package org.kuali.student.lum.lu.ui.course.client.requirements;

 import org.kuali.student.common.ui.client.configurable.mvc.layouts.BasicLayout;

 import org.kuali.student.common.ui.client.configurable.mvc.views.SectionView;

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

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

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

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

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

 import org.kuali.student.common.ui.client.widgets.buttongroups.ButtonEnumerations;

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

 import org.kuali.student.common.ui.client.widgets.field.layout.button.ButtonGroup;

 import org.kuali.student.common.ui.client.widgets.field.layout.button.YesNoCancelGroup;

 import com.google.gwt.core.client.GWT;

 public class CourseRequirementsViewController extends BasicLayout {

     public enum CourseRequirementsViews {

         PREVIEW,

         MANAGE

     }

     public static final String COURSE_RULES_MODEL_ID = "courseRulesModelId";

     public static final String COURSE_PROPOSAL_MODEL = "courseProposalModel";    

     private CourseRequirementsSummaryView preview;

     public CourseRequirementsViewController(Controller controller, String name, Enum<?> viewType, boolean isReadOnly, boolean showSaveButtons) {

                 super(CourseRequirementsViewController.class.getName());

                 super.setController(controller);

                 super.setName(name);

                 super.setViewEnum(viewType);

         super.setDefaultModelId(COURSE_RULES_MODEL_ID);

         super.setParentController(controller);

                 this.setDefaultView(CourseRequirementsViews.PREVIEW);

         //not used

         super.registerModel(COURSE_RULES_MODEL_ID, new ModelProvider<DataModel>() {

             @Override

             public void requestModel(final ModelRequestCallback<DataModel> callback) {

                 callback.onModelReady(new DataModel());

             }

         });

         //no name for the view so that breadcrumbs do not extra link

         preview = GWT.create(CourseRequirementsSummaryView.class);

         preview.init(

                 this,

                 CourseRequirementsViews.PREVIEW,

                 (isReadOnly ? "Course Requirements" : ""),

                 COURSE_PROPOSAL_MODEL,

                 (controller instanceof HasRequirements ? ((HasRequirements) controller).getReqDataModel()

                         : new CourseRequirementsDataModel(this)),

                 isReadOnly, showSaveButtons);

         super.addView(preview);

         if (!isReadOnly) {

             CourseRequirementsManageView manageView = GWT.create(CourseRequirementsManageView.class);

             manageView.init(this, CourseRequirementsViews.MANAGE, "Add and Combine Rules", COURSE_RULES_MODEL_ID);

             super.addView(manageView);

         }

     }

     @Override

     public void updateModel() {

         preview.updateModel();    

     }

     @Override

     public void beforeViewChange(final Enum<?> viewChangingTo, final Callback<Boolean> okToChange) {

         if (getCurrentView() == null) {

             okToChange.exec(true);

             return;

         }

         super.beforeViewChange(viewChangingTo, new Callback<Boolean>() {

             @Override

             public void exec(Boolean result) {

                 //no dialog if user clicks on the 'Save' button on Manage Rule page

                 if (getCurrentView() instanceof CourseRequirementsManageView) {

                     okToChange.exec(true);

                     return;

                 }

                 //no dialog if user is going to the Manage Rule page

                 if (viewChangingTo.name().equals(CourseRequirementsViewController.CourseRequirementsViews.MANAGE.name()))

                 {

                     //TODO show dialog if user clicks on a menu from Manage Rules page

                     okToChange.exec(true);

                     return;

                 }

                 //user is moving to another course proposal section and no changes were made to the rules so allow it to happen

                 if (!((SectionView) getCurrentView()).isDirty()) {

                     okToChange.exec(true);

                     return;

                 }

                 //user is moving to another course proposal section and rules have been changed, user needs to either save rules or abondon changes before proceeding

                 ButtonGroup<ButtonEnumerations.YesNoCancelEnum> buttonGroup = new YesNoCancelGroup();

                 final ButtonMessageDialog<ButtonEnumerations.YesNoCancelEnum> dialog =

                         new ButtonMessageDialog<ButtonEnumerations.YesNoCancelEnum>("Warning", "You may have unsaved changes.  Save changes?", buttonGroup);

                 buttonGroup.addCallback(new Callback<ButtonEnumerations.YesNoCancelEnum>() {

                     @Override

                     public void exec(ButtonEnumerations.YesNoCancelEnum result) {

                         switch (result) {

                             case YES:

                                 dialog.hide();

                                 preview.storeRules(true, new Callback<Boolean>() {

                                     @Override

                                     public void exec(Boolean result) {

                                         okToChange.exec(result);

                                     }

                                 });

                                 break;

                             case NO:

                                 dialog.hide();

                                 preview.revertRuleChanges();                                

                                 okToChange.exec(true);

                                 break;

                             case CANCEL:

                                 okToChange.exec(false);

                                 dialog.hide();

                                 break;

                         }

                     }

                 });

                 dialog.show();

             }

         });

     }

     @Override

         public void beforeShow(final Callback<Boolean> onReadyCallback){

                 showDefaultView(onReadyCallback);

         }

     public void storeRules(Callback<Boolean> callback){

             preview.storeRules(true, callback);

     }

 }