/*
    * 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 com.google.common.collect.Sets;
  import eu.ehri.extension.base.AbstractAccessibleResource;
  import eu.ehri.extension.base.AbstractResource;
  import eu.ehri.extension.base.DeleteResource;
  import eu.ehri.extension.base.GetResource;
  import eu.ehri.extension.base.ListResource;
  import eu.ehri.extension.base.UpdateResource;
  import eu.ehri.project.api.Api;
  import eu.ehri.project.api.EventsApi;
  import eu.ehri.project.core.Tx;
  import eu.ehri.project.definitions.Entities;
  import eu.ehri.project.exceptions.DeserializationError;
  import eu.ehri.project.exceptions.ItemNotFound;
  import eu.ehri.project.exceptions.PermissionDenied;
  import eu.ehri.project.exceptions.ValidationError;
  import eu.ehri.project.models.EntityClass;
  import eu.ehri.project.models.Group;
  import eu.ehri.project.models.base.Accessible;
  import eu.ehri.project.models.base.Accessor;
  import eu.ehri.project.models.base.Actioner;
  import eu.ehri.project.persistence.Bundle;
  import org.neo4j.graphdb.GraphDatabaseService;
  
  import javax.ws.rs.Consumes;
  import javax.ws.rs.DELETE;
  import javax.ws.rs.DefaultValue;
  import javax.ws.rs.GET;
  import javax.ws.rs.POST;
  import javax.ws.rs.PUT;
  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;
  import java.util.List;
  import java.util.Set;
  
  /**
   * Provides a web service interface for the Group model.
   */
  @Path(AbstractResource.RESOURCE_ENDPOINT_PREFIX + "/" + Entities.GROUP)
  public class GroupResource
          extends AbstractAccessibleResource<Group>
          implements GetResource, ListResource, UpdateResource, DeleteResource {
  
      public static final String MEMBER_PARAM = "member";
  
      public GroupResource(@Context GraphDatabaseService database) {
          super(database, Group.class);
      }
  
      @GET
      @Produces(MediaType.APPLICATION_JSON)
      @Path("{id:[^/]+}")
      @Override
      public Response get(@PathParam("id") String id) throws ItemNotFound {
          return getItem(id);
      }
  
      @GET
      @Produces(MediaType.APPLICATION_JSON)
      @Override
      public Response list() {
          return listItems();
      }
  
      @POST
      @Consumes(MediaType.APPLICATION_JSON)
      @Produces(MediaType.APPLICATION_JSON)
      public Response createGroup(Bundle bundle,
              @QueryParam(ACCESSOR_PARAM) List<String> accessors,
              @QueryParam(MEMBER_PARAM) List<String> members)
              throws PermissionDenied, ValidationError, DeserializationError, ItemNotFound {
          try (final Tx tx = beginTx()) {
              final Api.Acl acl = api().acl();
              final Set<Accessor> groupMembers = Sets.newHashSet();
             for (String member : members) {
                 groupMembers.add(manager.getEntity(member, Accessor.class));
             }
             Response item = createItem(bundle, accessors, group -> {
                 for (Accessor member : groupMembers) {
                     acl.addAccessorToGroup(group, member);
                 }
             });
             tx.success();
             return item;
         } catch (ItemNotFound e) {
             throw new DeserializationError("User or group not found: " + e.getValue());
         }
     }
 
     @PUT
     @Consumes(MediaType.APPLICATION_JSON)
     @Produces(MediaType.APPLICATION_JSON)
     @Path("{id:[^/]+}")
     @Override
     public Response update(@PathParam("id") String id, Bundle bundle)
             throws PermissionDenied, ValidationError, DeserializationError, ItemNotFound {
         try (final Tx tx = beginTx()) {
             Response item = updateItem(id, bundle);
             tx.success();
             return item;
         }
     }
 
     /**
      * Add an accessor to a group.
      */
     @POST
     @Path("{id:[^/]+}/{aid:[^/]+}")
     public void addMember(@PathParam("id") String id, @PathParam("aid") String aid)
             throws PermissionDenied, ItemNotFound {
         try (final Tx tx = beginTx()) {
             Group group = manager.getEntity(id, EntityClass.GROUP, Group.class);
             Accessor accessor = manager.getEntity(aid, Accessor.class);
             api().acl().addAccessorToGroup(group, accessor);
             tx.success();
         }
     }
 
     /**
      * Remove an accessor from a group.
      */
     @DELETE
     @Path("{id:[^/]+}/{aid:[^/]+}")
     public void removeMember(@PathParam("id") String id, @PathParam("aid") String aid)
             throws PermissionDenied, ItemNotFound {
         try (final Tx tx = beginTx()) {
             Group group = manager.getEntity(id, EntityClass.GROUP, Group.class);
             Accessor accessor = manager.getEntity(aid, Accessor.class);
             api().acl().removeAccessorFromGroup(group, accessor);
             tx.success();
         }
     }
 
     /**
      * list members of the specified group;
      * UserProfiles and sub-Groups (direct descendants)
      */
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     @Path("{id:[^/]+}/list")
     public Response listChildren(
             @PathParam("id") String id,
             @QueryParam(ALL_PARAM) @DefaultValue("false") boolean all) throws ItemNotFound {
         try (final Tx tx = beginTx()) {
             Group group = manager.getEntity(id, EntityClass.GROUP, Group.class);
             Response response = streamingPage(() -> {
                 Iterable<Accessible> members = all
                         ? group.getAllUserProfileMembers()
                         : group.getMembersAsEntities();
                 return getQuery().page(members, Accessible.class);
             });
             tx.success();
             return response;
         }
     }
 
     @DELETE
     @Path("{id:[^/]+}")
     @Override
     public void delete(@PathParam("id") String id)
             throws PermissionDenied, ItemNotFound, ValidationError {
         try (final Tx tx = beginTx()) {
             deleteItem(id);
             tx.success();
         }
     }
 
     /**
      * Fetch an aggregate list of a user's actions.
      *
      * @param userId      the user's ID
      * @param aggregation the manner in which to aggregate the results, accepting
      *                    "user", "strict" or "off" (no aggregation). Default is
      *                    <b>strict</b>.
      * @return a list of event ranges
      */
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     @Path("{id:[^/]+}/actions")
     public Response aggregateUserActions(
             @PathParam("id") String userId,
             @QueryParam(AGGREGATION_PARAM) @DefaultValue("strict") EventsApi.Aggregation aggregation)
             throws ItemNotFound {
         try (final Tx tx = beginTx()) {
             Actioner group = manager.getEntity(userId, Actioner.class);
             EventsApi eventsApi = getEventsApi()
                     .withAggregation(aggregation);
             Response response = streamingListOfLists(() -> eventsApi.aggregateActions(group));
             tx.success();
             return response;
         }
     }
 }