/*
    * 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.impl.endpoint;
  
  import org.opencastproject.execute.api.ExecuteException;
  import org.opencastproject.execute.api.ExecuteService;
  import org.opencastproject.job.api.JaxbJob;
  import org.opencastproject.job.api.Job;
  import org.opencastproject.job.api.JobProducer;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageElement;
  import org.opencastproject.mediapackage.MediaPackageElementParser;
  import org.opencastproject.mediapackage.MediaPackageException;
  import org.opencastproject.mediapackage.MediaPackageParser;
  import org.opencastproject.rest.AbstractJobProducerEndpoint;
  import org.opencastproject.serviceregistry.api.ServiceRegistry;
  import org.opencastproject.util.doc.rest.RestParameter;
  import org.opencastproject.util.doc.rest.RestQuery;
  import org.opencastproject.util.doc.rest.RestResponse;
  import org.opencastproject.util.doc.rest.RestService;
  
  import org.apache.commons.lang3.StringUtils;
  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 javax.servlet.http.HttpServletResponse;
  import javax.ws.rs.FormParam;
  import javax.ws.rs.POST;
  import javax.ws.rs.Path;
  import javax.ws.rs.Produces;
  import javax.ws.rs.core.MediaType;
  import javax.ws.rs.core.Response;
  
  /**
   * The REST endpoint for {@link ExecuteService}s
   */
  @Path("/execute")
  // Endpoint to the execute service, that runs CLI commands using MediaPackageElement's as parameters
  @RestService(name = "execute", title = "Execute Service", notes = {"" }, abstractText = "Runs CLI commands with MediaPackageElement's as parameters")
  @Component(
      immediate = true,
      service = ExecuteRestEndpoint.class,
      property = {
          "service.description=Execute REST Endpoint",
          "opencast.service.type=org.opencastproject.execute",
          "opencast.service.path=/execute",
          "opencast.service.jobproducer=true"
      }
  )
  @JaxrsResource
  public class ExecuteRestEndpoint extends AbstractJobProducerEndpoint {
  
    /** The logging facility */
    private static final Logger logger = LoggerFactory.getLogger(ExecuteRestEndpoint.class);
  
    /** The service registry */
    protected ServiceRegistry serviceRegistry = null;
  
    /** The execute service */
    protected ExecuteService service;
  
    @POST
    @Produces(MediaType.TEXT_XML)
    @Path(ExecuteService.ENDPOINT_NAME)
    @RestQuery(name = "name", description = "Executes the given command", restParameters = {
            @RestParameter(description = "The command to execute", isRequired = true, name = ExecuteService.EXEC_FORM_PARAM, type = RestParameter.Type.STRING),
            @RestParameter(description = "The arguments to the command", isRequired = true, name = ExecuteService.PARAMS_FORM_PARAM, type = RestParameter.Type.STRING),
            @RestParameter(description = "The estimated load placed on the system by this command", isRequired = false, name = ExecuteService.LOAD_FORM_PARAM, type = RestParameter.Type.FLOAT),
            @RestParameter(description = "The mediapackage to apply the command to. Either this or " + ExecuteService.INPUT_ELEM_FORM_PARAM + " are required",
            isRequired = false, name = ExecuteService.INPUT_MP_FORM_PARAM, type = RestParameter.Type.TEXT),
            @RestParameter(description = "The mediapackage element to apply the command to. Either this or " + ExecuteService.INPUT_MP_FORM_PARAM + " are required",
            isRequired = false, name = ExecuteService.INPUT_ELEM_FORM_PARAM, type = RestParameter.Type.TEXT),
            @RestParameter(description = "The mediapackage element produced by the command", isRequired = false, name = ExecuteService.OUTPUT_NAME_FORM_PARAMETER,
            type = RestParameter.Type.STRING),
            @RestParameter(description = "The type of the returned element", isRequired = false, name = ExecuteService.TYPE_FORM_PARAMETER, type = RestParameter.Type.STRING) },
            responses = {
           @RestResponse(description = "XML-encoded Job is returned.", responseCode = HttpServletResponse.SC_NO_CONTENT),
           @RestResponse(description = "Service unavailabe or not currently present", responseCode = HttpServletResponse.SC_SERVICE_UNAVAILABLE),
           @RestResponse(description = "Incorrect parameters", responseCode = HttpServletResponse.SC_BAD_REQUEST),
           @RestResponse(description = "Problem executing the command or serializing the arguments/results", responseCode = HttpServletResponse.SC_INTERNAL_SERVER_ERROR)
           },
           returnDescription = "")
   public Response execute(@FormParam(ExecuteService.EXEC_FORM_PARAM) String exec,
           @FormParam(ExecuteService.PARAMS_FORM_PARAM) String params,
           @FormParam(ExecuteService.LOAD_FORM_PARAM) Float loadParam,
           @FormParam(ExecuteService.INPUT_ELEM_FORM_PARAM) String inputElementStr,
           @FormParam(ExecuteService.INPUT_MP_FORM_PARAM) String inputMpStr,
           @FormParam(ExecuteService.OUTPUT_NAME_FORM_PARAMETER) String outputFileName,
           @FormParam(ExecuteService.TYPE_FORM_PARAMETER) String elementTypeStr) {
 
