/*
    * Copyright (C) 2009 Jayway AB
    *
    * Licensed 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 com.simpligility.maven.plugins.android.asm;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.codehaus.plexus.util.DirectoryWalkListener;
  import org.codehaus.plexus.util.DirectoryWalker;
  import org.objectweb.asm.ClassReader;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.util.LinkedList;
  import java.util.List;
  
  /**
   * Finds Android instrumentation test classes to be run by InstrumentationTestRunner 
   * in a directory of compiled Java classes.
   *
   * @author hugo.josefson@jayway.com
   */
  public class AndroidTestFinder
  {
  
      private static final String[] TEST_PACKAGES = { "junit/framework/", "android/test/" };
  
      public static boolean containsAndroidTests( File classesBaseDirectory ) throws MojoExecutionException
      {
  
          if ( classesBaseDirectory == null || ! classesBaseDirectory.isDirectory() )
          {
              throw new IllegalArgumentException( "classesBaseDirectory must be a valid directory!" );
          }
  
          final List<File> classFiles = findEligebleClassFiles( classesBaseDirectory );
          final DescendantFinder descendantFinder = new DescendantFinder( TEST_PACKAGES );
          final AnnotatedFinder annotationFinder = new AnnotatedFinder( TEST_PACKAGES );
  
          for ( File classFile : classFiles )
          {
              ClassReader classReader;
              FileInputStream inputStream = null;
              try
              {
                  inputStream = new FileInputStream( classFile );
                  classReader = new ClassReader( inputStream );
  
                  classReader.accept( descendantFinder, ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES
                          | ClassReader.SKIP_CODE );
                  classReader.accept( annotationFinder, ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES
                          | ClassReader.SKIP_CODE );
              }
              catch ( IOException e )
              {
                  throw new MojoExecutionException( "Error reading " + classFile + ".\nCould not determine whether it "
                          + "contains tests. Please specify with plugin config parameter "
                          + "<enableIntegrationTest>true|false</enableIntegrationTest>.", e );
              }
              finally
              {
                  IOUtils.closeQuietly( inputStream );
              }
          }
  
          return descendantFinder.isDescendantFound() || annotationFinder.isDescendantFound();
      }
  
      private static List<File> findEligebleClassFiles( File classesBaseDirectory )
      {
          final List<File> classFiles = new LinkedList<File>();
          final DirectoryWalker walker = new DirectoryWalker();
          walker.setBaseDir( classesBaseDirectory );
          walker.addSCMExcludes();
          walker.addInclude( "**/*.class" );
          walker.addDirectoryWalkListener( new DirectoryWalkListener()
          {
              public void directoryWalkStarting( File basedir )
              {
              }
  
              public void directoryWalkStep( int percentage, File file )
              {
                  classFiles.add( file );
              }
  
             public void directoryWalkFinished()
             {
             }
 
             public void debug( String message )
             {
             }
         } );
         walker.scan();
         return classFiles;
     }
 
 
 }