/*
    * Copyright 2006-2012 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.maven.util.report;
  
  import java.io.File;
  import java.util.List;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.maven.model.ReportPlugin;
  import org.apache.maven.plugin.logging.Log;
  import org.apache.maven.project.MavenProject;
  import org.codehaus.plexus.util.PathTool;
  
  import de.smartics.maven.util.PathUtils;
  import de.smartics.maven.util.report.link.ExternalReport;
  import de.smartics.maven.util.report.link.ExternalReportFactory;
  import de.smartics.maven.util.report.link.LinkConstructorStrategy;
  import de.smartics.maven.util.report.link.LinkConstructorStrategyConfig;
  import de.smartics.maven.util.report.link.ReportId;
  
  /**
   * Factory to create external reports within a Maven project.
   */
  public class MavenExternalReportFactory implements ExternalReportFactory
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * The artifact ID of the surefire plugin.
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    public static final String MAVEN_SUREFIRE_PLUGIN =
        "maven-surefire-report-plugin";
  
    /**
     * The artifact ID of the Javadoc plugin.
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    public static final String MAVEN_JAVADOC_PLUGIN = "maven-javadoc-plugin";
  
    /**
     * The artifact ID of the jxr plugin.
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    public static final String MAVEN_JXR_PLUGIN = "maven-jxr-plugin";
  
    /**
     * The artifact ID of the cobertura plugin.
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    public static final String MAVEN_COBERTURA_PLUGIN = "maven-cobertura-plugin";
  
    // --- members --------------------------------------------------------------
  
    /**
     * The Maven project.
     */
    private final MavenProject project;
  
    /**
     * The Maven logger to use. May be <code>null</code> if no logging is
     * requested.
     */
    private final Log log;
  
    /**
     * The path up to the root directory from the report directory.
     */
    private final String upPath;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Convenience constructor using no logging.
    *
    * @param project the Maven project.
    * @param reportRelDir the project's relative path within the project.
    * @throws IllegalArgumentException if <code>project</code> is
    *           <code>null</code> or <code>reportRelDir</code> is
    *           <code>null</code> or contains only whitespaces.
    */
   public MavenExternalReportFactory(final MavenProject project,
       final String reportRelDir) throws IllegalArgumentException
   {
     this(null, project, reportRelDir);
   }
 
   /**
    * Default constructor.
    *
    * @param log the Maven logger to use.
    * @param project the Maven project.
    * @param reportRelDir the project's relative path within the project.
    * @throws IllegalArgumentException if <code>project</code> is
    *           <code>null</code> or <code>reportRelDir</code> is
    *           <code>null</code> or contains only whitespaces.
    */
   public MavenExternalReportFactory(final Log log, final MavenProject project,
       final String reportRelDir) throws IllegalArgumentException
   {
     checkArguments(project, reportRelDir);
     this.log = log;
     this.project = project;
     this.upPath = PathUtils.getUpPath(reportRelDir);
   }
 
   // ****************************** Inner Classes *****************************
 
   // ********************************* Methods ********************************
 
   // --- init -----------------------------------------------------------------
 
   private static void checkArguments(final MavenProject project,
       final String reportRelDir) throws IllegalArgumentException
   {
     if (project == null)
     {
       throw new IllegalArgumentException("The project must not be 'null'.");
     }
     if (reportRelDir == null
         || (StringUtils.isBlank(reportRelDir) && StringUtils
             .isNotEmpty(reportRelDir)))
     {
       throw new IllegalArgumentException(
           "The report relative directory within the project base"
               + " directory must not be 'null' or contain only whitespaces.");
     }
   }
 
   // --- get&set --------------------------------------------------------------
 
   // --- business -------------------------------------------------------------
 
   private String calcRelativePath(final File reportLocation)
   {
     final String reportBaseDir = project.getReporting().getOutputDirectory();
     final String reportLocationAbsolutePath = reportLocation.getAbsolutePath();
 
     final String relativePathBase;
     if (reportLocationAbsolutePath.contains(".."))
     {
       relativePathBase = ".."; // Fix for BUG 622: Referencing Aggregate Reports
     }
     else
     {
       relativePathBase =
           PathTool.getRelativePath(reportBaseDir, reportLocationAbsolutePath);
     }
     final String relativePath =
         upPath + '/' + (getPathFragment(relativePathBase))
             + reportLocation.getName();
     return relativePath;
   }
 
   private static String getPathFragment(final String relativePathBase)
   {
     return isNotCurrentDir(relativePathBase) ? relativePathBase + '/' : "";
   }
 
   private static boolean isNotCurrentDir(final String relativePathBase)
   {
     return StringUtils.isNotEmpty(relativePathBase)
            && !".".equals(relativePathBase);
   }
 
   @SuppressWarnings("unchecked")
   private boolean isReportPluginRegistered(final String reportArtifactId)
   {
     final List<ReportPlugin> reportPlugins =
         (List<ReportPlugin>) project.getReportPlugins();
     for (final ReportPlugin report : reportPlugins)
     {
       final String artifactId = report.getArtifactId();
       if (reportArtifactId.equals(artifactId))
       {
         return true;
       }
     }
     return false;
   }
 
   /**
    * {@inheritDoc}
    */
   public ExternalReport createExternalReport(final ReportId reportId,
       final LinkConstructorStrategy strategy)
   {
     if (reportId == null)
     {
       throw new IllegalArgumentException("The report ID is required.");
     }
     if (strategy == null)
     {
       throw new IllegalArgumentException(
           "The link construction strategy is required.");
     }
 
     final String reportBasePath =
         createRelativeReportLocationLink(reportId, strategy);
     if (reportBasePath != null)
     {
       return new ExternalReport(reportId, reportBasePath, strategy);
     }
     else
     {
       return null;
     }
   }
 
   private String createRelativeReportLocationLink(final ReportId reportId,
       final LinkConstructorStrategy strategy)
   {
     final LinkConstructorStrategyConfig config = strategy.getConfig();
 
     final File reportLocation = config.getReportLocation();
     final String reportArtifactId = reportId.getReportArtifactId();
 
     final String location;
     if (reportLocation.exists() || isReportPluginRegistered(reportArtifactId))
     {
       location = calcRelativePath(reportLocation);
     }
     else
     {
       location = null;
       if (log != null && log.isWarnEnabled())
       {
         log.warn("Cannot locate report of '" + reportArtifactId
                  + "'. Disabling references to that report.");
       }
     }
 
     return location;
   }
 
   // --- object basics --------------------------------------------------------
 
 }