/*
    * 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 javax.faces.view;
  
  import java.beans.BeanInfo;
  import java.io.IOException;
  import java.net.MalformedURLException;
  import java.util.List;
  import java.util.Map;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  import java.util.stream.Stream;
  
  import javax.faces.application.Resource;
  import javax.faces.application.ResourceVisitOption;
  import javax.faces.application.ViewVisitOption;
  import javax.faces.component.UIComponent;
  import javax.faces.component.UIViewRoot;
  import javax.faces.context.FacesContext;
  
  /**
   * @since 2.0
   */
  public abstract class ViewDeclarationLanguage
  {
      /**
       * @since 2.1
       */
      public static final String JSP_VIEW_DECLARATION_LANGUAGE_ID = "java.faces.JSP";
  
      /**
       * @since 2.1
       */
      public static final String FACELETS_VIEW_DECLARATION_LANGUAGE_ID = "java.faces.Facelets";
      
      public abstract void buildView(FacesContext context, UIViewRoot view) throws IOException;
  
      public abstract UIViewRoot createView(FacesContext context, String viewId);
  
      public abstract BeanInfo getComponentMetadata(FacesContext context, Resource componentResource);
  
      public abstract Resource getScriptComponentResource(FacesContext context, Resource componentResource);
      
      public abstract StateManagementStrategy getStateManagementStrategy(FacesContext context, String viewId); 
  
      public abstract ViewMetadata getViewMetadata(FacesContext context, String viewId);
  
      public abstract void renderView(FacesContext context, UIViewRoot view) throws IOException;
  
      public abstract UIViewRoot restoreView(FacesContext context, String viewId);
      
      public void retargetAttachedObjects(FacesContext context, UIComponent topLevelComponent,
                                          List<AttachedObjectHandler> handlers)
      {
          throw new UnsupportedOperationException(); 
      }
  
      public void retargetMethodExpressions(FacesContext context, UIComponent topLevelComponent)
      {
          throw new UnsupportedOperationException(); 
      }
      
      /**
       * 
       * @since 2.1
       * @return
       */
      public String getId()
      {
          return this.getClass().getName();
      }
      
      /**
       * 
       * @since 2.1
       * @param facesContext
       * @param viewId
       * @return
       */
      public boolean viewExists(FacesContext facesContext, String viewId)
      {
          try
          {
             return facesContext.getExternalContext().getResource(viewId) != null;
         }
         catch (MalformedURLException e)
         {
             Logger log = Logger.getLogger(ViewDeclarationLanguage.class.getName());
             if (log.isLoggable(Level.SEVERE))
             {
                 log.log(Level.SEVERE, "Malformed URL viewId: "+viewId, e);
             }
         }
         return false;
     }
     
     /**
      * @since 2.2
      * @param context
      * @param taglibURI
      * @param tagName
      * @param attributes
      * @return 
      */
     public UIComponent createComponent(FacesContext context,
                                    String taglibURI,
                                    String tagName,
                                    Map<String,Object> attributes)
     {
         return null;
     }
     
     /**
      * @since 2.2
      * @param context
      * @param viewId
      * @return 
      */
     public List<String> calculateResourceLibraryContracts(FacesContext context,
                                                       String viewId)
     {
         return null;
     }
     
     /**
      * @since 2.3
      * @param facesContext
      * @param path
      * @param options
      * @return 
      */
     public Stream<java.lang.String> getViews(FacesContext facesContext, String path, ViewVisitOption... options)
     {
         return getViews(facesContext, path, Integer.MAX_VALUE, options);
     }
     
     
     /**
      * 
      * @since 2.3
      * @param facesContext
      * @param path
      * @param maxDepth
      * @param options
      * @return 
      */
     public Stream<java.lang.String> getViews(FacesContext facesContext, String path, 
             int maxDepth, ViewVisitOption... options)
     {
         // Here by default we follow what spec javadoc says
         // "...This method works as if invoking it were equivalent to evaluating the expression:
         //     getViewResources(facesContext, start, Integer.MAX_VALUE, options) ..."
         // The problem here is ViewVisitOption != ResourceVisitOption. But whatever return
         // getViews must always have TOP_LEVEL_VIEWS_ONLY, because otherwise it will return 
         // everything (css, js, ...). There is ViewVisitOption.RETURN_AS_MINIMAL_IMPLICIT_OUTCOME,
         // but this is a filter on top of the stream.
         
         return facesContext.getApplication().getResourceHandler().getViewResources(
                 facesContext, path, maxDepth, ResourceVisitOption.TOP_LEVEL_VIEWS_ONLY);
     }
 }