package org.apache.maven.surefire.util;
   
   /*
    * 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 java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  import java.util.Set;
  import org.apache.maven.surefire.testset.TestSetFailedException;
  
  /**
   * Contains all the tests that have been found according to specified include/exclude
   * specification for a given surefire run.
   *
   * @author Kristian Rosenvold (junit core adaption)
   */
  public class TestsToRun implements Iterable<Class<?>>
  {
      private final Set<Class<?>> locatedClasses;
  
      private volatile boolean finished;
  
      /**
       * Constructor
       *
       * @param locatedClasses A set of java.lang.Class objects representing tests to run
       */
      public TestsToRun( Set<Class<?>> locatedClasses )
      {
          this.locatedClasses = Collections.unmodifiableSet( locatedClasses );
      }
  
      public static TestsToRun fromClass( Class<?> clazz )
          throws TestSetFailedException
      {
          return new TestsToRun( Collections.<Class<?>>singleton( clazz ) );
      }
  
      /**
       * Returns an iterator over the located java.lang.Class objects
       *
       * @return an unmodifiable iterator
       */
      public Iterator<Class<?>> iterator()
      {
          return new ClassesIterator();
      }
  
      private final class ClassesIterator
          implements Iterator<Class<?>>
      {
          private final Iterator<Class<?>> it = TestsToRun.this.locatedClasses.iterator();
  
          private Boolean finishCurrentIteration;
  
          public boolean hasNext()
          {
              popMarker();
              return !finishCurrentIteration && it.hasNext();
          }
  
          public Class<?> next()
          {
              try
              {
                  if ( popMarker() && finishCurrentIteration )
                  {
                      throw new NoSuchElementException();
                  }
                  return it.next();
              }
              finally
              {
                  finishCurrentIteration = null;
              }
          }
  
          public void remove()
          {
              throw new UnsupportedOperationException();
         }
 
         /**
          * @return {@code true} if marker changed from NULL to anything
          */
         private boolean popMarker()
         {
             if ( finishCurrentIteration == null )
             {
                 finishCurrentIteration = TestsToRun.this.finished;
                 return true;
             }
             return false;
         }
     }
 
     public final void markTestSetFinished()
     {
         finished = true;
     }
 
     public String toString()
     {
         StringBuilder sb = new StringBuilder();
         sb.append( "TestsToRun: [" );
         for ( Class<?> clazz : this )
         {
             sb.append( " " ).append( clazz.getName() );
         }
 
         sb.append( ']' );
         return sb.toString();
     }
 
     public boolean containsAtLeast( int atLeast )
     {
         return containsAtLeast( iterator(), atLeast );
     }
 
     private boolean containsAtLeast( Iterator<Class<?>> it, int atLeast )
     {
         for ( int i = 0; i < atLeast; i++ )
         {
             if ( !it.hasNext() )
             {
                 return false;
             }
 
             it.next();
         }
 
         return true;
     }
 
     public boolean containsExactly( int items )
     {
         Iterator<Class<?>> it = iterator();
         return containsAtLeast( it, items ) && !it.hasNext();
     }
 
     /**
      * @return {@code true}, if the classes may be read eagerly. {@code false},
      *         if the classes must only be read lazy.
      */
     public boolean allowEagerReading()
     {
         return true;
     }
 
     public Class<?>[] getLocatedClasses()
     {
         if ( !allowEagerReading() )
         {
             throw new IllegalStateException( "Cannot eagerly read" );
         }
         Collection<Class<?>> result = new ArrayList<Class<?>>();
         for ( Class<?> clazz : this )
         {
             result.add( clazz );
         }
         return result.toArray( new Class<?>[result.size()] );
     }
 
     /**
      * Get test class which matches className
      *
      * @param className string used to find the test class
      * @return Class object with the matching name, null if could not find a class with the matching name
      */
     public Class<?> getClassByName( String className )
     {
         for ( Class<?> clazz : this )
         {
             if ( clazz.getName().equals( className ) )
             {
                 return clazz;
             }
         }
         return null;
     }
 }