package org.kuali.student.common.ui.client.widgets.rules;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.Map;

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

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

 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.dialog.ConfirmationDialog;

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

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

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

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

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

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

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

 public class RulePreviewWidget extends FlowPanel {

     //Widgets

     private SpanPanel rulePanel = new SpanPanel();

     private KSButton editButton = new KSButton("Edit", KSButtonAbstract.ButtonStyle.DEFAULT_ANCHOR);

     private SpanPanel separator = new SpanPanel(" | ");

     private KSButton deleteButton = new KSButton("Delete", KSButtonAbstract.ButtonStyle.DEFAULT_ANCHOR);

     private KSButton addSubRuleBtn = new KSButton("Add a Rule", KSButtonAbstract.ButtonStyle.FORM_SMALL);

     private List<SubrulePreviewWidget> subRulePreviewWidgets = new ArrayList<SubrulePreviewWidget>();

     private Map<String, Widget> clusetWidgets;

     private SectionTitle progReqHeader = SectionTitle.generateH4Title("");

     private KSLabel ruleDescLabel = new KSLabel();

     private SpanPanel actions = new SpanPanel();

     //data

     private StatementTreeViewInfo stmtTreeInfo;     //program rule e.g. program completion rule

     private boolean isReadOnly;

     private boolean addRuleOperator = false;        //first subrule does not have operator following it

     private Integer internalProgReqID;

     private Callback<SubRuleInfo> editSubRuleCallback;

     private Callback<Integer> deleteSubRuleCallback;

     public RulePreviewWidget(Integer internalProgReqID, String ruleName, String ruleCreditsText, String ruleDesc, StatementTreeViewInfo stmtTreeInfo,

                              Boolean isReadOnly,  Map<String, Widget> clusetWidgets) {

         super();

         this.internalProgReqID = internalProgReqID;

         this.stmtTreeInfo = stmtTreeInfo;

         this.isReadOnly = isReadOnly;

         this.clusetWidgets = clusetWidgets;

         //prepare widgets

         this.addStyleName("KS-Rule-Preview-Box");

         progReqHeader.setStyleName("KS-Rule-Preview-header");

         ruleDescLabel.addStyleName("KS-Rule-Preview-Desc");

         if (!isReadOnly) {

             buildEditActionsWidget();

         }

         updateProgInfoFields(ruleName, ruleCreditsText, ruleDesc);

         displayRule();

     }

     public void updateProgInfoFields(String ruleName, String ruleCreditsText, String ruleDesc) {

         progReqHeader.clear();

         progReqHeader.setHTML("<b>" + ruleName + "</b>" + "  " + ruleCreditsText);

         //do not show edit,delete etc. if user is only viewing the rule in non-edit mode

         if (!isReadOnly) {

             progReqHeader.add(actions);

         }

         ruleDescLabel.setText(ruleDesc);

     }

     private void displayRule() {

         //start with a header for the entire rule

         buildRuleHeader();

         //show sub-rules if we have any

         if (stmtTreeInfo == null) {

             displayNoRule();

         }

         if ((stmtTreeInfo.getStatements() == null) || (stmtTreeInfo.getStatements().isEmpty())) {

             if ((stmtTreeInfo.getReqComponents() == null) || (stmtTreeInfo.getReqComponents().isEmpty())) {

                 displayNoRule();

             } else {

                 addSubRule(stmtTreeInfo);

             }

         } else {

             for (final StatementTreeViewInfo subTree : stmtTreeInfo.getStatements()) {

                 addSubRule(subTree);

             }

         }

         //button below has to be spaced

         SpanPanel spacer = new SpanPanel();

         spacer.addStyleName("KS-Rule-Last-Preview-Spacer");

         rulePanel.add(spacer);

         //add a button for user to add additional subrule

         if (!isReadOnly) {

             addSubRuleBtn.addStyleName("KS-Rule-Preview-Add-Subrule");

             rulePanel.add(addSubRuleBtn);

         }

         this.add(rulePanel);

     }

     private void displayNoRule() {

         KSLabel noRulesAddedYet = new KSLabel("No rules have been added yet.");

         noRulesAddedYet.addStyleName("KS-Rule-Preview-NoRule");

         rulePanel.add(noRulesAddedYet);

     }

     private void addSubRule(final StatementTreeViewInfo subTree) {

         //display AND/OR operator between subrules

         if (addRuleOperator) {

             buildANDOperator(stmtTreeInfo.getOperator());

         }

         final SubrulePreviewWidget newSubRuleWidget = new SubrulePreviewWidget(subTree, isReadOnly, clusetWidgets);        

         subRulePreviewWidgets.add(newSubRuleWidget);

         newSubRuleWidget.addEditButtonClickHandler(new ClickHandler(){

             public void onClick(ClickEvent event) {

                 SubRuleInfo subRuleInfo = new SubRuleInfo();

                 subRuleInfo.setSubrule(subTree);

                 subRuleInfo.setInternalProgReqID(internalProgReqID);

                 editSubRuleCallback.exec(subRuleInfo);

