/*
    * 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.endpoint;
  
  import static javax.servlet.http.HttpServletResponse.SC_BAD_REQUEST;
  import static javax.servlet.http.HttpServletResponse.SC_CONFLICT;
  import static javax.servlet.http.HttpServletResponse.SC_FORBIDDEN;
  import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;
  import static javax.servlet.http.HttpServletResponse.SC_NO_CONTENT;
  import static javax.servlet.http.HttpServletResponse.SC_OK;
  import static javax.servlet.http.HttpServletResponse.SC_UNAUTHORIZED;
  import static org.opencastproject.util.doc.rest.RestParameter.Type.STRING;
  import static org.opencastproject.util.doc.rest.RestParameter.Type.TEXT;
  
  import org.opencastproject.job.api.JobProducer;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageElement;
  import org.opencastproject.mediapackage.MediaPackageImpl;
  import org.opencastproject.mediapackage.MediaPackageParser;
  import org.opencastproject.mediapackage.MediaPackageSupport;
  import org.opencastproject.rest.AbstractJobProducerEndpoint;
  import org.opencastproject.rest.RestConstants;
  import org.opencastproject.security.api.Permissions;
  import org.opencastproject.security.api.UnauthorizedException;
  import org.opencastproject.serviceregistry.api.ServiceRegistry;
  import org.opencastproject.systems.OpencastConstants;
  import org.opencastproject.util.LocalHashMap;
  import org.opencastproject.util.NotFoundException;
  import org.opencastproject.util.UrlSupport;
  import org.opencastproject.util.doc.rest.RestParameter;
  import org.opencastproject.util.doc.rest.RestParameter.Type;
  import org.opencastproject.util.doc.rest.RestQuery;
  import org.opencastproject.util.doc.rest.RestResponse;
  import org.opencastproject.util.doc.rest.RestService;
  import org.opencastproject.workflow.api.JaxbWorkflowInstance;
  import org.opencastproject.workflow.api.WorkflowDatabaseException;
  import org.opencastproject.workflow.api.WorkflowDefinition;
  import org.opencastproject.workflow.api.WorkflowDefinitionImpl;
  import org.opencastproject.workflow.api.WorkflowDefinitionSet;
  import org.opencastproject.workflow.api.WorkflowException;
  import org.opencastproject.workflow.api.WorkflowInstance;
  import org.opencastproject.workflow.api.WorkflowInstance.WorkflowState;
  import org.opencastproject.workflow.api.WorkflowOperationHandler;
  import org.opencastproject.workflow.api.WorkflowParsingException;
  import org.opencastproject.workflow.api.WorkflowService;
  import org.opencastproject.workflow.api.WorkflowSetImpl;
  import org.opencastproject.workflow.api.WorkflowStateException;
  import org.opencastproject.workflow.api.XmlWorkflowParser;
  import org.opencastproject.workflow.impl.WorkflowServiceImpl;
  import org.opencastproject.workflow.impl.WorkflowServiceImpl.HandlerRegistration;
  import org.opencastproject.workspace.api.Workspace;
  
  import com.google.common.util.concurrent.Striped;
  
  import org.apache.commons.lang3.StringUtils;
  import org.apache.commons.lang3.exception.ExceptionUtils;
  import org.json.simple.JSONArray;
  import org.json.simple.JSONObject;
  import org.osgi.service.component.ComponentContext;
  import org.osgi.service.component.annotations.Activate;
  import org.osgi.service.component.annotations.Component;
  import org.osgi.service.component.annotations.Reference;
  import org.osgi.service.jaxrs.whiteboard.propertytypes.JaxrsResource;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  import java.util.concurrent.locks.Lock;
  
  import javax.servlet.http.HttpServletResponse;
  import javax.ws.rs.DELETE;
  import javax.ws.rs.FormParam;
  import javax.ws.rs.GET;
  import javax.ws.rs.POST;
  import javax.ws.rs.Path;
  import javax.ws.rs.PathParam;
  import javax.ws.rs.Produces;
 import javax.ws.rs.QueryParam;
 import javax.ws.rs.WebApplicationException;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 import javax.ws.rs.core.Response.Status;
 
