/*
    * 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.project.models.base;
  
  import com.tinkerpop.blueprints.Direction;
  import com.tinkerpop.blueprints.Vertex;
  import com.tinkerpop.frames.Adjacency;
  import com.tinkerpop.frames.modules.javahandler.JavaHandler;
  import com.tinkerpop.frames.modules.javahandler.JavaHandlerContext;
  import eu.ehri.project.definitions.Ontology;
  import eu.ehri.project.models.UserProfile;
  import eu.ehri.project.models.annotations.Fetch;
  
  import static eu.ehri.project.models.utils.JavaHandlerUtils.*;
  
  /**
   * An entity that can be promoted and demoted.
   */
  public interface Promotable extends Accessible {
      String PROMOTION_SCORE = "_promotionScore";
  
      @Fetch(value = Ontology.PROMOTED_BY, numLevels = 1)
      @Adjacency(label = Ontology.PROMOTED_BY, direction = Direction.OUT)
      Iterable<UserProfile> getPromoters();
  
      @Fetch(value = Ontology.DEMOTED_BY, numLevels = 1)
      @Adjacency(label = Ontology.DEMOTED_BY, direction = Direction.OUT)
      Iterable<UserProfile> getDemoters();
  
      @JavaHandler
      void addPromotion(UserProfile user);
  
      @JavaHandler
      void addDemotion(UserProfile user);
  
      @JavaHandler
      void removePromotion(UserProfile user);
  
      @JavaHandler
      void removeDemotion(UserProfile user);
  
      @JavaHandler
      boolean isPromoted();
  
      @JavaHandler
      boolean isPromotedBy(UserProfile user);
  
      @JavaHandler
      boolean isPromotable();
  
      @JavaHandler
      int getPromotionScore();
  
      /**
       * Implementation of complex methods.
       */
      abstract class Impl implements JavaHandlerContext<Vertex>, Promotable {
  
          private void updatePromotionScoreCache() {
              int score = Math.toIntExact(gremlin().out(Ontology.PROMOTED_BY).count()
                      - gremlin().out(Ontology.DEMOTED_BY).count());
              it().setProperty(PROMOTION_SCORE, score);
          }
  
          @Override
          public void addPromotion(UserProfile user) {
              addUniqueRelationship(it(), user.asVertex(), Ontology.PROMOTED_BY);
              removeAllRelationships(it(), user.asVertex(), Ontology.DEMOTED_BY);
              updatePromotionScoreCache();
          }
  
          @Override
          public void removePromotion(UserProfile user) {
              removeAllRelationships(it(), user.asVertex(), Ontology.PROMOTED_BY);
              updatePromotionScoreCache();
          }
  
          @Override
          public void addDemotion(UserProfile user) {
              addUniqueRelationship(it(), user.asVertex(), Ontology.DEMOTED_BY);
              removeAllRelationships(it(), user.asVertex(), Ontology.PROMOTED_BY);
              updatePromotionScoreCache();
         }
 
         @Override
         public void removeDemotion(UserProfile user) {
             removeAllRelationships(it(), user.asVertex(), Ontology.DEMOTED_BY);
             updatePromotionScoreCache();
         }
 
         @Override
         public boolean isPromoted() {
             return gremlin().out(Ontology.PROMOTED_BY).count() > gremlin().out(Ontology.DEMOTED_BY).count();
         }
 
         @Override
         public int getPromotionScore() {
             Integer score = it().getProperty(PROMOTION_SCORE);
             return score == null
                     ? Math.toIntExact(gremlin().out(Ontology.PROMOTED_BY).count()
                             - gremlin().out(Ontology.DEMOTED_BY).count())
                     : score;
         }
 
         @Override
         public boolean isPromotedBy(UserProfile user) {
             return hasRelationship(it(), user.asVertex(), Ontology.PROMOTED_BY);
         }
 
         @Override
         public boolean isPromotable() {
             Boolean promotable = it().getProperty(Ontology.IS_PROMOTABLE);
             return promotable != null && promotable;
         }
     }
 }