// ========================================================================
   // Copyright (c) 2009-2010 Mortbay, 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. 
  // Contributors:
  //    Greg Wilkins - initial API and implementation
  // ========================================================================
  package org.eclipse.jetty.osgi.boot;
  
  import java.io.File;
  import java.io.FilenameFilter;
  import java.io.IOException;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.Map.Entry;
  import java.util.Set;
  
  import org.eclipse.jetty.deploy.App;
  import org.eclipse.jetty.deploy.AppProvider;
  import org.eclipse.jetty.deploy.DeploymentManager;
  import org.eclipse.jetty.deploy.providers.ContextProvider;
  import org.eclipse.jetty.deploy.providers.ScanningAppProvider;
  import org.eclipse.jetty.osgi.boot.utils.internal.PackageAdminServiceTracker;
  import org.eclipse.jetty.server.handler.ContextHandler;
  import org.eclipse.jetty.util.Scanner;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.resource.Resource;
  import org.eclipse.jetty.webapp.WebAppContext;
  import org.osgi.framework.Bundle;
  import org.osgi.framework.BundleContext;
  import org.osgi.framework.BundleException;
  import org.osgi.framework.Constants;
  
  /**
   * AppProvider for OSGi. Supports the configuration of ContextHandlers and
   * WebApps. Extends the AbstractAppProvider to support the scanning of context
   * files located outside of the bundles.
   * <p>
   * This provider must not be called outside of jetty.boot: it should always be
   * called via the OSGi service listener.
   * </p>
   * <p>
   * This provider supports the same set of parameters than the WebAppProvider as
   * it supports the deployment of WebAppContexts. Except for the scanning of the
   * webapps directory.
   * </p>
   * <p>
   * When the parameter autoInstallOSGiBundles is set to true, OSGi bundles that
   * are located in the monitored directory are installed and started after the
   * framework as finished auto-starting all the other bundles.
   * Warning: only use this for development.
   * </p>
   */
  public class OSGiAppProvider extends ScanningAppProvider implements AppProvider
  {
  
      private boolean _extractWars = true;
      private boolean _parentLoaderPriority = false;
      private String _defaultsDescriptor;
      private String _tldBundles;
      private String[] _configurationClasses;
      private boolean _autoInstallOSGiBundles = true;
      
      //Keep track of the bundles that were installed and that are waiting for the
      //framework to complete its initialization.
      Set<Bundle> _pendingBundlesToStart = null;
          
      /**
       * When a context file corresponds to a deployed bundle and is changed we
       * reload the corresponding bundle.
       */
      private static class Filter implements FilenameFilter
      {
          OSGiAppProvider _enclosedInstance;
          
          public boolean accept(File dir, String name)
          {
              File file = new File(dir,name);
              if (fileMightBeAnOSGiBundle(file))
              {
                  return true;
              }
              if (!file.isDirectory())
              {
                  String contextName = getDeployedAppName(name);
                  if (contextName != null)
                  {
                      App app = _enclosedInstance.getDeployedApps().get(contextName);
                      return app != null;
                  }
              }
              return false;
         }
     }
 
     /**
      * @param contextFileName
      *            for example myContext.xml
      * @return The context, for example: myContext; null if this was not a
      *         suitable contextFileName.
      */
     private static String getDeployedAppName(String contextFileName)
     {
         String lowername = contextFileName.toLowerCase();
         if (lowername.endsWith(".xml"))
         {
             String contextName = contextFileName.substring(0,lowername.length() - ".xml".length());
             return contextName;
         }
         return null;
     }
 
     /**
      * Reading the display name of a webapp is really not sufficient for indexing the various
      * deployed ContextHandlers.
      * 
      * @param context
      * @return
      */
     private String getContextHandlerAppName(ContextHandler context) {
         String appName = context.getDisplayName();
         if (appName == null || appName.length() == 0  || getDeployedApps().containsKey(appName)) {
         	if (context instanceof WebAppContext)
         	{
         		appName = ((WebAppContext)context).getContextPath();
         		if (getDeployedApps().containsKey(appName)) {
             		appName = "noDisplayName"+context.getClass().getSimpleName()+context.hashCode();
             	}
         	} else {
         		appName = "noDisplayName"+context.getClass().getSimpleName()+context.hashCode();
         	}
         }
         return appName;
     }
     
