package org.kuali.student.lum.common.client.widgets;

 import java.util.ArrayList;

 import java.util.HashMap;

 import java.util.Iterator;

 import java.util.List;

 import org.kuali.student.common.ui.client.application.Application;

 import org.kuali.student.common.ui.client.configurable.mvc.sections.BaseSection;

 import org.kuali.student.common.ui.client.configurable.mvc.sections.Section;

 import org.kuali.student.common.ui.client.configurable.mvc.sections.SwapSection;

 import org.kuali.student.common.ui.client.event.SectionUpdateEvent;

 import org.kuali.student.common.ui.client.widgets.dialog.ConfirmationDialog;

 import org.kuali.student.common.ui.client.widgets.field.layout.layouts.VerticalFieldLayout;

 import org.kuali.student.common.ui.client.widgets.list.KSSelectItemWidgetAbstract;

 import org.kuali.student.common.ui.client.widgets.list.SelectionChangeEvent;

 import org.kuali.student.common.ui.client.widgets.list.SelectionChangeHandler;

 import com.google.gwt.event.dom.client.ClickEvent;

 import com.google.gwt.event.dom.client.ClickHandler;

 public class SwitchSection extends BaseSection {

     private HashMap<String, Section> swapSectionMap = new HashMap<String, Section>();

     private KSSelectItemWidgetAbstract selectableWidget;

     private List<Section> deleted = new ArrayList<Section>();

     private ConfirmationDialog dialog; 

     private boolean showConfirmation = true;

     private List<String> lastSelection = new ArrayList<String>();

     private List<String> deletionParentKeys;

     /**

      * Constructor for SwapSection, note that the SelectableWidget passed in is not added to the

      * UI but is instead used as reference to show different sections.  The widget must still be added

      * to a layout as a field or a widget to show in the UI.  A default confirmation dialog will be used.

      * @param selectableWidget

      */

     public SwitchSection(KSSelectItemWidgetAbstract selectableWidget){

         this.init(selectableWidget);

     }

     public SwitchSection(KSSelectItemWidgetAbstract selectableWidget, ConfirmationDialog dialog){

         this.dialog = dialog;

         this.init(selectableWidget);

     }

     private void init(KSSelectItemWidgetAbstract selectableWidget){

         this.selectableWidget = selectableWidget;

         if(dialog == null){

             dialog = 

                 new ConfirmationDialog(Application.getApplicationContext().getMessage("fieldDeletionTitle"),  

                         Application.getApplicationContext().getMessage("fieldDeletionConfirmMessage"));

         }

         dialog.getConfirmButton().addClickHandler(new ClickHandler(){

             @Override

             public void onClick(ClickEvent event) {

                 handleUserSelection();

                 dialog.hide();

             }

         });

         selectableWidget.addSelectionChangeHandler(new SelectionChangeHandler(){

             @Override

             public void onSelectionChange(SelectionChangeEvent event) {

                 if(event.isUserInitiated() && showConfirmation){

                     if(SwitchSection.this.selectableWidget.getSelectedItems().size() < lastSelection.size()){

                         dialog.show();

                     }

                     else if(!SwitchSection.this.selectableWidget.getSelectedItems().containsAll(lastSelection)){

 //                      List<String> selected  = SwapSection.this.selectableWidget.getSelectedItems();

 //                      for(int i = 0; i < selected.size(); i++){

 //                          String key = selected.get(i);

 //                          Section section = swapSectionMap.get(key);

 //                          if(section!=null){

 //                              if(section.getLayout().isVisible()){

 //                                  dialog.show();

 //                              }

 //                          }

 //                      }

                         dialog.show();

                     }

                     else{

                         handleUserSelection();

                     }

                 }

                 else if(event.isUserInitiated()){

                     handleUserSelection();

                 }

                 else{

                     handleSelection();

                 }

                 lastSelection.clear();

                 lastSelection.addAll(SwitchSection.this.selectableWidget.getSelectedItems());

             }

         });

         layout = new VerticalFieldLayout();

         this.add(layout);

     }

     private void handleUserSelection(){

         List<String> selected  = SwitchSection.this.selectableWidget.getSelectedItems();

         for(int i = 0; i < selected.size(); i++){

             String key = selected.get(i);

             showSwappableSection(key);

         }

         Iterator<String> it = swapSectionMap.keySet().iterator();

         while(it.hasNext()){

             String key = it.next();

             if(!selected.contains(key)){

                 removeSwappableSection(key);

             }

         }

     }

     /**

      * This is handled differently than handleUserSelection because it is assumed that the client

      * is setting the correct values into the widgets, therefore no need to delete sections

      * (also reduces chance of actually deleting data before it is even shown)

      */

     private void handleSelection(){

         List<String> selected  = SwitchSection.this.selectableWidget.getSelectedItems();

         for(int i = 0; i < selected.size(); i++){

             String key = selected.get(i);

             showSwappableSection(key);

         }

         Iterator<String> it = swapSectionMap.keySet().iterator();

         while(it.hasNext()){

             String key = it.next();

             if(!selected.contains(key)){

                 removeSwappableSection(key);

             }

         }

     }

     private void showSwappableSection(String key){

         Section section = swapSectionMap.get(key);

         if(section != null){

             if(deleted.contains(section)){

                 deleted.remove(section);

             }

             if(!section.getLayout().isVisible()){

                 section.enableValidation(true);

                 section.getLayout().setVisible(true);

             }

         }

     }

     private void removeSwappableSection(String key){

         Section section = swapSectionMap.get(key);

         if(section != null){

             if(!deleted.contains(section)){

                 deleted.add(section);

             }

             if(section.getLayout().isVisible()){

                 section.enableValidation(false);

                 section.getLayout().setVisible(false);

             }

         }

     }

     public void enableConfirmation(boolean enable){

         showConfirmation = enable;

     }

     public String addSection(Section section, String swapKey){

         swapSectionMap.put(swapKey, section);

         String key = layout.addLayout(section.getLayout());

         section.getLayout().setVisible(false);

         if(selectableWidget.getSelectedItems().contains(swapKey)){

             handleSelection();

         }

         sections.add(section);

         return key;

     }

     public String addSection(String key, Section section, String swapKey){

         swapSectionMap.put(swapKey, section);

         section.getLayout().setKey(key);

         String rkey = layout.addLayout(section.getLayout());

         section.getLayout().setVisible(false);

         if(selectableWidget.getSelectedItems().contains(swapKey)){

             handleSelection();

         }

         sections.add(section);

         return rkey;

     }

     @Override

     public String addSection(Section section) {

         throw new UnsupportedOperationException("Sections can be added to swappable section only through " +

                 "the addSection(Section section, String swapKey) method");

     }

     @Override

     public String addSection(String key, Section section) {

         throw new UnsupportedOperationException("Sections can be added to swappable section only through " +

                 "the addSection(Section section, String swapKey) method");

     }

 }