class is "selected" if-and-only-if
       * the class matches one of the criteria defined via the addXXX methods.
       * In other words, the criteria specify which classes are included
       * (selected) in the resulting class set.
       * <p>
       * When mode is MODE_UNLESS, then a class is "selected" unless the class
       * matches one of the criteria defined via the addXXX methods. In other
       * words, the criteria specify which classes are excluded from the
       * resulting class set.
       */
      public ClassSelector(Mode mode)
      {
          this.mode = mode;
      }
  
      /***
       * Matches any class which is in the named package.
       */
      publicong> void addPackage(String packageName)
      {
          packages.add(packageName);
      }
  
      /***
       * Matches any class which is in the named package or any subpackage of it.
       */
      publicong> void addPackageTree(String packageName)
      {
          packages.add(packageName);
      }
  
      /***
       * Matches the class with exactly this name, plus any of its inner classes.
       */
      public void addClass(String classname)
      {
          classes.add(classname);
      }
  
      /***
       * Return true if this class is one selected by the criteria stored
       * in this object.
       */
     public boolean isSelected(JavaClass clazz)
     {
         if (isAnonymousInnerClass(clazz))
         {
             return false;
         }
 
         boolean matches = matchesCriteria(clazz);
         if (mode == MODE_IF)
         {
             return matches;
         }
         else // mode == MODE_UNLESS
         {
             return !matches;
         }
     }
 
     /***
      * Return true if this class is an anonymous inner class.
      * Not even developers working on a package would be interested
      * in API changes in these classes...
      */
     private boolean isAnonymousInnerClass(JavaClass clazz)
     {
         String name = clazz.getClassName();
         int dollarPos = name.indexOf('$');
         if (dollarPos == -1)
         {
             return false;
         }
 
         for (int i = dollarPos + 1; i < name.length(); ++i)
         {
             if (!Character.isDigit(name.charAt(i)))
             {
                 return false;
             }
         }
 
         // ok, we have a class name which contains a dollar sign, and
         // every subsequent character is a digit.
         return true;
     }
 
     /***
      * Return true if this class matches one of the criteria stored
      * in this object.
      */
     private boolean matchesCriteria(JavaClass clazz)
     {
         String packageName = clazz.getPackageName();
         if</strong> (packages.contains(packageName))
         {
             return true;
         }
 
         for (Iterator i = packageTrees.iterator(); i.hasNext();)
         {
             String entry = (String) i.next();
             >if (packageName.startsWith(entry))
             {
                 rong>if (packageName.length() == entry.length())
                 {
                     // they are exactly equal
                     return true;
                 }
 
                 rong>if (packageName.charAt(entry.length()) == '.')
                 {
                     return true;
                 }
 
                 // else packagename is like "com.acmegadgets" and entryname
                 // is like "com.acme", which is not a match, so keep looking.
             }
         }
 
         String className = clazz.getClassName();
         for (Iterator i = classes.iterator(); i.hasNext();)
         {
             String entry = (String) i.next();
 
             if (className.startsWith(entry))
             {
                 if (className.length() == entry.length())
                 {
                     // they are exactly equal
                     return true;
                 }
 
                 if (className.charAt(entry.length()) == '$')
                 {
                     // this is an inner class of the named class
                     return true;
                 }
             }
         }
 
         return false;
     }
 }