     /**
      * Default OSGiAppProvider consutructed when none are defined in the
      * jetty.xml configuration.
      */
     public OSGiAppProvider()
     {
         super(new Filter());
         ((Filter)super._filenameFilter)._enclosedInstance = this;
     }
 
     /**
      * Default OSGiAppProvider consutructed when none are defined in the
      * jetty.xml configuration.
      * 
      * @param contextsDir
      */
     public OSGiAppProvider(File contextsDir) throws IOException
     {
         this();
         setMonitoredDirResource(Resource.newResource(contextsDir.toURI()));
     }
     
     /**
      * Returns the ContextHandler that was created by WebappRegistractionHelper
      * 
      * @see AppProvider
      */
     public ContextHandler createContextHandler(App app) throws Exception
     {
         // return pre-created Context
         ContextHandler wah = app.getContextHandler();
         if (wah == null)
         {
             // for some reason it was not defined when the App was constructed.
             // we don't support this situation at this point.
             // once the WebAppRegistrationHelper is refactored, the code
             // that creates the ContextHandler will actually be here.
             throw new IllegalStateException("The App must be passed the " + "instance of the ContextHandler when it is construsted");
         }
         if (_configurationClasses != null && wah instanceof WebAppContext) 
         {
             ((WebAppContext)wah).setConfigurationClasses(_configurationClasses);
         }
         return app.getContextHandler();
     }
 
     /**
      * @see AppProvider
      */
     public void setDeploymentManager(DeploymentManager deploymentManager)
     {
         // _manager=deploymentManager;
         super.setDeploymentManager(deploymentManager);
     }
 
     private static String getOriginId(Bundle contributor, String pathInBundle)
     {
     	return contributor.getSymbolicName() + "-" + contributor.getVersion().toString() +
     		(pathInBundle.startsWith("/") ? pathInBundle : "/" + pathInBundle);
     }
     
     /**
      * @param context
      * @throws Exception
      */
     public void addContext(Bundle contributor, String pathInBundle, ContextHandler context) throws Exception
     {
     	addContext(getOriginId(contributor, pathInBundle), context);
     }
     /**
      * @param context
      * @throws Exception
      */
     public void addContext(String originId, ContextHandler context) throws Exception
     {
         // TODO apply configuration specific to this provider
     	if (context instanceof WebAppContext)
     	{
            ((WebAppContext)context).setExtractWAR(isExtract());
     	}
 
         // wrap context as an App
         App app = new App(getDeploymentManager(),this,originId,context);
         String appName = getContextHandlerAppName(context);
         getDeployedApps().put(appName,app);
         getDeploymentManager().addApp(app);
     }
     
     
 
     /**
      * Called by the scanner of the context files directory. If we find the
      * corresponding deployed App we reload it by returning the App. Otherwise
      * we return null and nothing happens: presumably the corresponding OSGi
      * webapp is not ready yet.
      * 
      * @return the corresponding already deployed App so that it will be
      *         reloaded. Otherwise returns null.
      */
     @Override
     protected App createApp(String filename)
     {
         // find the corresponding bundle and ContextHandler or WebAppContext
         // and reload the corresponding App.
         // see the 2 pass of the refactoring of the WebAppRegistrationHelper.
         String name = getDeployedAppName(filename);
         if (name != null)
         {
             return getDeployedApps().get(name);
         }
         return null;
     }
 
     public void removeContext(ContextHandler context) throws Exception
     {
     	String appName = getContextHandlerAppName(context);
         App app = getDeployedApps().remove(context.getDisplayName());
         if (app == null) {
         	//try harder to undeploy this context handler.
         	//see bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=330098
         	appName = null;
         	for (Entry<String,App> deployedApp : getDeployedApps().entrySet()) {
         		if (deployedApp.getValue().getContextHandler() == context) {
         			app = deployedApp.getValue();
         			appName = deployedApp.getKey();
         			break;
         		}
         	}
         	if (appName != null) {
         		getDeployedApps().remove(appName);
         	}
         }
         if (app != null)
         {
             getDeploymentManager().removeApp(app);
         }
     }
 
