/**
    * Copyright 2005-2012 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.datadictionary;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.kuali.rice.krad.service.DataDictionaryService;
  import org.kuali.rice.krad.service.KRADServiceLocator;
  import org.kuali.rice.krad.service.KRADServiceLocatorWeb;
  import org.springframework.beans.BeansException;
  import org.springframework.beans.MutablePropertyValues;
  import org.springframework.beans.PropertyValue;
  import org.springframework.beans.factory.config.BeanDefinition;
  import org.springframework.beans.factory.config.BeanDefinitionHolder;
  import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
  import org.springframework.beans.factory.config.TypedStringValue;
  import org.springframework.beans.factory.support.BeanDefinitionRegistry;
  import org.springframework.beans.factory.support.ManagedArray;
  import org.springframework.beans.factory.support.ManagedList;
  import org.springframework.beans.factory.support.ManagedMap;
  import org.springframework.beans.factory.support.ManagedSet;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.Stack;
  
  /**
   * Post processor for the data dictionary bean factory
   *
   * <p>
   * The 'driver' for other post processors. Essentially this iterates through each bean and its properties,
   * making calls to the message and expression processors
   * </p>
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class DictionaryBeanFactoryPostProcessor {
      private static final Log LOG = LogFactory.getLog(DictionaryBeanFactoryPostProcessor.class);
  
      private DataDictionary dataDictionary;
      private ConfigurableListableBeanFactory beanFactory;
  
      private List<DictionaryBeanProcessor> beanProcessors;
  
      /**
       * Constructs a new processor for the given data dictionary and bean factory
       *
       * @param dataDictionary data dictionary instance that contains the bean factory
       * @param beanFactory bean factory to process
       */
      public DictionaryBeanFactoryPostProcessor(DataDictionary dataDictionary,
              ConfigurableListableBeanFactory beanFactory) {
          this.dataDictionary = dataDictionary;
          this.beanFactory = beanFactory;
  
          this.beanProcessors = new ArrayList<DictionaryBeanProcessor>();
          this.beanProcessors.add(new MessageBeanProcessor(dataDictionary, beanFactory));
      }
  
      /**
       * Iterates through all beans in the factory and invokes processing of root bean definitions
       *
       * @throws org.springframework.beans.BeansException
       */
      public void postProcessBeanFactory() throws BeansException {
          // check whether loading of external messages is enabled
          boolean loadExternalMessages = KRADServiceLocator.getKualiConfigurationService().getPropertyValueAsBoolean(
                  "load.dictionary.external.messages");
          if (!loadExternalMessages) {
              return;
          }
  
          LOG.info("Beginning dictionary bean post processing");
  
          List<DictionaryBeanProcessor> beanProcessors = new ArrayList<DictionaryBeanProcessor>();
          beanProcessors.add(new MessageBeanProcessor(dataDictionary, beanFactory));
  
          String[] beanNames = beanFactory.getBeanDefinitionNames();
          for (int i = 0; i < beanNames.length; i++) {
              String beanName = beanNames[i];
              BeanDefinition beanDefinition = beanFactory.getBeanDefinition(beanName);
  
              processRootBeanDefinition(beanName, beanDefinition);
         }
 
         LOG.info("Finished dictionary bean post processing");
     }
 
     /**
      * Invokes processors to handle the root bean definition then processes the bean properties
      *
      * @param beanName name of the bean within the factory
      * @param beanDefinition root bean definition to process
      */
     protected void processRootBeanDefinition(String beanName, BeanDefinition beanDefinition) {
         for (DictionaryBeanProcessor beanProcessor : beanProcessors) {
             beanProcessor.processRootBeanDefinition(beanName, beanDefinition);
         }
 
