// ========================================================================
   // Copyright (c) 2009 Intalio, Inc.
   // ------------------------------------------------------------------------
   // All rights reserved. This program and the accompanying materials
   // are made available under the terms of the Eclipse Public License v1.0
   // and Apache License v2.0 which accompanies this distribution.
   // The Eclipse Public License is available at 
   // http://www.eclipse.org/legal/epl-v10.html
   // The Apache License v2.0 is available at
  // http://www.opensource.org/licenses/apache2.0.php
  // You may elect to redistribute this code under either of these licenses. 
  // ========================================================================
  package org.eclipse.jetty.osgi.boot.utils.internal;
  
  import java.io.File;
  import java.lang.reflect.Field;
  import java.lang.reflect.Method;
  import java.net.URI;
  import java.net.URL;
  import java.net.URLConnection;
  import java.net.URLDecoder;
  import java.util.ArrayList;
  import java.util.Enumeration;
  import java.util.zip.ZipFile;
  
  import org.eclipse.jetty.osgi.boot.utils.BundleFileLocatorHelper;
  import org.eclipse.jetty.util.URIUtil;
  import org.eclipse.jetty.util.resource.FileResource;
  import org.osgi.framework.Bundle;
  
  /**
   * From a bundle to its location on the filesystem. Assumes the bundle is not a
   * jar.
   * 
   * @author hmalphettes
   */
  public class DefaultFileLocatorHelper implements BundleFileLocatorHelper
  {
  
      // hack to locate the file-system directly from the bundle.
      // support equinox, felix and nuxeo's osgi implementations.
      // not tested on nuxeo and felix just yet.
      // The url nuxeo and felix return is created directly from the File so it
      // should work.
      private static Field BUNDLE_ENTRY_FIELD = null;
      private static Field FILE_FIELD = null;
  
      private static Field BUNDLE_FILE_FIELD_FOR_DIR_ZIP_BUNDLE_ENTRY = null;// ZipBundleFile
                                                                             // inside
                                                                             // DirZipBundleEntry
  
