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

 import java.util.*;

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

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

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

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

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

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

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

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

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

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

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

 import org.kuali.student.common.ui.client.widgets.field.layout.element.SpanPanel;

 import org.kuali.student.common.ui.client.widgets.rules.RulesUtil;

 import org.kuali.student.common.ui.client.widgets.rules.SubrulePreviewWidget;

 import org.kuali.student.core.dto.RichTextInfo;

 import org.kuali.student.core.statement.dto.ReqCompFieldInfo;

 import org.kuali.student.core.statement.dto.ReqComponentInfo;

 import org.kuali.student.core.statement.dto.StatementTreeViewInfo;

 import org.kuali.student.core.statement.dto.StatementTypeInfo;

 import org.kuali.student.lum.common.client.widgets.AppLocations;

 import org.kuali.student.lum.common.client.widgets.CluSetDetailsWidget;

 import org.kuali.student.lum.common.client.widgets.CluSetRetriever;

 import org.kuali.student.lum.common.client.widgets.CluSetRetrieverImpl;

 import org.kuali.student.lum.lu.ui.course.client.configuration.AbstractCourseConfigurer;

 import org.kuali.student.lum.lu.ui.course.client.configuration.CourseConfigurer;

 import org.kuali.student.lum.lu.ui.course.client.controllers.CourseProposalController;

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

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

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

 import com.google.gwt.user.client.Window;

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

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

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

 public class CourseRequirementsSummaryView extends VerticalSectionView {

     private static CluSetRetriever cluSetRetriever = new CluSetRetrieverImpl();

     //view's widgets

     private FlowPanel layout = new FlowPanel();

     private ActionCancelGroup actionCancelButtons = new ActionCancelGroup(ButtonEnumerations.SaveContinueCancelEnum.SAVE_CONTINUE, ButtonEnumerations.SaveContinueCancelEnum.CANCEL);

     private Map<String, Widget> addButtonsList = new HashMap<String, Widget>();

     //view's data

     private CourseRequirementsViewController parentController;

     private CourseRequirementsDataModel rules;

     private boolean isReadOnly;

     private static int tempProgReqInfoID = 9999;

     public static final String NEW_STMT_TREE_ID = "NEWSTMTTREE";

     public static final String NEW_REQ_COMP_ID = "NEWREQCOMP";    

     private Map<String, SpanPanel> perCourseRequisiteTypePanel = new LinkedHashMap<String, SpanPanel>();

     public CourseRequirementsSummaryView(final CourseRequirementsViewController parentController, Enum<?> viewEnum, String name,

                                                             String modelId, CourseRequirementsDataModel rulesData, boolean isReadOnly) {

         super(viewEnum, name, modelId);

         this.parentController = parentController;

         rules = rulesData;

         rules.setInitialized(false);

         this.isReadOnly = isReadOnly;

         if (!isReadOnly) {

             setupSaveCancelButtons();

         }

     }

     @Override

     public boolean isDirty() {

         return rules.isDirty();

     }

     @Override

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

         //only when user wants to see rules then load requirements from database if they haven't been loaded yet

         if (!rules.isInitialized()) {

             rules.retrieveCourseRequirements(AbstractCourseConfigurer.CLU_PROPOSAL_MODEL, new Callback<Boolean>() {

                 @Override

                 public void exec(Boolean result) {

                     if (result) {

                         displayRules();

                     }

                     onReadyCallback.exec(result);

                 }

             });

             return;

         }

         //for read-only view, we don't need to worry about rules being added or modified

         if (isReadOnly) {

             displayRules();            

             onReadyCallback.exec(true);

             return;

         }

         //see if we need to update a rule if user is returning from rule manage screen

         parentController.getView(CourseRequirementsViewController.CourseRequirementsViews.MANAGE, new Callback<View>(){

                         @Override

                         public void exec(View result) {

                                 CourseRequirementsManageView manageView = (CourseRequirementsManageView) result;

                                 //return if user did not added or updated a rule

                 if (!manageView.isDirty() || !manageView.isUserClickedSaveButton()) {

                     rules.removeEmptyRules();

                     onReadyCallback.exec(true);

                     return;

