package org.kuali.rice.kns.uif.container;

 import java.io.Serializable;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.Map;

 import java.util.Map.Entry;

 import org.kuali.rice.core.util.Node;

 import org.kuali.rice.core.util.Tree;

 import org.kuali.rice.kns.uif.UifConstants;

 import org.kuali.rice.kns.uif.core.BindingInfo;

 import org.kuali.rice.kns.uif.core.Component;

 import org.kuali.rice.kns.uif.field.MessageField;

 import org.kuali.rice.kns.uif.util.ComponentUtils;

 import org.kuali.rice.kns.uif.util.ObjectPropertyUtils;

 import org.kuali.rice.kns.uif.widget.TreeWidget;

 /**

  * 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)

  */

 public class TreeGroup extends Group {

     private static final long serialVersionUID = 5841343037089286740L;

     private String propertyName;

     private BindingInfo bindingInfo;

     private Map<Class<?>, NodePrototype> nodeProtypeMap;

     private NodePrototype defaultNodePrototype;

     private Tree<Group, MessageField> treeGroups;

     private TreeWidget treeWidget;

     public TreeGroup() {

         super();

         treeGroups = new Tree<Group, MessageField>();

     }

     /**

      * 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>

      *

      * @see org.kuali.rice.kns.uif.core.ComponentBase#performInitialization(org.kuali.rice.kns.uif.container.View)

      */

     @Override

     public void performInitialization(View view) {

         setFieldBindingObjectPath(getBindingInfo().getBindingObjectPath());

         super.performInitialization(view);

         if (bindingInfo != null) {

             bindingInfo.setDefaults(view, getPropertyName());

         }

         // TODO: set object path for prototypes equal to the tree group object path?

         initializeNodePrototypeComponents(view);

     }

     /**

      * This method initializes {@link org.kuali.rice.kns.uif.core.Component}s within the {@link NodePrototype}s

      * 

      * @param view

      */

     private void initializeNodePrototypeComponents(View view) {

         view.getViewHelperService().performComponentInitialization(view, defaultNodePrototype.getLabelPrototype());

         view.getViewHelperService().performComponentInitialization(view, defaultNodePrototype.getDataGroupPrototype());

         if (nodeProtypeMap != null) for (Entry<Class<?>, NodePrototype> prototypeEntry : nodeProtypeMap.entrySet()) {

             NodePrototype prototype = prototypeEntry.getValue();

             if (prototype != null) {

                 if (prototype.getLabelPrototype() != null) {

                     view.getViewHelperService().performComponentInitialization(view, prototype.getLabelPrototype());

                 } else {

                     throw new IllegalStateException("encountered null NodePrototype.labelPrototype");

                 }

                 if (prototype.getDataGroupPrototype() != null) {

                     view.getViewHelperService().performComponentInitialization(view, prototype.getDataGroupPrototype());

                 } else {

                     throw new IllegalStateException("encountered null NodePrototype.dataGroupPrototype");

                 }

             } else {

                 throw new IllegalStateException("encountered null NodePrototype");

             }

         }

     }

     /**

      * @see org.kuali.rice.kns.uif.container.ContainerBase#performApplyModel(org.kuali.rice.kns.uif.container.View,

      *      java.lang.Object)

      */

     @Override

     public void performApplyModel(View view, Object model) {

         super.performApplyModel(view, model);

         buildTreeGroups(view, 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>MessageField</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 view - view instance the tree group belongs to

      * @param model - object containing the view data from which the tree data will be retrieved

      */

     protected void buildTreeGroups(View view, 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, MessageField> treeGroups = new Tree<Group, MessageField>();

         String bindingPrefix = getBindingInfo().getBindingPrefixForNested();

         Node<Group, MessageField> rootNode = buildTreeNode(treeData.getRootElement(), bindingPrefix, 0);

         treeGroups.setRootElement(rootNode);

         setTreeGroups(treeGroups);

     }

     protected Node<Group, MessageField> buildTreeNode(Node<Object, String> nodeData, String bindingPrefix, int nodeCounter) {

         Node<Group, MessageField> node = new Node<Group, MessageField>();

         node.setNodeType(nodeData.getNodeType());

         String idSuffix = "_n" + nodeCounter;

         NodePrototype prototype = getNodePrototype(nodeData);

         MessageField messageField = ComponentUtils.copy(prototype.getLabelPrototype(), idSuffix);

