package org.kuali.student.common.ui.client.configurable.mvc.sections;

 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.LayoutController;

 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 SwapSection extends BaseSection implements HasSectionDeletion{

         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 SwapSection(KSSelectItemWidgetAbstract selectableWidget){

                 this.init(selectableWidget);

         }

         public SwapSection(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(SwapSection.this.selectableWidget.getSelectedItems().size() < lastSelection.size()){

                                                 dialog.show();

                                         }

                                         else if(!SwapSection.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(SwapSection.this.selectableWidget.getSelectedItems());

                         }

                 });

                 layout = new VerticalFieldLayout();

                 this.add(layout);

         }

         private void handleUserSelection(){

                 List<String> selected  = SwapSection.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);

                         }

                 }

                 SectionUpdateEvent e = new SectionUpdateEvent();

                 e.setSection(this);

                 LayoutController.findParentLayout(layout).fireApplicationEvent(e);

         }

         /**

          * 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  = SwapSection.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");

         }

         @Override

         public List<Section> getDeletedSections() {

                 return deleted;

         }

     @Override

     public List<String> getDeletionParentKeys() {

         return deletionParentKeys;

     }

     /**

      * deletionParentKeys is optional and is only needed when you want to delete the

      * entire structure in addition to individual fields with in deleted sections.

      * 

      * @see SectionBinding#setModelValue(Section, org.kuali.student.common.ui.client.mvc.DataModel, String)

      */

     @Override

     public void setDeletionParentKey(List<String> deletionParentKeys) {

         this.deletionParentKeys = deletionParentKeys;

     }

 }