/*
 * Author: Joseph Wang
 */
package com.leadpoint.syndication.db.mongo.mortgage;

import java.util.ArrayList;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.leadpoint.config.Meta;
import com.mongodb.Mongo;
import com.mongodb.MongoOptions;
import com.mongodb.ServerAddress;

public class MongoConnnection {
	private static final int SERVER_INFORMATION_FIELD_SIZE = 2;
	private static final int SERVER_NAME_FIELD = 0;
	private static final int SERVER_PORT_FIELD = 1;
	private static Meta META = Meta.getMeta(MongoConnnection.class);
	private static String mongodb_servers = META.getString("mongodb_servers",
			"ip-10-160-86-4:10000,ip-10-161-50-230:10000");
	private static int max_connection = META.getInteger("max_connection", 400);
	public static final int MAX_OBJECT_CHUNKS = 1000;
	private static Mongo m = null;
	private static Log log = LogFactory.getLog(MongoConnnection.class);

	private static MongoConnnection instance;

	private MongoConnnection() {
		init(mongodb_servers);
	}

	public static synchronized MongoConnnection getInstance() {
		if (instance == null) {
			instance = new MongoConnnection();
		}
		return instance;
	}

	public Object clone() throws CloneNotSupportedException {
		throw new CloneNotSupportedException();
	}

	public Mongo getMongo() {
		if (m == null) {
			init(mongodb_servers);
		}

		return m;
	}

	public void reconnect() {
		close();
		init(mongodb_servers);
	}

	public void init(String server_list) {
		if (m == null) {
			MongoOptions opt = new MongoOptions();
			opt.autoConnectRetry = true;
			opt.connectionsPerHost = max_connection;

			String[] servers = server_list.split(",");
			ArrayList<ServerAddress> addr = new ArrayList<ServerAddress>();
			int serverCount = 0;
			for (int i = 0; i < servers.length; ++i) {
				String[] serverInfo = servers[i].split(":");

				try {
					if (serverInfo.length == SERVER_INFORMATION_FIELD_SIZE) {
						log.info("MongoConnnection: add server "
								+ serverInfo[SERVER_NAME_FIELD] + " at port "
								+ serverInfo[SERVER_PORT_FIELD]);
						ServerAddress host = new ServerAddress(
								serverInfo[SERVER_NAME_FIELD],
								Integer.parseInt(serverInfo[SERVER_PORT_FIELD]));
						addr.add(host);

						serverCount++;
					}
				} catch (Exception ex) {
					log.fatal(
							"MongoConnnection: problem with adding server list "
									+ server_list, ex);
				}
			}

			if (serverCount > 0) {
				try {
					m = new Mongo(addr, opt);
				} catch (Exception ex) {
					log.fatal("MongoConnnection: problem with creating MongoDB instance for server list "
									+ server_list, ex);
					m = null;
				}
			} else {
				log.fatal("MongoConnnection: empty server list " + server_list);
			}
		}
	}

	public void close() {
		if (m != null) {
			m.close();
			m = null;

			log.info("MongoConnnection: close MongoDB instance for server list "
							+ mongodb_servers);
		}
	}
}