Chatto/chatto/src/main/java/org/ros/chatto/service/DBInitializerService.java

package org.ros.chatto.service;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.transaction.Transactional;

import org.hibernate.Session;
import org.ros.chatto.model.ApplicationStatus;
import org.ros.chatto.model.UserSession;
import org.ros.chatto.repository.UserSessionRepository;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.event.ApplicationReadyEvent;
import org.springframework.context.annotation.PropertySource;
import org.springframework.context.event.EventListener;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.support.EncodedResource;
import org.springframework.jdbc.datasource.init.ScriptUtils;
import org.springframework.stereotype.Service;

@Service
@PropertySource(value = "classpath:queries.properties")

public class DBInitializerService {

	@Value("${spring.datasource.url}")
	private String url;

	@Value("${spring.datasource.username}")
	private String userName;

	@Value("${spring.datasource.password}")
	private String password;

	@Value("${database-name}")
	private String dbName;

	@Value("${num-tables}")
	private String numTablesQuery;

	@Value("${test.bindAddress}")
	private String bindAddress;

	private Connection connection;

	@Autowired
	private UserSessionRepository userSessionRepository;

	private final Logger logger = LoggerFactory.getLogger(DBInitializerService.class);

	@PersistenceContext
	private EntityManager entityManager;

	public void connectDB() throws SQLException {
		connection = DriverManager.getConnection(url, userName, password);
	}

	public int getNumTables() throws SQLException {
		PreparedStatement preparedStatement = connection.prepareStatement(numTablesQuery);
//   	 preparedStatement.get
		preparedStatement.setString(1, dbName);
		ResultSet resultSet = preparedStatement.executeQuery();
//   	 while(resultSet.next())
//   	 {
//   		 System.out.println(resultSet.get);
//   	 }
		resultSet.next();
		int numTables = resultSet.getInt("num_tables");
//		System.out.println(numTables);
		return numTables;
	}
	
	public int getNumTables(Connection connection) throws SQLException {
		PreparedStatement preparedStatement = connection.prepareStatement(numTablesQuery);
//   	 preparedStatement.get
		preparedStatement.setString(1, dbName);
		ResultSet resultSet = preparedStatement.executeQuery();
//   	 while(resultSet.next())
//   	 {
//   		 System.out.println(resultSet.get);
//   	 }
		resultSet.next();
		int numTables = resultSet.getInt("num_tables");
//		System.out.println(numTables);
		return numTables;
	}

	@EventListener(ApplicationReadyEvent.class)
	@Transactional
	public void doSomethingAfterStartup() throws SQLException, IOException {
//		setProperties();

//		connectDB();

		logger.info("Application Started - running initializer service");
//		System.out.println("Checking database and application state");

		Session session = entityManager.unwrap(Session.class);

		session.doWork(connection -> {
			if (getNumTables(connection) == 0) {
				logger.info("Database is empty. Populating tables and roles");
				try {
					populateDB(connection);
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		});

//		if (getNumTables() == 0) {
//			logger.info("Database is empty. Populating tables and roles");
//			populateDB();
//		}
//		closeConnection();

		session.doWork(connection -> {
			resetAllUserSessions(connection);
		});

		resetAllUserSessions(userSessionRepository.findAll());
	}

	private void populateDB() throws SQLException, IOException {
		ScriptUtils.executeSqlScript(connection,
				new EncodedResource(new ClassPathResource("scheme.sql"), StandardCharsets.UTF_8));
		ScriptUtils.executeSqlScript(connection,
				new EncodedResource(new ClassPathResource("datae.sql"), StandardCharsets.UTF_8));

	}

	private void populateDB(Connection connection) throws SQLException, IOException {
		ScriptUtils.executeSqlScript(connection,
				new EncodedResource(new ClassPathResource("scheme.sql"), StandardCharsets.UTF_8));
		ScriptUtils.executeSqlScript(connection,
				new EncodedResource(new ClassPathResource("datae.sql"), StandardCharsets.UTF_8));

	}

	private void populateTables() {
		ScriptUtils.executeSqlScript(connection,
				new EncodedResource(new ClassPathResource("scheme.sql"), StandardCharsets.UTF_8));
	}

	private void populateRoles() {
		ScriptUtils.executeSqlScript(connection,
				new EncodedResource(new ClassPathResource("datae.sql"), StandardCharsets.UTF_8));
	}

	Map<String, Boolean> listToMap(List<ApplicationStatus> applicationStatusList) {
		Map<String, Boolean> statusMap = new HashMap<>();
		for (ApplicationStatus applicationStatus : applicationStatusList) {
			statusMap.put(applicationStatus.getName(), applicationStatus.isDone());
		}
		return statusMap;
	}

	public void closeConnection() throws SQLException {
		connection.close();
	}

	private void resetAllUserSessions(List<UserSession> userSessionsList) {
		List<UserSession> userSessionsResetList = userSessionsList.stream().map(us -> {
			us.setNumSessions(0);
			us.setOnline(false);
			return us;
		}).collect(Collectors.toList());
		userSessionRepository.saveAll(userSessionsResetList);
	}
	
	private void resetAllUserSessions(Connection connection) throws SQLException
	{
		String sql = "update user_sessions set online=0, num_sessions=0";
		
		PreparedStatement preparedStatement = connection.prepareStatement(sql);
		
		preparedStatement.executeUpdate();
	}

}