     // //copied from WebAppProvider as the parameters are identical.
     // //only removed the parameer related to extractWars.
     /* ------------------------------------------------------------ */
     /**
      * Get the parentLoaderPriority.
      * 
      * @return the parentLoaderPriority
      */
     public boolean isParentLoaderPriority()
     {
         return _parentLoaderPriority;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * Set the parentLoaderPriority.
      * 
      * @param parentLoaderPriority
      *            the parentLoaderPriority to set
      */
     public void setParentLoaderPriority(boolean parentLoaderPriority)
     {
         _parentLoaderPriority = parentLoaderPriority;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * Get the defaultsDescriptor.
      * 
      * @return the defaultsDescriptor
      */
     public String getDefaultsDescriptor()
     {
         return _defaultsDescriptor;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * Set the defaultsDescriptor.
      * 
      * @param defaultsDescriptor
      *            the defaultsDescriptor to set
      */
     public void setDefaultsDescriptor(String defaultsDescriptor)
     {
         _defaultsDescriptor = defaultsDescriptor;
     }
 
     /**
      * The context xml directory. In fact it is the directory watched by the
      * scanner.
      */
     public File getContextXmlDirAsFile()
     {
         try
         {
             Resource monitoredDir = getMonitoredDirResource();
             if (monitoredDir == null)
                 return null;
             return monitoredDir.getFile();
         }
         catch (IOException e)
         {
             e.printStackTrace();
             return null;
         }
     }
 
     /* ------------------------------------------------------------ */
     /**
      * The context xml directory. In fact it is the directory watched by the
      * scanner.
      */
     public String getContextXmlDir()
     {
         try
         {
             Resource monitoredDir = getMonitoredDirResource();
             if (monitoredDir == null)
                 return null;
             return monitoredDir.getFile().toURI().toString();
         }
         catch (IOException e)
         {
             e.printStackTrace();
             return null;
         }
     }
     
     public boolean isExtract()
     {
         return _extractWars;
     }
 
     public void setExtract(boolean extract)
     {
         _extractWars=extract;
     }
 
     /**
      * @return true when this app provider locates osgi bundles and features in
      * its monitored directory and installs them. By default true if there is a folder to monitor.
      */
     public boolean isAutoInstallOSGiBundles()
     {
     	return _autoInstallOSGiBundles;
     }
 
     /**
      * &lt;autoInstallOSGiBundles&gt;true&lt;/autoInstallOSGiBundles&gt;
      * @param installingOSGiBundles
      */
     public void setAutoInstallOSGiBundles(boolean installingOSGiBundles)
     {
         _autoInstallOSGiBundles=installingOSGiBundles;
     }
 
 
     /* ------------------------------------------------------------ */
     /**
      * Set the directory in which to look for context XML files.
      * <p>
      * If a webapp call "foo/" or "foo.war" is discovered in the monitored
      * directory, then the ContextXmlDir is examined to see if a foo.xml file
      * exists. If it does, then this deployer will not deploy the webapp and the
      * ContextProvider should be used to act on the foo.xml file.
      * </p>
      * <p>
      * Also if this directory contains some osgi bundles, it will install them.
      * </p>
      * 
      * @see ContextProvider
      * @param contextsDir
      */
     public void setContextXmlDir(String contextsDir)
     {
         setMonitoredDirName(contextsDir);
     }
     