     checkNotNull(service);
     try {
 
       MediaPackageElement.Type expectedType = null;
       if (StringUtils.isNotBlank(elementTypeStr)) {
         for (MediaPackageElement.Type candidateType : MediaPackageElement.Type.values())
           if (candidateType.toString().equalsIgnoreCase(elementTypeStr)) {
             expectedType = candidateType;
             break;
           }
         if (expectedType == null) {
           logger.error("Wrong element type specified: {}", elementTypeStr);
           return Response.status(Response.Status.BAD_REQUEST).build();
         }
       }
 
       float load = 1.0f;
       if (loadParam != null) {
         load = loadParam;
       }
 
       Job retJob = null;
       if (StringUtils.isNotBlank(inputElementStr) && StringUtils.isNotBlank(inputMpStr)) {
         logger.error("Only one input MediaPackage OR input MediaPackageElement can be set at the same time");
         return Response.status(Response.Status.BAD_REQUEST).build();
       } else if (StringUtils.isNotBlank(inputElementStr)) {
         MediaPackageElement inputElement = MediaPackageElementParser.getFromXml(inputElementStr);
         retJob = service.execute(exec, params, inputElement, outputFileName, expectedType, load);
       } else if (StringUtils.isNotBlank(inputMpStr)) {
         MediaPackage inputMp = MediaPackageParser.getFromXml(inputMpStr);
         retJob = service.execute(exec, params, inputMp, outputFileName, expectedType, load);
       } else {
         logger.error("A MediaPackage OR MediaPackageElement must be provided");
         return Response.status(Response.Status.BAD_REQUEST).build();
       }
 
       return Response.ok(new JaxbJob(retJob)).build();
 
     } catch (IllegalArgumentException e) {
       logger.error("The expected element type is required if an output filename is specified");
       return Response.status(Response.Status.BAD_REQUEST).build();
     } catch (MediaPackageException e) {
       logger.error("Received excepcion: {}", e.getMessage());
       return Response.serverError().build();
     } catch (ExecuteException e) {
       logger.error("Received error from the execute service: {}", e.getMessage());
       return Response.serverError().build();
     }
   }
 
 
   /**
    * Sets the service
    *
    * @param service
    */
   @Reference
   public void setExecuteService(ExecuteService service) {
     this.service = service;
   }
 
   /**
    * {@inheritDoc}
    * 
    * @see org.opencastproject.rest.AbstractJobProducerEndpoint#getService()
    */
   @Override
   public JobProducer getService() {
     if (service instanceof JobProducer)
       return (JobProducer) service;
     else
       return null;
   }
 
   /**
    * Checks if the service or services are available, if not it handles it by returning a 503 with a message
    * 
    * @param services
    *          an array of services to check
    */
   protected void checkNotNull(Object... services) {
     if (services != null) {
       for (Object object : services) {
         if (object == null) {
           throw new javax.ws.rs.WebApplicationException(javax.ws.rs.core.Response.Status.SERVICE_UNAVAILABLE);
         }
       }
     }
   }
 
   /**
    * 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;
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.rest.AbstractJobProducerEndpoint#getServiceRegistry()
    */
   @Override
   public ServiceRegistry getServiceRegistry() {
     return serviceRegistry;
   }
 }