/*
    * Licensed to The Apereo Foundation under one or more contributor license
    * agreements. See the NOTICE file distributed with this work for additional
    * information regarding copyright ownership.
    *
    *
    * The Apereo Foundation licenses this file to you under the Educational
    * Community 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://opensource.org/licenses/ecl2.txt
   *
   * 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.opencastproject.workflow.handler.workflow;
  
  import static java.lang.String.format;
  
  import org.opencastproject.job.api.JobContext;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageElement;
  import org.opencastproject.mediapackage.MediaPackageElementFlavor;
  import org.opencastproject.mediapackage.selector.AbstractMediaPackageElementSelector;
  import org.opencastproject.mediapackage.selector.SimpleElementSelector;
  import org.opencastproject.serviceregistry.api.ServiceRegistry;
  import org.opencastproject.util.FileSupport;
  import org.opencastproject.util.NotFoundException;
  import org.opencastproject.util.UrlSupport;
  import org.opencastproject.util.data.Option;
  import org.opencastproject.workflow.api.AbstractWorkflowOperationHandler;
  import org.opencastproject.workflow.api.ConfiguredTagsAndFlavors;
  import org.opencastproject.workflow.api.WorkflowInstance;
  import org.opencastproject.workflow.api.WorkflowOperationException;
  import org.opencastproject.workflow.api.WorkflowOperationHandler;
  import org.opencastproject.workflow.api.WorkflowOperationInstance;
  import org.opencastproject.workflow.api.WorkflowOperationResult;
  import org.opencastproject.workflow.api.WorkflowOperationResult.Action;
  import org.opencastproject.workspace.api.Workspace;
  
  import org.apache.commons.io.FilenameUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.osgi.service.component.annotations.Component;
  import org.osgi.service.component.annotations.Reference;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.Collection;
  import java.util.List;
  
  /**
   * Workflow operation handler for copying video data through NFS
   */
  @Component(
      immediate = true,
      service = WorkflowOperationHandler.class,
      property = {
          "service.description=Copy Workflow Operation Handler",
          "workflow.operation=copy"
      }
  )
  public class CopyWorkflowOperationHandler extends AbstractWorkflowOperationHandler {
    /** Configuration key for the \"tag\" of the track to use as a source input */
    public static final String OPT_SOURCE_TAGS = "source-tags";
  
    /** Configuration key for the \"flavor\" of the track to use as a source input */
    public static final String OPT_SOURCE_FLAVORS = "source-flavors";
  
    /** Configuration key for the directory where the file must be delivered */
    public static final String OPT_TARGET_DIRECTORY = "target-directory";
  
    /** Configuration key for the name of the target file */
    public static final String OPT_TARGET_FILENAME = "target-filename";
  
    /** The logging facility */
    private static final Logger logger = LoggerFactory.getLogger(CopyWorkflowOperationHandler.class);
  
    /** The workspace reference */
    protected Workspace workspace = null;
  
    /**
     * Callback for the OSGi environment to set the workspace reference.
     *
     * @param workspace
     *          the workspace
     */
    @Reference
    protected void setWorkspace(Workspace workspace) {
      this.workspace = workspace;
    }
  
   /**
    * {@inheritDoc}
    */
   @Override
   public WorkflowOperationResult start(WorkflowInstance workflowInstance, JobContext context)
           throws WorkflowOperationException {
     logger.debug("Running copy workflow operation on workflow {}", workflowInstance.getId());
 
     MediaPackage mediaPackage = workflowInstance.getMediaPackage();
     WorkflowOperationInstance currentOperation = workflowInstance.getCurrentOperation();
 
     // Check which tags have been configured
     ConfiguredTagsAndFlavors tagsAndFlavors = getTagsAndFlavors(workflowInstance,
         Configuration.many, Configuration.many, Configuration.none, Configuration.none);
     List<String> sourceTagsOption = tagsAndFlavors.getSrcTags();
     List<MediaPackageElementFlavor> sourceFlavorsOption = tagsAndFlavors.getSrcFlavors();
     String targetDirectoryOption = StringUtils.trimToNull(currentOperation.getConfiguration(OPT_TARGET_DIRECTORY));
     Option<String> targetFilenameOption = Option.option(StringUtils.trimToNull(currentOperation
             .getConfiguration(OPT_TARGET_FILENAME)));
 
