/*
 * Copyright (C) 2014 hu
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
package cn.edu.hfut.dmic.webcollector.plugin.berkeley;

import cn.edu.hfut.dmic.webcollector.crawldb.Generator;
import cn.edu.hfut.dmic.webcollector.model.CrawlDatum;
import cn.edu.hfut.dmic.webcollector.util.Config;
import com.sleepycat.je.Cursor;
import com.sleepycat.je.CursorConfig;
import com.sleepycat.je.Database;
import com.sleepycat.je.DatabaseEntry;
import com.sleepycat.je.Environment;
import com.sleepycat.je.EnvironmentConfig;
import com.sleepycat.je.LockMode;
import com.sleepycat.je.OperationStatus;

import java.io.File;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author hu
 */
public class BerkeleyGenerator extends Generator {

    public static final Logger LOG = LoggerFactory.getLogger(BerkeleyGenerator.class);

    Cursor cursor = null;
    Database crawldbDatabase = null;
    Environment env = null;


    public BerkeleyGenerator(Environment env) {
        this.env = env;
        crawldbDatabase = env.openDatabase(null, "crawldb", BerkeleyDBUtils.defaultDBConfig);
        cursor = crawldbDatabase.openCursor(null, CursorConfig.DEFAULT);
    }


    @Override
    public CrawlDatum nextWithoutFilter() throws Exception {
        if (cursor.getNext(key, value, LockMode.DEFAULT) == OperationStatus.SUCCESS) {
            CrawlDatum datum = BerkeleyDBUtils.createCrawlDatum(key, value);
            return datum;
        }else{
            return null;
        }
    }

    public void close() throws Exception {

        if (cursor != null) {
            cursor.close();
        }
//        cursor = null;
        if (crawldbDatabase != null) {
            crawldbDatabase.close();
        }
    }

    protected DatabaseEntry key = new DatabaseEntry();
    protected DatabaseEntry value = new DatabaseEntry();

//    @Override
//    public CrawlDatum next() {
//
//
//
//
//        while (true) {
//            if (cursor.getNext(key, value, LockMode.DEFAULT) == OperationStatus.SUCCESS) {
//
//                try {
//                    CrawlDatum datum = BerkeleyDBUtils.createCrawlDatum(key, value);
//                    if (datum.getStatus() == CrawlDatum.STATUS_DB_SUCCESS) {
//                        continue;
//                    } else {
//                        if (datum.getExecuteCount() > maxExecuteCount) {
//                            continue;
//                        }
//                        totalGenerate++;
//                        return datum;
//                    }
//                } catch (Exception ex) {
//                    LOG.info("Exception when generating", ex);
//                    continue;
//                }
//            } else {
//                return null;
//            }
//        }
//    }
//
//    @Override
//    public CrawlDatum nextWithoutFilter() {
//        if (cursor == null) {
//            crawldbDatabase = env.openDatabase(null, "crawldb", BerkeleyDBUtils.defaultDBConfig);
//            cursor = crawldbDatabase.openCursor(null, CursorConfig.DEFAULT);
//        }
//
//        if (cursor.getNext(key, value, LockMode.DEFAULT) == OperationStatus.SUCCESS){
//            CrawlDatum datum = BerkeleyDBUtils.createCrawlDatum(key, value);
//        }
//    }

   
}