/**
    * Copyright 2005-2014 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.uif.view;
  
  import java.io.Serializable;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Set;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.log4j.Logger;
  import org.kuali.rice.krad.uif.component.Component;
  import org.kuali.rice.krad.uif.container.CollectionGroup;
  import org.kuali.rice.krad.uif.container.Container;
  import org.kuali.rice.krad.uif.field.DataField;
  import org.kuali.rice.krad.uif.util.ComponentUtils;
  import org.kuali.rice.krad.uif.util.LifecycleElement;
  import org.kuali.rice.krad.uif.util.ViewCleaner;
  
  /**
   * Holds component indexes of a {@link View} instance for convenient retrieval during the
   * lifecycle and persisting components for the refresh process.
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class ViewIndex implements Serializable {
      private static final long serialVersionUID = 4700818801272201371L;
      
      private static final Logger LOG = Logger.getLogger(ViewIndex.class);
  
      private Map<String, Component> index;
      private Map<String, DataField> dataFieldIndex;
  
      private Map<String, CollectionGroup> collectionsIndex;
      private Map<String, LifecycleElement> lifecycleElementsByPath;
  
      private Set<String> idsToHoldInIndex;
      private Set<String> assignedIds;
  
      /**
       * Default Constructor.
       */
      public ViewIndex() {
          index = new HashMap<String, Component>();
          dataFieldIndex = new HashMap<String, DataField>();
          collectionsIndex = new HashMap<String, CollectionGroup>();
          lifecycleElementsByPath = new HashMap<String, LifecycleElement>();
          idsToHoldInIndex = new HashSet<String>();
          assignedIds = new HashSet<String>();
      }
  
      /**
       * Clears view indexes, for reinitializing indexes at the start of each phase.
       */
      protected void clearIndex(View view) {
          index = new HashMap<String, Component>();
          dataFieldIndex = new HashMap<String, DataField>();
          collectionsIndex = new HashMap<String, CollectionGroup>();
          lifecycleElementsByPath = new HashMap<String, LifecycleElement>();
      }
  
      /**
       * Adds an entry to the main index for the given component. If the component is of type
       * <code>DataField</code> or <code>CollectionGroup</code> an entry is created in the
       * corresponding indexes for those types as well. Then the #indexComponent method is called for
       * each of the component's children
       *
       * <p>
       * If the component is already contained in the indexes, it will be replaced
       * </p>
       *
       * <p>
       * <code>DataField</code> instances are indexed by the attribute path. This is useful for
       * retrieving the InputField based on the incoming request parameter
       * </p>
       *
       * <p>
       * <code>CollectionGroup</code> instances are indexed by the collection path. This is useful for
       * retrieving the CollectionGroup based on the incoming request parameter
       * </p>
       *
       * @param component component instance to index
       */
      public void indexComponent(Component component) {
         if (component == null) {
             return;
         }
 
         synchronized (index) {
             index.put(component.getId(), component);
         }
 
         synchronized (lifecycleElementsByPath) {
             lifecycleElementsByPath.put(component.getViewPath(), component);
         }
 
         if (component instanceof Container) {
             Container container = (Container) component;
             if (container.getLayoutManager() != null) {
                 synchronized (lifecycleElementsByPath) {
                     lifecycleElementsByPath.put(container.getLayoutManager().getViewPath(),
                             container.getLayoutManager());
                 }
             }
         }
 
         if (component instanceof DataField) {
             DataField field = (DataField) component;
 
             synchronized (dataFieldIndex) {
                 dataFieldIndex.put(field.getBindingInfo().getBindingPath(), field);
             }
         } else if (component instanceof CollectionGroup) {
             CollectionGroup collectionGroup = (CollectionGroup) component;
 
             synchronized (collectionsIndex) {
                 collectionsIndex.put(collectionGroup.getBindingInfo().getBindingPath(), collectionGroup);
             }
         }
     }
 
     /**
      * Invoked after the view lifecycle or component refresh has run to clear indexes that are not
      * needed for the post.
      */
     public void clearIndexesAfterRender() {
         // build list of ids for components whose final state needs to be kept
         for (Component component : index.values()) {
             if (component == null) {
                 continue;
             }
 
             if (component.isDisableSessionPersistence()) {
                 continue;
             }
 
             // if component is a collection we need to keep it for  add/delete and other collection functions
             if (component.isForceSessionPersistence() || ComponentUtils.canBeRefreshed(component) ||
                     (component instanceof CollectionGroup)) {
                 synchronized (idsToHoldInIndex) {
                     idsToHoldInIndex.add(component.getId());
                 }
             }
         }
 
         Map<String, Component> holdComponentStates = new HashMap<String, Component>();
         synchronized (index) {
             for (Entry<String, Component> indexEntry : index.entrySet()) {
                 if (idsToHoldInIndex.contains(indexEntry.getKey())) {
                     Component component = indexEntry.getValue();
 
                     ViewCleaner.cleanComponent(component, this);
                     holdComponentStates.put(indexEntry.getKey(), component);
                 }
             }
         }
         index = holdComponentStates;
 
         for (CollectionGroup collectionGroup : collectionsIndex.values()) {
             ViewCleaner.cleanComponent(collectionGroup, this);
         }
 
         dataFieldIndex.clear();
         assignedIds.clear();
     }
 
     /**
      * Indicates whether the given component id is for a component maintained by the view index for
      * the refresh process
      *
      * @param componentId id for the component to check
      * @return true if the component id is for a refreshed component, false if not
      */
     public boolean isIdForRefreshComponent(String componentId) {
         return idsToHoldInIndex != null && idsToHoldInIndex.contains(componentId);
     }
 