 /**
  * A REST endpoint for the {@link WorkflowService}
  */
 @Path("/workflow")
 @RestService(name = "workflowservice", title = "Workflow Service", abstractText = "This service lists available workflows and starts, stops, suspends and resumes workflow instances.", notes = {
         "All paths above are relative to the REST endpoint base (something like http://your.server/files)",
         "If the service is down or not working it will return a status 503, this means the the underlying service is "
                 + "not working and is either restarting or has failed",
         "A status code 500 means a general failure has occurred which is not recoverable and was not anticipated. In "
                 + "other words, there is a bug! You should file an error report with your server logs from the time when the "
                 + "error occurred: <a href=\"https://github.com/opencast/opencast/issues\">Opencast Issue Tracker</a>" })
 @Component(
     immediate = true,
     service = WorkflowRestService.class,
     property = {
         "service.description=Workflow REST Endpoint",
         "opencast.service.type=org.opencastproject.workflow",
         "opencast.service.path=/workflow",
         "opencast.service.jobproducer=true"
     }
 )
 @JaxrsResource
 public class WorkflowRestService extends AbstractJobProducerEndpoint {
 
   /** The default number of results returned */
   private static final int DEFAULT_LIMIT = 20;
   /** The constant used to negate a querystring parameter. This is only supported on some parameters. */
   public static final String NEGATE_PREFIX = "-";
   /** The constant used to switch the direction of the sorting querystring parameter. */
   public static final String DESCENDING_SUFFIX = "_DESC";
   /** The logger */
   private static final Logger logger = LoggerFactory.getLogger(WorkflowRestService.class);
 
   /** The default server URL */
   protected String serverUrl = UrlSupport.DEFAULT_BASE_URL;
   /** The default service URL */
   protected String serviceUrl = serverUrl + "/workflow";
   /** The workflow service instance */
   private WorkflowService service;
   /** The service registry */
   protected ServiceRegistry serviceRegistry = null;
   /** The workspace */
   private Workspace workspace;
 
   /** Resource lock */
   private final Striped<Lock> lock = Striped.lazyWeakLock(1024);
 
   /**
    * Callback from the OSGi declarative services to set the service registry.
    *
    * @param serviceRegistry
    *          the service registry
    */
   @Reference
   protected void setServiceRegistry(ServiceRegistry serviceRegistry) {
     this.serviceRegistry = serviceRegistry;
   }
 
   /**
    * Sets the workflow service
    *
    * @param service
    *          the workflow service instance
    */
   @Reference
   public void setService(WorkflowService service) {
     this.service = service;
   }
 
   /**
    * Callback from the OSGi declarative services to set the workspace.
    *
    * @param workspace
    *          the workspace
    */
   @Reference
   public void setWorkspace(Workspace workspace) {
     this.workspace = workspace;
   }
 
   /**
    * OSGI callback for component activation
    *
    * @param cc
    *          the OSGI declarative services component context
    */
   @Activate
   public void activate(ComponentContext cc) {
     // Get the configured server URL
     if (cc == null) {
       serverUrl = UrlSupport.DEFAULT_BASE_URL;
     } else {
       String ccServerUrl = cc.getBundleContext().getProperty(OpencastConstants.SERVER_URL_PROPERTY);
       logger.info("configured server url is {}", ccServerUrl);
       if (ccServerUrl == null) {
         serverUrl = UrlSupport.DEFAULT_BASE_URL;
       } else {
         serverUrl = ccServerUrl;
       }
       serviceUrl = (String) cc.getProperties().get(RestConstants.SERVICE_PATH_PROPERTY);
     }
   }
 
   @GET
   @Produces(MediaType.TEXT_PLAIN)
   @Path("/count")
   @RestQuery(name = "count", description = "Returns the number of workflow instances in a specific state", returnDescription = "Returns the number of workflow instances in a specific state", restParameters = {
           @RestParameter(name = "state", isRequired = false, description = "The workflow state", type = STRING)},
           responses = { @RestResponse(responseCode = SC_OK, description = "The number of workflow instances.") })
   public Response getCount(@QueryParam("state") WorkflowInstance.WorkflowState state,
           @QueryParam("operation") String operation) {
     try {
       Long count = service.countWorkflowInstances(state);
       return Response.ok(count).build();
     } catch (WorkflowDatabaseException e) {
       throw new WebApplicationException(e);
     }
   }
 
