//
   //  ========================================================================
   //  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.websocket.jsr356;
  
  import java.util.Map;
  import java.util.Objects;
  import java.util.concurrent.ConcurrentHashMap;
  
  import javax.websocket.Encoder;
  import javax.websocket.EndpointConfig;
  
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  import org.eclipse.jetty.websocket.common.scopes.WebSocketContainerScope;
  import org.eclipse.jetty.websocket.common.scopes.WebSocketSessionScope;
  import org.eclipse.jetty.websocket.jsr356.metadata.EncoderMetadata;
  import org.eclipse.jetty.websocket.jsr356.metadata.EncoderMetadataSet;
  
  /**
   * Represents all of the declared {@link Encoder}s that the Container is aware of.
   */
  public class EncoderFactory implements Configurable
  {
      public static class Wrapper implements Configurable
      {
          private final Encoder encoder;
          private final EncoderMetadata metadata;
  
          private Wrapper(Encoder encoder, EncoderMetadata metadata)
          {
              this.encoder = encoder;
              this.metadata = metadata;
          }
  
          public Encoder getEncoder()
          {
              return encoder;
          }
  
          public EncoderMetadata getMetadata()
          {
              return metadata;
          }
  
          @Override
          public void init(EndpointConfig config)
          {
              this.encoder.init(config);
          }
      }
  
      private static final Logger LOG = Log.getLogger(EncoderFactory.class);
  
      private final EncoderMetadataSet metadatas;
      private final WebSocketContainerScope containerScope;
      private EncoderFactory parentFactory;
      private Map<Class<?>, Wrapper> activeWrappers;
  
      public EncoderFactory(WebSocketContainerScope containerScope, EncoderMetadataSet metadatas)
      {
          this(containerScope,metadatas,null);
      }
  
      public EncoderFactory(WebSocketSessionScope sessionScope, EncoderMetadataSet metadatas, EncoderFactory parentFactory)
      {
          this(sessionScope.getContainerScope(),metadatas,parentFactory);
      }
  
      protected EncoderFactory(WebSocketContainerScope containerScope, EncoderMetadataSet metadatas, EncoderFactory parentFactory)
      {
          Objects.requireNonNull(containerScope,"Container Scope cannot be null");
          this.containerScope = containerScope;
          this.metadatas = metadatas;
          this.activeWrappers = new ConcurrentHashMap<>();
          this.parentFactory = parentFactory;
      }
  
      public Encoder getEncoderFor(Class<?> type)
      {
          Wrapper wrapper = getWrapperFor(type);
          if (wrapper == null)
          {
              return null;
         }
         return wrapper.encoder;
     }
 
     public EncoderMetadata getMetadataFor(Class<?> type)
     {
         if (LOG.isDebugEnabled())
         {
             LOG.debug("getMetadataFor({})",type);
         }
         EncoderMetadata metadata = metadatas.getMetadataByType(type);
 
         if (metadata != null)
         {
             return metadata;
         }
 
         if (parentFactory != null)
         {
             return parentFactory.getMetadataFor(type);
         }
 
         return null;
     }
 
     public Wrapper getWrapperFor(Class<?> type)
     {
         synchronized (activeWrappers)
         {
             Wrapper wrapper = activeWrappers.get(type);
 
             // Try parent (if needed)
             if ((wrapper == null) && (parentFactory != null))
             {
                 wrapper = parentFactory.getWrapperFor(type);
             }
 
             if (wrapper == null)
             {
                 // Attempt to create Wrapper on demand
                 EncoderMetadata metadata = metadatas.getMetadataByType(type);
                 if (metadata == null)
                 {
                     return null;
                 }
                 wrapper = newWrapper(metadata);
                 // track wrapper
                 activeWrappers.put(type,wrapper);
             }
 
             return wrapper;
         }
     }
 
     @Override
     public void init(EndpointConfig config)
     {
         if (LOG.isDebugEnabled())
         {
             LOG.debug("init({})",config);
         }
 
         // Instantiate all declared encoders
         for (EncoderMetadata metadata : metadatas)
         {
             Wrapper wrapper = newWrapper(metadata);
             activeWrappers.put(metadata.getObjectType(),wrapper);
         }
 
         // Initialize all encoders
         for (Wrapper wrapper : activeWrappers.values())
         {
             wrapper.encoder.init(config);
         }
     }
 
     private Wrapper newWrapper(EncoderMetadata metadata)
     {
         Class<? extends Encoder> encoderClass = metadata.getCoderClass();
         try
         {
             Encoder encoder = containerScope.getObjectFactory().createInstance(encoderClass);
             return new Wrapper(encoder,metadata);
         }
         catch (InstantiationException | IllegalAccessException e)
         {
             throw new IllegalStateException("Unable to instantiate Encoder: " + encoderClass.getName());
         }
     }
 }