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

 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.widgets.KSButton;

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

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

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

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

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

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

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

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

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

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

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

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

 public class SubrulePreviewWidget extends FlowPanel {

     private static final String OPERATOR_HEADER_OR = "Must meet 1 of the following:";

     private static final String OPERATOR_HEADER_AND = "Must meet all of the following:";

     private static final String SUBRULE_LI_CSS_CLASS = "KS-Rule-Preview-Subrule-li";

     private static final String SUBRULE_UL_CSS_CLASS = "KS-Program-Rule-Preview-Subrule-ul";

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

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

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

     private boolean isReadOnly = true;

     private Map<String, Widget> clusetWidgets;

     public SubrulePreviewWidget(StatementTreeViewInfo stmtTreeInfo, boolean isReadOnly, Map<String, Widget> clusetWidgets) {

         super();

         this.isReadOnly = isReadOnly;

         this.clusetWidgets = clusetWidgets;

         addStyleName("KS-Rule-Preview-Subrule-Box");

         showSubrule(stmtTreeInfo);

     }

     public void showSubrule(StatementTreeViewInfo stmtTreeInfo) {

         this.clear();

         if (stmtTreeInfo == null) {

             return;

         }

         buildRequirementHeader(stmtTreeInfo);

         buildRequirement(stmtTreeInfo);

     }

     private void buildRequirementHeader(StatementTreeViewInfo stmtTreeInfo) {

         SectionTitle header = SectionTitle.generateH6Title("");

         if (stmtTreeInfo.getOperator() == StatementOperatorTypeKey.AND) {

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

         } else {

             header.setHTML("Must meet <b>1 of the following:</b>");

         }

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

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

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

         if (!isReadOnly) {

             buildEditActionsWidget(header);

         }

         this.add(header);

     }

     private void buildEditActionsWidget(SectionTitle header) {

         SpanPanel actions = new SpanPanel();

         actions.add(editButton);

         actions.add(separator);

         actions.add(deleteButton);

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

         header.add(actions);

     }

     private void buildRequirement(StatementTreeViewInfo stmtTreeInfo) {

         Widget requirementsWidget = buildRequirementsWidget(stmtTreeInfo);

         if(requirementsWidget != null) {

             this.add(requirementsWidget);

         }

     }

     /**

      * 

      * This method handles creating the requirements preview widget at the parent level.  Further sub-statements are 

      * handled with recursive calls of another method 

      * 

      * @param rootStatement

      * @return

      */

     private ComplexPanel buildRequirementsWidget(StatementTreeViewInfo rootStatement) {

         ULPanel statementBulletList = new ULPanel();

         statementBulletList.setULClassName(SUBRULE_UL_CSS_CLASS);

         // handle simplest leaf case, where the statement has only requirement components

         if(rootStatement.getReqComponents() != null && !rootStatement.getReqComponents().isEmpty()) {

             populateRequirementComponentWidgets(rootStatement, statementBulletList);

         }

         else {

             // if no sub statements or requirement components, then return null, nothing to do

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

                 return null;

             }

             // statement has sub-statements, so prepare for recursion

             boolean firstInList = true;

             for(StatementTreeViewInfo subStatement : rootStatement.getStatements()) {

                 statementBulletList.add(buildSubStatementWidget(subStatement, rootStatement, firstInList));

                 firstInList = false;

             }

         }

         return statementBulletList;

     }

     /**

      * 

      * This method adds LI elements to the provided ULPanel.  Each element consists of the panel 

      * returned by buildRequirementPanel using each RequirementComponentInfo found in the provided 

      * StatementTreeViewInfo

      * 

      * @param statement

      * @param list

      */

     private void populateRequirementComponentWidgets(StatementTreeViewInfo statement, ULPanel list) {

         StatementOperatorTypeKey includedOperator = null;

         for (ReqComponentInfo reqComp : statement.getReqComponents()) {

             String nl = getPreviewNaturalLanguageForReqComponent(reqComp);

             list.add(buildRequirementPanel(reqComp, includedOperator, nl), SUBRULE_LI_CSS_CLASS);

             // only pass the operator after the first requirement panel is built

             if(includedOperator == null) {

                 includedOperator = statement.getOperator();