                 }

                 //update the rule because user added or edited the rule

                 ((SectionView)parentController.getCurrentView()).setIsDirty(false);

                 manageView.setUserClickedSaveButton(false);

                 //if rule storage updated successfully, update the display as well

                 StatementTreeViewInfo affectedRule = rules.updateRules(manageView.getRuleTree(), manageView.getInternalCourseReqID(), manageView.isNewRule());

                 updateRequirementWidgets(affectedRule);

                         onReadyCallback.exec(true);

                         }

                 });        

     }

     public void revertRuleChanges() {

         rules.revertRuleChanges();

         displayRules();

     }

     private void updateRequirementWidgets(StatementTreeViewInfo rule) {

         if (rule != null) {

             StatementTypeInfo affectedStatementTypeInfo = rules.getStmtTypeInfo(rule.getType());

             SpanPanel reqPanel = perCourseRequisiteTypePanel.get(affectedStatementTypeInfo.getId());

             //don't show 'add rule' button if we have one rule already

             addButtonsList.get(rule.getType()).setVisible(false);

             //if this is a new rule then add it to the panel

             if (reqPanel.getWidgetCount() == 0) {

                 SubrulePreviewWidget newRulePreviewWidget = addCourseRequisite(reqPanel, rule);

                 reqPanel.add(newRulePreviewWidget);

                 return;

             }

             for (int i = 0; i < reqPanel.getWidgetCount(); i++) {

                 SubrulePreviewWidget subrulePreviewWidget = (SubrulePreviewWidget)reqPanel.getWidget(i);

                 SubrulePreviewWidget newRulePreviewWidget = addCourseRequisite(reqPanel, rule);

                 reqPanel.insert(newRulePreviewWidget, i);

                 reqPanel.remove(subrulePreviewWidget);

                 break; //there should be only one rule per requisite type

             }

         }

     }    

     public void displayRules() {       

         remove(layout);

         layout.clear();

         //display 'Course Requirements' page title (don't add if read only because the section itself will display the title)

         if (!isReadOnly) {

             SectionTitle pageTitle = SectionTitle.generateH2Title("Course Requisites");

             pageTitle.addStyleName("ks-layout-header");  //make the header orange

             layout.add(pageTitle);

         }

         //iterate and display rules for each Course Requirement type e.g. Pre-Requisites, Co-Requisites, Anti-Requisites

         boolean firstSubHeader = true;

         for (StatementTypeInfo stmtTypeInfo : rules.getStmtTypes()) {

             //Show only headers for top statement types

             if (isTopStatement(stmtTypeInfo)) {

                 SectionTitle title = SectionTitle.generateH3Title(stmtTypeInfo.getName());

                 title.addStyleName("KS-Course-Requisites-Top-Stmt-Header");

                 layout.add(title);

                 firstSubHeader = true;

                 continue;

             }

             //create and display one type of Course Requisites section

             SpanPanel requirementsPanel = new SpanPanel();

             perCourseRequisiteTypePanel.put(stmtTypeInfo.getId(), requirementsPanel);

             displayRequirementSectionForGivenType(requirementsPanel, stmtTypeInfo, firstSubHeader);

             firstSubHeader = false;

             //now display each requirement for this Course Requisites type; should be only one for courses

             for (StatementTreeViewInfo ruleInfo : rules.getCourseReqInfo(stmtTypeInfo.getId())) {

                 SubrulePreviewWidget subrulePreviewWidget = addCourseRequisite(requirementsPanel, ruleInfo);

                 requirementsPanel.add(subrulePreviewWidget);

             }

         }

         //save and cancel buttons

         if (!isReadOnly) {

             layout.add(actionCancelButtons);

         }

         addWidget(layout);

     }

     private void displayRequirementSectionForGivenType(final SpanPanel requirementsPanel, final StatementTypeInfo stmtTypeInfo, boolean firstSubHeader) {

         //display header for this Course Requisites type e.g. Enrollment Eligibility

         SectionTitle title = SectionTitle.generateH3Title(stmtTypeInfo.getName());

         title.setStyleName((firstSubHeader ? "KS-Course-Requisites-Preview-Rule-Type-First-Header" : "KS-Course-Requisites-Preview-Rule-Type-Header"));

         layout.add(title);

