//
   //  ========================================================================
   //  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.annotations;
  
  import java.lang.annotation.Annotation;
  import java.lang.reflect.Method;
  import java.util.Map;
  
  import javax.websocket.DecodeException;
  import javax.websocket.Decoder;
  
  import org.eclipse.jetty.websocket.api.InvalidWebSocketException;
  import org.eclipse.jetty.websocket.common.events.annotated.CallableMethod;
  import org.eclipse.jetty.websocket.common.events.annotated.InvalidSignatureException;
  import org.eclipse.jetty.websocket.common.util.ReflectUtils;
  import org.eclipse.jetty.websocket.jsr356.JsrSession;
  import org.eclipse.jetty.websocket.jsr356.annotations.Param.Role;
  
  public abstract class JsrCallable extends CallableMethod
  {
      protected final Param[] params;
      protected final Object[] args;
      protected int idxSession = -1;
      protected int idxConfig = -1;
  
      public JsrCallable(Class<?> pojo, Method method)
      {
          super(pojo,method);
  
          Class<?> ptypes[] = method.getParameterTypes();
          Annotation pannos[][] = method.getParameterAnnotations();
          int len = ptypes.length;
          params = new Param[len];
          for (int i = 0; i < len; i++)
          {
              params[i] = new Param(i,ptypes[i],pannos[i]);
          }
  
          args = new Object[len];
      }
  
      /**
       * Copy Constructor
       * @param copy the JsrCallable to copy from 
       */
      public JsrCallable(JsrCallable copy)
      {
          this(copy.getPojo(),copy.getMethod());
          this.idxSession = copy.idxSession;
          this.idxConfig = copy.idxConfig;
          System.arraycopy(copy.params,0,this.params,0,params.length);
          System.arraycopy(copy.args,0,this.args,0,args.length);
      }
  
      protected void assertRoleRequired(int index, String description)
      {
          if (index < 0)
          {
              StringBuilder err = new StringBuilder();
              err.append("Unable to find parameter with role [");
              err.append(description).append("] in method: ");
              err.append(ReflectUtils.toString(pojo,method));
              throw new InvalidSignatureException(err.toString());
          }
      }
  
      /**
       * Search the list of parameters for first one matching the role specified.
       * 
       * @param role
       *            the role to look for
       * @return the index for the role specified (or -1 if not found)
       */
      protected int findIndexForRole(Role role)
      {
          Param param = findParamForRole(role);
          if (param != null)
          {
              return param.index;
          }
          return -1;
      }
  
     /**
      * Find first param for specified role.
      * 
      * @param role
      *            the role specified
      * @return the param (or null if not found)
      */
     protected Param findParamForRole(Role role)
     {
         for (Param param : params)
         {
             if (param.role == role)
             {
                 return param;
             }
         }
         return null;
     }
 
     public Param[] getParams()
     {
         return params;
     }
 
     public void init(JsrSession session)
     {
         // Default for the session.
         // Session is an optional parameter (always)
         idxSession = findIndexForRole(Param.Role.SESSION);
         if (idxSession >= 0)
         {
             args[idxSession] = session;
         }
 
         // Optional EndpointConfig
         idxConfig = findIndexForRole(Param.Role.ENDPOINT_CONFIG);
         if (idxConfig >= 0)
         {
             args[idxConfig] = session.getEndpointConfig();
         }
 
         // Default for the path parameters
         // PathParam's are optional parameters (always)
         Map<String, String> pathParams = session.getPathParameters();
         if ((pathParams != null) && (pathParams.size() > 0))
         {
             for (Param param : params)
             {
                 if (param.role == Role.PATH_PARAM)
                 {
                     int idx = param.index;
                     String rawvalue = pathParams.get(param.getPathParamName());
 
                     Decoder decoder = session.getDecoderFactory().getDecoderFor(param.type);
                     if (decoder instanceof Decoder.Text<?>)
                     {
                         Decoder.Text<?> textDecoder = (Decoder.Text<?>)decoder;
                         try
                         {
                             args[idx] = textDecoder.decode(rawvalue);
                         }
                         catch (DecodeException e)
                         {
                             session.notifyError(e);
                         }
                     }
                     else
                     {
                         throw new InvalidWebSocketException("PathParam decoders must use Decoder.Text");
                     }
                 }
             }
         }
     }
 
     public abstract void setDecoderClass(Class<? extends Decoder> decoderClass);
 }