      private static Field ZIP_FILE_FILED_FOR_ZIP_BUNDLE_FILE = null;// ZipFile
  
      /**
       * Works with equinox, felix, nuxeo and probably more. Not exactly in the
       * spirit of OSGi but quite necessary to support self-contained webapps and
       * other situations.
       * 
       * @param bundle
       *            The bundle
       * @return Its installation location as a file.
       * @throws Exception
       */
      public File getBundleInstallLocation(Bundle bundle) throws Exception
      {
          // String installedBundles = System.getProperty("osgi.bundles");
          // grab the MANIFEST.MF's url
          // and then do what it takes.
          URL url = bundle.getEntry("/META-INF/MANIFEST.MF");
  //        System.err.println(url.toString() + " " + url.toURI() + " " + url.getProtocol());
          if (url.getProtocol().equals("file"))
          {
              // some osgi frameworks do use the file protocole directly in some
              // situations. Do use the FileResource to transform the URL into a File: URL#toURI is broken
              return new FileResource(url).getFile().getParentFile().getParentFile();
          }
          else if (url.getProtocol().equals("bundleentry"))
          {
              // say hello to equinox who has its own protocol.
              // we use introspection like there is no tomorrow to get access to
              // the File
              URLConnection con = url.openConnection();
              if (BUNDLE_ENTRY_FIELD == null)
              {
                  BUNDLE_ENTRY_FIELD = con.getClass().getDeclaredField("bundleEntry");
                  BUNDLE_ENTRY_FIELD.setAccessible(true);
              }
              Object bundleEntry = BUNDLE_ENTRY_FIELD.get(con);
              if (bundleEntry.getClass().getName().equals("org.eclipse.osgi.baseadaptor.bundlefile.FileBundleEntry"))
              {
                  if (FILE_FIELD == null)
                  {
                      FILE_FIELD = bundleEntry.getClass().getDeclaredField("file");
                      FILE_FIELD.setAccessible(true);
                  }
                  File f = (File)FILE_FIELD.get(bundleEntry);
                  return f.getParentFile().getParentFile();
              }
              else if (bundleEntry.getClass().getName().equals("org.eclipse.osgi.baseadaptor.bundlefile.ZipBundleEntry"))
             {
                 url = bundle.getEntry("/");
                 con = url.openConnection();
                 if (BUNDLE_ENTRY_FIELD == null)
                 {// this one will be a DirZipBundleEntry
                     BUNDLE_ENTRY_FIELD = con.getClass().getDeclaredField("bundleEntry");
                     BUNDLE_ENTRY_FIELD.setAccessible(true);
                 }
                 bundleEntry = BUNDLE_ENTRY_FIELD.get(con);
                 if (BUNDLE_FILE_FIELD_FOR_DIR_ZIP_BUNDLE_ENTRY == null)
                 {
                     BUNDLE_FILE_FIELD_FOR_DIR_ZIP_BUNDLE_ENTRY = bundleEntry.getClass().getDeclaredField("bundleFile");
                     BUNDLE_FILE_FIELD_FOR_DIR_ZIP_BUNDLE_ENTRY.setAccessible(true);
                 }
                 Object zipBundleFile = BUNDLE_FILE_FIELD_FOR_DIR_ZIP_BUNDLE_ENTRY.get(bundleEntry);
                 if (ZIP_FILE_FILED_FOR_ZIP_BUNDLE_FILE == null)
                 {
                     ZIP_FILE_FILED_FOR_ZIP_BUNDLE_FILE = zipBundleFile.getClass().getDeclaredField("zipFile");
                     ZIP_FILE_FILED_FOR_ZIP_BUNDLE_FILE.setAccessible(true);
                 }
                 ZipFile zipFile = (ZipFile)ZIP_FILE_FILED_FOR_ZIP_BUNDLE_FILE.get(zipBundleFile);
                 return new File(zipFile.getName());
             }
             else if (bundleEntry.getClass().getName().equals("org.eclipse.osgi.baseadaptor.bundlefile.DirZipBundleEntry"))
             {
                 // that will not happen as we did ask for the manifest not a
                 // directory.
             }
         }
         else if ("bundle".equals(url.getProtocol()))
         {
             // observed this on felix-2.0.0
             String location = bundle.getLocation();
 //            System.err.println("location  " + location);
             if (location.startsWith("file:/"))
             {
                 URI uri = new URI(URIUtil.encodePath(location));
                 return new File(uri);
             }
             else if (location.startsWith("file:"))
             {
             	//location defined in the BundleArchive m_bundleArchive
             	//it is relative to relative to the  BundleArchive's m_archiveRootDir
             	File res = new File(location.substring("file:".length()));
             	if (!res.exists())
             	{
             		return null;
 //                	Object bundleArchive = getFelixBundleArchive(bundle);
 //                	File archiveRoot = getFelixBundleArchiveRootDir(bundleArchive);
 //                	String currentLocation = getFelixBundleArchiveCurrentLocation(bundleArchive);
 //                	System.err.println("Got the archive root " + archiveRoot.getAbsolutePath()
 //                	+ " current location " + currentLocation + " is directory ?");
 //                	res = new File(archiveRoot, currentLocation != null
 //                			? currentLocation : location.substring("file:".length()));
             	}
             	return res;
             }
             else if (location.startsWith("reference:file:"))
             {
             	location = URLDecoder.decode(location.substring("reference:".length()), "UTF-8");
             	File file = new File(location.substring("file:".length()));
             	return file;
             }
         }
         return null;
     }
 
     /**
      * Locate a file inside a bundle.
      * 
      * @param bundle
      * @param path
      * @return file object
      * @throws Exception
      */
     public File getFileInBundle(Bundle bundle, String path) throws Exception
     {
         if (path != null && path.length() > 0 && path.charAt(0) == '/')
         {
             path = path.substring(1);
         }
         File bundleInstall = getBundleInstallLocation(bundle);
         File webapp = path != null && path.length() != 0?new File(bundleInstall,path):bundleInstall;
         if (!webapp.exists())
         {
             throw new IllegalArgumentException("Unable to locate " + path + " inside " + bundle.getSymbolicName() + " ("
                     + (bundleInstall != null?bundleInstall.getAbsolutePath():" no_bundle_location ") + ")");
         }
         return webapp;
     }
     
     /**
 	 * Helper method equivalent to Bundle#getEntry(String entryPath) except that
 	 * it searches for entries in the fragments by using the Bundle#findEntries method.
 	 * 
 	 * @param bundle
 	 * @param entryPath
 	 * @return null or all the entries found for that path.
 	 */
 	public Enumeration<URL> findEntries(Bundle bundle, String entryPath)
 	{
     	int last = entryPath.lastIndexOf('/');
     	String path = last != -1 && last < entryPath.length() -2
     		? entryPath.substring(0, last) : "/";
     	if (!path.startsWith("/"))
     	{
     		path = "/" + path;
     	}
     	String pattern = last != -1 && last < entryPath.length() -2
 			? entryPath.substring(last+1) : entryPath;
 		Enumeration<URL> enUrls = bundle.findEntries(path, pattern, false);
 		return enUrls;
 	}
 
