/*
    * 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.maven.plugins.war.packaging;
  
  import java.io.File;
  import java.io.IOException;
  
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugins.war.Overlay;
  import org.apache.maven.plugins.war.util.PathSet;
  import org.codehaus.plexus.util.FileUtils;
  
  /**
   * Handles an overlay.
   *
   * @author Stephane Nicoll
   */
  public class OverlayPackagingTask extends AbstractWarPackagingTask {
      private final Overlay overlay;
  
      /**
       * @param overlay {@link #overlay}
       * @param currentProjectOverlay current overlay.
       */
      public OverlayPackagingTask(Overlay overlay, Overlay currentProjectOverlay) {
          if (overlay == null) {
              throw new NullPointerException("overlay could not be null.");
          }
          if (overlay.equals(currentProjectOverlay)) {
              throw new IllegalStateException("Could not handle the current project with this task.");
          }
          this.overlay = overlay;
      }
  
      @Override
      public void performPackaging(WarPackagingContext context) throws MojoExecutionException {
          context.getLog()
                  .debug("OverlayPackagingTask performPackaging overlay.getTargetPath() " + overlay.getTargetPath());
          if (overlay.shouldSkip()) {
              context.getLog().info("Skipping overlay [" + overlay + "]");
          } else {
              try {
                  context.getLog().info("Processing overlay [" + overlay + "]");
  
                  // Step1: Extract if necessary
                  final File tmpDir = unpackOverlay(context, overlay);
  
                  // Step2: setup
                  final PathSet includes = getFilesToIncludes(tmpDir, overlay.getIncludes(), overlay.getExcludes());
  
                  // Copy
                  if (null == overlay.getTargetPath()) {
                      copyFiles(overlay.getId(), context, tmpDir, includes, overlay.isFiltered());
                  } else {
                      // overlay.getTargetPath() must ended with /
                      // if not we add it
                      String targetPath = overlay.getTargetPath();
                      if (!targetPath.endsWith("/")) {
                          targetPath = targetPath + "/";
                      }
                      copyFiles(overlay.getId(), context, tmpDir, includes, targetPath, overlay.isFiltered());
                  }
              } catch (IOException e) {
                  throw new MojoExecutionException("Failed to copy file for overlay [" + overlay + "]", e);
              }
          }
      }
  
      /**
       * Unpacks the specified overlay.
       *
       * Makes sure to skip the unpack process if the overlay has already been unpacked.
       *
       * @param context the packaging context
       * @param overlay the overlay
       * @return the directory containing the unpacked overlay
       * @throws MojoExecutionException if an error occurred while unpacking the overlay
       */
      protected File unpackOverlay(WarPackagingContext context, Overlay overlay) throws MojoExecutionException {
          final File tmpDir = getOverlayTempDirectory(context, overlay);
  
          // TODO: not sure it's good, we should reuse the markers of the dependency plugin
          if (FileUtils.sizeOfDirectory(tmpDir) == 0
                 || overlay.getArtifact().getFile().lastModified() > tmpDir.lastModified()) {
             doUnpack(context, overlay.getArtifact().getFile(), tmpDir);
         } else {
             context.getLog().debug("Overlay [" + overlay + "] was already unpacked");
         }
         return tmpDir;
     }
 
     /**
      * Returns the directory to use to unpack the specified overlay.
      *
      * @param context the packaging context
      * @param overlay the overlay
      * @return the temp directory for the overlay
      */
     protected File getOverlayTempDirectory(WarPackagingContext context, Overlay overlay) {
         final File groupIdDir = new File(context.getOverlaysWorkDirectory(), overlay.getGroupId());
         if (!groupIdDir.exists()) {
             groupIdDir.mkdir();
         }
         String directoryName = overlay.getArtifactId();
         if (overlay.getClassifier() != null) {
             directoryName = directoryName + "-" + overlay.getClassifier();
         }
         final File result = new File(groupIdDir, directoryName);
         if (!result.exists()) {
             result.mkdirs();
         }
         return result;
     }
 }