oglimmer/lunchy

package de.oglimmer.lunchy.database.connection;

import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Enumeration;

import javax.sql.DataSource;

import lombok.Getter;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;

import org.jooq.SQLDialect;

import com.google.gson.JsonObject;
import com.mchange.v2.c3p0.DataSources;
import com.mysql.jdbc.AbandonedConnectionCleanupThread;

import de.oglimmer.lunchy.services.LunchyProperties;
import de.oglimmer.lunchy.services.MBeanService;

@Slf4j
public enum DBConn {
    INSTANCE;

    @Getter
    private SQLDialect sqlDialect;
    private String registeredDriver = "uninitialized";
    private DataSource pooledDS;

    @SneakyThrows(value = SQLException.class)
    public Connection getUnPooled() {
        setupEnv();
        log.debug("Creating single-use-con for {} with user {}", getConnectionUrl(), LunchyProperties.INSTANCE.getDbUser());
        return DriverManager.getConnection(getConnectionUrl(), LunchyProperties.INSTANCE.getDbUser(),
                LunchyProperties.INSTANCE.getDbPassword());
    }

    @SneakyThrows(value = SQLException.class)
    public Connection get() {
        return pooledDS.getConnection();
    }
    
    private String getConnectionUrl() {
        String additionalParameter = "";
        // HACK. avoid mysql warning
        if("com.mysql.jdbc.Driver".equals(LunchyProperties.INSTANCE.getDbDriver())) {
            additionalParameter = "?useSSL=false";
        }
        return LunchyProperties.INSTANCE.getDbServerUrl() + LunchyProperties.INSTANCE.getDbSchema() + additionalParameter;
    }

    private void setupEnv() {
        if (!registeredDriver.equals(LunchyProperties.INSTANCE.getDbDriver())) {
            registeredDriver = LunchyProperties.INSTANCE.getDbDriver();
            try {
                Class.forName(LunchyProperties.INSTANCE.getDbDriver());
            } catch (ClassNotFoundException e) {
                log.error("Failed to load jdbc driver", e);
            }
            switch (LunchyProperties.INSTANCE.getDbDriver()) {
            case "com.mysql.jdbc.Driver":
                sqlDialect = SQLDialect.MYSQL;
                break;
            case "org.hsqldb.jdbc.JDBCDriver":
                sqlDialect = SQLDialect.HSQLDB;
                break;
            default:
                throw new RuntimeException("Unsupported jdbc-driver:" + LunchyProperties.INSTANCE.getDbDriver());
            }
        }
    }

    @SneakyThrows(value = { SQLException.class })
    public void setupDriver() {
        setupEnv();
        log.debug("Creating con-pool for {} with user {}", getConnectionUrl(), LunchyProperties.INSTANCE.getDbUser());

        DataSource unpooledDS = DataSources.unpooledDataSource(getConnectionUrl(),
                LunchyProperties.INSTANCE.getDbUser(), LunchyProperties.INSTANCE.getDbPassword());

        pooledDS = DataSources.pooledDataSource(unpooledDS, "poolDS");
    }

    public JsonObject getDriverStats() {
        JsonObject data = new JsonObject();
        MBeanService.copyAllAttributes(MBeanService.getPoolDSJMXName(), data);
        return data;
    }

    @SneakyThrows(value = SQLException.class)
    public void shutdownDriver() {
        log.debug("Stopping DBConn...");
        // close pool
        DataSources.destroy(pooledDS);

        // mysql thread
        try {
            AbandonedConnectionCleanupThread.shutdown();
            Thread.sleep(500);
        } catch (InterruptedException e) {
            // dont care
        }

        // JdbcDriver
        Enumeration<Driver> drivers = DriverManager.getDrivers();
        while (drivers.hasMoreElements()) {
            log.debug("de-register: {}", drivers);
            DriverManager.deregisterDriver(drivers.nextElement());
        }
    }

}