   @GET
   @Path("definitions.json")
   @Produces(MediaType.APPLICATION_JSON)
   @RestQuery(name = "definitions", description = "List all available workflow definitions as JSON", returnDescription = "Returns the workflow definitions as JSON", responses = { @RestResponse(responseCode = SC_OK, description = "The workflow definitions.") })
   public WorkflowDefinitionSet getWorkflowDefinitionsAsJson() throws Exception {
     return getWorkflowDefinitionsAsXml();
   }
 
   @GET
   @Path("definitions.xml")
   @Produces(MediaType.APPLICATION_XML)
   @RestQuery(name = "definitions", description = "List all available workflow definitions as XML", returnDescription = "Returns the workflow definitions as XML", responses = { @RestResponse(responseCode = SC_OK, description = "The workflow definitions.") })
   public WorkflowDefinitionSet getWorkflowDefinitionsAsXml() throws Exception {
     List<WorkflowDefinition> list = service.listAvailableWorkflowDefinitions();
     return new WorkflowDefinitionSet(list);
   }
 
   @GET
   @Produces(MediaType.APPLICATION_JSON)
   @Path("definition/{id}.json")
   @RestQuery(name = "definitionasjson", description = "Returns a single workflow definition", returnDescription = "Returns a JSON representation of the workflow definition with the specified identifier", pathParameters = { @RestParameter(name = "id", isRequired = true, description = "The workflow definition identifier", type = STRING) }, responses = {
           @RestResponse(responseCode = SC_OK, description = "The workflow definition."),
           @RestResponse(responseCode = SC_NOT_FOUND, description = "Workflow definition not found.") })
   public Response getWorkflowDefinitionAsJson(@PathParam("id") String workflowDefinitionId)
           throws NotFoundException {
     WorkflowDefinition def;
     try {
       def = service.getWorkflowDefinitionById(workflowDefinitionId);
     } catch (WorkflowDatabaseException e) {
       throw new WebApplicationException(e);
     }
     return Response.ok(def).build();
   }
 
   @GET
   @Produces(MediaType.TEXT_XML)
   @Path("definition/{id}.xml")
   @RestQuery(name = "definitionasxml", description = "Returns a single workflow definition", returnDescription = "Returns an XML representation of the workflow definition with the specified identifier", pathParameters = { @RestParameter(name = "id", isRequired = true, description = "The workflow definition identifier", type = STRING) }, responses = {
           @RestResponse(responseCode = SC_OK, description = "The workflow definition."),
           @RestResponse(responseCode = SC_NOT_FOUND, description = "Workflow definition not found.") })
   public Response getWorkflowDefinitionAsXml(@PathParam("id") String workflowDefinitionId)
           throws NotFoundException {
     return getWorkflowDefinitionAsJson(workflowDefinitionId);
   }
 
   /**
    * Returns the workflow configuration panel HTML snippet for the workflow definition specified by
    *
    * @param definitionId
    * @return config panel HTML snippet
    */
   @GET
   @Produces(MediaType.TEXT_HTML)
   @Path("configurationPanel")
   @RestQuery(name = "configpanel", description = "Get the configuration panel for a specific workflow", returnDescription = "The HTML workflow configuration panel", restParameters = { @RestParameter(name = "definitionId", isRequired = false, description = "The workflow definition identifier", type = STRING) }, responses = { @RestResponse(responseCode = SC_OK, description = "The workflow configuration panel.") })
   public Response getConfigurationPanel(@QueryParam("definitionId") String definitionId)
           throws NotFoundException {
     try {
       final WorkflowDefinition def = service.getWorkflowDefinitionById(definitionId);
       final String out = def.getConfigurationPanel();
       return Response.ok(out).build();
     } catch (WorkflowDatabaseException e) {
       throw new WebApplicationException(Status.INTERNAL_SERVER_ERROR);
     }
   }
 
