/*
    * 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.renderkit.html;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  import java.util.RandomAccess;
  
  import javax.faces.FacesException;
  import javax.faces.component.ActionSource;
  import javax.faces.component.EditableValueHolder;
  import javax.faces.component.UIComponent;
  import javax.faces.component.behavior.AjaxBehavior;
  import javax.faces.component.behavior.ClientBehavior;
  import javax.faces.component.behavior.ClientBehaviorContext;
  import javax.faces.context.FacesContext;
  import javax.faces.event.AjaxBehaviorEvent;
  import javax.faces.event.PhaseId;
  import javax.faces.render.ClientBehaviorRenderer;
  import org.apache.myfaces.shared.renderkit.html.util.SharedStringBuilder;
  
  /**
   * @author Werner Punz  (latest modification by $Author$)
   * @version $Revision$ $Date$
   */
  public class HtmlAjaxBehaviorRenderer extends ClientBehaviorRenderer
  {
  
      private static final String QUOTE = "'";
      private static final String BLANK = " ";
  
      private static final String AJAX_KEY_ONERROR = "onerror";
      private static final String AJAX_KEY_ONEVENT = "onevent";
      private static final String AJAX_KEY_EXECUTE = "execute";
      private static final String AJAX_KEY_RENDER = "render";
      private static final String AJAX_KEY_DELAY = "delay";
      private static final String AJAX_KEY_RESETVALUES = "resetValues";
  
      private static final String AJAX_VAL_THIS = "this";
      private static final String AJAX_VAL_EVENT = "event";
      private static final String JS_AJAX_REQUEST = "jsf.ajax.request";
  
      private static final String COLON = ":";
      private static final String EMPTY = "";
      private static final String COMMA = ",";
  
      private static final String ERR_NO_AJAX_BEHAVIOR = "The behavior must be an instance of AjaxBehavior";
      private static final String L_PAREN = "(";
      private static final String R_PAREN = ")";
  
      /*if this marker is present in the request we have to dispatch a behavior event*/
      /*if an attached behavior triggers an ajax request this request param must be added*/
      private static final String BEHAVIOR_EVENT = "javax.faces.behavior.event";
      private static final String IDENTIFYER_MARKER = "@";
      
      private static final String AJAX_SB = "oam.renderkit.AJAX_SB";
      private static final String AJAX_PARAM_SB = "oam.renderkit.AJAX_PARAM_SB";
  
      public void decode(FacesContext context, UIComponent component,
                         ClientBehavior behavior)
      {
          assertBehavior(behavior);
          AjaxBehavior ajaxBehavior = (AjaxBehavior) behavior;
          if (ajaxBehavior.isDisabled() || !component.isRendered())
          {
              return;
          }
  
          dispatchBehaviorEvent(component, ajaxBehavior);
      }
  
  
      public String getScript(ClientBehaviorContext behaviorContext,
                              ClientBehavior behavior)
      {
          assertBehavior(behavior);
          AjaxBehavior ajaxBehavior = (AjaxBehavior) behavior;
  
          if (ajaxBehavior.isDisabled())
          {
              return null;
         }
 
         return makeAjax(behaviorContext, ajaxBehavior).toString();
     }
 
 
     private final void dispatchBehaviorEvent(UIComponent component, AjaxBehavior ajaxBehavior)
     {
         AjaxBehaviorEvent event = new AjaxBehaviorEvent(component, ajaxBehavior);
         
         boolean isImmediate = false;
         if (ajaxBehavior.isImmediateSet())
         {
             isImmediate = ajaxBehavior.isImmediate();
         }            
         else
         {
             isImmediate = isComponentImmediate(component);
         }
         PhaseId phaseId = isImmediate ?
                 PhaseId.APPLY_REQUEST_VALUES :
                 PhaseId.INVOKE_APPLICATION;
 
         event.setPhaseId(phaseId);
 
         component.queueEvent(event);
     }
 
 
     private final boolean isComponentImmediate(UIComponent component)
     {
         boolean isImmediate = false;
         if (component instanceof EditableValueHolder)
         {
             isImmediate = ((EditableValueHolder)component).isImmediate();
         }
         else if (component instanceof ActionSource)
         {
             isImmediate = ((ActionSource)component).isImmediate();
         }
         return isImmediate;
     }
 
 
     /**
      * builds the generic ajax call depending upon
      * the ajax behavior parameters
      *
      * @param context  the Client behavior context
      * @param behavior the behavior
      * @return a fully working javascript with calls into jsf.js
      */
     private final StringBuilder makeAjax(ClientBehaviorContext context, AjaxBehavior behavior)
     {
         StringBuilder retVal = SharedStringBuilder.get(context.getFacesContext(), AJAX_SB, 60);
         StringBuilder paramBuffer = SharedStringBuilder.get(context.getFacesContext(), AJAX_PARAM_SB, 20);
 
         String executes = mapToString(context, paramBuffer, AJAX_KEY_EXECUTE, behavior.getExecute());
         String render = mapToString(context, paramBuffer, AJAX_KEY_RENDER, behavior.getRender());
 