         Stack<BeanDefinitionHolder> nestedBeanStack = new Stack<BeanDefinitionHolder>();
         nestedBeanStack.push(new BeanDefinitionHolder(beanDefinition, beanName));
 
         processBeanProperties(beanDefinition, nestedBeanStack);
     }
 
     /**
      * Invokes the processors to handle the given nested bean definition
      *
      * <p>
      * A check is also made to determine if the nested bean has a non-generated id which is not registered in the
      * factory, if so the bean is added as a registered bean (so it can be found by id)
      * </p>
      *
      * @param beanName name of the nested bean definition in the bean factory
      * @param beanDefinition nested bean definition to process
      * @param nestedPropertyPath the property path to the nested bean from the parent bean definition
      * @param isCollectionBean indicates whether the nested bean is in a collection, if so a different handler
      * method is called on the processors
      * @param nestedBeanStack the stack of bean containers(those beans which contain the bean)
      */
     public void processNestedBeanDefinition(String beanName, BeanDefinition beanDefinition, String nestedPropertyPath,
             boolean isCollectionBean, Stack<BeanDefinitionHolder> nestedBeanStack) {
         // if bean name is given and factory does not have it registered we need to add it (inner beans that
         // were given an id)
         if (StringUtils.isNotBlank(beanName) && !StringUtils.contains(beanName, "$") && !StringUtils.contains(beanName,
                 "#") && !beanFactory.containsBean(beanName)) {
             ((BeanDefinitionRegistry) beanFactory).registerBeanDefinition(beanName, beanDefinition);
         }
 
         // invoke the processors to handle the nested bean
         for (DictionaryBeanProcessor beanProcessor : beanProcessors) {
             if (isCollectionBean) {
                 beanProcessor.processCollectionBeanDefinition(beanName, beanDefinition, nestedPropertyPath,
                         nestedBeanStack);
             } else {
                 beanProcessor.processNestedBeanDefinition(beanName, beanDefinition, nestedPropertyPath,
                         nestedBeanStack);
             }
         }
 
         BeanDefinitionHolder nestedBeanDefinitionHolder = new BeanDefinitionHolder(beanDefinition, beanName);
         nestedBeanStack.push(nestedBeanDefinitionHolder);
 
         processBeanProperties(beanDefinition, nestedBeanStack);
 
         nestedBeanStack.pop();
     }
 
     /**
      * Invokes the processors to handle the string value (which may be changed)
      *
      * @param propertyName name of the property that is being processed
      * @param propertyValue the string property value to process
      * @param nestedBeanStack the stack of bean containers, including the bean that contains the property
      * @return String new property value (possibly modified by processors)
      */
     protected String processStringPropertyValue(String propertyName, String propertyValue,
             Stack<BeanDefinitionHolder> nestedBeanStack) {
         String processedStringValue = propertyValue;
 
         for (DictionaryBeanProcessor beanProcessor : beanProcessors) {
             processedStringValue = beanProcessor.processStringPropertyValue(propertyName, processedStringValue,
                     nestedBeanStack);
         }
 
         return processedStringValue;
     }
 
     /**
      * Invokes the processors to handle an array string value (which may be changed)
      *
      * @param propertyName name of the property that is being processed
      * @param propertyValue the array which contains the string
      * @param elementValue the string element value
      * @param elementIndex the index of the string within the array
      * @param nestedBeanStack the stack of bean containers, including the bean that contains the property
      * @return String new property value (possibly modified by processors)
      */
     protected String processArrayStringPropertyValue(String propertyName, Object[] propertyValue, String elementValue,
             int elementIndex, Stack<BeanDefinitionHolder> nestedBeanStack,
             List<DictionaryBeanProcessor> beanProcessors) {
         String processedStringValue = elementValue;
 
         for (DictionaryBeanProcessor beanProcessor : beanProcessors) {
             processedStringValue = beanProcessor.processArrayStringPropertyValue(propertyName, propertyValue,
                     elementValue, elementIndex, nestedBeanStack);
         }
 
         return processedStringValue;
     }
 
     /**
      * Invokes the processors to handle an list string value (which may be changed)
      *
      * @param propertyName name of the property that is being processed
      * @param propertyValue the list which contains the string
      * @param elementValue the string element value
      * @param elementIndex the index of the string within the list
      * @param nestedBeanStack the stack of bean containers, including the bean that contains the property
      * @return String new property value (possibly modified by processors)
      */
     protected String processListStringPropertyValue(String propertyName, List<?> propertyValue, String elementValue,
             int elementIndex, Stack<BeanDefinitionHolder> nestedBeanStack,
             List<DictionaryBeanProcessor> beanProcessors) {
         String processedStringValue = elementValue;
 
