IdUpdatedArticleOmitter.java

/*
 * Copyright (c) 2015, Nils Braden
 *
 * This file is part of ttrss-reader-fork. This program is free software; you
 * can redistribute it and/or modify it under the terms of the GNU
 * 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
 * General Public License for more details. You should have received a
 * copy of the GNU General Public License along with this program; If
 * not, see http://www.gnu.org/licenses/.
 */

package org.ttrssreader.net;

import android.util.Log;

import org.ttrssreader.controllers.DBHelper;
import org.ttrssreader.model.pojos.Article;

import java.util.HashSet;
import java.util.Map;
import java.util.Set;

/**
 * the instance of this class will be used for filtering out already cached articles, which was not updated while
 * parsing of JSON response from server
 *
 * @author igor
 */
public class IdUpdatedArticleOmitter implements IArticleOmitter {

	/**
	 * map of article IDs to it's updated date
	 */
	public Map<Integer, Long> idUpdatedMap;
	/**
	 * articles, that were skipped
	 */
	private Set<Integer> omittedArticles = new HashSet<>();

	public IdUpdatedArticleOmitter(final long sinceId) {
		String selectSince = "_id >= " + sinceId;
		init(selectSince);
	}

	public IdUpdatedArticleOmitter(final String selection) {
		init(selection);
	}

	public IdUpdatedArticleOmitter(final String selection, final long sinceId) {
		String selectSince = "_id >= " + sinceId;
		if (selection != null) selectSince = selectSince + " AND " + selection;
		init(selectSince);
	}

	private void init(String selectSince) {
		idUpdatedMap = DBHelper.getInstance().getArticleIdUpdatedMap(selectSince);
		Log.d("Data", "Filter-Size: " + idUpdatedMap.size() + " Selection: " + selectSince);
	}

	/**
	 * article should be omitted if it's ID already exist in DB and updated date is not after date, which is stored in
	 * DB
	 *
	 * @param field current article field added to article on this iteration
	 * @param a     article to test
	 * @return {@code true} if given article should be omitted, {@code false} otherwise
	 */
	public boolean omitArticle(Article.ArticleField field, Article a) {
		boolean ret = false;
		switch (field) {
			case id:
			case updated:
				if (a.id > 0 && a.updated != null) {
					Long updated = idUpdatedMap.get(a.id);
					if (updated != null && a.updated.getTime() <= updated) {
						omittedArticles.add(a.id);
						ret = true;
					}
				}
			default:
				break;
		}
		return ret;
	}

	@Override
	public Set<Integer> getOmittedArticles() {
		return omittedArticles;
	}
}