/**
    * 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.container;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.core.api.util.tree.Node;
  import org.kuali.rice.core.api.util.tree.Tree;
  import org.kuali.rice.krad.datadictionary.parse.BeanTag;
  import org.kuali.rice.krad.datadictionary.parse.BeanTagAttribute;
  import org.kuali.rice.krad.datadictionary.parse.BeanTags;
  import org.kuali.rice.krad.uif.UifConstants;
  import org.kuali.rice.krad.uif.component.BindingInfo;
  import org.kuali.rice.krad.uif.component.Component;
  import org.kuali.rice.krad.uif.component.DataBinding;
  import org.kuali.rice.krad.uif.element.Message;
  import org.kuali.rice.krad.uif.lifecycle.ViewLifecycle;
  import org.kuali.rice.krad.uif.lifecycle.ViewLifecycleRestriction;
  import org.kuali.rice.krad.uif.util.ComponentUtils;
  import org.kuali.rice.krad.uif.util.ContextUtils;
  import org.kuali.rice.krad.uif.util.CopyUtils;
  import org.kuali.rice.krad.uif.util.LifecycleElement;
  import org.kuali.rice.krad.uif.util.ObjectPropertyUtils;
  
  /**
   * Group component that is backed by a <code>Tree</code> data structure and typically
   * rendered as a tree in the user interface
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  @BeanTags({@BeanTag(name = "treeGroup", parent = "Uif-TreeGroup"),
          @BeanTag(name = "treeSection", parent = "Uif-TreeSection"),
          @BeanTag(name = "treeSubSection", parent = "Uif-TreeSubSection")})
  public class TreeGroup extends GroupBase implements DataBinding {
      private static final long serialVersionUID = 5841343037089286740L;
  
      private String propertyName;
      private BindingInfo bindingInfo;
  
      private Map<Class<?>, NodePrototype> nodePrototypeMap;
      private NodePrototype defaultNodePrototype;
  
      private Tree<Group, Message> treeGroups;
  
      private org.kuali.rice.krad.uif.widget.Tree tree;
  
      public TreeGroup() {
          super();
  
          treeGroups = new Tree<Group, Message>();
      }
  
      /**
       * The following actions are performed:
       *
       * <ul>
       * <li>Set fieldBindModelPath to the collection model path (since the fields
       * have to belong to the same model as the collection)</li>
       * <li>Set defaults for binding</li>
       * <li>Calls view helper service to initialize prototypes</li>
       * </ul>
       */
      @Override
      public void performInitialization(Object model) {
          setFieldBindingObjectPath(getBindingInfo().getBindingObjectPath());
  
          super.performInitialization(model);
  
          if (bindingInfo != null) {
              bindingInfo.setDefaults(ViewLifecycle.getActiveLifecycle().getView(), getPropertyName());
          }
  
          // TODO: set object path for prototypes equal to the tree group object path?
      }
  
      @Override
      public void performApplyModel(Object model, LifecycleElement parent) {
          super.performApplyModel(model, parent);
  
          buildTreeGroups(model);
      }
  
      /**
      * Builds the components that will be rendered as part of the tree group
      *
      * <p>
      * The component tree group mirrors the tree data structure on the model. For each node of
      * the data structure, a corresponding <code>Message</code>  will be created for the node
      * label, and a <code>Group</code> component for the node data. These are placed into a new
      * node for the component tree. After the tree is built it is set as a property on the tree group
      * to be read by the renderer
      * </p>
      *
      * @param model object containing the view data from which the tree data will be retrieved
      */
     protected void buildTreeGroups(Object model) {
         // get Tree data property
         Tree<Object, String> treeData = ObjectPropertyUtils.getPropertyValue(model, getBindingInfo().getBindingPath());
 
         // build component tree that corresponds with tree data
         Tree<Group, Message> treeGroups = new Tree<Group, Message>();
 
