/*
    * 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.myfaces.flow;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import javax.el.MethodExpression;
  import javax.el.ValueExpression;
  import javax.faces.flow.MethodCallNode;
  import javax.faces.flow.Parameter;
  
  /**
   *
   * @since 2.2
   * @author Leonardo Uribe
   */
  public class MethodCallNodeImpl extends MethodCallNode implements Freezable
  {
      private String _id;
      private MethodExpression _methodExpression;
      private ValueExpression _outcome;
      
      private List<Parameter> _parameters;
      private List<Parameter> _unmodifiableParameters;
      
      private boolean _initialized;
      
      public MethodCallNodeImpl(String methodCallNodeId)
      {
          this._id = methodCallNodeId;
          _parameters = new ArrayList<Parameter>();
          _unmodifiableParameters = Collections.unmodifiableList(_parameters);
      }
  
      @Override
      public MethodExpression getMethodExpression()
      {
          return _methodExpression;
      }
  
      @Override
      public ValueExpression getOutcome()
      {
          return _outcome;
      }
  
      @Override
      public List<Parameter> getParameters()
      {
          return _unmodifiableParameters;
      }
      
      public void addParameter(Parameter parameter)
      {
          checkInitialized();
          _parameters.add(parameter);
      }
  
      @Override
      public String getId()
      {
          return _id;
      }
      
      public void freeze()
      {
          _initialized = true;
          
          for (Parameter value : _parameters)
          {
              if (value instanceof Freezable)
              {
                  ((Freezable)value).freeze();
              }
          }
      }
      
      private void checkInitialized() throws IllegalStateException
      {
          if (_initialized)
          {
              throw new IllegalStateException("Flow is inmutable once initialized");
         }
     }
 
     public void setMethodExpression(MethodExpression methodExpression)
     {
         checkInitialized();
         this._methodExpression = methodExpression;
     }
 
     public void setOutcome(ValueExpression outcome)
     {
         checkInitialized();
         this._outcome = outcome;
     }
 
     public void setId(String id)
     {
         checkInitialized();
         this._id = id;
     }
 }