         String onError = behavior.getOnerror();
         if (onError != null && !onError.trim().equals(EMPTY))
         {
             //onError = AJAX_KEY_ONERROR + COLON + onError;
             paramBuffer.setLength(0);
             paramBuffer.append(AJAX_KEY_ONERROR);
             paramBuffer.append(COLON);
             paramBuffer.append(onError);
             onError = paramBuffer.toString();
         }
         else
         {
             onError = null;
         }
         String onEvent = behavior.getOnevent();
         if (onEvent != null && !onEvent.trim().equals(EMPTY))
         {
             paramBuffer.setLength(0);
             paramBuffer.append(AJAX_KEY_ONEVENT);
             paramBuffer.append(COLON);
             paramBuffer.append(onEvent);
             onEvent = paramBuffer.toString();
         }
         else
         {
             onEvent = null;
         }
         /*
          * since version 2.2
          */
         String delay = behavior.getDelay();
         if (delay != null && !delay.trim().equals(EMPTY))
         {
             paramBuffer.setLength(0);
             paramBuffer.append(AJAX_KEY_DELAY);
             paramBuffer.append(COLON);
             if ("none".equals(delay))
             {
                 paramBuffer.append('\'');
                 paramBuffer.append(delay);
                 paramBuffer.append('\'');
             }
             else
             {
                 paramBuffer.append(delay);
             }
             delay = paramBuffer.toString();
         }
         else
         {
             delay = null;
         }
         /*
          * since version 2.2
          */
         String resetValues = Boolean.toString(behavior.isResetValues());
         if (resetValues.equals("true"))
         {
             paramBuffer.setLength(0);
             paramBuffer.append(AJAX_KEY_RESETVALUES);
             paramBuffer.append(COLON);
             paramBuffer.append(resetValues);
             resetValues = paramBuffer.toString();
         }
         else
         {
             resetValues = null;
         }
 
         String sourceId = null;
         if (context.getSourceId() == null) 
         {
             sourceId = AJAX_VAL_THIS;
         }
         else
         {
             paramBuffer.setLength(0);
             paramBuffer.append('\'');
             paramBuffer.append(context.getSourceId());
             paramBuffer.append('\'');
             sourceId = paramBuffer.toString();
             
             if (!context.getSourceId().trim().equals(
                 context.getComponent().getClientId(context.getFacesContext())))
             {
                 // Check if sourceId is not a clientId and there is no execute set
                 UIComponent ref = context.getComponent();
                 ref = (ref.getParent() == null) ? ref : ref.getParent();
                 UIComponent instance = null;
                 try
                 {
                     instance = ref.findComponent(context.getSourceId());
                 }
                 catch (IllegalArgumentException e)
                 {
                     // No Op
                 }
                 if (instance == null && executes == null)
                 {
                     // set the clientId of the component so the behavior can be decoded later, 
                     // otherwise the behavior will fail
                     List<String> list = new ArrayList<String>();
                     list.add(context.getComponent().getClientId(context.getFacesContext()));
                     executes = mapToString(context, paramBuffer, AJAX_KEY_EXECUTE, list);
                 }
             }
         }
 
 
         String event = context.getEventName();
 
         retVal.append(JS_AJAX_REQUEST);
         retVal.append(L_PAREN);
         retVal.append(sourceId);
         retVal.append(COMMA);
         retVal.append(AJAX_VAL_EVENT);
         retVal.append(COMMA);
 
         Collection<ClientBehaviorContext.Parameter> params = context.getParameters();
         int paramSize = (params != null) ? params.size() : 0;
 
         List<String> parameterList = new ArrayList<String>(paramSize + 2);
         if (executes != null)
         {
             parameterList.add(executes);
         }
         if (render != null)
         {
             parameterList.add(render);
         }
         if (onError != null)
         {
             parameterList.add(onError);
         }
         if (onEvent != null)
         {
             parameterList.add(onEvent);
         }
         /*
          * since version 2.2
          */
         if (delay != null)
         {
             parameterList.add(delay);
         }
         /*
          * since version 2.2
          */
         if (resetValues != null)
         {
             parameterList.add(resetValues);
         }
         if (paramSize > 0)
         {
             /**
              * see ClientBehaviorContext.html of the spec
              * the param list has to be added in the post back
              */
             // params are in 99% RamdonAccess instace created in 
             // HtmlRendererUtils.getClientBehaviorContextParameters(Map<String, String>)
             if (params instanceof RandomAccess)
             {
                 List<ClientBehaviorContext.Parameter> list = (List<ClientBehaviorContext.Parameter>) params;
                 for (int i = 0, size = list.size(); i < size; i++)
                 {
                     ClientBehaviorContext.Parameter param = list.get(i);
                     append(paramBuffer, parameterList, param);
                 }
             }
             else
             {
                 for (ClientBehaviorContext.Parameter param : params)
                 {
                     append(paramBuffer, parameterList, param);
                 }
             }
         }
 