         String bindingPrefix = getBindingInfo().getBindingPrefixForNested();
         Node<Group, Message> rootNode = buildTreeNode(treeData.getRootElement(),
                 bindingPrefix + /* TODO: hack */ ".rootElement", "root");
         treeGroups.setRootElement(rootNode);
 
         setTreeGroups(treeGroups);
     }
 
     protected Node<Group, Message> buildTreeNode(Node<Object, String> nodeData, String bindingPrefix,
             String parentNode) {
         if (nodeData == null) {
             return null;
         }
 
         Node<Group, Message> node = new Node<Group, Message>();
         node.setNodeType(nodeData.getNodeType());
 
         NodePrototype prototype = getNodePrototype(nodeData);
 
         Message message = ComponentUtils.copy(prototype.getLabelPrototype(), parentNode);
         ContextUtils.pushObjectToContextDeep(message, UifConstants.ContextVariableNames.NODE, nodeData);
         message.setMessageText(nodeData.getNodeLabel());
         node.setNodeLabel(message);
 
         Group nodeGroup = ComponentUtils.copyComponent(prototype.getDataGroupPrototype(), bindingPrefix + ".data",
                 parentNode);
         ContextUtils.pushObjectToContextDeep(nodeGroup, UifConstants.ContextVariableNames.NODE, nodeData);
 
         String nodePath = bindingPrefix + ".data";
         if (StringUtils.isNotBlank(getBindingInfo().getBindingObjectPath())) {
             nodePath = getBindingInfo().getBindingObjectPath() + "." + nodePath;
         }
         ContextUtils.pushObjectToContextDeep(nodeGroup, UifConstants.ContextVariableNames.NODE_PATH, nodePath);
         node.setData(nodeGroup);
 
         List<Node<Group, Message>> nodeChildren = new ArrayList<Node<Group, Message>>();
 
         int childIndex = 0;
         for (Node<Object, String> childDataNode : nodeData.getChildren()) {
             String nextBindingPrefix = bindingPrefix + ".children[" + childIndex + "]";
             Node<Group, Message> childNode = buildTreeNode(childDataNode, nextBindingPrefix,
                     "_node_" + childIndex + ("root".equals(parentNode) ? "_parent_" : "_parent") + parentNode);
 
             nodeChildren.add(childNode);
 
             // Don't forget about me:
             ++childIndex;
         }
         node.setChildren(nodeChildren);
 
         return node;
     }
 
     /**
      * Gets the NodePrototype to use for the given Node
      */
     private NodePrototype getNodePrototype(Node<Object, String> nodeData) {
         NodePrototype result = null;
         if (nodeData != null && nodeData.getData() != null) {
             Class<?> dataClass = nodeData.getData().getClass();
             result = nodePrototypeMap.get(dataClass);
 
             // somewhat lame fallback - to do this right we'd find all entries that are assignable from the data class
             // and then figure out which one is the closest relative
             if (result == null) {
                 for (Map.Entry<Class<?>, NodePrototype> prototypeEntry : nodePrototypeMap.entrySet()) {
                     if (prototypeEntry.getKey().isAssignableFrom(dataClass)) {
                         result = prototypeEntry.getValue();
                         break;
                     }
                 }
             }
         }
 
         if (result == null) {
             result = defaultNodePrototype;
         }
 
         return result;
     }
 
     /**
      * Gets all node components within the tree.
      * 
      * @return list of node components
      */
     public List<Component> getNodeComponents() {
         List<Component> components = new ArrayList<Component>();
         addNodeComponents(treeGroups.getRootElement(), components);
         return components;
     }
 
