/*
    * Copyright 2015 Data Archiving and Networked Services (an institute of
    * Koninklijke Nederlandse Akademie van Wetenschappen), King's College London,
    * Georg-August-Universitaet Goettingen Stiftung Oeffentlichen Rechts
    *
    * Licensed under the EUPL, Version 1.1 or – as soon they will be approved by
    * the European Commission - subsequent versions of the EUPL (the "Licence");
    * You may not use this work except in compliance with the Licence.
    * You may obtain a copy of the Licence at:
   *
   * https://joinup.ec.europa.eu/software/page/eupl
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the Licence is distributed on an "AS IS" basis,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the Licence for the specific language governing
   * permissions and limitations under the Licence.
   */
  
  package eu.ehri.extension;
  
  import eu.ehri.extension.base.AbstractAccessibleResource;
  import eu.ehri.extension.base.AbstractResource;
  import eu.ehri.extension.base.GetResource;
  import eu.ehri.project.api.EventsApi;
  import eu.ehri.project.core.Tx;
  import eu.ehri.project.definitions.Entities;
  import eu.ehri.project.exceptions.AccessDenied;
  import eu.ehri.project.exceptions.ItemNotFound;
  import eu.ehri.project.models.base.Accessible;
  import eu.ehri.project.models.events.SystemEvent;
  import org.neo4j.graphdb.GraphDatabaseService;
  
  import javax.ws.rs.DefaultValue;
  import javax.ws.rs.GET;
  import javax.ws.rs.Path;
  import javax.ws.rs.PathParam;
  import javax.ws.rs.Produces;
  import javax.ws.rs.QueryParam;
  import javax.ws.rs.core.Context;
  import javax.ws.rs.core.MediaType;
  import javax.ws.rs.core.Response;
  
  /**
   * Provides a web service interface for the Event model. Note: Event instances
   * are created by the system, so we do not have create/update/delete methods
   * here.
   * <p>
   * The following query parameters apply to all actions in this
   * resource to apply filtering to the event streams.
   * <p>
   * <dl>
   * <dt>eventTypes</dt><dd>Filter events by type</dd>
   * <dt>itemTypes</dt><dd>Filter events based on the item type of their subjects</dd>
   * <dt>itemIds</dt><dd>Filter events pertaining to specific item IDs</dd>
   * <dt>users</dt><dd>Filter events based on the user IDs they involve</dd>
   * <dt>from</dt><dd>Exclude events prior to this date (ISO 8601 format)</dd>
   * <dt>to</dt><dd>Exclude events after this date (ISO 8601 format)</dd>
   * </dl>
   * <p>
   * Additionally the aggregate* end-points accept an <code>aggregation</code>
   * parameter that groups sequential events according to one of two different
   * strategies:
   * <dl>
   * <dt>user</dt>
   * <dd>Groups sequential events of all types that are initiated by the same actioner</dd>
   * <dt>strict</dt>
   * <dd>
   * Groups sequential events that:
   * <ul>
   * <li>have the same type</li>
   * <li>have the same actioner</li>
   * <li>have the same subjects</li>
   * <li>have the same scope</li>
   * <li>have the same log message</li>
   * </ul>
   * </dd>
   * </dl>
   * <p>
   * Additionally, aggregation can be disabled by using <code>aggregation=off</code>.
   * <p>
   * Standard paging parameters apply to all end-points.
   */
  @Path(AbstractResource.RESOURCE_ENDPOINT_PREFIX + "/" + Entities.SYSTEM_EVENT)
  public class SystemEventResource extends AbstractAccessibleResource<SystemEvent>
          implements GetResource {
  
  
      public SystemEventResource(@Context GraphDatabaseService database) {
          super(database, SystemEvent.class);
      }
  
      @GET
      @Produces(MediaType.APPLICATION_JSON)
      @Path("{id:[^/]+}")
      @Override
      public Response get(@PathParam("id") String id) throws ItemNotFound {
          return getItem(id);
      }
 
     /**
      * List aggregated global events. Standard list parameters for paging apply.
      *
      * @param aggregation The manner in which to aggregate the results, accepting
      *                    "user", "strict" or "off" (no aggregation). Default is
      *                    "user".
      */
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     public Response list(
             @QueryParam(AGGREGATION_PARAM) @DefaultValue("user") EventsApi.Aggregation aggregation) {
         try (final Tx tx = beginTx()) {
             EventsApi eventsApi = getEventsApi()
                     .withAggregation(aggregation);
             Response response = streamingListOfLists(eventsApi::aggregate);
             tx.success();
             return response;
         }
     }
 
     /**
      * Fetch a page of subjects for a given event.
      *
      * @param id the event id
      * @return a list of subject items
      */
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     @Path("{id:[^/]+}/subjects")
     public Response pageSubjectsForEvent(@PathParam("id") String id)
             throws ItemNotFound, AccessDenied {
         try (final Tx tx = beginTx()) {
             SystemEvent event = api().detail(id, cls);
             // Subjects are only serialized to depth 1 for efficiency...
             Response response = streamingPage(() -> getQuery()
                             .page(event.getSubjects(), Accessible.class),
                     getSerializer().withDepth(1).withCache());
             tx.success();
             return response;
         }
     }
 }