/*
    * 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.custom.datalist;
  
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.Map;
  
  import javax.el.ValueExpression;
  import javax.faces.FacesException;
  import javax.faces.component.ContextCallback;
  import javax.faces.component.UIComponent;
  import javax.faces.component.UINamingContainer;
  import javax.faces.component.visit.VisitCallback;
  import javax.faces.component.visit.VisitContext;
  import javax.faces.component.visit.VisitResult;
  import javax.faces.context.FacesContext;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.myfaces.component.UserRoleAware;
  
  /**
   * Similar to dataTable, but does not render a table. 
   * 
   * Instead the layout attribute controls how each dataRow is rendered. 
   * 
   * Unless otherwise specified, all attributes accept static values or EL expressions.
   * 
   * @JSFComponent
   *   name = "t:dataList"
   *   class = "org.apache.myfaces.custom.datalist.HtmlDataList"
   *   tagClass = "org.apache.myfaces.custom.datalist.HtmlDataListTag"
   * @since 1.1.7
   * @author Manfred Geiler (latest modification by $Author: lu4242 $)
   * @version $Revision: 940152 $ $Date: 2010-05-01 21:03:39 -0500 (Sáb, 01 May 2010) $
   */
  public abstract class AbstractHtmlDataList
          extends org.apache.myfaces.component.html.ext.HtmlDataTableHack
          implements UserRoleAware
  {
      public static final String COMPONENT_TYPE = "org.apache.myfaces.HtmlDataList";
      private static final String DEFAULT_RENDERER_TYPE = "org.apache.myfaces.List";
          
      private static Log log = LogFactory.getLog(AbstractHtmlDataList.class);
      private static final int PROCESS_DECODES = 1;
      private static final int PROCESS_VALIDATORS = 2; // not currently in use
      private static final int PROCESS_UPDATES = 3; // not currently in use
      private static final String SKIP_ITERATION_HINT = "javax.faces.visit.SKIP_ITERATION";
      
      private transient FacesContext _facesContext;
  
      /**
       * Throws NullPointerException if context is null.  Sets row index to -1, 
       * calls processChildren, sets row index to -1.
       */
  
      public void processDecodes(FacesContext context)
      {
  
          if (context == null)
              throw new NullPointerException("context");
          if (!isRendered())
              return;
  
          setRowIndex(-1);
          processChildren(context, PROCESS_DECODES);
          setRowIndex(-1);
          try
          {
              decode(context);
          }
          catch (RuntimeException e)
          {
              context.renderResponse();
              throw e;
          }        
      }
  
      public void processUpdates(FacesContext context)
      {
          if (context == null)
              throw new NullPointerException("context");
         if (!isRendered())
             return;
 
         setRowIndex(-1);
         processChildren(context, PROCESS_UPDATES);
         setRowIndex(-1);
         checkUpdateModelError(context);
     }
 
     public void processValidators(FacesContext context)
     {
         if (context == null)
             throw new NullPointerException("context");
         if (!isRendered())
             return;
 
         setRowIndex(-1);
         processChildren(context, PROCESS_VALIDATORS);
         setRowIndex(-1);
         checkUpdateModelError(context);        
     }
 
     /**
      * Iterates over all children, processes each according to the specified 
      * process action if the child is rendered.
      */
 
     public void processChildren(FacesContext context, int processAction)
     {
         // use this method for processing other than decode ?
         int first = getFirst();
         int rows = getRows();
         int last = rows == 0 ? getRowCount() : first + rows;
 
         if (log.isTraceEnabled())
         {
             log.trace("processing " + getChildCount()
                             + " children: starting at " + first
                             + ", ending at " + last);
         }
 
         for (int rowIndex = first; last == -1 || rowIndex < last; rowIndex++)
         {
 
             setRowIndex(rowIndex);
 
             if (!isRowAvailable())
             {
                 if (log.isTraceEnabled())
                 {
                     log.trace("scrolled past the last row, aborting");
                 }
                 break;
             }
 
             for (Iterator it = getChildren().iterator(); it.hasNext();)
             {
                 UIComponent child = (UIComponent) it.next();
                 if (child.isRendered())
                     process(context, child, processAction);
             }
         }
     }
 
