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

 import java.util.ArrayList;

 import java.util.List;

 import org.kuali.student.common.assembly.data.MetadataInterrogator;

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

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

 import org.kuali.student.common.ui.client.configurable.mvc.FieldDescriptor;

 import org.kuali.student.common.ui.client.mvc.Callback;

 import org.kuali.student.common.ui.client.widgets.KSLabel;

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

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

 import com.google.gwt.user.client.ui.Anchor;

 import com.google.gwt.user.client.ui.Composite;

 import com.google.gwt.user.client.ui.FlowPanel;

 import com.google.gwt.user.client.ui.Widget;

 /**

  * This class creates a toggle that is used to hide or show all non-required fields.

  * 

  * @author SW Genis

  */

 public class RequiredContainer extends WarnContainer {

     final static ApplicationContext context = Application.getApplicationContext();

     private boolean showAll = false;

     private Section mainSection;

     private KSLabel label;

     private Anchor link;

     private List<Callback<Boolean>> callbacks = new ArrayList<Callback<Boolean>>();

     public RequiredContainer() {

         super();

         label = new KSLabel(context.getMessage("showingRequiredFields"));

         link = new Anchor(context.getMessage("showAllFields"));

         this.showWarningLayout(true);

         this.addHandler();

         this.addWarnWidget(label);

         this.addWarnWidget(link);

     }

     private void addHandler() {

         link.addClickHandler(new ClickHandler() {

             @Override

             public void onClick(ClickEvent event) {

                 if (showAll) {

                     label.setText(context.getMessage("showingRequiredFields"));

                     link.setText(context.getMessage("showAllFields"));

                     showAll = false;

                 } else {

                     label.setText(context.getMessage("showingAllFields"));

                     link.setText(context.getMessage("showRequiredFields"));

                     showAll = true;

                 }

                 processMainSection();

             }

         });

     }

     public boolean isShowAll() {

         return showAll;

     }

     public void setShowAll(boolean showAll) {

         this.showAll = showAll;

     }

     public Section getMainSection() {

         return mainSection;

     }

     public void setMainSection(Section mainSection) {

         this.mainSection = mainSection;

         this.processMainSection();

     }

     public void addCallback(Callback<Boolean> callback) {

         callbacks.add(callback);

     }

     public List<Callback<Boolean>> getCallbacks() {

         return callbacks;

     }

     /**

      * This method loop through all the sections on the main section, process them accordingly and sets the "Show All" link

      * to visible if there is no components displayed on the section and visa versa.

      */

     public void processMainSection() {

         for (Section innerSection : mainSection.getSections()) {

             boolean hasComponents = processInnerSection(innerSection, showAll);

             setLinkVisibility(innerSection, !hasComponents);

         }

         for (Callback<Boolean> c : callbacks) {

             c.exec(showAll);

         }

     }

     /**

      * This method loop through all the fields and sections on a section and sets the visibility accordingly.

      * 

      * @param section

      * @param showAll

      * @return

      */

     public boolean processInnerSection(Section section, boolean showAll) {

         boolean hasComponents = false;

         for (FieldDescriptor field : section.getUnnestedFields()) {

             if (processFieldDescriptor(field, showAll)) {

                 hasComponents = true;

             }

         }

         for (Section innerSection : section.getSections()) {

             if (processInnerSection(innerSection, showAll)) {

                 hasComponents = true;

                 setSectionVisibility(innerSection, true);

             } else {

                 setSectionVisibility(innerSection, false);

             }

         }

         return hasComponents;

     }

     /**

      * This method hides or show the "Show All" link.

      * 

      * @param section

      * @param visibility

      */

     private void setLinkVisibility(Section section, boolean visibility) {

         if (section instanceof VerticalSection) {

             if (((VerticalSection) section).getShowAllLink() != null) {

                 ((VerticalSection) section).getShowAllLink().setVisible(visibility);

             }

         }

     }

     /**

      * This method hide or show a section. Used for sections within other sections that does not have any required components

      * to show.

      * 

      * @param section

      * @param visibility

      */

     private void setSectionVisibility(Section section, boolean visibility) {

         if (section instanceof BaseSection) {

             ((BaseSection) section).getLayout().setVisible(visibility);

         }

     }

     /**

      * This method check if the component is required or not to set all non-required fields to the required visibility.

      * Returns true if widget is required.

      * 

      * @param descriptor

      * @param showAll

      * @return boolean

      */

     private boolean processFieldDescriptor(FieldDescriptor descriptor, boolean showAll) {

         if (!MetadataInterrogator.isRequired(descriptor.getMetadata()) && (!MetadataInterrogator.isRequiredForNextState(descriptor.getMetadata()))) {

             descriptor.getFieldElement().setVisible(showAll);

             return showAll;

         }

         return true;

     }

     public Composite createShowAllLink(ClickHandler handler) {

         return new ShowAllLink(handler);

     }

     public class ShowAllLink extends Composite {

         private FlowPanel layout = new FlowPanel();

         public ShowAllLink(ClickHandler handler) {

             layout.addStyleName("ks-message-static-margin");

             add(new KSLabel(context.getMessage("requiredFields")));

             // Link

             Anchor link = new Anchor(context.getMessage("allFields"));

             link.addClickHandler(handler);   

             add(link);

             this.initWidget(layout);

         }

         public void add(Widget w) {

             layout.add(w);

             w.getElement().setAttribute("style", "display: inline");

         }

     }

 }