package org.kuali.student.lum.program.client.requirements;

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

 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.*;

 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 org.kuali.student.lum.program.client.ProgramConstants;

 import org.kuali.student.lum.program.client.ProgramMsgConstants;

 import org.kuali.student.lum.program.client.widgets.EditableHeader;

 import com.google.gwt.event.shared.HandlerManager;

 public class ProgramRequirementsViewController extends BasicLayout {

     public enum ProgramRequirementsViews {

         PREVIEW,

         MANAGE

     }

     public static final String PROGRAM_RULES_MODEL_ID = "programRulesModelId";

     private ProgramRequirementsSummaryView preview;

     boolean reloadFlag;

     public ProgramRequirementsViewController(Controller controller, HandlerManager eventBus, String name, Enum<?> viewType, boolean isReadOnly, EditableHeader header, boolean reloadFlag){

         this(controller, eventBus, name, viewType, isReadOnly, header);

         this.reloadFlag = reloadFlag;

     }

     public ProgramRequirementsViewController(Controller controller, HandlerManager eventBus, String name, Enum<?> viewType, boolean isReadOnly, EditableHeader header) {

         super(ProgramRequirementsViewController.class.getName());

         super.setController(controller);

         super.setName(name);

         super.setViewEnum(viewType);

         super.setDefaultModelId(PROGRAM_RULES_MODEL_ID);

         super.setParentController(controller);

         this.setDefaultView(ProgramRequirementsViews.PREVIEW);

         //not used

         super.registerModel(PROGRAM_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

         String previewTitle = getLabel(ProgramMsgConstants.PROGRAM_MENU_SECTIONS_REQUIREMENTS);

         if (isReadOnly && (header != null)) {

             preview = new ProgramRequirementsSummaryView(this, eventBus, ProgramRequirementsViews.PREVIEW, "", ProgramConstants.PROGRAM_MODEL_ID, isReadOnly, header);                                                            

         } else {

             preview = new ProgramRequirementsSummaryView(this, eventBus, ProgramRequirementsViews.PREVIEW, (isReadOnly ? previewTitle : ""), ProgramConstants.PROGRAM_MODEL_ID, isReadOnly);

         }

         super.addView(preview);

         if (!isReadOnly) {

             ProgramRequirementsManageView manageView = new ProgramRequirementsManageView(this, ProgramRequirementsViews.MANAGE, "Add and Combine Rules", PROGRAM_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) {

                 //moving from PREVIEW to MANAGE page

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

                 if (viewChangingTo.name().equals(ProgramRequirementsViews.MANAGE.name()))

                 {

                     okToChange.exec(true);

                     return;

                 }

                 //moving from MANAGE to PREVIEW page

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

                 if (getCurrentView() instanceof ProgramRequirementsManageView) {

                     okToChange.exec(true);

                     return;

                 }

                 //moving from MANAGE to other page

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

                 //moving from other page to PREVIEW page

                 if (viewChangingTo.name().equals(ProgramRequirementsViews.PREVIEW.name())) {

                     preview.getRules().setupRules(ProgramRequirementsViewController.this, ProgramConstants.PROGRAM_MODEL_ID, new Callback<Boolean>() {

                         @Override

                         public void exec(Boolean result) {

                             okToChange.exec(result);

                             return;

                         }

                     });

                     return;

                 }

                 //moving from PREVIEW to other page (rules have NOT changed)

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

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

                     okToChange.exec(true);

                     return;

                 }

                 //moving from PREVIEW to other page (rules have changed)

                 //user is moving to another program section and rules have been changed, user needs to either save rules or abandon 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(new Callback<Boolean>() {

                                     @Override

                                     public void exec(Boolean result) {

                                         okToChange.exec(true);

                                     }

                                 });

                                 break;

                             case NO:

                                 dialog.hide();

                                 //preview.revertRuleChanges();     //TODO put back if we will NOT reset rules every time user comes to PREVIEW page above...

                                 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 ProgramRequirementsSummaryView getProgramRequirementsView() {

         return preview;

     }

     protected String getLabel(String messageKey) {

         return Application.getApplicationContext().getUILabel(ProgramMsgConstants.PROGRAM_MSG_GROUP, messageKey);

     }

 }