     StringBuilder sb = new StringBuilder();
     sb.append("Parameters passed to copy workflow operation:");
     sb.append("\n source-tags: ").append(sourceTagsOption);
     sb.append("\n source-flavors: ").append(sourceFlavorsOption);
     sb.append("\n target-directory: ").append(targetDirectoryOption);
     sb.append("\n target-filename: ").append(targetFilenameOption);
     logger.debug(sb.toString());
 
     AbstractMediaPackageElementSelector<MediaPackageElement> elementSelector = new SimpleElementSelector();
 
     // Make sure either one of tags or flavors are provided
     if (sourceTagsOption.isEmpty() && sourceFlavorsOption.isEmpty()) {
       logger.info("No source tags or flavors have been specified, not matching anything");
       return createResult(mediaPackage, Action.CONTINUE);
     }
 
     // Make the target filename and directory are provided
     if (StringUtils.isBlank(targetDirectoryOption)) {
       throw new WorkflowOperationException("No target directory has been set for the copy operation!");
     }
 
     // Select the source flavors
     for (MediaPackageElementFlavor flavor : sourceFlavorsOption) {
       try {
         elementSelector.addFlavor(flavor);
       } catch (IllegalArgumentException e) {
         throw new WorkflowOperationException("Source flavor '" + flavor + "' is malformed");
       }
     }
 
     // Select the source tags
     for (String tag : sourceTagsOption) {
       elementSelector.addTag(tag);
     }
 
     // Look for elements matching the tag
     Collection<MediaPackageElement> elements = elementSelector.select(mediaPackage, true);
 
     // Check the the number of element returned
     if (elements.size() == 0) {
       // If no one found, we skip the operation
       return createResult(mediaPackage, Action.SKIP);
     } else if (elements.size() == 1) {
       for (MediaPackageElement element : elements) {
         logger.debug("Copy single element to: {}", targetDirectoryOption);
         final String fileName;
         if (targetFilenameOption.isSome()) {
           fileName = targetFilenameOption.get();
         } else {
           fileName = FilenameUtils.getBaseName(element.getURI().toString());
         }
 
         String ext = FilenameUtils.getExtension(element.getURI().toString());
         ext = ext.length() > 0 ? ".".concat(ext) : "";
         File targetFile = new File(UrlSupport.concat(targetDirectoryOption, fileName.concat(ext)));
 
         copyElement(element, targetFile);
       }
     } else {
       logger.debug("Copy multiple elements to: {}", targetDirectoryOption);
       int i = 1;
       for (MediaPackageElement element : elements) {
         final String fileName;
         if (targetFilenameOption.isSome()) {
           fileName = String.format(targetFilenameOption.get(), i);
         } else {
           fileName = FilenameUtils.getBaseName(element.getURI().toString());
         }
 
         String ext = FilenameUtils.getExtension(element.getURI().toString());
         ext = ext.length() > 0 ? ".".concat(ext) : "";
         File targetFile = new File(UrlSupport.concat(targetDirectoryOption, fileName + ext));
 
         copyElement(element, targetFile);
         i++;
       }
     }
 
     return createResult(mediaPackage, Action.CONTINUE);
   }
 
   private void copyElement(MediaPackageElement element, File targetFile) throws WorkflowOperationException {
     File sourceFile;
     try {
       sourceFile = workspace.get(element.getURI());
     } catch (NotFoundException e) {
       throw new WorkflowOperationException("Unable to find " + element.getURI() + " in the workspace", e);
     } catch (IOException e) {
       throw new WorkflowOperationException("Error loading " + element.getURI() + " from the workspace", e);
     }
 
     logger.debug("Start copying element {} to target {}.", sourceFile.getPath(), targetFile.getPath());
     try {
       FileSupport.copy(sourceFile, targetFile);
     } catch (IOException e) {
       throw new WorkflowOperationException(format("Unable to copy %s to %s: %s", sourceFile.getPath(),
               targetFile.getPath(), e.getMessage()));
     }
     logger.debug("Element {} copied to target {}.", sourceFile.getPath(), targetFile.getPath());
   }
 
   @Reference
   @Override
   public void setServiceRegistry(ServiceRegistry serviceRegistry) {
     super.setServiceRegistry(serviceRegistry);
   }
 
 }