     /**
      * If the bundle is a jar, returns the jar. If the bundle is a folder, look
      * inside it and search for jars that it returns.
      * <p>
      * Good enough for our purpose (TldLocationsCache when it scans for tld
      * files inside jars alone. In fact we only support the second situation for
      * development purpose where the bundle was imported in pde and the classes
      * kept in a jar.
      * </p>
      * 
      * @param bundle
      * @return The jar(s) file that is either the bundle itself, either the jars
      *         embedded inside it.
      */
     public File[] locateJarsInsideBundle(Bundle bundle) throws Exception
     {
         File jasperLocation = getBundleInstallLocation(bundle);
         if (jasperLocation.isDirectory())
         {
             // try to find the jar files inside this folder
             ArrayList<File> urls = new ArrayList<File>();
             for (File f : jasperLocation.listFiles())
             {
                 if (f.getName().endsWith(".jar") && f.isFile())
                 {
                     urls.add(f);
                 }
                 else if (f.isDirectory() && f.getName().equals("lib"))
                 {
                     for (File f2 : jasperLocation.listFiles())
                     {
                         if (f2.getName().endsWith(".jar") && f2.isFile())
                         {
                             urls.add(f2);
                         }
                     }
                 }
             }
             return urls.toArray(new File[urls.size()]);
         }
         else
         {
             return new File[] { jasperLocation };
         }
     }
     
 
 	//introspection on equinox to invoke the getLocalURL method on BundleURLConnection
     //equivalent to using the FileLocator without depending on an equinox class.
 	private static Method BUNDLE_URL_CONNECTION_getLocalURL = null;
 	private static Method BUNDLE_URL_CONNECTION_getFileURL = null;
 	/**
 	 * Only useful for equinox: on felix we get the file:// or jar:// url already.
 	 * Other OSGi implementations have not been tested
 	 * <p>
 	 * Get a URL to the bundle entry that uses a common protocol (i.e. file:
 	 * jar: or http: etc.).  
 	 * </p>
 	 * @return a URL to the bundle entry that uses a common protocol
 	 */
 	public static URL getLocalURL(URL url) {
 		if ("bundleresource".equals(url.getProtocol()) || "bundleentry".equals(url.getProtocol())) {
 			try {
 				URLConnection conn = url.openConnection();
 				if (BUNDLE_URL_CONNECTION_getLocalURL == null && 
 						conn.getClass().getName().equals(
 								"org.eclipse.osgi.framework.internal.core.BundleURLConnection")) {
 					BUNDLE_URL_CONNECTION_getLocalURL = conn.getClass().getMethod("getLocalURL", null);
 					BUNDLE_URL_CONNECTION_getLocalURL.setAccessible(true);
 				}
 				if (BUNDLE_URL_CONNECTION_getLocalURL != null) {
 					return (URL)BUNDLE_URL_CONNECTION_getLocalURL.invoke(conn, null);
 				}
 			} catch (Throwable t) {
 				System.err.println("Unable to locate the OSGi url: '" + url + "'.");
 				t.printStackTrace();
 			}
 		}
 		return url;
 	}
 	/**
 	 * Only useful for equinox: on felix we get the file:// url already.
 	 * Other OSGi implementations have not been tested
 	 * <p>
 	 * Get a URL to the content of the bundle entry that uses the file: protocol.
 	 * The content of the bundle entry may be downloaded or extracted to the local
 	 * file system in order to create a file: URL.
 	 * @return a URL to the content of the bundle entry that uses the file: protocol
 	 * </p>
 	 */
 	public static URL getFileURL(URL url)
 	{
 		if ("bundleresource".equals(url.getProtocol()) || "bundleentry".equals(url.getProtocol()))
 		{
 			try
 			{
 				URLConnection conn = url.openConnection();
 				if (BUNDLE_URL_CONNECTION_getFileURL == null && 
 						conn.getClass().getName().equals(
 								"org.eclipse.osgi.framework.internal.core.BundleURLConnection"))
 				{
 					BUNDLE_URL_CONNECTION_getFileURL = conn.getClass().getMethod("getFileURL", null);
 					BUNDLE_URL_CONNECTION_getFileURL.setAccessible(true);
 				}
 				if (BUNDLE_URL_CONNECTION_getFileURL != null)
 				{
 					return (URL)BUNDLE_URL_CONNECTION_getFileURL.invoke(conn, null);
 				}
 			}
 			catch (Throwable t)
 			{
 				t.printStackTrace();
 			}
 		}
 		return url;
 	}
 
 }