package org.apache.maven.plugin.compiler;
   
   /*
    * 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.io.File;
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.Paths;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Set;
  
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugins.annotations.LifecyclePhase;
  import org.apache.maven.plugins.annotations.Mojo;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.apache.maven.plugins.annotations.ResolutionScope;
  import org.apache.maven.toolchain.Toolchain;
  import org.apache.maven.toolchain.java.DefaultJavaToolChain;
  import org.codehaus.plexus.compiler.util.scan.SimpleSourceInclusionScanner;
  import org.codehaus.plexus.compiler.util.scan.SourceInclusionScanner;
  import org.codehaus.plexus.compiler.util.scan.StaleSourceScanner;
  import org.codehaus.plexus.languages.java.jpms.JavaModuleDescriptor;
  import org.codehaus.plexus.languages.java.jpms.LocationManager;
  import org.codehaus.plexus.languages.java.jpms.ResolvePathsRequest;
  import org.codehaus.plexus.languages.java.jpms.ResolvePathsResult;
  
  /**
   * Compiles application test sources.
   *
   * @author <a href="mailto:jason@maven.org">Jason van Zyl</a>
   * @since 2.0
   */
  @Mojo( name = "testCompile", defaultPhase = LifecyclePhase.TEST_COMPILE, threadSafe = true,
                  requiresDependencyResolution = ResolutionScope.TEST )
  public class TestCompilerMojo
      extends AbstractCompilerMojo
  {
      /**
       * Set this to 'true' to bypass compilation of test sources.
       * Its use is NOT RECOMMENDED, but quite convenient on occasion.
       */
      @Parameter ( property = "maven.test.skip" )
      private boolean skip;
  
      /**
       * The source directories containing the test-source to be compiled.
       */
      @Parameter ( defaultValue = "${project.testCompileSourceRoots}", readonly = true, required = true )
      private List<String> compileSourceRoots;
  
      /**
       * The directory where compiled test classes go.
       */
      @Parameter ( defaultValue = "${project.build.testOutputDirectory}", required = true, readonly = true )
      private File outputDirectory;
  
      /**
       * A list of inclusion filters for the compiler.
       */
      @Parameter
      private Set<String> testIncludes = new HashSet<>();
  
      /**
       * A list of exclusion filters for the compiler.
       */
      @Parameter
      private Set<String> testExcludes = new HashSet<>();
  
      /**
       * The -source argument for the test Java compiler.
       *
       * @since 2.1
       */
      @Parameter ( property = "maven.compiler.testSource" )
      private String testSource;
 
     /**
      * The -target argument for the test Java compiler.
      *
      * @since 2.1
      */
     @Parameter ( property = "maven.compiler.testTarget" )
     private String testTarget;
 
     /**
      * the -release argument for the test Java compiler
      * 
      * @since 3.6
      */
     @Parameter ( property = "maven.compiler.testRelease" )
     private String testRelease;
 
     /**
      * <p>
      * Sets the arguments to be passed to test compiler (prepending a dash) if fork is set to true.
      * </p>
      * <p>
      * This is because the list of valid arguments passed to a Java compiler
      * varies based on the compiler version.
      * </p>
      *
      * @since 2.1
      */
     @Parameter
     private Map<String, String> testCompilerArguments;
 
     /**
      * <p>
      * Sets the unformatted argument string to be passed to test compiler if fork is set to true.
      * </p>
      * <p>
      * This is because the list of valid arguments passed to a Java compiler
      * varies based on the compiler version.
      * </p>
      *
      * @since 2.1
      */
     @Parameter
     private String testCompilerArgument;
 
     /**
      * <p>
      * Specify where to place generated source files created by annotation processing.
      * Only applies to JDK 1.6+
      * </p>
      *
      * @since 2.2
      */
     @Parameter ( defaultValue = "${project.build.directory}/generated-test-sources/test-annotations" )
     private File generatedTestSourcesDirectory;
 
     @Parameter( defaultValue = "${project.testClasspathElements}", readonly = true )
     private List<String> testPath;
 
     final LocationManager locationManager = new LocationManager();
 
     private Map<String, JavaModuleDescriptor> pathElements;
     
     private Collection<String> classpathElements;
 
     private Collection<String> modulepathElements;
 
     public void execute()
         throws MojoExecutionException, CompilationFailureException
     {
         if ( skip )
         {
             getLog().info( "Not compiling test sources" );
             return;
         }
         super.execute();
     }
 
     protected List<String> getCompileSourceRoots()
     {
         return compileSourceRoots;
     }
 