   @GET
   @Produces(MediaType.APPLICATION_JSON)
   @Path("mediaPackage/{id}/hasActiveWorkflows")
   @RestQuery(name = "hasactiveworkflows", description = "Returns if a media package has active workflows",
           returnDescription = "Returns wether the media package has active workflows as a boolean.",
           pathParameters = {
                   @RestParameter(name = "id", isRequired = true, description = "The media package identifier", type = STRING) },
           responses = {
                   @RestResponse(responseCode = SC_OK, description = "Whether the media package has active workflows.")})
   public Response mediaPackageHasActiveWorkflows(@PathParam("id") String mediaPackageId) {
     try {
       return Response.ok(Boolean.toString(service.mediaPackageHasActiveWorkflows(mediaPackageId))).build();
 
     } catch (WorkflowDatabaseException e) {
       throw new WebApplicationException(Status.INTERNAL_SERVER_ERROR);
     }
   }
 
   @GET
   @Produces(MediaType.APPLICATION_JSON)
   @Path("mediaPackage/{id}/instances.json")
   @RestQuery(name = "workflowsofmediapackage", description = "Returns the workflows for a media package",
           returnDescription = "Returns the workflows that are associated with the media package as JSON.",
           pathParameters = {
                   @RestParameter(name = "id", isRequired = true, description = "The media package identifier", type = STRING) },
           responses = {
                   @RestResponse(responseCode = SC_OK, description = "Returns the workflows for a media package.")})
   public Response getWorkflowsOfMediaPackage(@PathParam("id") String mediaPackageId) {
     try {
       return Response.ok(new WorkflowSetImpl(service.getWorkflowInstancesByMediaPackage(mediaPackageId))).build();
     } catch (UnauthorizedException e) {
       return Response.status(Status.FORBIDDEN).build();
     } catch (WorkflowDatabaseException e) {
       throw new WebApplicationException(Status.INTERNAL_SERVER_ERROR);
     }
   }
 
   @GET
   @Produces(MediaType.APPLICATION_JSON)
   @Path("mediaPackage/{id}/currentInstance.json")
   @RestQuery(name = "currentworkflowofmediapackage", description = "Returns the current workflow for a media package",
           returnDescription = "Returns the currentworkflow that are associated with the media package as JSON.",
           pathParameters = {
                   @RestParameter(name = "id", isRequired = true, description = "The media package identifier", type = STRING) },
           responses = {
                   @RestResponse(responseCode = SC_OK, description = "Returns the workflows for a media package."),
                   @RestResponse(responseCode = SC_NOT_FOUND, description = "Current workflow not found.") })
   public Response getRunningWorkflowOfMediaPackage(@PathParam("id") String mediaPackageId) {
     try {
       Optional<WorkflowInstance> optWorkflowInstance = service.
               getRunningWorkflowInstanceByMediaPackage(mediaPackageId, Permissions.Action.READ.toString());
       if (optWorkflowInstance.isPresent()) {
         return Response.ok(new JaxbWorkflowInstance(optWorkflowInstance.get())).build();
       } else {
         return Response.status(Response.Status.NOT_FOUND).build();
       }
 
     } catch (WorkflowException | UnauthorizedException e) {
       throw new WebApplicationException(Status.INTERNAL_SERVER_ERROR);
     }
   }
 
   @GET
   @Produces(MediaType.APPLICATION_JSON)
   @Path("user/{id}/hasActiveWorkflows")
   @RestQuery(name = "userhasactiveworkflows", description = "Returns if there are currently workflow(s) running that"
           + "were started by the given user",
           returnDescription = "Returns if there are currently workflow(s) running that were started by the given user "
                   + "as a boolean.",
           pathParameters = {
                   @RestParameter(name = "id", isRequired = true, description = "The user identifier", type = STRING) },
           responses = {
                   @RestResponse(responseCode = SC_OK, description = "Whether there are active workflow for the user.")})
   public Response userHasActiveWorkflows(@PathParam("id") String userId) {
     try {
       return Response.ok(Boolean.toString(service.userHasActiveWorkflows(userId))).build();
 
     } catch (WorkflowDatabaseException e) {
       throw new WebApplicationException(Status.INTERNAL_SERVER_ERROR);
     }
   }
 
