/*
    * 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.
   */
  
  package org.apache.commons.jci.compilers;
  
  import groovy.lang.GroovyClassLoader;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import org.apache.commons.jci.problems.CompilationProblem;
  import org.apache.commons.jci.readers.ResourceReader;
  import org.apache.commons.jci.stores.ResourceStore;
  import org.apache.commons.jci.utils.ConversionUtils;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.codehaus.groovy.control.CompilationFailedException;
  import org.codehaus.groovy.control.CompilationUnit;
  import org.codehaus.groovy.control.CompilerConfiguration;
  import org.codehaus.groovy.control.ErrorCollector;
  import org.codehaus.groovy.control.MultipleCompilationErrorsException;
  import org.codehaus.groovy.control.Phases;
  import org.codehaus.groovy.control.SourceUnit;
  import org.codehaus.groovy.control.messages.Message;
  import org.codehaus.groovy.control.messages.WarningMessage;
  import org.codehaus.groovy.tools.GroovyClass;
  
  /**
   * Groovy implementation of the JavaCompiler interface
   * 
   * @author tcurdt
   */
  public final class GroovyJavaCompiler extends AbstractJavaCompiler {
  
      private final Log log = LogFactory.getLog(GroovyJavaCompiler.class);
      private final GroovyJavaCompilerSettings defaultSettings;
      
      public GroovyJavaCompiler() {
          defaultSettings = new GroovyJavaCompilerSettings(new CompilerConfiguration());
      }
          
      public CompilationResult compile(
              final String[] pResourceNames,
              final ResourceReader pReader,
              final ResourceStore pStore,
              final ClassLoader pClassLoader,
              final JavaCompilerSettings pSettings
              ) {
  
          final CompilerConfiguration configuration = ((GroovyJavaCompilerSettings) pSettings).getCompilerConfiguration();
          final ErrorCollector collector = new ErrorCollector(configuration);
          final GroovyClassLoader groovyClassLoader = new GroovyClassLoader(pClassLoader);
          final CompilationUnit unit = new CompilationUnit(configuration, null, groovyClassLoader);
          final SourceUnit[] source = new SourceUnit[pResourceNames.length];
          for (int i = 0; i < source.length; i++) {
              final String resourceName = pResourceNames[i];
              source[i] = new SourceUnit(
                      ConversionUtils.convertResourceToClassName(resourceName),
                      new String(pReader.getBytes(resourceName)), // FIXME delay the read
                      configuration,
                      groovyClassLoader,
                      collector
                      );
              unit.addSource(source[i]);
          }
          
          final Collection<CompilationProblem> problems = new ArrayList<CompilationProblem>();
  
          try {
              log.debug("compiling");
              unit.compile(Phases.CLASS_GENERATION);
              
              @SuppressWarnings("unchecked") // Groovy library is not yet generic
              final List<GroovyClass> classes = unit.getClasses();
              for (GroovyClass clazz : classes) {
                  final byte[] bytes = clazz.getBytes();
                  pStore.write(ConversionUtils.convertClassToResourcePath(clazz.getName()), bytes);
              }
          } catch (final MultipleCompilationErrorsException e) {
              final ErrorCollector col = e.getErrorCollector();
              @SuppressWarnings("unchecked") // Groovy library is not yet generic
              final Collection<WarningMessage> warnings = col.getWarnings();
              if (warnings != null) {
                  for (WarningMessage warning : warnings) {
                     final CompilationProblem problem = new GroovyCompilationProblem(warning); 
                     if (problemHandler != null) {
                         problemHandler.handle(problem);
                     }
                     problems.add(problem);
                 }
             }
 
             @SuppressWarnings("unchecked") // Groovy library is not yet generic
             final Collection<Message> errors = col.getErrors();
             if (errors != null) {
                 for (Message message : errors) {
                     final CompilationProblem problem = new GroovyCompilationProblem(message); 
                     if (problemHandler != null) {
                         problemHandler.handle(problem);
                     }
                     problems.add(problem);
                 }
             }
         } catch (CompilationFailedException e) {
             throw new RuntimeException("no expected");
         }
 
         final CompilationProblem[] result = new CompilationProblem[problems.size()];
         problems.toArray(result);
         return new CompilationResult(result);
     }
 
     public JavaCompilerSettings createDefaultSettings() {
         return defaultSettings;
     }
 }