         for (DictionaryBeanProcessor beanProcessor : beanProcessors) {
             processedStringValue = beanProcessor.processListStringPropertyValue(propertyName, propertyValue,
                     elementValue, elementIndex, nestedBeanStack);
         }
 
         return processedStringValue;
     }
 
     /**
      * Invokes the processors to handle an set string value (which may be changed)
      *
      * @param propertyName name of the property that is being processed
      * @param propertyValue the set which contains the string
      * @param elementValue the string element value
      * @param nestedBeanStack the stack of bean containers, including the bean that contains the property
      * @return String new property value (possibly modified by processors)
      */
     protected String processSetStringPropertyValue(String propertyName, Set<?> propertyValue, String elementValue,
             Stack<BeanDefinitionHolder> nestedBeanStack, List<DictionaryBeanProcessor> beanProcessors) {
         String processedStringValue = elementValue;
 
         for (DictionaryBeanProcessor beanProcessor : beanProcessors) {
             processedStringValue = beanProcessor.processSetStringPropertyValue(propertyName, propertyValue,
                     elementValue, nestedBeanStack);
         }
 
         return processedStringValue;
     }
 
     /**
      * Invokes the processors to handle an map string value (which may be changed)
      *
      * @param propertyName name of the property that is being processed
      * @param propertyValue the map which contains the string
      * @param elementValue the string element value
      * @param elementKey the key for the string within the map
      * @param nestedBeanStack the stack of bean containers, including the bean that contains the property
      * @return String new property value (possibly modified by processors)
      */
     protected String processMapStringPropertyValue(String propertyName, Map<?, ?> propertyValue, String elementValue,
             Object elementKey, Stack<BeanDefinitionHolder> nestedBeanStack,
             List<DictionaryBeanProcessor> beanProcessors) {
         String processedStringValue = elementValue;
 
         for (DictionaryBeanProcessor beanProcessor : beanProcessors) {
             processedStringValue = beanProcessor.processMapStringPropertyValue(propertyName, propertyValue,
                     elementValue, elementKey, nestedBeanStack);
         }
 
         return processedStringValue;
     }
 
     /**
      * Iterates through the properties defined for the bean definition and invokes helper methods to process
      * the property value
      *
      * @param beanDefinition bean definition whose properties will be processed
      * @param nestedBeanStack stack of beans which contain the given bean
      */
     protected void processBeanProperties(BeanDefinition beanDefinition, Stack<BeanDefinitionHolder> nestedBeanStack) {
         // iterate through properties and check for any configured message keys within the value
         MutablePropertyValues pvs = beanDefinition.getPropertyValues();
         PropertyValue[] pvArray = pvs.getPropertyValues();
         for (PropertyValue pv : pvArray) {
             Object newPropertyValue = null;
             if (isStringValue(pv.getValue())) {
                 newPropertyValue = processStringPropertyValue(pv.getName(), getString(pv.getValue()), nestedBeanStack);
             } else {
                 newPropertyValue = visitPropertyValue(pv.getName(), pv.getValue(), nestedBeanStack);
             }
 
             pvs.removePropertyValue(pv.getName());
             pvs.addPropertyValue(pv.getName(), newPropertyValue);
         }
     }
 
     /**
      * Determines if the property value is a bean or collection, and calls the appropriate helper method
      * to process further. Ultimately this invokes the processors to modify the property value if necessary
      *
      * @param propertyName name for the property being processed
      * @param propertyValue value for the property to process
      * @param nestedBeanStack stack of beans which contain the property
      * @return Object the new property value (which may be modified0
      */
     protected Object visitPropertyValue(String propertyName, Object propertyValue,
             Stack<BeanDefinitionHolder> nestedBeanStack) {
         if (isBeanDefinitionValue(propertyValue)) {
             String beanName = getBeanName(propertyValue);
             BeanDefinition beanDefinition = getBeanDefinition(propertyValue);
 
             processNestedBeanDefinition(beanName, beanDefinition, propertyName, false, nestedBeanStack);
         } else if (isCollectionValue(propertyValue)) {
             visitCollection(propertyValue, propertyName, nestedBeanStack);
         }
 