     @Override
     protected Map<String, JavaModuleDescriptor> getPathElements()
     {
         return pathElements;
     }
 
     protected List<String> getClasspathElements()
     {
         return new ArrayList<>( classpathElements );
     }
 
     @Override
     protected List<String> getModulepathElements()
     {
         return new ArrayList<>( modulepathElements );
     }
 
     protected File getOutputDirectory()
     {
         return outputDirectory;
     }
 
     @Override
     protected void preparePaths( Set<File> sourceFiles )
     {
         File mainOutputDirectory = new File( getProject().getBuild().getOutputDirectory() );
 
         File mainModuleDescriptorClassFile = new File( mainOutputDirectory, "module-info.class" );
         JavaModuleDescriptor mainModuleDescriptor = null;
 
         File testModuleDescriptorJavaFile = new File( "module-info.java" );
         JavaModuleDescriptor testModuleDescriptor = null;
 
         // Go through the source files to respect includes/excludes
         for ( File sourceFile : sourceFiles )
         {
             // @todo verify if it is the root of a sourcedirectory?
             if ( "module-info.java".equals( sourceFile.getName() ) ) 
             {
                 testModuleDescriptorJavaFile = sourceFile;
                 break;
             }
         }
 
         // Get additional information from the main module descriptor, if available
         if ( mainModuleDescriptorClassFile.exists() )
         {
             ResolvePathsResult<String> result;
 
             try
             {
                 ResolvePathsRequest<String> request =
                         ResolvePathsRequest.ofStrings( testPath )
                                 .setMainModuleDescriptor( mainModuleDescriptorClassFile.getAbsolutePath() );
 
                 Toolchain toolchain = getToolchain();
                 if ( toolchain instanceof DefaultJavaToolChain )
                 {
                     request.setJdkHome( ( (DefaultJavaToolChain) toolchain ).getJavaHome() );
                 }
 
                 result = locationManager.resolvePaths( request );
                 
                 for ( Entry<String, Exception> pathException : result.getPathExceptions().entrySet() )
                 {
                     Throwable cause = pathException.getValue();
                     while ( cause.getCause() != null )
                     {
                         cause = cause.getCause();
                     }
                     String fileName = Paths.get( pathException.getKey() ).getFileName().toString();
                     getLog().warn( "Can't extract module name from " + fileName + ": " + cause.getMessage() );
                 }
             }
             catch ( IOException e )
             {
                 throw new RuntimeException( e );
             }
 
             mainModuleDescriptor = result.getMainModuleDescriptor();
 
             pathElements = new LinkedHashMap<>( result.getPathElements().size() );
             pathElements.putAll( result.getPathElements() );
 
             modulepathElements = result.getModulepathElements().keySet();
             classpathElements = result.getClasspathElements();
         }
 
         // Get additional information from the test module descriptor, if available
         if ( testModuleDescriptorJavaFile.exists() )
         {
             ResolvePathsResult<String> result;
 
             try
             {
                 ResolvePathsRequest<String> request =
                         ResolvePathsRequest.ofStrings( testPath )
                                 .setMainModuleDescriptor( testModuleDescriptorJavaFile.getAbsolutePath() );
 
                 Toolchain toolchain = getToolchain();
                 if ( toolchain instanceof DefaultJavaToolChain )
                 {
                     request.setJdkHome( ( (DefaultJavaToolChain) toolchain ).getJavaHome() );
                 }
 
                 result = locationManager.resolvePaths( request );
             }
             catch ( IOException e )
             {
                 throw new RuntimeException( e );
             }
 
             testModuleDescriptor = result.getMainModuleDescriptor();
         }
 
         if ( release != null )
         {
             if ( Integer.valueOf( release ) < 9 )
             {
                 pathElements = Collections.emptyMap();
                 modulepathElements = Collections.emptyList();
                 classpathElements = testPath;
                 return;
             }
         }
         else if ( Double.valueOf( getTarget() ) < Double.valueOf( MODULE_INFO_TARGET ) )
         {
             pathElements = Collections.emptyMap();
             modulepathElements = Collections.emptyList();
             classpathElements = testPath;
             return;
         }
             
         if ( testModuleDescriptor != null )
         {
             modulepathElements = testPath;
             classpathElements = Collections.emptyList();
 
             if ( mainModuleDescriptor != null )
             {
                 if ( getLog().isDebugEnabled() )
                 {
                     getLog().debug( "Main and test module descriptors exist:" );
                     getLog().debug( "  main module = " + mainModuleDescriptor.name() );
                     getLog().debug( "  test module = " + testModuleDescriptor.name() );
                 }
 
                 if ( testModuleDescriptor.name().equals( mainModuleDescriptor.name() ) )
                 {
                     if ( compilerArgs == null )
                     {
                         compilerArgs = new ArrayList<>();
                     }
                     compilerArgs.add( "--patch-module" );
 