     /**
      * Copy and pasted from UIData in order to maintain binary compatibility.
      */
 
     private void process(FacesContext context, UIComponent component,
             int processAction)
     {
         switch (processAction)
         {
         case PROCESS_DECODES:
             component.processDecodes(context);
             break;
         case PROCESS_VALIDATORS:
             component.processValidators(context);
             break;
         case PROCESS_UPDATES:
             component.processUpdates(context);
             break;
         }
     }
     
     public void setRowIndex(int rowIndex)
     {
         super.setRowIndex(rowIndex);
         String rowIndexVar = getRowIndexVar();
         String rowCountVar = getRowCountVar();
         if (rowIndexVar != null || rowCountVar != null)
         {
             Map requestMap = FacesContext.getCurrentInstance().getExternalContext().getRequestMap();
             if (rowIndex >= 0)
             {
                 //regular row index, update request scope variables
                 if (rowIndexVar != null)
                 {
                     requestMap.put(getRowIndexVar(), new Integer(rowIndex));
                 }
                 if (rowCountVar != null)
                 {
                     requestMap.put(getRowCountVar(), new Integer(getRowCount()));
                 }
             }
             else
             {
                 //rowIndex == -1 means end of loop --> remove request scope variables
                 if (rowIndexVar != null)
                 {
                     requestMap.remove(getRowIndexVar());
                 }
                 if (rowCountVar != null)
                 {
                     requestMap.remove(getRowCountVar());
                 }
             }
         }
     }
     
     @Override
     protected void restoreDescendantComponentStates(Object state)
     {
         restoreDescendantComponentStates(getChildren().iterator(), state, true);
     }
 
     @Override
     protected Object saveDescendantComponentStates()
     {
         return saveDescendantComponentStates(getChildren().iterator(), true);
     }
     
     @Override
     protected Map<String,Object> saveFullDescendantComponentStates(FacesContext facesContext)
     {
         return saveFullDescendantComponentStates(facesContext, null, getChildren().iterator(), true, getContainerClientId(facesContext));
     }
     
     @Override
     protected void restoreFullDescendantComponentStates(FacesContext facesContext, Object initialState)
     {
         restoreFullDescendantComponentStates(facesContext, getChildren().iterator(), initialState, true);
     }
 
     @Override
     protected void restoreFullDescendantComponentDeltaStates(FacesContext facesContext,
             Map<String, Object> rowState, Object initialState)
     {
         restoreFullDescendantComponentDeltaStates(facesContext, getChildren().iterator(), rowState, initialState, true, getContainerClientId(facesContext));
     }
     
     @Override
     protected Collection<Object[]> saveDescendantInitialComponentStates(FacesContext facesContext)
     {
         return saveDescendantInitialComponentStates(facesContext, getChildren().iterator(), true);
     }
 
     @Override
     public boolean invokeOnComponent(FacesContext context, String clientId, ContextCallback callback)
         throws FacesException
     {
         if (context == null || clientId == null || callback == null)
         {
             throw new NullPointerException();
         }
         
         final String baseClientId = getClientId(context);
 
         // searching for this component?
         boolean returnValue = baseClientId.equals(clientId);
 
         boolean isCachedFacesContext = isTemporalFacesContext();
         if (!isCachedFacesContext)
         {
             setTemporalFacesContext(context);
         }
         
         pushComponentToEL(context, this);
         try
         {
             if (returnValue)
             {
                 try
                 {
                     callback.invokeContextCallback(context, this);
                     return true;
                 }
                 catch (Exception e)
                 {
                     throw new FacesException(e);
                 }
             }
     