         return propertyValue;
     }
 
     /**
      * Determines what kind of collection (or array) the given value is and call handlers based on the determined type
      *
      * @param value collection value to process
      * @param propertyName name of the property which has the collection value
      * @param nestedBeanStack stack of bean containers which contains the collection property
      */
     protected void visitCollection(Object value, String propertyName, Stack<BeanDefinitionHolder> nestedBeanStack) {
         if (value instanceof Object[] || (value instanceof ManagedArray)) {
             visitArray(value, propertyName, nestedBeanStack);
         } else if (value instanceof List) {
             visitList((List<?>) value, propertyName, nestedBeanStack);
         } else if (value instanceof Set) {
             visitSet((Set<?>) value, propertyName, nestedBeanStack);
         } else if (value instanceof Map) {
             visitMap((Map<?, ?>) value, propertyName, nestedBeanStack);
         }
     }
 
     /**
      * Iterates through the array values and calls helpers to process the value
      *
      * @param array the array to process
      * @param propertyName name of the property which has the array value
      * @param nestedBeanStack stack of bean containers which contains the array property
      */
     protected void visitArray(Object array, String propertyName, Stack<BeanDefinitionHolder> nestedBeanStack) {
         Object[] arrayVal = null;
         if (array instanceof ManagedArray) {
             arrayVal = (Object[]) ((ManagedArray) array).getSource();
         } else {
             arrayVal = (Object[]) array;
         }
 
         Object[] newArray = new Object[arrayVal.length];
         for (int i = 0; i < arrayVal.length; i++) {
             Object elem = arrayVal[i];
 
             if (isStringValue(elem)) {
                 elem = processArrayStringPropertyValue(propertyName, arrayVal, getString(elem), i, nestedBeanStack,
                         beanProcessors);
             } else {
                 elem = visitPropertyValue(propertyName, elem, nestedBeanStack);
             }
 
             newArray[i] = elem;
         }
 
         if (array instanceof ManagedArray) {
             ((ManagedArray) array).setSource(newArray);
         } else {
             array = newArray;
         }
     }
 
     /**
      * Iterates through the list values and calls helpers to process the value
      *
      * @param listVal the list to process
      * @param propertyName name of the property which has the list value
      * @param nestedBeanStack stack of bean containers which contains the list property
      */
     protected void visitList(List<?> listVal, String propertyName, Stack<BeanDefinitionHolder> nestedBeanStack) {
         boolean isMergeEnabled = false;
         if (listVal instanceof ManagedList) {
             isMergeEnabled = ((ManagedList) listVal).isMergeEnabled();
         }
 
         ManagedList newList = new ManagedList();
         newList.setMergeEnabled(isMergeEnabled);
 
         for (int i = 0; i < listVal.size(); i++) {
             Object elem = listVal.get(i);
 
             if (isStringValue(elem)) {
                 elem = processListStringPropertyValue(propertyName, listVal, getString(elem), i, nestedBeanStack,
                         beanProcessors);
             } else {
                 elem = visitPropertyValue(propertyName, elem, nestedBeanStack);
             }
 
             newList.add(i, elem);
         }
 
         listVal.clear();
         listVal.addAll(newList);
     }
 
     /**
      * Iterates through the set values and calls helpers to process the value
      *
      * @param setVal the set to process
      * @param propertyName name of the property which has the set value
      * @param nestedBeanStack stack of bean containers which contains the set property
      */
     protected void visitSet(Set setVal, String propertyName, Stack<BeanDefinitionHolder> nestedBeanStack) {
         boolean isMergeEnabled = false;
         if (setVal instanceof ManagedSet) {
             isMergeEnabled = ((ManagedSet) setVal).isMergeEnabled();
         }
 
         ManagedSet newSet = new ManagedSet();
         newSet.setMergeEnabled(isMergeEnabled);
 
         for (Object elem : setVal) {
             if (isStringValue(elem)) {
                 elem = processSetStringPropertyValue(propertyName, setVal, getString(elem), nestedBeanStack,
                         beanProcessors);
             } else {
                 elem = visitPropertyValue(propertyName, elem, nestedBeanStack);
             }
 
             newSet.add(elem);
         }
 
         setVal.clear();
         setVal.addAll(newSet);
     }
 
     /**
      * Iterates through the map values and calls helpers to process the value
      *
      * @param mapVal the set to process
      * @param propertyName name of the property which has the map value
      * @param nestedBeanStack stack of bean containers which contains the map property
      */
     protected void visitMap(Map<?, ?> mapVal, String propertyName, Stack<BeanDefinitionHolder> nestedBeanStack) {
         boolean isMergeEnabled = false;
         if (mapVal instanceof ManagedMap) {
             isMergeEnabled = ((ManagedMap) mapVal).isMergeEnabled();
         }
 
