package com.savantdegrees.gms.util;

import org.apache.log4j.Logger;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import com.mchange.v2.c3p0.PooledDataSource;
import com.mchange.v2.c3p0.C3P0Registry;
import java.sql.SQLException;

import java.lang.reflect.Field;
import org.apache.catalina.loader.WebappClassLoader;

public class C3POServletContextListener implements ServletContextListener{

	private Logger log = Logger.getLogger(this.class);

	public void contextInitialized(ServletContextEvent contextEvent) {
	}

	public void contextDestroyed(ServletContextEvent contextEvent) {
        Set<PooledDataSource> pooledDataSourceSet = (Set<PooledDataSource>) C3P0Registry.getPooledDataSources();

        for (PooledDataSource dataSource : pooledDataSourceSet) {
            try {
                dataSource.hardReset();
                dataSource.close();
            } catch (SQLException e) {
                // note - do not use log4j since it may have been unloaded by this point
                System.out.println("Unable to hard reset and close data source.", e);
            }
        }


        //Get a list of all classes loaded by the current webapp classloader
        WebappClassLoader classLoader = (WebappClassLoader) getClass().getClassLoader();
        Field classLoaderClassesField = null;
        Class clazz = WebappClassLoader.class;
        while (classLoaderClassesField == null && clazz != null) {
            try {
                classLoaderClassesField = clazz.getDeclaredField("classes");
            } catch (Exception exception) {
                //do nothing
            }
            clazz = clazz.getSuperclass();
        }
        classLoaderClassesField.setAccessible(true);

        List classes = new ArrayList((Vector)classLoaderClassesField.get(classLoader));

        for (Object o : classes) {
            Class c = (Class)o;
            //Make sure you identify only the packages that are holding references to the classloader.
            //Allowing this code to clear all static references will result in all sorts
            //of horrible things (like java segfaulting).
            if (c.getName().startsWith("com.savantdegrees")) {
                //Kill any static references within all these classes.
                for (Field f : c.getDeclaredFields()) {
                    if (Modifier.isStatic(f.getModifiers())
                            && !Modifier.isFinal(f.getModifiers())
                            && !f.getType().isPrimitive()) {
                        try {
                            f.setAccessible(true);
                            f.set(null, null);
                        } catch (Exception exception) {
                            //Log the exception
                        }
                    }
                }
            }
        }

        classes.clear();
        System.out.println("SDASDA==========================");

		System.out.println("CP30 contextDestroyed");
	}
}