/**
    * Copyright 2005-2013 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.rice.krad.web.bind;
  
  import org.kuali.rice.krad.uif.view.ViewIndex;
  import org.kuali.rice.krad.uif.view.ViewModel;
  import org.springframework.beans.BeanWrapperImpl;
  import org.springframework.beans.BeansException;
  import org.springframework.beans.InvalidPropertyException;
  import org.springframework.beans.NullValueInNestedPathException;
  import org.springframework.beans.PropertyAccessorUtils;
  import org.springframework.beans.PropertyValue;
  import org.springframework.util.StringUtils;
  
  import java.beans.PropertyDescriptor;
  import java.beans.PropertyEditor;
  import java.util.ArrayList;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  /**
   * Class is a top level BeanWrapper for a UIF View Model
   *
   * <p>
   * Registers custom property editors configured on the field associated with the property name for which
   * we are getting or setting a value. In addition determines if the field requires encryption and if so applies
   * the {@link UifEncryptionPropertyEditorWrapper}
   * </p>
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class UifViewBeanWrapper extends BeanWrapperImpl {
      private static org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(UifViewBeanWrapper.class);
  
      // this is a handle to the target object so we don't have to cast so often
      private ViewModel model;
  
      // this stores all properties this wrapper has already checked
      // with the view so the service isn't called again
      private Set<String> processedProperties;
  
      public UifViewBeanWrapper(ViewModel model) {
          super(model);
  
          this.model = model;
          this.processedProperties = new HashSet<String>();
      }
  
      /**
       * Attempts to find a corresponding data field for the given property name in the current view or previous view,
       * then if the field has a property editor configured it is registered with the property editor registry to use
       * for this property
       *
       * @param propertyName - name of the property to find field and editor for
       */
      protected void registerEditorFromView(String propertyName) {
          if (LOG.isDebugEnabled()) {
              LOG.debug("Attempting to find property editor for property '" + propertyName + "'");
          }
  
          // check if we already processed this property for this BeanWrapper instance
          if (processedProperties.contains(propertyName)) {
              return;
          }
  
          // when rendering the page, we will use the view that was just built, for post
          // we need to use the posted view (not the newly initialized view)
          ViewIndex viewIndex = null;
          if (model.getView() != null) {
              viewIndex = model.getView().getViewIndex();
          } else if (model.getPostedView() != null) {
              viewIndex = model.getPostedView().getViewIndex();
          }
  
          // if view index instance not established we cannot determine property editors
          if (viewIndex == null) {
              return;
          }
  
          PropertyEditor propertyEditor = null;
          boolean requiresEncryption = false;
  
          if (viewIndex.getFieldPropertyEditors().containsKey(propertyName)) {
              propertyEditor = viewIndex.getFieldPropertyEditors().get(propertyName);
          } else if (viewIndex.getSecureFieldPropertyEditors().containsKey(propertyName)) {
             propertyEditor = viewIndex.getSecureFieldPropertyEditors().get(propertyName);
             requiresEncryption = true;
         }
 
         if (propertyEditor != null) {
             if (LOG.isDebugEnabled()) {
                 LOG.debug("Registering custom editor for property path '" + propertyName
                         + "' and property editor class '" + propertyEditor.getClass().getName() + "'");
             }
 
             if (requiresEncryption) {
                 if (LOG.isDebugEnabled()) {
                     LOG.debug("Enabling encryption for custom editor '" + propertyName +
                             "' and property editor class '" + propertyEditor.getClass().getName() + "'");
                 }
                 this.registerCustomEditor(null, propertyName, new UifEncryptionPropertyEditorWrapper(propertyEditor));
             } else {
                 this.registerCustomEditor(null, propertyName, propertyEditor);
             }
         } else if (requiresEncryption) {
             if (LOG.isDebugEnabled()) {
                 LOG.debug("No custom formatter for property path '" + propertyName
                         + "' but property does require encryption");
             }
 
             this.registerCustomEditor(null, propertyName, new UifEncryptionPropertyEditorWrapper(
                     findEditorForPropertyName(propertyName)));
         }
 
         processedProperties.add(propertyName);
     }
 
     protected PropertyEditor findEditorForPropertyName(String propertyName) {
         Class<?> clazz = getPropertyType(propertyName);
         if (LOG.isDebugEnabled()) {
             LOG.debug("Attempting retrieval of property editor using class '"
                     + clazz
                     + "' and property path '"
                     + propertyName
                     + "'");
         }
 