     /**
      * @param tldBundles Comma separated list of bundles that contain tld jars
      * that should be setup on the jetty instances created here.
      */
     public void setTldBundles(String tldBundles)
     {
     	_tldBundles = tldBundles;
     }
     
     /**
      * @return The list of bundles that contain tld jars that should be setup
      * on the jetty instances created here.
      */
     public String getTldBundles()
     {
     	return _tldBundles;
     }
     
     /**
      * @param configurations The configuration class names.
      */
     public void setConfigurationClasses(String[] configurations)
     {
         _configurationClasses = configurations==null?null:(String[])configurations.clone();
     }  
     
     /* ------------------------------------------------------------ */
     /**
      * 
      */
     public String[] getConfigurationClasses()
     {
         return _configurationClasses;
     }
 
     /**
      * Overridden to install the OSGi bundles found in the monitored folder.
      */
     protected void doStart() throws Exception
     {
         if (isAutoInstallOSGiBundles())
         {
         	if (getMonitoredDirResource()  == null)
         	{
         		setAutoInstallOSGiBundles(false);
         		Log.info("Disable autoInstallOSGiBundles as there is not contexts folder to monitor.");
         	}
 	    	else
         	{
 	    		File scandir = null;
 	    		try
 	    		{
 	                scandir = getMonitoredDirResource().getFile();
 	                if (!scandir.exists() || !scandir.isDirectory())
 	                {
 	                	setAutoInstallOSGiBundles(false);
 	            		Log.warn("Disable autoInstallOSGiBundles as the contexts folder '" + scandir.getAbsolutePath() + " does not exist.");
 	            		scandir = null;
 	                }
 	    		}
 	    		catch (IOException ioe)
 	    		{
                 	setAutoInstallOSGiBundles(false);
             		Log.warn("Disable autoInstallOSGiBundles as the contexts folder '" + getMonitoredDirResource().getURI() + " does not exist.");
             		scandir = null;
 	    		}
 	    		if (scandir != null)
 	    		{
 		            for (File file : scandir.listFiles())
 		            {
 		                if (fileMightBeAnOSGiBundle(file))
 		                {
 		                    installBundle(file, false);
 		                }
 		            }
 	    		}
         	}
         }
         super.doStart();
         if (isAutoInstallOSGiBundles())
         {
             Scanner.ScanCycleListener scanCycleListner = new AutoStartWhenFrameworkHasCompleted(this);
             super.addScannerListener(scanCycleListner);
         }
     }
     
     /**
      * When the file is a jar or a folder, we look if it looks like an OSGi bundle.
      * In that case we install it and start it.
      * <p>
      * Really a simple trick to get going quickly with development.
      * </p>
      */
     @Override
     protected void fileAdded(String filename) throws Exception
     {
         File file = new File(filename);
         if (isAutoInstallOSGiBundles() && file.exists() && fileMightBeAnOSGiBundle(file))
         {
             installBundle(file, true);
         }
         else
         {
             super.fileAdded(filename);
         }
     }
     
     /**
      * @param file
      * @return
      */
     private static boolean fileMightBeAnOSGiBundle(File file)
     {
         if (file.isDirectory())
         {
             if (new File(file,"META-INF/MANIFEST.MF").exists())
             {
                 return true;
             }
         }
         else if (file.getName().endsWith(".jar"))
         {
             return true;
         }
         return false;
     }
 
     @Override
     protected void fileChanged(String filename) throws Exception
     {
         File file = new File(filename);
         if (isAutoInstallOSGiBundles() && fileMightBeAnOSGiBundle(file))
         {
             updateBundle(file);
         }
         else
         {
             super.fileChanged(filename);
         }
     }
 
     @Override
     protected void fileRemoved(String filename) throws Exception
     {
         File file = new File(filename);
         if (isAutoInstallOSGiBundles() && fileMightBeAnOSGiBundle(file))
         {
             uninstallBundle(file);
         }
         else
         {
             super.fileRemoved(filename);
         }
     }
     