                     StringBuilder patchModuleValue = new StringBuilder();
                     patchModuleValue.append( testModuleDescriptor.name() );
                     patchModuleValue.append( '=' );
 
                     for ( String root : getProject().getCompileSourceRoots() )
                     {
                         if ( Files.exists( Paths.get( root ) ) )
                         {
                             patchModuleValue.append( root ).append( PS );
                         }
                     }
 
                     compilerArgs.add( patchModuleValue.toString() );
                 }
                 else
                 {
                     getLog().debug( "Black-box testing - all is ready to compile" );
                 }
             }
             else
             {
                 // No main binaries available? Means we're a test-only project.
                 if ( !mainOutputDirectory.exists() )
                 {
                     return;
                 }
                 // very odd
                 // Means that main sources must be compiled with -modulesource and -Xmodule:<moduleName>
                 // However, this has a huge impact since you can't simply use it as a classpathEntry 
                 // due to extra folder in between
                 throw new UnsupportedOperationException( "Can't compile test sources "
                     + "when main sources are missing a module descriptor" );
             }
         }
         else
         {
             if ( mainModuleDescriptor != null )
             {
                 if ( compilerArgs == null )
                 {
                     compilerArgs = new ArrayList<>();
                 }
                 compilerArgs.add( "--patch-module" );
                 
                 StringBuilder patchModuleValue = new StringBuilder( mainModuleDescriptor.name() )
                                 .append( '=' )
                                 .append( mainOutputDirectory )
                                 .append( PS );
                 for ( String root : compileSourceRoots )
                 {
                     patchModuleValue.append( root ).append( PS );
                 }
                 
                 compilerArgs.add( patchModuleValue.toString() );
                 
                 compilerArgs.add( "--add-reads" );
                 compilerArgs.add( mainModuleDescriptor.name() + "=ALL-UNNAMED" );
             }
             else
             {
                 modulepathElements = Collections.emptyList();
                 classpathElements = testPath;
             }
         }
     }
 
     protected SourceInclusionScanner getSourceInclusionScanner( int staleMillis )
     {
         SourceInclusionScanner scanner;
 
         if ( testIncludes.isEmpty() && testExcludes.isEmpty() )
         {
             scanner = new StaleSourceScanner( staleMillis );
         }
         else
         {
             if ( testIncludes.isEmpty() )
             {
                 testIncludes.add( "**/*.java" );
             }
             scanner = new StaleSourceScanner( staleMillis, testIncludes, testExcludes );
         }
 
         return scanner;
     }
 
     protected SourceInclusionScanner getSourceInclusionScanner( String inputFileEnding )
     {
         SourceInclusionScanner scanner;
 
         // it's not defined if we get the ending with or without the dot '.'
         String defaultIncludePattern = "**/*" + ( inputFileEnding.startsWith( "." ) ? "" : "." ) + inputFileEnding;
 
         if ( testIncludes.isEmpty() && testExcludes.isEmpty() )
         {
             testIncludes = Collections.singleton( defaultIncludePattern );
             scanner = new SimpleSourceInclusionScanner( testIncludes, Collections.<String>emptySet() );
         }
         else
         {
             if ( testIncludes.isEmpty() )
             {
                 testIncludes.add( defaultIncludePattern );
             }
             scanner = new SimpleSourceInclusionScanner( testIncludes, testExcludes );
         }
 
         return scanner;
     }
 
     protected String getSource()
     {
         return testSource == null ? source : testSource;
     }
 
     protected String getTarget()
     {
         return testTarget == null ? target : testTarget;
     }
     
     @Override
     protected String getRelease()
     {
         return testRelease == null ? release : testRelease;
     }
 
     protected String getCompilerArgument()
     {
         return testCompilerArgument == null ? compilerArgument : testCompilerArgument;
     }
 
     protected Map<String, String> getCompilerArguments()
     {
         return testCompilerArguments == null ? compilerArguments : testCompilerArguments;
     }
 
     protected File getGeneratedSourcesDirectory()
     {
         return generatedTestSourcesDirectory;
     }
 
     @Override
     protected boolean isTestCompile()
     {
         return true;
     }
 
 }