         ManagedMap newMap = new ManagedMap();
         newMap.setMergeEnabled(isMergeEnabled);
 
         for (Map.Entry entry : mapVal.entrySet()) {
             Object key = entry.getKey();
             Object val = entry.getValue();
 
             if (isStringValue(val)) {
                 val = processMapStringPropertyValue(propertyName, mapVal, getString(val), key, nestedBeanStack,
                         beanProcessors);
             } else {
                 val = visitPropertyValue(propertyName, val, nestedBeanStack);
             }
 
             newMap.put(key, val);
         }
 
         mapVal.clear();
         mapVal.putAll(newMap);
     }
 
     /**
      * Indicate whether the given value is a string or holds a string
      *
      * @param value value to test
      * @return boolean true if the value is a string, false if not
      */
     protected boolean isStringValue(Object value) {
         boolean isString = false;
 
         if (value instanceof TypedStringValue || (value instanceof String)) {
             isString = true;
         }
 
         return isString;
     }
 
     /**
      * Determines whether the given value is of String type and if so returns the string value
      *
      * @param value object value to check
      * @return String string value for object or null if object is not a string type
      */
     protected String getString(Object value) {
         String stringValue = null;
 
         if (value instanceof TypedStringValue || (value instanceof String)) {
             if (value instanceof TypedStringValue) {
                 TypedStringValue typedStringValue = (TypedStringValue) value;
                 stringValue = typedStringValue.getValue();
             } else {
                 stringValue = (String) value;
             }
         }
 
         return stringValue;
     }
 
     /**
      * Indicate whether the given value is a bean definition (or holder)
      *
      * @param value value to test
      * @return boolean true if the value is a bean definition, false if not
      */
     protected boolean isBeanDefinitionValue(Object value) {
         boolean isBean = false;
 
         if ((value instanceof BeanDefinition) || (value instanceof BeanDefinitionHolder)) {
             isBean = true;
         }
 
         return isBean;
     }
 
     /**
      * Returns the given value as a bean definition (parsing from holder if necessary)
      *
      * @param value value to convert
      * @return BeanDefinition converted bean definition
      */
     protected BeanDefinition getBeanDefinition(Object value) {
         BeanDefinition beanDefinition = null;
 
         if ((value instanceof BeanDefinition) || (value instanceof BeanDefinitionHolder)) {
             if (value instanceof BeanDefinition) {
                 beanDefinition = (BeanDefinition) value;
             } else {
                 beanDefinition = ((BeanDefinitionHolder) value).getBeanDefinition();
             }
         }
 
         return beanDefinition;
     }
 
     /**
      * Gets the bean name from the given value which is assumed to be a bean definition holder
      *
      * @param value value retrieve bean name from
      * @return String bean name, or null if value is not a bean definition holder
      */
     protected String getBeanName(Object value) {
         String beanName = null;
 
         if (value instanceof BeanDefinitionHolder) {
             beanName = ((BeanDefinitionHolder) value).getBeanName();
         }
 
         return beanName;
     }
 
     /**
      * Indicate whether the given value is a collection
      *
      * @param value value to test
      * @return boolean true if the value is a collection, false if not
      */
     protected boolean isCollectionValue(Object value) {
         boolean isCollection = false;
 
         if (value instanceof Object[] || (value instanceof ManagedArray) || (value instanceof List) ||
                 (value instanceof Set) || (value instanceof Map)) {
             isCollection = true;
         }
 
         return isCollection;
     }
 
     /**
      * Retrieves the data dictionary service using the KRAD service locator
      *
      * @return DataDictionaryService instance
      */
     protected DataDictionaryService getDataDictionaryService() {
         return KRADServiceLocatorWeb.getDataDictionaryService();
     }
 
 }