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package eu.dnetlib.oa.graph.datasetsusagestats.export;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

import org.apache.log4j.Logger;

/**
 * @author D. Pierrakos, S. Zoupanos
 */
/**
 * @author D. Pierrakos, S. Zoupanos
 */
import com.mchange.v2.c3p0.ComboPooledDataSource;

public abstract class ConnectDB {

	public static Connection DB_HIVE_CONNECTION;
	public static Connection DB_IMPALA_CONNECTION;

	private static String dbHiveUrl;
	private static String dbImpalaUrl;
	private static String datasetUsageStatsDBSchema;
	private static String statsDBSchema;
	private final static Logger logger = Logger.getLogger(ConnectDB.class);
	private Statement stmt = null;

	static void init() throws ClassNotFoundException {

		dbHiveUrl = ExecuteWorkflow.dbHiveUrl;
		dbImpalaUrl = ExecuteWorkflow.dbImpalaUrl;
		datasetUsageStatsDBSchema = ExecuteWorkflow.datasetUsageStatsDBSchema;
		statsDBSchema = ExecuteWorkflow.statsDBSchema;

		Class.forName("org.apache.hive.jdbc.HiveDriver");
	}

	public static Connection getHiveConnection() throws SQLException {
		if (DB_HIVE_CONNECTION != null && !DB_HIVE_CONNECTION.isClosed()) {
			return DB_HIVE_CONNECTION;
		} else {
			DB_HIVE_CONNECTION = connectHive();

			return DB_HIVE_CONNECTION;
		}
	}

	public static Connection getImpalaConnection() throws SQLException {
		if (DB_IMPALA_CONNECTION != null && !DB_IMPALA_CONNECTION.isClosed()) {
			return DB_IMPALA_CONNECTION;
		} else {
			DB_IMPALA_CONNECTION = connectImpala();

			return DB_IMPALA_CONNECTION;
		}
	}

	public static String getDataSetUsageStatsDBSchema() {
		return ConnectDB.datasetUsageStatsDBSchema;
	}

	public static String getStatsDBSchema() {
		return ConnectDB.statsDBSchema;
	}

	private static Connection connectHive() throws SQLException {
		/*
		 * Connection connection = DriverManager.getConnection(dbHiveUrl); Statement stmt =
		 * connection.createStatement(); log.debug("Opened database successfully"); return connection;
		 */
		ComboPooledDataSource cpds = new ComboPooledDataSource();
		cpds.setJdbcUrl(dbHiveUrl);
		cpds.setUser("dimitris.pierrakos");
		cpds.setAcquireIncrement(1);
		cpds.setMaxPoolSize(100);
		cpds.setMinPoolSize(1);
		cpds.setInitialPoolSize(1);
		cpds.setMaxIdleTime(300);
		cpds.setMaxConnectionAge(36000);

		cpds.setAcquireRetryAttempts(5);
		cpds.setAcquireRetryDelay(2000);
		cpds.setBreakAfterAcquireFailure(false);

		cpds.setCheckoutTimeout(0);
		cpds.setPreferredTestQuery("SELECT 1");
		cpds.setIdleConnectionTestPeriod(60);

		logger.info("Opened database successfully");

		return cpds.getConnection();

	}

	private static Connection connectImpala() throws SQLException {
		/*
		 * Connection connection = DriverManager.getConnection(dbImpalaUrl); Statement stmt =
		 * connection.createStatement(); log.debug("Opened database successfully"); return connection;
		 */
		ComboPooledDataSource cpds = new ComboPooledDataSource();
		cpds.setJdbcUrl(dbImpalaUrl);
		cpds.setUser("dimitris.pierrakos");
		cpds.setAcquireIncrement(1);
		cpds.setMaxPoolSize(100);
		cpds.setMinPoolSize(1);
		cpds.setInitialPoolSize(1);
		cpds.setMaxIdleTime(300);
		cpds.setMaxConnectionAge(36000);

		cpds.setAcquireRetryAttempts(5);
		cpds.setAcquireRetryDelay(2000);
		cpds.setBreakAfterAcquireFailure(false);

		cpds.setCheckoutTimeout(0);
		cpds.setPreferredTestQuery("SELECT 1");
		cpds.setIdleConnectionTestPeriod(60);

		logger.info("Opened database successfully");
		return cpds.getConnection();

	}
}