package database;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Properties;

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

public class DatabaseConnection {

    private static final ThreadLocal<Connection> con = new ThreadLocalConnection();
    private final static Logger log = LoggerFactory.getLogger(DatabaseConnection.class);
    private static Properties props = null;

    public static Connection getConnection() {
        if (props == null) {
            throw new RuntimeException("DatabaseConnection not initialized");
        }
        Connection conn = con.get();
        try {
            if (conn.isValid(1)) {
                return conn;
            }
        } catch (SQLException sqle) {
            log.info("Lost connection to database, reconnecting...", sqle);
            try {
                conn.close();
            } catch (SQLException sqle2) {
                log.warn("Unable to close connection with database after losing connection", sqle2);
            }
        }
        ThreadLocalConnection.allConnections.remove(conn);
        con.remove();
        return con.get();
    }

    public static boolean isInitialized() {
        return props != null;
    }

    public static void setProps(Properties aProps) {
        props = aProps;
    }

    public static void cleanup(PreparedStatement ps, ResultSet rs) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        if (ps != null) {
            try {
                ps.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
    }

    public static void closeAll() throws SQLException {
        for (Connection cons : ThreadLocalConnection.allConnections) {
            cons.close();
        }
    }

    private static class ThreadLocalConnection extends ThreadLocal<Connection> {

        public static Collection<Connection> allConnections = new ArrayList<>();

        @Override
        protected Connection initialValue() {
            String driver = props.getProperty("driver");
            String url = props.getProperty("url");
            String user = props.getProperty("user");
            String password = props.getProperty("password");
            try {
                Class.forName(driver); // Touch the mysql driver.
            } catch (ClassNotFoundException e) {
                log.error("ERROR", e);
            }
            try {
                Connection con = DriverManager.getConnection(url, user, password);
                allConnections.add(con);
                return con;
            } catch (SQLException e) {
                log.error("ERROR", e);
                return null;
            }
        }
    }
}