/*
    * 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.execute.operation.handler;
  
  import org.opencastproject.execute.api.ExecuteException;
  import org.opencastproject.execute.api.ExecuteService;
  import org.opencastproject.inspection.api.MediaInspectionException;
  import org.opencastproject.inspection.api.MediaInspectionService;
  import org.opencastproject.job.api.Job;
  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.MediaPackageElementParser;
  import org.opencastproject.mediapackage.MediaPackageException;
  import org.opencastproject.serviceregistry.api.ServiceRegistry;
  import org.opencastproject.util.NotFoundException;
  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.workflow.api.WorkflowOperationResultImpl;
  import org.opencastproject.workspace.api.Workspace;
  
  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.FileInputStream;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.net.URI;
  import java.nio.charset.StandardCharsets;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  
  /**
   * Runs an operation once with using elements within a certain MediaPackage as parameters
   */
  @Component(
      immediate = true,
      service = WorkflowOperationHandler.class,
      property = {
          "service.description=Execute Once Workflow Operation Handler",
          "workflow.operation=execute-once"
      }
  )
  public class ExecuteOnceWorkflowOperationHandler extends AbstractWorkflowOperationHandler {
  
    /** The logging facility */
    private static final Logger logger = LoggerFactory.getLogger(ExecuteOnceWorkflowOperationHandler.class);
  
    /** Property containing the command to run */
    public static final String EXEC_PROPERTY = "exec";
  
    /** Property containing the list of command parameters */
    public static final String PARAMS_PROPERTY = "params";
  
    /** Property containingn an approximation of the load imposed by running this operation */
    public static final String LOAD_PROPERTY = "load";
  
    /** Property containing the filename of the elements created by this operation */
    public static final String OUTPUT_FILENAME_PROPERTY = "output-filename";
  
    /** Property containing the expected type of the element generated by this operation */
    public static final String EXPECTED_TYPE_PROPERTY = "expected-type";
  
    /** Property containing the flavor that the resulting mediapackage elements will be assigned */
    public static final String TARGET_FLAVOR_PROPERTY = "target-flavor";
  
    /** Property should be empty, but is needed in order to parse optional target-flavors */
   public static final String TARGET_FLAVORS_PROPERTY = "target-flavors";
 
   /** Property containing the tags that the resulting mediapackage elements will be assigned */
   public static final String TARGET_TAGS_PROPERTY = "target-tags";
 
   /** Property should be empty, but will be checked, if target-tags is empty */
   public static final String TARGET_TAG_PROPERTY = "target-tag";
 
   /** Property to control whether command output will be used to set workflow properties */
   public static final String SET_WF_PROPS_PROPERTY = "set-workflow-properties";
 
   /** The text analyzer */
   protected ExecuteService executeService;
 
   /** Reference to the media inspection service */
   private MediaInspectionService inspectionService = null;
 
   /** The workspace service */
   protected Workspace workspace;
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.workflow.api.WorkflowOperationHandler#start(org.opencastproject.workflow.api.WorkflowInstance, JobContext)
    */
   @Override
   public WorkflowOperationResult start(WorkflowInstance workflowInstance, JobContext context) throws WorkflowOperationException {
 
     MediaPackage mediaPackage = workflowInstance.getMediaPackage();
     WorkflowOperationInstance operation = workflowInstance.getCurrentOperation();
 
     logger.debug("Running execute workflow operation with ID {}", operation.getId());
 
     // Get operation parameters
     String exec = StringUtils.trimToNull(operation.getConfiguration(EXEC_PROPERTY));
     String params = StringUtils.trimToNull(operation.getConfiguration(PARAMS_PROPERTY));
     float load = 1.0f;
     String loadPropertyStr = StringUtils.trimToEmpty(operation.getConfiguration(LOAD_PROPERTY));
     if (StringUtils.isNotBlank(loadPropertyStr)) {
       try {
         load = Float.parseFloat(loadPropertyStr);
       } catch (NumberFormatException e) {
         String description = StringUtils.trimToEmpty(operation.getDescription());
         logger.warn("Ignoring invalid load value '{}' on execute operation with description '{}'", loadPropertyStr, description);
       }
     }
     ConfiguredTagsAndFlavors tagsAndFlavors = getTagsAndFlavors(workflowInstance,
         Configuration.none, Configuration.none, Configuration.many, Configuration.many);
     List<MediaPackageElementFlavor> targetFlavorStr = tagsAndFlavors.getTargetFlavors();
     ConfiguredTagsAndFlavors.TargetTags targetTags = tagsAndFlavors.getTargetTags();
     String outputFilename = StringUtils.trimToNull(operation.getConfiguration(OUTPUT_FILENAME_PROPERTY));
     String expectedTypeStr = StringUtils.trimToNull(operation.getConfiguration(EXPECTED_TYPE_PROPERTY));
 
     boolean setWfProps = Boolean.valueOf(StringUtils.trimToNull(operation.getConfiguration(SET_WF_PROPS_PROPERTY)));
 
     // Unmarshall target flavor
     MediaPackageElementFlavor targetFlavor = null;
     if (!targetFlavorStr.isEmpty())
       targetFlavor = targetFlavorStr.get(0);
 
