package me.libraryaddict.disguise.utilities;

import org.bukkit.entity.Entity;

import java.io.IOException;
import java.net.URL;
import java.security.CodeSource;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

/**
 * User: Austin Date: 4/22/13 Time: 11:47 PM (c) lazertester
 */

// Code for this taken and slightly modified from
// https://github.com/ddopson/java-class-enumerator
public class ClassGetter {

    public static ArrayList<Class<?>> getClassesForPackage(String pkgname) {
        ArrayList<Class<?>> classes = new ArrayList<Class<?>>();
        // String relPath = pkgname.replace('.', '/');

        // Get a File object for the package
        CodeSource src = Entity.class.getProtectionDomain().getCodeSource();
        if (src != null) {
            URL resource = src.getLocation();
            resource.getPath();
            processJarfile(resource, pkgname, classes);
        }
        return classes;
    }

    private static Class<?> loadClass(String className) {
        try {
            return Class.forName(className);
        } catch (ClassNotFoundException e) {
            throw new RuntimeException("Unexpected ClassNotFoundException loading class '" + className + "'");
        } catch (NoClassDefFoundError e) {
            return null;
        }
    }

    private static void processJarfile(URL resource, String pkgname, ArrayList<Class<?>> classes) {
        String relPath = pkgname.replace('.', '/');
        String resPath = resource.getPath().replace("%20", " ");
        String jarPath = resPath.replaceFirst("[.]jar[!].*", ".jar").replaceFirst("file:", "");
        JarFile jarFile;
        try {
            jarFile = new JarFile(jarPath);
        } catch (IOException e) {
            throw new RuntimeException("Unexpected IOException reading JAR File '" + jarPath
                    + "'. Do you have strange characters in your folders? Such as #?", e);
        }
        Enumeration<JarEntry> entries = jarFile.entries();
        while (entries.hasMoreElements()) {
            JarEntry entry = entries.nextElement();
            String entryName = entry.getName();
            String className = null;
            if (entryName.endsWith(".class") && entryName.startsWith(relPath)
                    && entryName.length() > (relPath.length() + "/".length())) {
                className = entryName.replace('/', '.').replace('\\', '.').replace(".class", "");
            }
            if (className != null) {
                Class<?> c = loadClass(className);
                if (c != null)
                    classes.add(c);
            }
        }
    }
}