/*

 * Copyright (c) 2009, 2010, 2011, 2012, B3log Team

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package org.b3log.solo.repository.impl;



import java.util.List;

import java.util.logging.Logger;

import org.b3log.solo.model.Article;

import org.b3log.solo.model.Tag;

import org.b3log.solo.repository.TagArticleRepository;

import org.b3log.latke.Keys;

import org.b3log.latke.repository.*;

import org.b3log.latke.util.CollectionUtils;

import org.json.JSONArray;

import org.json.JSONObject;



/**

 * Tag-Article relation repository.

 *

 * @author <a href="mailto:DL88250@gmail.com">Liang Ding</a>

 * @version 1.0.0.9, Nov 9, 2011

 * @since 0.3.1

 */

public final class TagArticleRepositoryImpl extends AbstractRepository implements TagArticleRepository {



    /**

     * Logger.

     */

    private static final Logger LOGGER = Logger.getLogger(TagArticleRepositoryImpl.class.getName());

    /**

     * Singleton.

     */

    private static final TagArticleRepositoryImpl SINGLETON = new TagArticleRepositoryImpl(Tag.TAG + "_" + Article.ARTICLE);



    @Override

    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);



        final JSONObject result = get(query);

        final JSONArray array = result.optJSONArray(Keys.RESULTS);



        return CollectionUtils.jsonArrayToList(array);

    }



    @Override

    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).

                setCurrentPageNum(currentPageNum).

                setPageSize(pageSize).

                setPageCount(1);



        return get(query);

    }



    /**

     * Gets the {@link TagArticleRepositoryImpl} singleton.

     *

     * @return the singleton

     */

    public static TagArticleRepositoryImpl getInstance() {

        return SINGLETON;

    }



    /**

     * Private constructor.

     * 

     * @param name the specified name

     */

    private TagArticleRepositoryImpl(final String name) {

        super(name);

    }

}