/*
    * 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.tobago.servlet;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.faces.FactoryFinder;
  import javax.faces.application.Application;
  import javax.faces.application.NavigationHandler;
  import javax.faces.application.ViewHandler;
  import javax.faces.component.UIViewRoot;
  import javax.faces.context.FacesContext;
  import javax.faces.context.FacesContextFactory;
  import javax.faces.lifecycle.Lifecycle;
  import javax.faces.lifecycle.LifecycleFactory;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import java.io.IOException;
  
  public abstract class NonFacesRequestServlet extends HttpServlet {
  
    private static final long serialVersionUID = -7448621953821447997L;
  
    private static final Logger LOG = LoggerFactory.getLogger(NonFacesRequestServlet.class);
  
    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
  
      LifecycleFactory lFactory = (LifecycleFactory) FactoryFinder.getFactory(FactoryFinder.LIFECYCLE_FACTORY);
      Lifecycle lifecycle = lFactory.getLifecycle(LifecycleFactory.DEFAULT_LIFECYCLE);
      FacesContextFactory fcFactory = (FacesContextFactory) FactoryFinder.getFactory(FactoryFinder.FACES_CONTEXT_FACTORY);
      FacesContext facesContext = fcFactory.getFacesContext(getServletContext(), request, response, lifecycle);
      try {
  
        // invoke application
        String outcome = invokeApplication(facesContext);
  
        if (facesContext.getResponseComplete()) {
          return;
        }
        if (LOG.isDebugEnabled()) {
          LOG.debug("outcome = '" + outcome + "'");
        }
  
        Application application = facesContext.getApplication();
        if (facesContext.getViewRoot() == null) {
          ViewHandler viewHandler = application.getViewHandler();
          String viewId = getFromViewId();
          UIViewRoot view = viewHandler.createView(facesContext, viewId);
          facesContext.setViewRoot(view);
        }
  
        NavigationHandler navigationHandler = application.getNavigationHandler();
        navigationHandler.handleNavigation(facesContext, null, outcome);
  
  
        lifecycle.render(facesContext);
      } finally {
        facesContext.release();
      }
    }
  
    public abstract String invokeApplication(FacesContext facesContext);
  
    /**
     * will be called to initialize the first ViewRoot,
     * may be overwritten by extended classes
     */
    public String getFromViewId() {
      return "";
    }
  }