//
   //  ========================================================================
   //  Copyright (c) 1995-2016 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  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.jmx;
  
  import java.io.IOException;
  import java.util.Locale;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import javax.management.InstanceNotFoundException;
  import javax.management.MBeanRegistrationException;
  import javax.management.MBeanServer;
  import javax.management.ObjectName;
  
  import org.eclipse.jetty.util.annotation.ManagedObject;
  import org.eclipse.jetty.util.component.Container;
  import org.eclipse.jetty.util.component.ContainerLifeCycle;
  import org.eclipse.jetty.util.component.Destroyable;
  import org.eclipse.jetty.util.component.Dumpable;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  /**
   * Container class for the MBean instances
   */
  @ManagedObject("The component that registers beans as MBeans")
  public class MBeanContainer implements Container.InheritedListener, Dumpable, Destroyable
  {
      private final static Logger LOG = Log.getLogger(MBeanContainer.class.getName());
      private final static ConcurrentMap<String, AtomicInteger> __unique = new ConcurrentHashMap<>();
  
      public static void resetUnique()
      {
          __unique.clear();
      }
  
      private final MBeanServer _mbeanServer;
      private final Map<Object, ObjectName> _beans = new ConcurrentHashMap<>();
      private String _domain = null;
  
      /**
       * Lookup an object name by instance
       *
       * @param object instance for which object name is looked up
       * @return object name associated with specified instance, or null if not found
       */
      public ObjectName findMBean(Object object)
      {
          return _beans.get(object);
      }
  
      /**
       * Lookup an instance by object name
       *
       * @param objectName object name of instance
       * @return instance associated with specified object name, or null if not found
       */
      public Object findBean(ObjectName objectName)
      {
          for (Map.Entry<Object, ObjectName> entry : _beans.entrySet())
          {
              if (entry.getKey().equals(objectName))
                  return entry.getValue();
          }
          return null;
      }
  
      /**
       * Constructs MBeanContainer
       *
       * @param server instance of MBeanServer for use by container
       */
      public MBeanContainer(MBeanServer server)
      {
          _mbeanServer = server;
      }
  
      /**
       * Retrieve instance of MBeanServer used by container
       *
       * @return instance of MBeanServer
      */
     public MBeanServer getMBeanServer()
     {
         return _mbeanServer;
     }
 
     /**
      * Set domain to be used to add MBeans
      *
      * @param domain domain name
      */
     public void setDomain(String domain)
     {
         _domain = domain;
     }
 
     /**
      * Retrieve domain name used to add MBeans
      *
      * @return domain name
      */
     public String getDomain()
     {
         return _domain;
     }
 
 
     @Override
     public void beanAdded(Container parent, Object obj)
     {
         if (LOG.isDebugEnabled())
             LOG.debug("beanAdded {}->{}", parent, obj);
 
         // Is there an object name for the parent ?
         ObjectName parentObjectName = null;
         if (parent != null)
         {
             parentObjectName = findMBean(parent);
             if (parentObjectName == null)
             {
                 // Create the parent bean.
                 beanAdded(null, parent);
                 parentObjectName = findMBean(parent);
             }
         }
 
         // Does the mbean already exist ?
         if (obj == null || _beans.containsKey(obj))
             return;
 
         try
         {
             // Create an MBean for the object.
             Object mbean = ObjectMBean.mbeanFor(obj);
             if (mbean == null)
                 return;
 
             ObjectName objectName = null;
             if (mbean instanceof ObjectMBean)
             {
                 ((ObjectMBean)mbean).setMBeanContainer(this);
                 objectName = ((ObjectMBean)mbean).getObjectName();
             }
 
             // No override of the mbean's ObjectName, so make a generic one.
             if (objectName == null)
             {
                 // If no explicit domain, create one.
                 String domain = _domain;
                 if (domain == null)
                     domain = obj.getClass().getPackage().getName();
 
                 String type = obj.getClass().getName().toLowerCase(Locale.ENGLISH);
                 int dot = type.lastIndexOf('.');
                 if (dot >= 0)
                     type = type.substring(dot + 1);
 
                 StringBuilder buf = new StringBuilder();
 
                 String context = (mbean instanceof ObjectMBean) ? makeName(((ObjectMBean)mbean).getObjectContextBasis()) : null;
                 if (context == null && parentObjectName != null)
                     context = parentObjectName.getKeyProperty("context");
 
                 if (context != null && context.length() > 1)
                     buf.append("context=").append(context).append(",");
 
                 buf.append("type=").append(type);
 
                 String name = (mbean instanceof ObjectMBean) ? makeName(((ObjectMBean)mbean).getObjectNameBasis()) : context;
                 if (name != null && name.length() > 1)
                     buf.append(",").append("name=").append(name);
 
                 String basis = buf.toString();
 
                 AtomicInteger count = __unique.get(basis);
                 if (count == null)
                 {
                     count = new AtomicInteger();
                     AtomicInteger existing = __unique.putIfAbsent(basis, count);
                     if (existing != null)
                         count = existing;
                 }
 
                 objectName = ObjectName.getInstance(domain + ":" + basis + ",id=" + count.getAndIncrement());
             }
 
             _mbeanServer.registerMBean(mbean, objectName);
             if (LOG.isDebugEnabled())
                 LOG.debug("Registered {}", objectName);
 
             _beans.put(obj, objectName);
         }
         catch (Throwable x)
         {
             LOG.warn("bean: " + obj, x);
         }
     }
 
     @Override
     public void beanRemoved(Container parent, Object obj)
     {
         if (LOG.isDebugEnabled())
             LOG.debug("beanRemoved {}", obj);
 
         ObjectName objectName = _beans.remove(obj);
 
         if (objectName != null)
             unregister(objectName);
     }
 
     /**
      * @param basis name to strip of special characters.
      * @return normalized name
      */
     public String makeName(String basis)
     {
         if (basis == null)
             return null;
         return basis
                 .replace(':', '_')
                 .replace('*', '_')
                 .replace('?', '_')
                 .replace('=', '_')
                 .replace(',', '_')
                 .replace(' ', '_');
     }
 
     @Override
     public void dump(Appendable out, String indent) throws IOException
     {
         ContainerLifeCycle.dumpObject(out,this);
         ContainerLifeCycle.dump(out, indent, _beans.entrySet());
     }
 
     @Override
     public String dump()
     {
         return ContainerLifeCycle.dump(this);
     }
 
     @Override
     public void destroy()
     {
         _beans.values().stream()
                 .filter(objectName -> objectName != null)
                 .forEach(this::unregister);
     }
 
     private void unregister(ObjectName objectName)
     {
         try
         {
             getMBeanServer().unregisterMBean(objectName);
             if (LOG.isDebugEnabled())
                 LOG.debug("Unregistered {}", objectName);
         }
         catch (MBeanRegistrationException | InstanceNotFoundException x)
         {
             LOG.ignore(x);
         }
         catch (Throwable x)
         {
             LOG.warn(x);
         }
     }
 }