             // Now Look throught facets on this UIComponent
             for (Iterator<UIComponent> it = this.getFacets().values().iterator(); !returnValue && it.hasNext();)
             {
                 returnValue = it.next().invokeOnComponent(context, clientId, callback);
             }
     
             if (returnValue)
             {
                 return returnValue;
             }
             
             // is the component an inner component?
             if (clientId.startsWith(baseClientId))
             {
                 // Check if the clientId for the component, which we 
                 // are looking for, has a rowIndex attached
                 char separator = UINamingContainer.getSeparatorChar(context);
                 ValueExpression rowKeyVE = getValueExpression("rowKey");
                 boolean rowKeyFound = false;
                 
                 if (rowKeyVE != null)
                 {
                     int oldRow = this.getRowIndex();
                     try
                     {
                         // iterate over the rows
                         int rowsToProcess = getRows();
                         // if getRows() returns 0, all rows have to be processed
                         if (rowsToProcess == 0)
                         {
                             rowsToProcess = getRowCount();
                         }
                         int rowIndex = getFirst();
                         for (int rowsProcessed = 0; rowsProcessed < rowsToProcess; rowsProcessed++, rowIndex++)
                         {
                             setRowIndex(rowIndex);
                             if (!isRowAvailable())
                             {
                                 break;
                             }
                             
                             if (clientId.startsWith(getContainerClientId(context)))
                             {
                                 rowKeyFound = true;
                                 break;
                             }
                         }
                         
                         if (rowKeyFound)
                         {
                             for (Iterator<UIComponent> it1 = getChildren().iterator(); 
                                     !returnValue && it1.hasNext();)
                             {
                                 //recursive call to find the component
                                 returnValue = it1.next().invokeOnComponent(context, clientId, callback);
                             }
                         }
                     }
                     finally
                     {
                         this.setRowIndex(oldRow);
                     }
                 }
                 //If the char next to baseClientId is the separator one and
                 //the subId matches the regular expression
                 if (rowKeyVE == null && clientId.matches(baseClientId + separator+"[0-9]+"+separator+".*"))
                 {
                     String subId = clientId.substring(baseClientId.length() + 1);
                     String clientRow = subId.substring(0, subId.indexOf(separator));
         
                     //Now we save the current position
                     int oldRow = this.getRowIndex();
                     
                     // try-finally --> make sure, that the old row index is restored
                     try
                     {
                         //The conversion is safe, because its already checked on the
                         //regular expresion
                         this.setRowIndex(Integer.parseInt(clientRow));
                         
                         // check, if the row is available
                         if (!isRowAvailable())
                         {
                             return false;
                         }
             
                         for (Iterator<UIComponent> it1 = getChildren().iterator(); 
                                 !returnValue && it1.hasNext();)
                         {
                             //recursive call to find the component
                             returnValue = it1.next().invokeOnComponent(context, clientId, callback);
                         }
                     }
                     finally
                     {
                         //Restore the old position. Doing this prevent
                         //side effects.
                         this.setRowIndex(oldRow);
                     }
                 }
             }
         }
         finally
         {
             //all components must call popComponentFromEl after visiting is finished
             popComponentFromEL(context);
             if (!isCachedFacesContext)
             {
                 setTemporalFacesContext(null);
             }
         }
 
         return returnValue;
     }
     
     @Override
     public boolean visitTree(VisitContext context, VisitCallback callback)
     {
         if (!isVisitable(context))
         {
             return false;
         }
 
         boolean isTemporalFacesContext = isTemporalFacesContext();
         if (!isTemporalFacesContext)
         {
             setTemporalFacesContext(context.getFacesContext());
         }
         // save the current row index
         int oldRowIndex = getRowIndex();
         // set row index to -1 to process the facets and to get the rowless clientId
         setRowIndex(-1);
         // push the Component to EL
         pushComponentToEL(context.getFacesContext(), this);
         try
         {
             VisitResult visitResult = context.invokeVisitCallback(this,
                     callback);
             switch (visitResult)
             {
             //we are done nothing has to be processed anymore
             case COMPLETE:
                 return true;
 
             case REJECT:
                 return false;
 
