/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    *
   * MyCoRe is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  package org.mycore.services.queuedjob;
  
  import java.io.OutputStream;
  import java.io.PrintStream;
  import java.nio.charset.StandardCharsets;
  import java.util.ArrayList;
  import java.util.Date;
  import java.util.List;
  import java.util.Locale;
  import java.util.stream.Collectors;
  import java.util.stream.StreamSupport;
  
  import org.mycore.frontend.jersey.filter.access.MCRRestrictedAccess;
  
  import jakarta.inject.Singleton;
  import jakarta.ws.rs.GET;
  import jakarta.ws.rs.Path;
  import jakarta.ws.rs.PathParam;
  import jakarta.ws.rs.Produces;
  import jakarta.ws.rs.core.MediaType;
  import jakarta.ws.rs.core.Response;
  import jakarta.ws.rs.core.StreamingOutput;
  import jakarta.xml.bind.annotation.XmlAttribute;
  import jakarta.xml.bind.annotation.XmlElement;
  import jakarta.xml.bind.annotation.XmlRootElement;
  import jakarta.xml.bind.annotation.XmlValue;
  
  /**
   * @author Ren\u00E9 Adler (eagle)
   *
   */
  @Path("jobqueue")
  @Singleton
  public class MCRJobQueueResource {
  
      @GET()
      @Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
      @MCRRestrictedAccess(MCRJobQueuePermission.class)
      public Response listJSON() {
          try {
              Queues queuesEntity = new Queues();
              queuesEntity.addAll(
                  MCRJobQueue.INSTANCES.keySet().stream().map(Queue::new).collect(Collectors.toList()));
  
              return Response
                  .ok()
                  .status(Response.Status.OK)
                  .entity(queuesEntity)
                  .build();
          } catch (Exception e) {
              final StreamingOutput so = (OutputStream os) -> e
                  .printStackTrace(new PrintStream(os, false, StandardCharsets.UTF_8.name()));
              return Response
                  .status(Response.Status.INTERNAL_SERVER_ERROR)
                  .type(MediaType.TEXT_PLAIN_TYPE)
                  .entity(so)
                  .build();
          }
      }
  
      @GET()
      @Path("{name:.+}")
      @Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
      @MCRRestrictedAccess(MCRJobQueuePermission.class)
      public Response queueJSON(@PathParam("name") String name) {
          try {
              Queue queue = MCRJobQueue.INSTANCES.entrySet().stream().filter(e -> e.getKey().equals(name)).findFirst()
                  .map(e -> {
                      Queue q = new Queue(e.getKey());
  
                      MCRJobQueue jq = e.getValue();
                      Iterable<MCRJob> iterable = () -> jq.iterator(null);
                      q.jobs = StreamSupport.stream(iterable.spliterator(), false).map(Job::new)
                          .collect(Collectors.toList());
  
                      return q;
                  }).orElse(null);
  
              return Response
                  .ok()
                  .status(Response.Status.OK)
                  .entity(queue)
                 .build();
         } catch (Exception e) {
             final StreamingOutput so = (OutputStream os) -> e
                 .printStackTrace(new PrintStream(os, false, StandardCharsets.UTF_8.name()));
             return Response
                 .status(Response.Status.INTERNAL_SERVER_ERROR)
                 .type(MediaType.TEXT_PLAIN_TYPE)
                 .entity(so)
                 .build();
         }
     }
 
     @XmlRootElement(name = "queues")
     static class Queues {
         @XmlElement(name = "queue")
         List<Queue> queues;
 
         void add(Queue queue) {
             if (queues == null) {
                 queues = new ArrayList<>();
             }
 
             queues.add(queue);
         }
 
         void addAll(List<Queue> queues) {
             if (this.queues == null) {
                 this.queues = new ArrayList<>();
             }
 
             this.queues.addAll(queues);
         }
     }
 
     @XmlRootElement(name = "queue")
     static class Queue {
         @XmlAttribute
         String name;
 
         @XmlElement(name = "job")
         List<Job> jobs;
 
         Queue() {
         }
 
         Queue(String name) {
             this.name = name;
         }
     }
 
     @XmlRootElement(name = "job")
     static class Job {
         @XmlAttribute
         long id;
 
         @XmlAttribute
         String status;
 
         @XmlElement(name = "date")
         List<TypedDate> dates;
 
         @XmlElement(name = "parameter")
         List<Parameter> parameters;
 
         Job() {
         }
 
         Job(MCRJob job) {
             this.id = job.getId();
             this.status = job.getStatus().toString().toLowerCase(Locale.ROOT);
 
             List<TypedDate> dates = new ArrayList<>();
             if (job.getAdded() != null) {
                 dates.add(new TypedDate("added", job.getAdded()));
             }
             if (job.getStart() != null) {
                 dates.add(new TypedDate("start", job.getStart()));
             }
             if (job.getFinished() != null) {
                 dates.add(new TypedDate("finished", job.getFinished()));
             }
 
             this.parameters = job.getParameters().entrySet().stream().map(e -> new Parameter(e.getKey(), e.getValue()))
                 .collect(Collectors.toList());
 
             if (!dates.isEmpty()) {
                 this.dates = dates;
             }
         }
     }
 
     @XmlRootElement(name = "date")
     static class TypedDate {
         @XmlAttribute
         String type;
 
         @XmlValue
         Date date;
 
         TypedDate() {
         }
 
         TypedDate(String type, Date date) {
             this.type = type;
             this.date = date;
         }
     }
 
     @XmlRootElement(name = "parameter")
     static class Parameter {
         @XmlAttribute
         String name;
 
         @XmlValue
         String value;
 
         Parameter() {
         }
 
         Parameter(String name, String value) {
             this.name = name;
             this.value = value;
         }
     }
 
 }