     /**
      * Gets all node components prototypes within the tree.
      * 
      * @return list of node component prototypes
      */
     @ViewLifecycleRestriction(UifConstants.ViewPhases.INITIALIZE)
     public List<Component> getComponentPrototypes() {
         List<Component> components = new ArrayList<Component>();
 
         if (defaultNodePrototype != null) {
             components.add(defaultNodePrototype.getLabelPrototype());
             components.add(defaultNodePrototype.getDataGroupPrototype());
         }
 
         if (nodePrototypeMap != null) {
             for (Map.Entry<Class<?>, NodePrototype> prototypeEntry : nodePrototypeMap.entrySet()) {
                 NodePrototype prototype = prototypeEntry.getValue();
                 if (prototype != null) {
                     components.add(prototype.getLabelPrototype());
                     components.add(prototype.getDataGroupPrototype());
                 }
             }
         }
 
         return components;
     }
     
     /**
      * Retrieves the <code>Component</code> instances from the node for building the nested
      * components list
      *
      * @param node node to pull components from
      * @param components list to add components to
      */
     protected void addNodeComponents(Node<Group, Message> node, List<Component> components) {
         if (node != null) {
             components.add(node.getNodeLabel());
             components.add(node.getData());
 
             for (Node<Group, Message> nodeChild : node.getChildren()) {
                 addNodeComponents(nodeChild, components);
             }
         }
     }
 
     @BeanTagAttribute
     public String getPropertyName() {
         return propertyName;
     }
 
     public void setPropertyName(String propertyName) {
         this.propertyName = propertyName;
     }
 
     @BeanTagAttribute
     public BindingInfo getBindingInfo() {
         return bindingInfo;
     }
 
     public void setBindingInfo(BindingInfo bindingInfo) {
         this.bindingInfo = bindingInfo;
     }
 
     /**
      * @return the defaultNodePrototype
      */
     @BeanTagAttribute(type = BeanTagAttribute.AttributeType.DIRECTORBYTYPE)
     public NodePrototype getDefaultNodePrototype() {
         return this.defaultNodePrototype;
     }
 
     /**
      * @param defaultNodePrototype the defaultNodePrototype to set
      */
     public void setDefaultNodePrototype(NodePrototype defaultNodePrototype) {
         this.defaultNodePrototype = defaultNodePrototype;
     }
 
     /**
      * @return the nodePrototypeMap
      */
     @BeanTagAttribute
     public Map<Class<?>, NodePrototype> getNodePrototypeMap() {
         return this.nodePrototypeMap;
     }
 
     /**
      * @param nodePrototypeMap the nodePrototypeMap to set
      */
     public void setNodePrototypeMap(Map<Class<?>, NodePrototype> nodePrototypeMap) {
         this.nodePrototypeMap = nodePrototypeMap;
     }
 
     @BeanTagAttribute
     public Tree<Group, Message> getTreeGroups() {
         return treeGroups;
     }
 
     public void setTreeGroups(Tree<Group, Message> treeGroups) {
         this.treeGroups = treeGroups;
     }
 
     @BeanTagAttribute
     public org.kuali.rice.krad.uif.widget.Tree getTree() {
         return tree;
     }
 
     public void setTree(org.kuali.rice.krad.uif.widget.Tree tree) {
         this.tree = tree;
     }
 
     /**
      * Copies a {@link Node} instance and then recursively copies each of its child nodes
      *
      * @param node node instance to copy
      * @return new node instance copied from given node
      */
     protected Node<Group, Message> copyNode(Node<Group, Message> node) {
         Node<Group, Message> nodeCopy = new Node<Group, Message>();
 
         if (node == null) {
             return null;
         }
 
         nodeCopy.setNodeType(node.getNodeType());
 
         if (node.getData() != null) {
             nodeCopy.setData((Group) CopyUtils.copy(node.getData()));
         }
 
         if (node.getNodeLabel() != null) {
             nodeCopy.setNodeLabel((Message) CopyUtils.copy(node.getNodeLabel()));
         }
 
         if (node.getChildren() != null) {
             List<Node<Group, Message>> childrenCopy = new ArrayList<Node<Group, Message>>();
             for (Node<Group, Message> childNode : node.getChildren()) {
                 childrenCopy.add(copyNode(childNode));
             }
 
             nodeCopy.setChildren(childrenCopy);
         }
 
         return nodeCopy;
     }
 }