package com.gmail.plasmavn.enchantmentapi.services;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Enumeration;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

import com.google.common.collect.Sets;

public class ClassLoaderUtils {

	private static final Set<URL> loadedURL = Sets.newHashSet();

	@SuppressWarnings({ "resource", "unlikely-arg-type" })
	public static Set<Class<?>> loadClasses(File... files) throws MalformedURLException {
		Set<Class<?>> classes = Sets.newHashSet();

		for (File file : files) {

			if (file == null || !file.exists() || loadedURL.contains(file.toURI())) continue;

			URI uri = file.toURI();
			JarFile jarFile;

			try {
				jarFile = new JarFile(new File(uri.getPath()));
			} catch (IOException e) {
				System.out.println("Jar unknown: " + uri.toString());
				continue;
			}

			Set<String> preclasses = Sets.newHashSet();
			Enumeration<JarEntry> e = jarFile.entries();

			while (e.hasMoreElements()) {
			    JarEntry je = e.nextElement();
			    if (je.isDirectory() || !je.getName().endsWith(".class"))
			        continue;

			    String className = je.getName().substring(0, je.getName().length() - 6).replace('/', '.');
			    preclasses.add(className);
			}

			if (preclasses.isEmpty()) {
				System.out.println("Empty name");
				continue;
			}


			addURL(uri.toURL());

			for (String clazz : preclasses) {
				try {
					Class<?> c = ClassLoaderUtils.class.getClassLoader().loadClass(clazz);
					classes.add(c);
				} catch (ClassNotFoundException ex) {
					Utils.debug("Fail on load class", ex);
					continue;
				}
			}

		}

		return classes;
	}

	private static void addURL(URL u) {

		URLClassLoader sysloader = (URLClassLoader) ClassLoaderUtils.class.getClassLoader();
		Class<?> sysclass = URLClassLoader.class;

		try {
			Method method = sysclass.getDeclaredMethod("addURL", URL.class);
			method.setAccessible(true);
			method.invoke(sysloader, u);
			loadedURL.add(u);
		} catch (Throwable t) {
			Utils.debug("Error, could not add URL to system classloader", t);
		}

	}


}