     // Unmarshall expected mediapackage element type
     MediaPackageElement.Type expectedType = null;
     if (expectedTypeStr != null) {
       for (MediaPackageElement.Type type : MediaPackageElement.Type.values())
         if (type.toString().equalsIgnoreCase(expectedTypeStr)) {
           expectedType = type;
           break;
         }
 
       if (expectedType == null)
         throw new WorkflowOperationException("'" + expectedTypeStr + "' is not a valid element type");
     }
 
     // Process the result element
     MediaPackageElement resultElement = null;
 
     try {
       Job job = executeService.execute(exec, params, mediaPackage, outputFilename, expectedType, load);
 
       WorkflowOperationResult result = null;
 
       // Wait for all jobs to be finished
       if (!waitForStatus(job).isSuccess())
         throw new WorkflowOperationException("Execute operation failed");
 
       if (StringUtils.isNotBlank(job.getPayload())) {
 
         if (setWfProps) {
           // The job payload is a file with set of properties for the workflow
           resultElement = MediaPackageElementParser.getFromXml(job.getPayload());
 
           final Properties properties = new Properties();
           File propertiesFile = workspace.get(resultElement.getURI());
           try (InputStreamReader reader = new InputStreamReader(new FileInputStream(propertiesFile), StandardCharsets.UTF_8)) {
             properties.load(reader);
           }
           logger.debug("Loaded {} properties from {}", properties.size(), propertiesFile);
           workspace.deleteFromCollection(ExecuteService.COLLECTION, propertiesFile.getName());
 
           Map<String, String> wfProps = new HashMap<String, String>((Map) properties);
 
           result = createResult(mediaPackage, wfProps, Action.CONTINUE, job.getQueueTime());
         } else {
           // The job payload is a new element for the MediaPackage
           resultElement = MediaPackageElementParser.getFromXml(job.getPayload());
 
           if (resultElement.getElementType() == MediaPackageElement.Type.Track) {
             // Have the track inspected and return the result
             Job inspectionJob = null;
             inspectionJob = inspectionService.inspect(resultElement.getURI());
 
             if (!waitForStatus(inspectionJob).isSuccess()) {
               throw new ExecuteException("Media inspection of " + resultElement.getURI() + " failed");
             }
 
             resultElement = MediaPackageElementParser.getFromXml(inspectionJob.getPayload());
           }
 
           // Store new element to mediaPackage
           mediaPackage.add(resultElement);
           URI uri = workspace.moveTo(resultElement.getURI(), mediaPackage.getIdentifier().toString(),
                   resultElement.getIdentifier(), outputFilename);
           resultElement.setURI(uri);
 
           // Set new flavor
           if (targetFlavor != null)
             resultElement.setFlavor(targetFlavor);
 
           // Set new tags
           applyTargetTagsToElement(targetTags, resultElement);
 
           result = createResult(mediaPackage, Action.CONTINUE, job.getQueueTime());
         }
       } else {
         // Payload is empty
         result = createResult(mediaPackage, Action.CONTINUE, job.getQueueTime());
       }
 
       logger.debug("Execute operation {} completed", operation.getId());
 
       return result;
 
     } catch (ExecuteException e) {
       throw new WorkflowOperationException(e);
     } catch (MediaPackageException e) {
       throw new WorkflowOperationException("Some result element couldn't be serialized", e);
     } catch (NotFoundException e) {
       throw new WorkflowOperationException("Could not find mediapackage", e);
     } catch (IOException e) {
       throw new WorkflowOperationException("Error unmarshalling a result mediapackage element", e);
     } catch (MediaInspectionException e) {
       throw new WorkflowOperationException("Media inspection of " + resultElement.getURI() + " failed", e);
     }
 
   }
 
   /**
    * {@inheritDoc}
    * 
    * @see org.opencastproject.workflow.api.WorkflowOperationHandler#skip(org.opencastproject.workflow.api.WorkflowInstance, JobContext)
    */
   @Override
   public WorkflowOperationResult skip(WorkflowInstance workflowInstance, JobContext context) throws WorkflowOperationException {
     return new WorkflowOperationResultImpl(workflowInstance.getMediaPackage(), null, Action.SKIP, 0);
   }
 
   @Override
   public String getId() {
     return "execute";
   }
 
   @Override
   public String getDescription() {
     return "Executes command line workflow operations in workers";
   }
 
   @Override
   public void destroy(WorkflowInstance workflowInstance, JobContext context) throws WorkflowOperationException {
     // Do nothing (nothing to clean up, the command line program should do this itself)
   }
 
   /**
    * Sets the service
    * 
    * @param service
    */
   @Reference
   public void setExecuteService(ExecuteService service) {
     this.executeService = service;
   }
 
   /**
    * Sets a reference to the workspace service.
    * 
    * @param workspace
    */
   @Reference
   public void setWorkspace(Workspace workspace) {
     this.workspace = workspace;
   }
 
   /**
    * Sets the media inspection service
    * 
    * @param mediaInspectionService
    *          an instance of the media inspection service
    */
   @Reference
   protected void setMediaInspectionService(MediaInspectionService mediaInspectionService) {
     this.inspectionService = mediaInspectionService;
   }
 
   @Reference
   @Override
   public void setServiceRegistry(ServiceRegistry serviceRegistry) {
     super.setServiceRegistry(serviceRegistry);
   }
 }