                 //accept
             default:
                 // determine if we need to visit our children 
                 Collection<String> subtreeIdsToVisit = context
                         .getSubtreeIdsToVisit(this);
                 boolean doVisitChildren = subtreeIdsToVisit != null
                         && !subtreeIdsToVisit.isEmpty();
                 if (doVisitChildren)
                 {
                     // visit the facets of the component
                     for (UIComponent facet : getFacets().values())
                     {
                         if (facet.visitTree(context, callback))
                         {
                             return true;
                         }
                     }
                     Boolean skipIterationHint = (Boolean) context.getFacesContext().getAttributes().get(SKIP_ITERATION_HINT);
                     if (skipIterationHint != null && skipIterationHint.booleanValue())
                     {
                         // If SKIP_ITERATION is enabled, do not take into account rows.
                         if (getChildCount() > 0) {
                             for (UIComponent child : getChildren()) {
                                 if (child.visitTree(context, callback)) {
                                     return true;
                                 }
                             }
                         }
                     }
                     else
                     {
                         // iterate over the rows
                         int rowsToProcess = getRows();
                         // if getRows() returns 0, all rows have to be processed
                         if (rowsToProcess == 0)
                         {
                             rowsToProcess = getRowCount();
                         }
                         int rowIndex = getFirst();
                         for (int rowsProcessed = 0; rowsProcessed < rowsToProcess; rowsProcessed++, rowIndex++)
                         {
                             setRowIndex(rowIndex);
                             if (!isRowAvailable())
                             {
                                 return false;
                             }
                             // visit the children of every child of the UIData that is an instance of UIColumn
                             for (UIComponent child : getChildren())
                             {
                                 if (child.visitTree(context, callback))
                                 {
                                     return true;
                                 }
                             }
                         }
                     }
                 }
             }
         }
         finally
         {
             // pop the component from EL and restore the old row index
             popComponentFromEL(context.getFacesContext());
             setRowIndex(oldRowIndex);
             if (!isTemporalFacesContext)
             {
                 setTemporalFacesContext(null);
             }
         }
 
         // Return false to allow the visiting to continue
         return false;
     }    
     
     @Override
     protected FacesContext getFacesContext()
     {
         if (_facesContext == null)
         {
             return super.getFacesContext();
         }
         else
         {
             return _facesContext;
         }
     }
     
     private boolean isTemporalFacesContext()
     {
         return _facesContext != null;
     }
     
     private void setTemporalFacesContext(FacesContext facesContext)
     {
         _facesContext = facesContext;
     }
 
     /**
      * A parameter name, under which the rowCount is set in request 
      * scope similar to the var parameter.
      * 
      * @JSFProperty
      */
     public abstract String getRowCountVar();
     
     /**
      *  A parameter name, under which the current rowIndex is set in 
      *  request scope similar to the var parameter.
      * 
      * @JSFProperty
      */
     public abstract String getRowIndexVar();
 
     /**
      * simple|unorderedList|orderedList
      * <ul>
      *   <li>simple = for each dataRow all children are simply rendered</li>
      *   <li>unorderedList = the list is rendered as HTML unordered list (= bullet list)</li>
      *   <li>orderedList = the list is rendered as HTML ordered list</li>
      * </ul>
      * Default: simple
      * 
      * @JSFProperty
      */
     public abstract String getLayout();
     
     /**
      * CSS class to be applied to individual items in the list
      * 
      * @JSFProperty
      */
     public abstract String getItemStyleClass();
     
     /**
      * OnClick handler to be applied to individual items in the list
      * 
      * @JSFProperty
      */
     public abstract String getItemOnClick();
 }