/*
    * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH
    *
    * 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 de.smartics.properties.report;
  
  import java.io.File;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import javax.annotation.concurrent.NotThreadSafe;
  
  import com.thoughtworks.qdox.JavaProjectBuilder;
  import com.thoughtworks.qdox.library.ErrorHandler;
  import com.thoughtworks.qdox.model.JavaClass;
  import com.thoughtworks.qdox.parser.ParseException;
  
  import de.smartics.properties.report.data.PropertyReport;
  import de.smartics.properties.report.data.ReportProblem;
  import de.smartics.properties.report.qdox.PropertyDescriptorSearcher;
  import de.smartics.properties.utils.RuntimeUtils;
  import de.smartics.util.lang.Arg;
  import de.smartics.util.lang.NullArgumentException;
  
  /**
   * Builder of reports on smartics properties.
   */
  @NotThreadSafe
  public final class ReportBuilder
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    // --- members --------------------------------------------------------------
  
    /**
     * The configuration to control the generation of the report.
     */
    private final ReportConfiguration configuration;
  
    /**
     * The parser of the Java sources.
     */
    private final JavaProjectBuilder javaProjectBuilder;
  
    /**
     * The error handler to log parsing problems.
     */
    private final ErrorHandler errorHandler = new ErrorHandler()
    {
      @Override
      public void handle(final ParseException parseException)
      {
        problems.add(new ReportProblem("Parse error", parseException));
      }
    };
  
    /**
     * The list of problems encountered while parsing sources and fetching report
     * information.
     */
    private final List<ReportProblem> problems = new ArrayList<ReportProblem>();
  
    /**
     * Helper to instantiate classes.
     */
    private final RuntimeUtils runtimeUtils;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    private ReportBuilder(final ReportConfiguration configuration)
    {
      this.configuration = configuration;
  
      javaProjectBuilder = createJavaProjectBuilder(configuration, errorHandler);
      runtimeUtils = createRuntimeUtils(configuration);
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
   private static JavaProjectBuilder createJavaProjectBuilder(
       final ReportConfiguration configuration, final ErrorHandler errorHandler)
   {
     final JavaProjectBuilder builder = new JavaProjectBuilder();
 
     builder.setEncoding(configuration.getEncoding());
     builder.setErrorHandler(errorHandler);
 
     for (final File sourceTree : configuration.getSourceTrees())
     {
       builder.addSourceTree(sourceTree);
     }
 
     return builder;
   }
 
   private RuntimeUtils createRuntimeUtils(
       final ReportConfiguration configuration)
   {
     final ClassLoader classLoader = configuration.getProjectClassLoader();
     return new RuntimeUtils(classLoader);
   }
 
   // --- create ---------------------------------------------------------------
 
   /**
    * Factory method to create an instance of a report builder.
    *
    * @param configuration the configuration to control the generation of the
    *          report.
    * @return the configured report builder.
    */
   public static ReportBuilder create(final ReportConfiguration configuration)
   {
     return new ReportBuilder(configuration);
   }
 
   // --- get&set --------------------------------------------------------------
 
   /**
    * Returns the configuration to control the generation of the report.
    *
    * @return the configuration to control the generation of the report.
    */
   public ReportConfiguration getConfiguration()
   {
     return configuration;
   }
 
   // --- business -------------------------------------------------------------
 
   /**
    * Runs the report process and writes to the given report.
    *
    * @param report the report to write to.
    * @throws NullArgumentException if {@code report} is <code>null</code>.
    */
   public void reportTo(final PropertyReport report)
     throws NullArgumentException
   {
     Arg.checkNotNull("report", report);
 
     notifyOfParseProblems(report);
 
     final PropertyDescriptorSearcher searcher =
         new PropertyDescriptorSearcher();
     final Collection<JavaClass> propertyDescriptorTypes =
         javaProjectBuilder.search(searcher);
     for (final JavaClass propertyDescriptorType : propertyDescriptorTypes)
     {
       try
       {
         final AddReportItemHelper helper =
             new AddReportItemHelper(runtimeUtils, javaProjectBuilder,
                 propertyDescriptorType);
         helper.addReportItems(report);
       }
       catch (final Exception e)
       {
         report.addProblem(new ReportProblem("Cannot add report item.", e));
       }
     }
   }
 
   private void notifyOfParseProblems(final PropertyReport report)
   {
     if (!problems.isEmpty())
     {
       for (final ReportProblem problem : problems)
       {
         report.addProblem(problem);
       }
     }
   }
 
   // --- object basics --------------------------------------------------------
 
 }