   @GET
   @Produces(MediaType.TEXT_XML)
   @Path("instance/{id}.xml")
   @RestQuery(name = "workflowasxml", description = "Get a specific workflow instance.", returnDescription = "An XML representation of a workflow instance", pathParameters = { @RestParameter(name = "id", isRequired = true, description = "The workflow instance identifier", type = STRING) }, responses = {
           @RestResponse(responseCode = SC_OK, description = "An XML representation of the workflow instance."),
           @RestResponse(responseCode = SC_NOT_FOUND, description = "No workflow instance with that identifier exists.") })
   public JaxbWorkflowInstance getWorkflowAsXml(@PathParam("id") long id) throws WorkflowDatabaseException,
           NotFoundException, UnauthorizedException {
     return new JaxbWorkflowInstance(service.getWorkflowById(id));
   }
 
   @GET
   @Produces(MediaType.APPLICATION_JSON)
   @Path("instance/{id}.json")
   @RestQuery(name = "workflowasjson", description = "Get a specific workflow instance.", returnDescription = "A JSON representation of a workflow instance", pathParameters = { @RestParameter(name = "id", isRequired = true, description = "The workflow instance identifier", type = STRING) }, responses = {
           @RestResponse(responseCode = SC_OK, description = "A JSON representation of the workflow instance."),
           @RestResponse(responseCode = SC_NOT_FOUND, description = "No workflow instance with that identifier exists.") })
   public JaxbWorkflowInstance getWorkflowAsJson(@PathParam("id") long id) throws WorkflowDatabaseException,
           NotFoundException, UnauthorizedException {
     return getWorkflowAsXml(id);
   }
 
   @POST
   @Path("start")
   @Produces(MediaType.TEXT_XML)
   @RestQuery(name = "start", description = "Start a new workflow instance.", returnDescription = "An XML representation of the new workflow instance", restParameters = {
           @RestParameter(name = "definition", isRequired = true, description = "The workflow definition ID or an XML representation of a workflow definition", type = TEXT, jaxbClass = WorkflowDefinitionImpl.class),
           @RestParameter(name = "mediapackage", isRequired = true, description = "The XML representation of a mediapackage", type = TEXT, jaxbClass = MediaPackageImpl.class),
           @RestParameter(name = "parent", isRequired = false, description = "An optional parent workflow instance identifier", type = STRING),
           @RestParameter(name = "properties", isRequired = false, description = "An optional set of key=value\\n properties", type = TEXT) }, responses = {
           @RestResponse(responseCode = SC_OK, description = "An XML representation of the new workflow instance."),
           @RestResponse(responseCode = SC_UNAUTHORIZED, description = "You do not have permission to resume. Maybe you need to authenticate."),
           @RestResponse(responseCode = SC_NOT_FOUND, description = "If the parent workflow does not exist") })
   public JaxbWorkflowInstance start(@FormParam("definition") String workflowDefinitionXmlOrId,
           @FormParam("mediapackage") MediaPackageImpl mp, @FormParam("parent") String parentWorkflowId,
           @FormParam("properties") LocalHashMap localMap) {
     if (mp == null || StringUtils.isBlank(workflowDefinitionXmlOrId))
       throw new WebApplicationException(Status.BAD_REQUEST);
 
     WorkflowDefinition workflowDefinition;
     try {
       workflowDefinition = service.getWorkflowDefinitionById(workflowDefinitionXmlOrId);
     } catch (Exception e) {
       // Not an ID. Let's try if it's an XML definition
       try {
         workflowDefinition = XmlWorkflowParser.parseWorkflowDefinition(workflowDefinitionXmlOrId);
       } catch (WorkflowParsingException wpe) {
         throw new WebApplicationException(wpe, Status.BAD_REQUEST);
       }
     }
 
     WorkflowInstance instance = null;
     try {
       instance = startWorkflow(workflowDefinition, mp, parentWorkflowId, localMap);
     } catch (UnauthorizedException e) {
       throw new WebApplicationException(e, Status.UNAUTHORIZED);
     }
     return new JaxbWorkflowInstance(instance);
   }
 
   private WorkflowInstance startWorkflow(WorkflowDefinition workflowDefinition, MediaPackageImpl mp,
           String parentWorkflowId, LocalHashMap localMap) throws UnauthorizedException {
     Map<String, String> properties = new HashMap<String, String>();
     if (localMap != null)
       properties = localMap.getMap();
 