         //add rule description

         KSLabel ruleTypeDesc = new KSLabel(stmtTypeInfo.getDescr());

         ruleTypeDesc.addStyleName("KS-Course-Requisites-Preview-Rule-Type-Desc");

         layout.add(ruleTypeDesc);

         //display "Add Rule" button if user is in 'edit' mode OR a rule is already defined

         final String stmtId = stmtTypeInfo.getId();

         if (!isReadOnly) { // && rules.getCourseReqInfo(stmtId).isEmpty()) {

             KSButton addCourseReqButton = new KSButton("Add " + stmtTypeInfo.getName(), KSButtonAbstract.ButtonStyle.FORM_SMALL);

             addCourseReqButton.addClickHandler(new ClickHandler(){

                 public void onClick(ClickEvent event) {

                     storeRules(false, new Callback<Boolean>() {

                         @Override

                         public void exec(Boolean courseExists) {

                             if (courseExists) {

                                 final StatementTreeViewInfo newRule = new StatementTreeViewInfo();

                                 newRule.setId(generateStatementTreeId());

                                 newRule.setType(stmtId);

                                 RichTextInfo text = new RichTextInfo();

                                 text.setPlain("");

                                 newRule.setDesc(text);

                                 parentController.getView(CourseRequirementsViewController.CourseRequirementsViews.MANAGE, new Callback<View>(){

                                     @Override

                                     public void exec(View result) {

                                         rules.addRule(newRule);

                                         ((CourseRequirementsManageView) result).setRuleTree(newRule, true, rules.getInternalCourseReqID(newRule));

                                         parentController.showView(CourseRequirementsViewController.CourseRequirementsViews.MANAGE);

                                     }

                                 });

                             }

                         }

                     });

                 };

             });

             addCourseReqButton.setVisible(rules.getCourseReqInfo(stmtId).isEmpty());

             addButtonsList.put(stmtId, addCourseReqButton);

             layout.add(addCourseReqButton);

             VerticalPanel spacer = new VerticalPanel();

             spacer.addStyleName("KS-Course-Requisites-Button-Spacer");            

             layout.add(spacer);

         }

         layout.add(requirementsPanel);

     }

     private SubrulePreviewWidget addCourseRequisite(final SpanPanel requirementsPanel,final StatementTreeViewInfo rule) {

         Integer internalProgReqID =  rules.getInternalCourseReqID(rule);

         String stmtTypeId = rule.getType();

         final SubrulePreviewWidget rulePreviewWidget = new SubrulePreviewWidget(rule, isReadOnly, getCluSetWidgetList(rule));

         addRulePreviewWidgetHandlers(requirementsPanel, rulePreviewWidget, stmtTypeId, internalProgReqID);

         return rulePreviewWidget;

     }

     private void addRulePreviewWidgetHandlers(final SpanPanel requirementsPanel, final SubrulePreviewWidget subRuleWidget, final String stmtTypeId, final Integer internalProgReqID) {

         subRuleWidget.addEditButtonClickHandler(new ClickHandler() {

             public void onClick(ClickEvent event) {

                 parentController.getView(CourseRequirementsViewController.CourseRequirementsViews.MANAGE, new Callback<View>(){

                     @Override

                     public void exec(View result) {

                         ((CourseRequirementsManageView) result).setRuleTree(rules.getRule(internalProgReqID), false, internalProgReqID);

                         parentController.showView(CourseRequirementsViewController.CourseRequirementsViews.MANAGE);

                     }

                 });                

             }

         });

         subRuleWidget.addDeleteButtonClickHandler(new ClickHandler() {

             public void onClick(ClickEvent event) {

                 //deleting subrule does not delete the requirement (rule) itself

                 rules.markRuleAsEdited(internalProgReqID);

                 //remove rule from display and storage

                 rules.deleteRule(internalProgReqID);

                 requirementsPanel.remove(subRuleWidget);

                 addButtonsList.get(stmtTypeId).setVisible(true);

             }

         });                   

