/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements. See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership. The ASF licenses this file

  * to you under the Apache License, Version 2.0 (the

  * "License"); you may not use this file except in compliance

  * with the License. You may obtain a copy of the License at

  *

  * http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an

  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

  * KIND, either express or implied. See the License for the

  * specific language governing permissions and limitations

  * under the License.

  */

 package org.apache.johnzon.websocket.mapper;

 import org.apache.johnzon.mapper.Mapper;

 import org.apache.johnzon.websocket.internal.mapper.MapperLocator;

 import java.io.Reader;

 import java.lang.annotation.Annotation;

 import java.lang.reflect.Method;

 import java.lang.reflect.Type;

 import javax.websocket.DecodeException;

 import javax.websocket.Decoder;

 import javax.websocket.EndpointConfig;

 import javax.websocket.OnMessage;

 import javax.websocket.Session;

 import javax.websocket.server.PathParam;

 import javax.websocket.server.ServerEndpointConfig;

 public class JohnzonTextDecoder implements Decoder.TextStream<Object> {

     protected Mapper mapper;

     protected Type type;

     public JohnzonTextDecoder() {

         // no-op

     }

     // for client side no way to guess the type so let the user provide it easily

     public JohnzonTextDecoder(final Type type) {

         this(null, type);

     }

     public JohnzonTextDecoder(final Mapper mapper, final Type type) {

         this.mapper = mapper;

         this.type = type;

     }

     @Override

     public Object decode(final Reader stream) throws DecodeException {

         return mapper.readObject(stream, type);

     }

     @Override

     public void init(final EndpointConfig endpointConfig) {

         if (mapper == null) {

             mapper = MapperLocator.locate();

         }

         if (type != null) {

             return;

         }

         if (ServerEndpointConfig.class.isInstance(endpointConfig)) {

             final Class<?> endpointClass = ServerEndpointConfig.class.cast(endpointConfig).getEndpointClass();

             for (final Method m : endpointClass.getMethods()) {

                 if (Object.class == m.getDeclaringClass()) {

                     continue;

                 }

                 if (m.getAnnotation(OnMessage.class) != null) {

                     final Type[] genericParameterTypes = m.getGenericParameterTypes();

                     for (int i = 0; i < genericParameterTypes.length; i++) {

                         if (genericParameterTypes[i] == Session.class) {

                             continue;

                         }

                         boolean param = false;

                         for (final Annotation a : m.getParameterAnnotations()[i]) {

                             if (PathParam.class == a.annotationType()) {

                                 param = true;

                                 break;

                             }

                         }

                         if (!param) {

                             this.type = genericParameterTypes[i];

                             break;

                         }

                     }

                     break;

                 }

             }

             if (type == null) {

                 throw new IllegalArgumentException("didn't find @OnMessage in " + endpointClass);

             }

         } else {

             type = Type.class.cast(endpointConfig.getUserProperties().get("johnzon.websocket.message.type"));

             if (type == null) {

                 throw new IllegalArgumentException("didn't find johnzon.websocket.message.type");

             }

         }

     }

     @Override

     public void destroy() {

         // no-op

     }

 }