//
   //  ========================================================================
   //  Copyright (c) 1995-2014 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.common.events.annotated;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.util.Objects;
  
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  import org.eclipse.jetty.websocket.api.WebSocketException;
  import org.eclipse.jetty.websocket.common.util.ReflectUtils;
  
  /**
   * A Callable Method
   */
  public class CallableMethod
  {
      private static final Logger LOG = Log.getLogger(CallableMethod.class);
      protected final Class<?> pojo;
      protected final Method method;
      protected Class<?>[] paramTypes;
  
      public CallableMethod(Class<?> pojo, Method method)
      {
          Objects.requireNonNull(pojo, "Pojo cannot be null");
          Objects.requireNonNull(method, "Method cannot be null");
          this.pojo = pojo;
          this.method = method;
          this.paramTypes = method.getParameterTypes();
      }
  
      public Object call(Object obj, Object... args)
      {
          if ((this.pojo == null) || (this.method == null))
          {
              LOG.warn("Cannot execute call: pojo={}, method={}",pojo,method);
              return null; // no call event method determined
          }
  
          if (obj == null)
          {
              LOG.warn("Cannot call {} on null object",this.method);
              return null;
          }
  
          if (args.length < paramTypes.length)
          {
              throw new IllegalArgumentException("Call arguments length [" + args.length + "] must always be greater than or equal to captured args length ["
                      + paramTypes.length + "]");
          }
  
          try
          {
              return this.method.invoke(obj,args);
          }
          catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e)
          {
              StringBuilder err = new StringBuilder();
              err.append("Cannot call method ");
              err.append(ReflectUtils.toString(pojo,method));
              err.append(" with args: [");
  
              boolean delim = false;
              for (Object arg : args)
              {
                  if (delim)
                  {
                      err.append(", ");
                  }
                  if (arg == null)
                  {
                      err.append("<null>");
                  }
                  else
                  {
                      err.append(arg.getClass().getName());
                  }
                  delim = true;
              }
              err.append("]");
  
              throw new WebSocketException(err.toString(),e);
         }
     }
 
     public Method getMethod()
     {
         return method;
     }
 
     public Class<?>[] getParamTypes()
     {
         return paramTypes;
     }
 
     public Class<?> getPojo()
     {
         return pojo;
     }
 
     @Override
     public String toString()
     {
         return String.format("%s[%s]",this.getClass().getSimpleName(),method.toGenericString());
     }
 }