/*

  * 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.builder;

 import javax.el.MethodExpression;

 import javax.el.ValueExpression;

 import javax.faces.context.FacesContext;

 import javax.faces.flow.Flow;

 import javax.faces.flow.builder.FlowBuilder;

 import javax.faces.flow.builder.FlowCallBuilder;

 import javax.faces.flow.builder.MethodCallBuilder;

 import javax.faces.flow.builder.NavigationCaseBuilder;

 import javax.faces.flow.builder.ReturnBuilder;

 import javax.faces.flow.builder.SwitchBuilder;

 import javax.faces.flow.builder.ViewBuilder;

 import org.apache.myfaces.flow.FlowImpl;

 import org.apache.myfaces.flow.ParameterImpl;

 /**

  *

  * @since 2.2

  * @author Leonardo Uribe

  */

 public class FlowBuilderImpl extends FlowBuilder

 {

     private static final Class[] EMPTY_PARAMS = new Class[]

     {

     };

     private FlowImpl _facesFlow;

     private FacesContext _facesContext;

     public FlowBuilderImpl()

     {

         _facesFlow = new FlowImpl();

     }

     public FlowBuilderImpl(FacesContext context)

     {

         super();

         _facesContext = context;

     }

     @Override

     public FlowBuilder id(String definingDocumentId, String id)

     {

         _facesFlow.setDefiningDocumentId(definingDocumentId);

         _facesFlow.setId(id);

         return this;

     }

     @Override

     public ViewBuilder viewNode(String viewNodeId, String vdlDocumentId)

     {

         return new ViewBuilderImpl(_facesFlow, viewNodeId, vdlDocumentId);

     }

     @Override

     public SwitchBuilder switchNode(String switchNodeId)

     {

         return new SwitchBuilderImpl(this, _facesFlow, switchNodeId);

     }

     @Override

     public ReturnBuilder returnNode(String returnNodeId)

     {

         return new ReturnBuilderImpl(this, _facesFlow, returnNodeId);

     }

     @Override

     public MethodCallBuilder methodCallNode(String methodCallNodeId)

     {

         return new MethodCallBuilderImpl(this, _facesFlow, methodCallNodeId);

     }

     @Override

     public FlowCallBuilder flowCallNode(String flowCallNodeId)

     {

         return new FlowCallBuilderImpl(this, _facesFlow, flowCallNodeId);

     }

     @Override

     public FlowBuilder initializer(MethodExpression methodExpression)

     {

         _facesFlow.setInitializer(methodExpression);

         return this;

     }

     @Override

     public FlowBuilder initializer(String methodExpression)

     {

         _facesFlow.setInitializer(createMethodExpression(methodExpression));

         return this;

     }

     @Override

     public FlowBuilder finalizer(MethodExpression methodExpression)

     {

         _facesFlow.setFinalizer(methodExpression);

         return this;

     }

     @Override

     public FlowBuilder finalizer(String methodExpression)

     {

         _facesFlow.setFinalizer(createMethodExpression(methodExpression));

         return this;

     }

     @Override

     public FlowBuilder inboundParameter(String name, ValueExpression value)

     {

         _facesFlow.putInboundParameter(name, new ParameterImpl(name, value));

         return this;

     }

     @Override

     public FlowBuilder inboundParameter(String name, String value)

     {

         _facesFlow.putInboundParameter(name, new ParameterImpl(name,

             createValueExpression(value)));

         return this;

     }

     @Override

     public Flow getFlow()

     {

         _facesContext = null;

         return _facesFlow;

     }

     /**

      * The idea is grab FacesContext just once and then when the flow is returned clear the variable.

      *

      * @return

      */

     FacesContext getFacesContext()

     {

         if (_facesContext == null)

         {

             _facesContext = FacesContext.getCurrentInstance();

         }

         return _facesContext;

     }

     public MethodExpression createMethodExpression(String methodExpression)

     {

         FacesContext facesContext = getFacesContext();

         return facesContext.getApplication().getExpressionFactory().createMethodExpression(

             facesContext.getELContext(), methodExpression, null, EMPTY_PARAMS);

     }

     public MethodExpression createMethodExpression(String methodExpression, Class[] paramTypes)

     {

         FacesContext facesContext = getFacesContext();

         return facesContext.getApplication().getExpressionFactory().createMethodExpression(

             facesContext.getELContext(), methodExpression, null, paramTypes);

     }

     public ValueExpression createValueExpression(String value)

     {

         FacesContext facesContext = getFacesContext();

         return facesContext.getApplication().getExpressionFactory()

             .createValueExpression(facesContext.getELContext(), value, Object.class); 

     }

     @Override

     public NavigationCaseBuilder navigationCase()

     {

         return new NavigationCaseBuilderImpl(this, _facesFlow);

     }

 }