     }

     static public boolean isTopStatement(StatementTypeInfo stmtInfo) {

         return ((stmtInfo.getAllowedStatementTypes() != null) && !stmtInfo.getAllowedStatementTypes().isEmpty());

     }

     static public Map<String, Widget> getCluSetWidgetList(StatementTreeViewInfo rule) {

         Map<String, Widget> widgetList = new HashMap<String, Widget>();

         Set<String> cluSetIds = new HashSet<String>();

         findCluSetIds(rule, cluSetIds);

         for (String clusetId : cluSetIds) {

             widgetList.put(clusetId, new CluSetDetailsWidget(clusetId, cluSetRetriever));

         }

         return widgetList;

     }

     static private void findCluSetIds(StatementTreeViewInfo rule, Set<String> list) {

         List<StatementTreeViewInfo> statements = rule.getStatements();

         List<ReqComponentInfo> reqComponentInfos = rule.getReqComponents();

         if ((statements != null) && (statements.size() > 0)) {

             // retrieve all statements

             for (StatementTreeViewInfo statement : statements) {

                 findCluSetIds(statement, list); // inside set the children of this statementTreeViewInfo

             }

         } else if ((reqComponentInfos != null) && (reqComponentInfos.size() > 0)) {

             // retrieve all req. component LEAFS

             for (ReqComponentInfo reqComponent : reqComponentInfos) {

                 List<ReqCompFieldInfo> fieldInfos = reqComponent.getReqCompFields();

                 for (ReqCompFieldInfo fieldInfo : fieldInfos) {

                     if (RulesUtil.isCluSetWidget(fieldInfo.getType())) {

                         list.add(fieldInfo.getValue());

                     }

                 }

             }

         }

     }

     private void setupSaveCancelButtons() {

         actionCancelButtons.addStyleName("KS-Course-Requisites-Save-Button");

         actionCancelButtons.addCallback(new Callback<ButtonEnumerations.ButtonEnum>(){

              @Override

             public void exec(ButtonEnumerations.ButtonEnum result) {

                 if (result == ButtonEnumerations.SaveContinueCancelEnum.SAVE_CONTINUE) {

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

                         @Override

                         public void exec(Boolean result) {

                             if (result) {

                                 ((CourseProposalController)parentController.getParentController()).showNextViewOnMenu();

                             }

                         }

                     });                    

                 } else {

                     if(! ((CourseProposalController)parentController.getController()).isNew()){

                         (parentController.getController()).showView(CourseConfigurer.CourseSections.SUMMARY);

                     }

                     else{

                         Application.navigate(AppLocations.Locations.CURRICULUM_MANAGEMENT.getLocation());

                     }

                 }

             }

         });

     }

     public void storeRules(final boolean storeRules, final Callback<Boolean> callback) {

         parentController.requestModel(CourseRequirementsViewController.CLU_PROPOSAL_MODEL, new ModelRequestCallback() {

             @Override

             public void onRequestFail(Throwable cause) {

                 Window.alert(cause.getMessage());

                 GWT.log("Unable to retrieve model for course requirements view", cause);

                 callback.exec(false);

             }

             @Override

             public void onModelReady(Model model) {

                 String courseId = ((DataModel)model).getRoot().get("id");

                 if (courseId == null) {

                     final ConfirmationDialog dialog = new ConfirmationDialog("Submit Course Title", "Before saving rules please submit course proposal title");

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

                         @Override

                         public void onClick(ClickEvent event) {

                             dialog.hide();

                         }

                     });

                     dialog.show();

                     callback.exec(false);

                 } else {

                     if (storeRules) {

                         rules.updateCourseRequisites(courseId, new Callback<List<StatementTreeViewInfo>>() {

                             @Override

                             public void exec(List<StatementTreeViewInfo> rules) {

                                 for (StatementTreeViewInfo rule : rules) {

                                     updateRequirementWidgets(rule);

                                 }

                                 callback.exec(true);                                

                             }

                         });

                     } else {

                         callback.exec(true);                         

                     }

                 }

             }

         });

     }

     static public String generateStatementTreeId() {

         return (NEW_STMT_TREE_ID + Integer.toString(tempProgReqInfoID++));

     }

 }