             }

         }

     }

     /**

      * 

      * This method is called recursively to return a preview widget for the data in subStatement

      * 

      * @param subStatement

      * @param parentStatement 

      * @param firstInList flag to indicate that this statement is the first of its siblings, and does not need to start with the operator keyword

      * 

      * @return

      */

     private Widget buildSubStatementWidget(StatementTreeViewInfo subStatement, StatementTreeViewInfo parentStatement, boolean firstInList) {

         StatementOperatorTypeKey prefixOperator = null;

         if(!firstInList) {

             prefixOperator = subStatement.getOperator();

         }

         boolean hasReqComponents = (subStatement.getReqComponents() != null && !subStatement.getReqComponents().isEmpty());

         // simplest case:  statement has one requisite component and its operator is the same as its parent

         if(hasReqComponents && subStatement.getReqComponents().size() == 1 && subStatement.getOperator() == parentStatement.getOperator()) {

             // return requirement component text, including operator text if applicable

             ReqComponentInfo reqComp = subStatement.getReqComponents().iterator().next();

             String nl = getPreviewNaturalLanguageForReqComponent(reqComp);

             return buildRequirementPanel(reqComp, prefixOperator, nl);

         }

         // The statement has one or more requisite components or sub-statements, so build the header text

         StringBuilder headerText = new StringBuilder();

         appendOperatorTag(headerText, prefixOperator);

         headerText.append(subStatement.getOperator() == StatementOperatorTypeKey.AND ? OPERATOR_HEADER_AND : OPERATOR_HEADER_OR);

         FlowPanel panel = new FlowPanel();

         panel.add(new HTML(headerText.toString()));

         if(hasReqComponents) {

             // requisite component case: a sub-statement with only requisite components

             ULPanel subrulePanel = new ULPanel();

             subrulePanel.setULClassName(SUBRULE_UL_CSS_CLASS);

             populateRequirementComponentWidgets(subStatement, subrulePanel);

             panel.add(subrulePanel);

         }

         else {

             // sub-statement case: for each sub statement, call this method recursively

             boolean firstInSubList = true;

             for(StatementTreeViewInfo childStatement : subStatement.getStatements()) {

                 panel.add(buildSubStatementWidget(childStatement, subStatement, firstInSubList));

                 firstInSubList = false;

             }

         }

         return panel;

     }

     private void appendOperatorTag(StringBuilder builder, StatementOperatorTypeKey operator) {

         if(operator != null && builder != null) {

             builder.append("<span class=\"KS-Program-Rule-Preview-Subrule-ORAND\">").append(operator.toString()).append(" ").append("</span>");

         }

     }

     private String getPreviewNaturalLanguageForReqComponent(ReqComponentInfo reqComp) {

         String nl = null;

         if (reqComp instanceof ReqComponentInfoUi) {

             nl = ((ReqComponentInfoUi)reqComp).getPreviewNaturalLanguageTranslation();

         }

         if ( nl == null) {

             nl = reqComp.getNaturalLanguageTranslation();

         }

         return nl;

     }

     private FlowPanel buildRequirementPanel(ReqComponentInfo reqComp, StatementOperatorTypeKey operator, String requirement) {

         FlowPanel requirementPanel = new FlowPanel();

         StringBuilder htmlBuilder = new StringBuilder();

         appendOperatorTag(htmlBuilder, operator);

         htmlBuilder.append(requirement);

         requirementPanel.add(new HTML(htmlBuilder.toString()));

         //we need to display clu set show/hide list widget if this req. component has a cluset

         if ((clusetWidgets != null) && (reqComp != null)) {

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

             for (ReqCompFieldInfo fieldInfo : fieldInfos) {

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

                     Widget csWidget = clusetWidgets.get(fieldInfo.getValue());

                     if (csWidget != null) {

                         requirementPanel.add(csWidget);

                         break;

                     }

                 }

             }

         }

         return requirementPanel;

     }

     public void addEditButtonClickHandler(ClickHandler handler) {

         editButton.addClickHandler(handler);

     }

     public void addDeleteButtonClickHandler(ClickHandler handler) {

         deleteButton.addClickHandler(handler);

     }

 }