/*****************************************************************
JADE - Java Agent DEvelopment Framework is a framework to develop 
multi-agent systems in compliance with the FIPA specifications.
Copyright (C) 2000 CSELT S.p.A. 

GNU Lesser General Public License

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation, 
version 2.1 of the License. 

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA  02111-1307, USA.
*****************************************************************/

package jade.content.onto;

//#J2ME_EXCLUDE_FILE
//#APIDOC_EXCLUDE_FILE

import jade.content.Concept;
import jade.util.Logger;

import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLDecoder;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

class ClassDiscover {
	private static Logger myLogger = Logger.getMyLogger(ClassDiscover.class.getName());
	
	static List<Class> getClassesForPackage(String pkgname) throws ClassNotFoundException {
		// This will hold a list of directories matching the pckgname.
		// There may be more than one if a package is split over multiple
		// jars/paths
		List<Class> classes = new ArrayList<Class>();
		ArrayList<File> directories = new ArrayList<File>();
		try {
			ClassLoader cld = Thread.currentThread().getContextClassLoader();
			if (cld == null) {
				throw new ClassNotFoundException("Can't get class loader.");
			}
			// Ask for all resources for the path
			Enumeration<URL> resources = cld.getResources(pkgname.replace('.', '/'));
			while (resources.hasMoreElements()) {
				URL res = resources.nextElement();
				if (res.getProtocol().equalsIgnoreCase("jar")) {
					JarURLConnection conn = (JarURLConnection) res.openConnection();
					JarFile jar = conn.getJarFile();
					for (JarEntry e : Collections.list(jar.entries())) {

						if (e.getName().startsWith(pkgname.replace('.', '/')) && e.getName().endsWith(".class") && !e.getName().contains("$")) {
							String className = e.getName().replace("/", ".").substring(0, e.getName().length() - 6);
							myLogger.log(Logger.CONFIG, "Adding class "+className);
							classes.add(Class.forName(className));
						}
					}
				} else
					directories.add(new File(URLDecoder.decode(res.getPath(), "UTF-8")));
			}
		} catch (NullPointerException x) {
			throw new ClassNotFoundException(pkgname + " does not appear to be " + "a valid package (Null pointer exception)");
		} catch (UnsupportedEncodingException encex) {
			throw new ClassNotFoundException(pkgname + " does not appear to be " + "a valid package (Unsupported encoding)");
		} catch (IOException ioex) {
			throw new ClassNotFoundException("IOException was thrown when trying " + "to get all resources for " + pkgname);
		}

		// For every directory identified capture all the .class files
		for (File directory : directories) {
			if (directory.exists()) {
				// Get the list of the files contained in the package
				String[] files = directory.list();
				for (String file : files) {
					// we are only interested in .class files
					if (file.endsWith(".class")) {
						// removes the .class extension
						classes.add(Class.forName(pkgname + '.' + file.substring(0, file.length() - 6)));
					}
				}
			} else {
				throw new ClassNotFoundException(pkgname + " (" + directory.getPath() + ") does not appear to be a valid package");
			}
		}
		return classes;
	}

	static List<Class> getClassessOfInterface(String thePackage, Class<Concept> theInterface) throws ClassNotFoundException {
		List<Class> classList = new ArrayList<Class>();
		for (Class discovered : getClassesForPackage(thePackage)) {
			if (Arrays.asList(discovered.getInterfaces()).contains(theInterface)) {
				classList.add(discovered);
			}
		}

		return classList;
	}
}