         //parameterList.add(QUOTE + BEHAVIOR_EVENT + QUOTE + COLON + QUOTE + event + QUOTE);
         paramBuffer.setLength(0);
         paramBuffer.append(QUOTE);
         paramBuffer.append(BEHAVIOR_EVENT);
         paramBuffer.append(QUOTE);
         paramBuffer.append(COLON);
         paramBuffer.append(QUOTE);
         paramBuffer.append(event);
         paramBuffer.append(QUOTE);
         parameterList.add(paramBuffer.toString());
         
         /**
          * I assume here for now that the options are the same which also
          * can be sent via the options attribute to javax.faces.ajax
          * this still needs further clarifications but I assume so for now
          */
         retVal.append(buildOptions(paramBuffer, parameterList));
 
         retVal.append(R_PAREN);
 
         return retVal;
     }
 
     private void append(StringBuilder paramBuffer, List<String> parameterList, ClientBehaviorContext.Parameter param)
     {
         //TODO we may need a proper type handling in this part
         //lets leave it for now as it is
         //quotes etc.. should be transferred directly
         //and the rest is up to the toString properly implemented
         //ANS: Both name and value should be quoted
         paramBuffer.setLength(0);
         paramBuffer.append(QUOTE);
         paramBuffer.append(param.getName());
         paramBuffer.append(QUOTE);
         paramBuffer.append(COLON);
         paramBuffer.append(QUOTE);
         paramBuffer.append(param.getValue().toString());
         paramBuffer.append(QUOTE);
         parameterList.add(paramBuffer.toString());
     }
 
 
     private StringBuilder buildOptions(StringBuilder retVal, List<String> options)
     {
         retVal.setLength(0);
 
         retVal.append("{");
 
         boolean first = true;
 
         for (int i = 0, size = options.size(); i < size; i++)
         {
             String option = options.get(i);
             if (option != null && !option.trim().equals(EMPTY))
             {
                 if (!first)
                 {
                     retVal.append(COMMA);
                 }
                 else
                 {
                     first = false;
                 }
                 retVal.append(option);
             }
         }
         retVal.append("}");
         return retVal;
     }
 
     private final String mapToString(ClientBehaviorContext context, StringBuilder retVal, 
             String target, Collection<String> dataHolder)
     {
         //Clear buffer
         retVal.setLength(0);
 
         if (dataHolder == null)
         {
             dataHolder = Collections.emptyList();
         }
         int executeSize = dataHolder.size();
         if (executeSize > 0)
         {
 
             retVal.append(target);
             retVal.append(COLON);
             retVal.append(QUOTE);
 
             int cnt = 0;
             
             // perf: dataHolder is a Collection : ajaxBehaviour.getExecute() 
             // and ajaxBehaviour.getRender() API
             // In most cases comes here a ArrayList, because 
             // javax.faces.component.behavior.AjaxBehavior.getCollectionFromSpaceSplitString
             // creates it.
             if (dataHolder instanceof RandomAccess)
             {
                 List<String> list = (List<String>) dataHolder;
                 for (; cnt  < executeSize; cnt++)
                 {
                     String strVal = list.get(cnt);
                     build(context, executeSize, retVal, cnt, strVal);
                 }
             }
             else
             {
                 for (String strVal : dataHolder)
                 {
                     cnt++;
                     build(context, executeSize, retVal, cnt, strVal);
                 }
             }
 
             retVal.append(QUOTE);
             return retVal.toString();
         }
         return null;
 
     }
 
     public void build(ClientBehaviorContext context,
             int size, StringBuilder retVal, int cnt,
             String strVal)
     {
         strVal = strVal.trim();
         if (!EMPTY.equals(strVal))
         {
             if (!strVal.startsWith(IDENTIFYER_MARKER))
             {
                 String componentId = getComponentId(context, strVal);
                 retVal.append(componentId);
             }
             else
             {
                 // @this should be resolved server side, because there are cases like in h:selectOneRadio where
                 // the id of the tag is not a clientId. @this could be valid to be resolve in the client if 
                 // jsf.ajax.request(...) is called manually (without f:ajax intervention)
                 if (strVal.equalsIgnoreCase("@this"))
                 {
                     retVal.append(context.getComponent().getClientId(context.getFacesContext()));
                 }
                 else
                 {
                     retVal.append(strVal);
                 }
             }
             if (cnt < size)
             {
                 retVal.append(BLANK);
             }
         }
     }
 
     private final String getComponentId(ClientBehaviorContext context, String id)
     {
 
         UIComponent contextComponent = context.getComponent();
         UIComponent target = contextComponent.findComponent(id);
         if (target == null)
         {
             target = contextComponent.findComponent(
                 context.getFacesContext().getNamingContainerSeparatorChar() + id);
         }
         if (target != null)
         {
             return target.getClientId(context.getFacesContext());
         }
         throw new FacesException("Component with id:" + id + " not found");
     }
 
     private final void assertBehavior(ClientBehavior behavior)
     {
         if (!(behavior instanceof AjaxBehavior))
         {
             throw new FacesException(ERR_NO_AJAX_BEHAVIOR);
         }
     }
 
 }