     /**
      * Returns a bundle according to its location.
      * In the version 1.6 of org.osgi.framework, BundleContext.getBundle(String) is what we want.
      * However to support older versions of OSGi. We use our own local refrence mechanism.
      * @param location
      * @return
      */
     protected Bundle getBundle(BundleContext bc, String location)
     {
     	//not available in older versions of OSGi:
     	//return bc.getBundle(location);
     	for (Bundle b : bc.getBundles())
     	{
     		if (b.getLocation().equals(location))
     		{
     			return b;
     		}
     	}
     	return null;
     }
 
     protected synchronized Bundle installBundle(File file, boolean start)
     {
     	
         try
         {
             BundleContext bc = JettyBootstrapActivator.getBundleContext();
             String location = file.toURI().toString();
             Bundle b = getBundle(bc, location);
             if (b == null) 
             {
                 b = bc.installBundle(location);
             }
             if (b == null)
             {
             	//not sure we will ever be here,
             	//most likely a BundleException was thrown
             	Log.warn("The file " + location + " is not an OSGi bundle.");
             	return null;
             }
             if (start && b.getHeaders().get(Constants.FRAGMENT_HOST) == null)
             {//not a fragment, try to start it. if the framework has finished auto-starting.
             	if (!PackageAdminServiceTracker.INSTANCE.frameworkHasCompletedAutostarts())
             	{
             		if (_pendingBundlesToStart == null)
             		{
             			_pendingBundlesToStart = new HashSet<Bundle>();
             		}
             		_pendingBundlesToStart.add(b);
             		return null;
             	}
             	else
             	{
             		b.start();
             	}
             }
             return b;
         }
         catch (BundleException e)
         {
             Log.warn("Unable to " + (start? "start":"install") + " the bundle " + file.getAbsolutePath(), e);
         }
         return null;
     }
     
     protected void uninstallBundle(File file)
     {
         try
         {
             Bundle b = getBundle(JettyBootstrapActivator.getBundleContext(), file.toURI().toString());
             b.stop();
             b.uninstall();
         }
         catch (BundleException e)
         {
             Log.warn("Unable to uninstall the bundle " + file.getAbsolutePath(), e);
         }
     }
     
     protected void updateBundle(File file)
     {
         try
         {
             Bundle b = getBundle(JettyBootstrapActivator.getBundleContext(), file.toURI().toString());
             if (b == null)
             {
                 installBundle(file, true);
             }
             else if (b.getState() == Bundle.ACTIVE)
             {
                 b.update();
             }
             else
             {
                 b.start();
             }
         }
         catch (BundleException e)
         {
             Log.warn("Unable to update the bundle " + file.getAbsolutePath(), e);
         }
     }
     
 
 }
 /**
  * At the end of each scan, if there are some bundles to be started,
  * look if the framework has completed its autostart. In that case start those bundles.
  */
 class AutoStartWhenFrameworkHasCompleted implements Scanner.ScanCycleListener
 {
 	private final OSGiAppProvider _appProvider;
 	
 	AutoStartWhenFrameworkHasCompleted(OSGiAppProvider appProvider)
 	{
 		_appProvider = appProvider;
 	}
 	
 	public void scanStarted(int cycle) throws Exception
 	{
 	}
 	
 	public void scanEnded(int cycle) throws Exception
 	{
 		if (_appProvider._pendingBundlesToStart != null && PackageAdminServiceTracker.INSTANCE.frameworkHasCompletedAutostarts())
 		{
 			Iterator<Bundle> it = _appProvider._pendingBundlesToStart.iterator();
 			while (it.hasNext())
 			{
 				Bundle b = it.next();
 				if (b.getHeaders().get(Constants.FRAGMENT_HOST) != null)
 				{
 					continue;
 				}
 				try
 				{
 					b.start();
 				}
 		        catch (BundleException e)
 		        {
 		            Log.warn("Unable to start the bundle " + b.getLocation(), e);
 		        }
 
 			}
 			_appProvider._pendingBundlesToStart = null;
 		}
 	}
 
 }