             }

         });

         newSubRuleWidget.addDeleteButtonClickHandler(new ClickHandler(){

             public void onClick(ClickEvent event) {

                 final ConfirmationDialog dialog = new ConfirmationDialog("Delete Rule", "Are you sure you want to delete this rule?"); //TODO app context for labels

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

                     @Override

                     public void onClick(ClickEvent event) {

                         removeSubRule(newSubRuleWidget, subTree);

                         dialog.hide();

                         deleteSubRuleCallback.exec(internalProgReqID);

                     }

                 });

                 dialog.show();

             }

         });

         rulePanel.add(newSubRuleWidget);

         addRuleOperator = true;

     }

     //user selected to delete this particular requirement

     public void removeSubRule(SubrulePreviewWidget subRuleWidget, StatementTreeViewInfo subTree) {

         //update data

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

         statements.remove(subTree);

         subRulePreviewWidgets.remove(subRuleWidget);

         //update display

         rulePanel.remove(subRuleWidget);

         //remove unnecessary operators

         int numberOfOperators = 0;

         boolean lastWidgetIsSubRule = true;

         boolean foundSubRule = false;

         int counter = 0;

         Widget widget = null;

         Widget widgetToRemove = null;

         Widget lastOperatorWidget = null;

         for (Object aRulePanel : rulePanel) {

             counter++;

             widget = (Widget) aRulePanel;

             if (widget instanceof KSLabel) {

                 if (((KSLabel) widget).getText().equals("AND") || ((KSLabel) widget).getText().equals("OR")) {

                     lastWidgetIsSubRule = false;

                     lastOperatorWidget = widget;

                     numberOfOperators++;

                     //remove 'AND' above the first sub-rule or two repeated instances

                     if ((numberOfOperators > 1) || (counter == 1) || !foundSubRule) {

                         widgetToRemove = widget;

                         numberOfOperators--;

                     }

                 }

             } else if (widget instanceof SubrulePreviewWidget) {

                 foundSubRule = true;

                 lastWidgetIsSubRule = true;

                 numberOfOperators = 0;

             }

         }

         if (!lastWidgetIsSubRule) {

             rulePanel.remove(lastOperatorWidget);

         }

         if (widgetToRemove != null) {

             rulePanel.remove(widgetToRemove);

         }

     }

     private void buildRuleHeader() {

         rulePanel.clear();

         rulePanel.addStyleName("KS-Rule-Preview-Box1");

         rulePanel.add(progReqHeader);

         rulePanel.add(ruleDescLabel);

         //build subheading

         SectionTitle header = SectionTitle.generateH6Title("");

         header.setHTML("Must meet <b>all of the following</b> rules");

         header.setStyleName("KS-Rule-Preview-header-Subrule");

         header.getElement().setAttribute("style", "font-weight: normal");        

         rulePanel.add(header);

     }

     private void buildEditActionsWidget() {       

         actions.add(editButton);

         actions.add(separator);

         actions.add(deleteButton);

         actions.addStyleName("KS-Rule-Preview-header-action");

     }

     private void buildANDOperator(StatementOperatorTypeKey operator) {

         KSLabel andLabel = new KSLabel((operator == StatementOperatorTypeKey.AND ? "AND" : "OR"));

         andLabel.addStyleName("KS-Rule-Preview-Operator");

         rulePanel.add(andLabel);        

     }

     public void addProgReqEditButtonClickHandler(ClickHandler handler) {

         editButton.addClickHandler(handler);

     }

     public void addProgReqDeleteButtonClickHandler(ClickHandler handler) {

         deleteButton.addClickHandler(handler);

     }

     public void addSubRuleAddButtonClickHandler(ClickHandler handler) {

         addSubRuleBtn.addClickHandler(handler);

     }

     public void addSubRuleEditButtonClickHandler(Callback<SubRuleInfo> callback) {

         this.editSubRuleCallback = callback;

     }

     public void addSubRuleDeleteCallback(Callback<Integer> callback) {

         this.deleteSubRuleCallback = callback;

     }

     public StatementTreeViewInfo getStatementTreeViewInfo() {

         return  stmtTreeInfo;

     }

     public Integer getInternalProgReqID() {

         return internalProgReqID;

     }

     public class SubRuleInfo {

         private StatementTreeViewInfo subrule;

         private Integer internalProgReqID;

         public StatementTreeViewInfo getSubrule() {

             return subrule;

         }

         public void setSubrule(StatementTreeViewInfo subrule) {

             this.subrule = subrule;

         }

         public Integer getInternalProgReqID() {

             return internalProgReqID;

         }

         public void setInternalProgReqID(Integer internalProgReqID) {

             this.internalProgReqID = internalProgReqID;

         }

     }

 }