     Long parentIdAsLong = null;
     if (StringUtils.isNotEmpty(parentWorkflowId)) {
       try {
         parentIdAsLong = Long.parseLong(parentWorkflowId);
       } catch (NumberFormatException e) {
         throw new WebApplicationException(e, Status.BAD_REQUEST);
       }
     }
 
     try {
       return (WorkflowInstance) service.start(workflowDefinition, mp, parentIdAsLong, properties);
     } catch (WorkflowException e) {
       throw new WebApplicationException(e);
     } catch (NotFoundException e) {
       throw new WebApplicationException(e);
     }
   }
 
   @POST
   @Path("stop")
   @Produces(MediaType.TEXT_XML)
   @RestQuery(name = "stop", description = "Stops a workflow instance.", returnDescription = "An XML representation of the stopped workflow instance", restParameters = { @RestParameter(name = "id", isRequired = true, description = "The workflow instance identifier", type = STRING) }, responses = {
           @RestResponse(responseCode = SC_OK, description = "An XML representation of the stopped workflow instance."),
           @RestResponse(responseCode = SC_NOT_FOUND, description = "No running workflow instance with that identifier exists.") })
   public JaxbWorkflowInstance stop(@FormParam("id") long workflowInstanceId) throws WorkflowException, NotFoundException,
           UnauthorizedException {
     WorkflowInstance instance = service.stop(workflowInstanceId);
     return new JaxbWorkflowInstance(instance);
   }
 
   @DELETE
   @Path("remove/{id}")
   @Produces(MediaType.TEXT_PLAIN)
   @RestQuery(name = "remove", description = "Danger! Permenantly removes a workflow instance including all its child jobs. In most circumstances, /stop is what you should use.", returnDescription = "HTTP 204 No Content", pathParameters = {
           @RestParameter(name = "id", isRequired = true, description = "The workflow instance identifier", type = STRING)}, restParameters = {
           @RestParameter(name = "force", isRequired = false, description = "If the workflow status should be ignored and the workflow removed anyway", type = Type.BOOLEAN, defaultValue = "false")}, responses = {
           @RestResponse(responseCode = HttpServletResponse.SC_NO_CONTENT, description = "If workflow instance could be removed successfully, no content is returned"),
           @RestResponse(responseCode = SC_NOT_FOUND, description = "No workflow instance with that identifier exists."),
           @RestResponse(responseCode = SC_FORBIDDEN, description = "It's not allowed to remove other workflow instance statues than STOPPED, SUCCEEDED and FAILED (use force parameter to override AT YOUR OWN RISK).") })
   public Response remove(@PathParam("id") long workflowInstanceId, @QueryParam("force") boolean force) throws WorkflowException, NotFoundException,
           UnauthorizedException {
     try {
       service.remove(workflowInstanceId, force);
     } catch (WorkflowStateException e) {
       return Response.status(Status.FORBIDDEN).build();
     }
     return Response.noContent().build();
   }
 
   @POST
   @Path("suspend")
   @Produces(MediaType.TEXT_XML)
   @RestQuery(name = "suspend", description = "Suspends a workflow instance.", returnDescription = "An XML representation of the suspended workflow instance", restParameters = { @RestParameter(name = "id", isRequired = true, description = "The workflow instance identifier", type = STRING) }, responses = {
           @RestResponse(responseCode = SC_OK, description = "An XML representation of the suspended workflow instance."),
           @RestResponse(responseCode = SC_NOT_FOUND, description = "No running workflow instance with that identifier exists.") })
   public Response suspend(@FormParam("id") long workflowInstanceId) throws NotFoundException, UnauthorizedException {
     try {
       WorkflowInstance workflow = service.suspend(workflowInstanceId);
       return Response.ok(new JaxbWorkflowInstance(workflow)).build();
     } catch (WorkflowException e) {
       throw new WebApplicationException(e);
     }
   }
 
