content: /*
   * Symphony - A modern community (forum/BBS/SNS/blog) platform written in Java.
   * Copyright (C) 2012-present, b3log.org
   *
   * This program is free software: you can redistribute it and/or modify
   * it under the terms of the GNU Affero General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or
   * (at your option) any later version.
   *
   * This program 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 Affero General Public License for more details.
   *
   * You should have received a copy of the GNU Affero General Public License
   * along with this program.  If not, see <https://www.gnu.org/licenses/>.
   */
  package org.b3log.symphony.repository;
  
  import org.b3log.latke.Keys;
  import org.b3log.latke.repository.*;
  import org.b3log.latke.repository.annotation.Repository;
  import org.b3log.symphony.model.Article;
  import org.b3log.symphony.model.Tag;
  import org.json.JSONObject;
  
  import java.util.List;
  
  /**
   * Tag-Article relation repository.
   *
   * @author <a href="http://88250.b3log.org">Liang Ding</a>
   * @version 1.1.0.1, Aug 27, 2018
   * @since 0.2.0
   */
  @Repository
  public class TagArticleRepository extends AbstractRepository {
  
      /**
       * Public constructor.
       */
      public TagArticleRepository() {
          super(Tag.TAG + "_" + Article.ARTICLE);
      }
  
      /**
       * Removes tag-articles relations by the specified article id.
       *
       * @param articleId the specified article id
       * @throws RepositoryException repository exception
       */
      public void removeByArticleId(final String articleId) throws RepositoryException {
          final List<JSONObject> relations = getByArticleId(articleId);
          for (final JSONObject relation : relations) {
              remove(relation.optString(Keys.OBJECT_ID));
          }
      }
  
      /**
       * Gets tag-article relations by the specified article id.
       *
       * @param articleId the specified article id
       * @return for example      <pre>
       * [{
       *         "oId": "",
       *         "tag_oId": "",
       *         "article_oId": articleId
       * }, ....], returns an empty list if not found
       * </pre>
       * @throws RepositoryException repository exception
       */
      public List<JSONObject> getByArticleId(final String articleId) throws RepositoryException {
          final Query query = new Query().setFilter(
                  new PropertyFilter(Article.ARTICLE + "_" + Keys.OBJECT_ID, FilterOperator.EQUAL, articleId)).
                  setPageCount(1);
  
          return getList(query);
      }
  
      /**
       * Gets tag-article relations by the specified tag id.
       *
       * @param tagId          the specified tag id
       * @param currentPageNum the specified current page number, MUST greater then {@code 0}
       * @param pageSize       the specified page size(count of a page contains objects), MUST greater then {@code 0}
       * @return for example      <pre>
       * {
       *     "pagination": {
       *       "paginationPageCount": 88250
       *     },
       *     "rslts": [{
       *         "oId": "",
       *         "tag_oId": tagId,
       *         "article_oId": ""
       *     }, ....]
       * }
       * </pre>
       * @throws RepositoryException repository exception
       */
      public JSONObject getByTagId(final String tagId, final int currentPageNum, final int pageSize)
              throws RepositoryException {
          final Query query = new Query().
                  setFilter(new PropertyFilter(Tag.TAG + "_" + Keys.OBJECT_ID, FilterOperator.EQUAL, tagId)).
                  addSort(Article.ARTICLE + "_" + Keys.OBJECT_ID, SortDirection.DESCENDING).
                  setPage(currentPageNum, pageSize).setPageCount(1);
  
          return get(query);
      }
  }
  