         PropertyEditor editor = findCustomEditor(clazz, propertyName);
         if (editor == null) {
             if (LOG.isDebugEnabled()) {
                 LOG.debug("No custom property editor found using class '"
                         + clazz
                         + "' and property path '"
                         + propertyName
                         + "'. Attempting to find default property editor class.");
             }
             editor = getDefaultEditor(clazz);
         }
 
         return editor;
     }
 
     @Override
     public Class<?> getPropertyType(String propertyName) throws BeansException {
         try {
             PropertyDescriptor pd = getPropertyDescriptorInternal(propertyName);
             if (pd != null) {
                 return pd.getPropertyType();
             }
 
             // Maybe an indexed/mapped property...
             Object value = super.getPropertyValue(propertyName);
             if (value != null) {
                 return value.getClass();
             }
 
             // Check to see if there is a custom editor,
             // which might give an indication on the desired target type.
             Class<?> editorType = guessPropertyTypeFromEditors(propertyName);
             if (editorType != null) {
                 return editorType;
             }
         } catch (InvalidPropertyException ex) {
             // Consider as not determinable.
         }
 
         return null;
     }
 
     @Override
     protected BeanWrapperImpl getBeanWrapperForPropertyPath(String propertyPath) {
         BeanWrapperImpl beanWrapper = super.getBeanWrapperForPropertyPath(propertyPath);
 
         PropertyTokenHolder tokens = getPropertyNameTokens(propertyPath);
         String canonicalName = tokens.canonicalName;
 
         int pos = PropertyAccessorUtils.getFirstNestedPropertySeparatorIndex(canonicalName);
         if (pos != -1) {
             canonicalName = canonicalName.substring(0, pos);
         }
 
         copyCustomEditorsTo(beanWrapper, canonicalName);
 
         return beanWrapper;
     }
 
     @Override
     public Object getPropertyValue(String propertyName) throws BeansException {
         registerEditorFromView(propertyName);
 
         Object value = null;
         try {
             value = super.getPropertyValue(propertyName);
         } catch (NullValueInNestedPathException e) {
            // swallow null values in path and return null as the value
         }
 
         return value;
     }
 
     @Override
     public void setPropertyValue(PropertyValue pv) throws BeansException {
         registerEditorFromView(pv.getName());
         super.setPropertyValue(pv);
     }
 
     @Override
     public void setPropertyValue(String propertyName, Object value) throws BeansException {
         registerEditorFromView(propertyName);
         super.setPropertyValue(propertyName, value);
     }
 
     @Override
     public void setWrappedInstance(Object object, String nestedPath, Object rootObject) {
         //TODO clear cache?
         model = (ViewModel) object;
         super.setWrappedInstance(object, nestedPath, rootObject);
     }
 
     @Override
     public void setWrappedInstance(Object object) {
         //TODO clear cache?
         model = (ViewModel) object;
         super.setWrappedInstance(object);
     }
 
     /**
      * Parse the given property name into the corresponding property name tokens.
      *
      * @param propertyName the property name to parse
      * @return representation of the parsed property tokens
      */
     private PropertyTokenHolder getPropertyNameTokens(String propertyName) {
         PropertyTokenHolder tokens = new PropertyTokenHolder();
         String actualName = null;
         List<String> keys = new ArrayList<String>(2);
         int searchIndex = 0;
         while (searchIndex != -1) {
             int keyStart = propertyName.indexOf(PROPERTY_KEY_PREFIX, searchIndex);
             searchIndex = -1;
             if (keyStart != -1) {
                 int keyEnd = propertyName.indexOf(PROPERTY_KEY_SUFFIX, keyStart + PROPERTY_KEY_PREFIX.length());
                 if (keyEnd != -1) {
                     if (actualName == null) {
                         actualName = propertyName.substring(0, keyStart);
                     }
                     String key = propertyName.substring(keyStart + PROPERTY_KEY_PREFIX.length(), keyEnd);
                     if ((key.startsWith("'") && key.endsWith("'")) || (key.startsWith("\"") && key.endsWith("\""))) {
                         key = key.substring(1, key.length() - 1);
                     }
                     keys.add(key);
                     searchIndex = keyEnd + PROPERTY_KEY_SUFFIX.length();
                 }
             }
         }
         tokens.actualName = (actualName != null ? actualName : propertyName);
         tokens.canonicalName = tokens.actualName;
         if (!keys.isEmpty()) {
             tokens.canonicalName += PROPERTY_KEY_PREFIX +
                     StringUtils.collectionToDelimitedString(keys, PROPERTY_KEY_SUFFIX + PROPERTY_KEY_PREFIX) +
                     PROPERTY_KEY_SUFFIX;
             tokens.keys = StringUtils.toStringArray(keys);
         }
         return tokens;
     }
 
     private static class PropertyTokenHolder {
 
         public String canonicalName;
 
         public String actualName;
 
         public String[] keys;
     }
 }