   @POST
   @Path("resume")
   @Produces(MediaType.TEXT_XML)
   @RestQuery(name = "resume", description = "Resumes a suspended workflow instance.", returnDescription = "An XML representation of the resumed workflow instance", restParameters = { @RestParameter(name = "id", isRequired = true, description = "The workflow instance identifier", type = STRING) }, responses = {
           @RestResponse(responseCode = SC_OK, description = "An XML representation of the resumed workflow instance."),
           @RestResponse(responseCode = SC_CONFLICT, description = "Can not resume workflow not in paused state"),
           @RestResponse(responseCode = SC_NOT_FOUND, description = "No suspended workflow instance with that identifier exists."),
           @RestResponse(responseCode = SC_UNAUTHORIZED, description = "You do not have permission to resume. Maybe you need to authenticate.") })
   public Response resume(@FormParam("id") long workflowInstanceId, @FormParam("properties") LocalHashMap properties)
           throws NotFoundException, UnauthorizedException {
     return resume(workflowInstanceId, null, properties);
   }
 
   @POST
   @Path("replaceAndresume")
   @Produces(MediaType.TEXT_XML)
   @RestQuery(name = "replaceAndresume", description = "Replaces a suspended workflow instance with an updated version, and resumes the workflow.", returnDescription = "An XML representation of the updated and resumed workflow instance", restParameters = {
           @RestParameter(name = "id", isRequired = true, description = "The workflow instance identifier", type = STRING),
           @RestParameter(name = "mediapackage", isRequired = false, description = "The new Mediapackage", type = TEXT),
           @RestParameter(name = "properties", isRequired = false, description = "Properties", type = TEXT) }, responses = {
           @RestResponse(responseCode = SC_OK, description = "An XML representation of the updated and resumed workflow instance."),
           @RestResponse(responseCode = SC_CONFLICT, description = "Can not resume workflow not in paused state"),
           @RestResponse(responseCode = SC_NOT_FOUND, description = "No suspended workflow instance with that identifier exists."),
           @RestResponse(responseCode = SC_UNAUTHORIZED, description = "You do not have permission to resume. Maybe you need to authenticate.") })
   public Response resume(@FormParam("id") long workflowInstanceId,
           @FormParam("mediapackage") final String mediaPackage, @FormParam("properties") LocalHashMap properties)
           throws NotFoundException, UnauthorizedException {
     final Map<String, String> map;
     if (properties == null) {
       map = new HashMap<String, String>();
     } else {
       map = properties.getMap();
     }
     final Lock lock = this.lock.get(workflowInstanceId);
     lock.lock();
     try {
       WorkflowInstance workflow = service.getWorkflowById(workflowInstanceId);
       if (!WorkflowState.PAUSED.equals(workflow.getState())) {
         logger.warn("Can not resume workflow '{}', not in state paused but {}", workflow, workflow.getState());
         return Response.status(Status.CONFLICT).build();
       }
 
       if (mediaPackage != null) {
         MediaPackage newMp = MediaPackageParser.getFromXml(mediaPackage);
         MediaPackage oldMp = workflow.getMediaPackage();
 
         // Delete removed elements from workspace
         for (MediaPackageElement elem : oldMp.getElements()) {
           if (MediaPackageSupport.contains(elem.getIdentifier(), newMp))
             continue;
           try {
             workspace.delete(elem.getURI());
             logger.info("Deleted removed mediapackge element {}", elem);
           } catch (NotFoundException e) {
             logger.info("Removed mediapackage element {} is already deleted", elem);
           }
         }
 
         workflow.setMediaPackage(newMp);
         service.update(workflow);
       }
       workflow = service.resume(workflowInstanceId, map);
       return Response.ok(new JaxbWorkflowInstance(workflow)).build();
     } catch (NotFoundException e) {
       return Response.status(Status.NOT_FOUND).build();
     } catch (UnauthorizedException e) {
       return Response.status(Status.UNAUTHORIZED).build();
     } catch (IllegalStateException e) {
       logger.warn(ExceptionUtils.getMessage(e));
       return Response.status(Status.CONFLICT).build();
     } catch (WorkflowException e) {
       logger.error(ExceptionUtils.getMessage(e), e);
       return Response.serverError().build();
     } catch (Exception e) {
       logger.error(ExceptionUtils.getMessage(e), e);
       return Response.serverError().build();
     }
     finally {
       lock.unlock();
     }
   }
 