         ComponentUtils.pushObjectToContext(messageField, UifConstants.ContextVariableNames.NODE, nodeData);

         messageField.setMessageText(nodeData.getNodeLabel());

         node.setNodeLabel(messageField);

         Group nodeGroup = ComponentUtils.copyComponent(prototype.getDataGroupPrototype(), bindingPrefix + ".data", idSuffix);

         ComponentUtils.pushObjectToContext(nodeGroup, UifConstants.ContextVariableNames.NODE, nodeData);

         node.setData(nodeGroup);

         List<Node<Group, MessageField>> nodeChildren = new ArrayList<Node<Group, MessageField>>();

         int childIndex = -1;

         for (Node<Object, String> childDataNode : nodeData.getChildren()) {

             String nextBindingPrefix = bindingPrefix + ".children[" + childIndex + "]";

             Node<Group, MessageField> childNode = buildTreeNode(childDataNode, nextBindingPrefix, nodeCounter++);

             nodeChildren.add(childNode);

         }

         node.setChildren(nodeChildren);

         return node;

     }

     /**

      * This method 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 = nodeProtypeMap.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 (Entry<Class<?>, NodePrototype> prototypeEntry : nodeProtypeMap.entrySet()) {

                 if (prototypeEntry.getKey().isAssignableFrom(dataClass)) {

                     result = prototypeEntry.getValue();

                     break;

                 }

             }

         } 

         if (result == null) result = defaultNodePrototype;

         return result;

     }

     /**

      * @see org.kuali.rice.kns.uif.container.ContainerBase#getNestedComponents()

      */

     @Override

     public List<Component> getNestedComponents() {

         List<Component> components = super.getNestedComponents();

         components.add(treeWidget);

         addNodeComponents(treeGroups.getRootElement(), components);

         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, MessageField> node, List<Component> components) {

         if (node != null) {

             components.add(node.getNodeLabel());

             components.add(node.getData());

             for (Node<Group, MessageField> nodeChild : node.getChildren()) {

                 addNodeComponents(nodeChild, components);

             }

         }

     }

     public String getPropertyName() {

         return propertyName;

     }

     public void setPropertyName(String propertyName) {

         this.propertyName = propertyName;

     }

     public BindingInfo getBindingInfo() {

         return bindingInfo;

     }

     public void setBindingInfo(BindingInfo bindingInfo) {

         this.bindingInfo = bindingInfo;

     }

     /**

      * @return the defaultNodePrototype

      */

     public NodePrototype getDefaultNodePrototype() {

         return this.defaultNodePrototype;

     }

     /**

      * @param defaultNodePrototype the defaultNodePrototype to set

      */

     public void setDefaultNodePrototype(NodePrototype defaultNodePrototype) {

         this.defaultNodePrototype = defaultNodePrototype;

     }

     /**

      * @return the nodeProtypeMap

      */

     public Map<Class<?>, NodePrototype> getNodeProtypeMap() {

         return this.nodeProtypeMap;

     }

     /**

      * @param nodeProtypeMap the nodeProtypeMap to set

      */

     public void setNodeProtypeMap(Map<Class<?>, NodePrototype> nodeProtypeMap) {

         this.nodeProtypeMap = nodeProtypeMap;

     }

     public Tree<Group, MessageField> getTreeGroups() {

         return treeGroups;

     }

     public void setTreeGroups(Tree<Group, MessageField> treeGroups) {

         this.treeGroups = treeGroups;

     }

     public TreeWidget getTreeWidget() {

         return treeWidget;

     }

     public void setTreeWidget(TreeWidget treeWidget) {

         this.treeWidget = treeWidget;

     }

     public static class NodePrototype implements Serializable {

         private static final long serialVersionUID = 1L;

         MessageField labelPrototype;

         Group dataGroupPrototype;

         /**

          * @param labelPrototype the labelPrototype to set

          */

         public void setLabelPrototype(MessageField labelPrototype) {

             this.labelPrototype = labelPrototype;

         }

         /**

          * @return the labelPrototype

          */

         public MessageField getLabelPrototype() {

             return this.labelPrototype;

         }

         /**

          * @param dataGroupPrototype the dataGroupPrototype to set

          */

         public void setDataGroupPrototype(Group dataGroupPrototype) {

             this.dataGroupPrototype = dataGroupPrototype;

         }

         /**

          * @return the dataGroupPrototype

          */

         public Group getDataGroupPrototype() {

             return this.dataGroupPrototype;

         }

     }

 }