     /**
      * Retrieves a <code>Component</code> from the view index by Id
      *
      * @param id id for the component to retrieve
      * @return Component instance found in index, or null if no such component exists
      */
     public Component getComponentById(String id) {
         return index.get(id);
     }
 
     /**
      * Retrieves a <code>DataField</code> instance from the index
      *
      * @param propertyPath full path of the data field (from the form)
      * @return DataField instance for the path or Null if not found
      */
     public DataField getDataFieldByPath(String propertyPath) {
         return dataFieldIndex.get(propertyPath);
     }
 
     /**
      * Retrieves a <code>DataField</code> instance that has the given property name specified (note
      * this is not the full binding path and first match is returned)
      *
      * @param propertyName property name for field to retrieve
      * @return DataField instance found or null if not found
      */
     public DataField getDataFieldByPropertyName(String propertyName) {
         DataField dataField = null;
 
         for (DataField field : dataFieldIndex.values()) {
             if (StringUtils.equals(propertyName, field.getPropertyName())) {
                 dataField = field;
                 break;
             }
         }
 
         return dataField;
     }
 
     /**
      * Returns a set of all data field paths that will be displayed (rendered).
      *
      * @return Set<String> set of property paths for data fields
      */
     public Set<String> getAllDisplayedPropertyPaths() {
         Set<String> propertyPaths = new HashSet<String>();
 
         for (DataField field : dataFieldIndex.values()) {
             if (field.isRender()) {
                 propertyPaths.add(field.getBindingInfo().getBindingPath());
             }
         }
 
         return propertyPaths;
     }
 
     public Map<String, LifecycleElement> getLifecycleElements() {
         return lifecycleElementsByPath;
     }
 
     public LifecycleElement getLifecycleElementByPath(String path) {
         if ((lifecycleElementsByPath != null) && lifecycleElementsByPath.containsKey(path)) {
             return lifecycleElementsByPath.get(path);
         }
 
         return null;
     }
 
     /**
      * Gets the Map that contains attribute field indexing information. The Map key points to an
      * attribute binding path, and the Map value is the <code>DataField</code> instance
      *
      * @return data fields index map
      */
     public Map<String, DataField> getDataFieldIndex() {
         return this.dataFieldIndex;
     }
 
     /**
      * Gets the Map that contains collection indexing information. The Map key gives the binding
      * path to the collection, and the Map value givens the <code>CollectionGroup</code> instance
      *
      * @return collection index map
      */
     public Map<String, CollectionGroup> getCollectionsIndex() {
         return this.collectionsIndex;
     }
 
     /**
      * Retrieves a <code>CollectionGroup</code> instance from the index
      *
      * @param collectionPath full path of the collection (from the form)
      * @return CollectionGroup instance for the collection path or Null if not found
      */
     public CollectionGroup getCollectionGroupByPath(String collectionPath) {
         return collectionsIndex.get(collectionPath);
     }
 
     /**
      * Observe an assigned ID.
      *
      * @param id The ID to observe.
      * @return True if the ID is unique, false if the ID has already been observed.
      */
     public boolean observeAssignedId(String id) {
         if (assignedIds.contains(id)) {
             return false;
         }
 
         synchronized (assignedIds) {
             return assignedIds.add(id);
         }
     }
 
     /**
      * Returns a clone of the view index.
      *
      * @return ViewIndex clone
      */
     public ViewIndex copy() {
         ViewIndex viewIndexCopy = new ViewIndex();
 
         if (this.index != null) {
             Map<String, Component> indexCopy = new HashMap<String, Component>();
             for (Map.Entry<String, Component> indexEntry : this.index.entrySet()) {
                 if (indexEntry.getValue() instanceof View) {
                     LOG.warn("view reference at " + indexEntry);
                 } else {
                     indexCopy.put(indexEntry.getKey(), (Component) indexEntry.getValue().copy());
                 }
             }
 
             viewIndexCopy.index = indexCopy;
         }
 
         if (this.dataFieldIndex != null) {
             Map<String, DataField> dataFieldIndexCopy = new HashMap<String, DataField>();
             for (Map.Entry<String, DataField> indexEntry : this.dataFieldIndex.entrySet()) {
                 dataFieldIndexCopy.put(indexEntry.getKey(), (DataField) indexEntry.getValue().copy());
             }
 
             viewIndexCopy.dataFieldIndex = dataFieldIndexCopy;
         }
 
         if (this.collectionsIndex != null) {
             Map<String, CollectionGroup> collectionsIndexCopy = new HashMap<String, CollectionGroup>();
             for (Map.Entry<String, CollectionGroup> indexEntry : this.collectionsIndex.entrySet()) {
                 collectionsIndexCopy.put(indexEntry.getKey(), (CollectionGroup) indexEntry.getValue().copy());
             }
 
             viewIndexCopy.collectionsIndex = collectionsIndexCopy;
         }
 
         return viewIndexCopy;
     }
 
 }