package org.openslx.imagemaster.db;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

public class MysqlConnection implements AutoCloseable
{

	private static final Logger LOGGER = LogManager.getLogger( MysqlConnection.class );

	private static final int CONNECTION_TIMEOUT_MS = 5 * 60 * 1000;

	private final long deadline = System.currentTimeMillis() + CONNECTION_TIMEOUT_MS;

	private final Connection rawConnection;

	private boolean hasPendingQueries = false;

	private List<MysqlStatement> openStatements = new ArrayList<>();

	MysqlConnection( Connection rawConnection )
	{
		this.rawConnection = rawConnection;
	}

	public MysqlStatement prepareStatement( String sql ) throws SQLException
	{
		if ( !sql.startsWith( "SELECT" ) && !sql.startsWith( "DESCRIBE" ) && !sql.startsWith( "SHOW" ) ) {
			hasPendingQueries = true;
		}
		MysqlStatement statement = new MysqlStatement( rawConnection, sql );
		openStatements.add( statement );
		return statement;
	}

	public void commit() throws SQLException
	{
		rawConnection.commit();
		hasPendingQueries = false;
	}

	public void rollback() throws SQLException
	{
		rawConnection.rollback();
		hasPendingQueries = false;
	}

	boolean isValid()
	{
		return System.currentTimeMillis() < deadline;
	}

	@Override
	public void close()
	{
		if ( hasPendingQueries ) {
			LOGGER.warn( "Mysql connection had uncommited queries on .close()",
					new RuntimeException( "Stack trace" ) );
			for ( MysqlStatement s : openStatements ) {
				LOGGER.info( s.getQuery() );
			}
			hasPendingQueries = false;
		}
		try {
			rawConnection.rollback();
		} catch ( SQLException e ) {
			LOGGER.warn( "Rolling back uncommited queries failed!", e );
		}
		if ( !openStatements.isEmpty() ) {
			for ( MysqlStatement statement : openStatements ) {
				statement.close();
			}
			openStatements.clear();
		}
		try {
			rawConnection.rollback();
			rawConnection.setAutoCommit( true );
		} catch ( SQLException e ) {
			LOGGER.warn( "Rolling back uncommited queries failed!", e );
		}
		Database.returnConnection( this );
	}

	void release()
	{
		try {
			rawConnection.close();
		} catch ( SQLException e ) {
			// Nothing meaningful to do
		}
	}

	void setAutoCommit( boolean b ) throws SQLException
	{
		rawConnection.setAutoCommit( b );
	}

}