   @POST
   @Path("update")
   @RestQuery(name = "update", description = "Updates a workflow instance.", returnDescription = "No content.", restParameters = { @RestParameter(name = "workflow", isRequired = true, description = "The XML representation of the workflow instance.", type = TEXT) }, responses = { @RestResponse(responseCode = SC_NO_CONTENT, description = "Workflow instance updated.") })
   public Response update(@FormParam("workflow") String workflowInstance) throws NotFoundException,
           UnauthorizedException {
     try {
       WorkflowInstance instance = XmlWorkflowParser.parseWorkflowInstance(workflowInstance);
       service.update(instance);
       return Response.noContent().build();
     } catch (WorkflowException e) {
       throw new WebApplicationException(e);
     }
   }
 
   @GET
   @Path("handlers.json")
   @SuppressWarnings("unchecked")
   @RestQuery(name = "handlers", description = "List all registered workflow operation handlers (implementations).", returnDescription = "A JSON representation of the registered workflow operation handlers.", responses = { @RestResponse(responseCode = SC_OK, description = "A JSON representation of the registered workflow operation handlers") })
   public Response getOperationHandlers() {
     JSONArray jsonArray = new JSONArray();
     for (HandlerRegistration reg : ((WorkflowServiceImpl) service).getRegisteredHandlers()) {
       WorkflowOperationHandler handler = reg.getHandler();
       JSONObject jsonHandler = new JSONObject();
       jsonHandler.put("id", handler.getId());
       jsonHandler.put("description", handler.getDescription());
       jsonArray.add(jsonHandler);
     }
     return Response.ok(jsonArray.toJSONString()).header("Content-Type", MediaType.APPLICATION_JSON).build();
   }
 
   @GET
   @Path("statemappings.json")
   @SuppressWarnings("unchecked")
   @RestQuery(name = "statemappings", description = "Get all workflow state mappings",
       returnDescription = "A JSON representation of the workflow state mappings.",
       responses = { @RestResponse(responseCode = SC_OK, description = "A JSON representation of the workflow state mappings") })
   public Response getStateMappings() {
     return Response.ok(new JSONObject(service.getWorkflowStateMappings()).toJSONString())
         .header("Content-Type", MediaType.APPLICATION_JSON).build();
   }
 
   @Path("/cleanup")
   @RestQuery(name = "cleanup", description = "Cleans up workflow instances", returnDescription = "No return value", responses = {
           @RestResponse(responseCode = SC_OK, description = "Cleanup OK"),
           @RestResponse(responseCode = SC_BAD_REQUEST, description = "Couldn't parse given state"),
           @RestResponse(responseCode = SC_UNAUTHORIZED, description = "You do not have permission to cleanup. Maybe you need to authenticate."),
           @RestResponse(responseCode = SC_FORBIDDEN, description = "It's not allowed to delete other workflow instance statues than STOPPED, SUCCEEDED and FAILED") }, restParameters = {
           @RestParameter(name = "buffer", type = Type.INTEGER, defaultValue = "30", isRequired = true, description = "Lifetime (buffer) in days a workflow instance should live"),
           @RestParameter(name = "state", type = Type.STRING, isRequired = true, description = "Workflow instance state, only STOPPED, SUCCEEDED and FAILED are allowed values here") })
   public Response cleanup(@FormParam("buffer") int buffer, @FormParam("state") String stateParam)
           throws UnauthorizedException {
 
     WorkflowInstance.WorkflowState state;
     try {
       state = WorkflowInstance.WorkflowState.valueOf(stateParam);
     } catch (IllegalArgumentException e) {
       return Response.status(Status.BAD_REQUEST).build();
     }
 
     if (state != WorkflowInstance.WorkflowState.SUCCEEDED && state != WorkflowInstance.WorkflowState.FAILED
             && state != WorkflowInstance.WorkflowState.STOPPED)
       return Response.status(Status.FORBIDDEN).build();
 
     try {
       service.cleanupWorkflowInstances(buffer, state);
       return Response.ok().build();
     } catch (WorkflowDatabaseException e) {
       throw new WebApplicationException(e);
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.rest.AbstractJobProducerEndpoint#getService()
    */
   @Override
   public JobProducer getService() {
     if (service instanceof JobProducer) {
       return (JobProducer) service;
     } else {
       return null;
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.rest.AbstractJobProducerEndpoint#getServiceRegistry()
    */
   @Override
   public ServiceRegistry getServiceRegistry() {
     return serviceRegistry;
   }
 }