/*
    * SPDX-FileCopyrightText: none
    * SPDX-License-Identifier: CC0-1.0
    */
   
   package dev.metaschema.core.metapath.cst.path;
   
   import java.util.List;
   
  import dev.metaschema.core.metapath.DynamicContext;
  import dev.metaschema.core.metapath.IExpression;
  import dev.metaschema.core.metapath.cst.IExpressionVisitor;
  import dev.metaschema.core.metapath.item.ISequence;
  import dev.metaschema.core.metapath.item.ItemUtils;
  import dev.metaschema.core.metapath.item.node.INodeItem;
  import dev.metaschema.core.util.CollectionUtil;
  import edu.umd.cs.findbugs.annotations.NonNull;
  
  /**
   * An expression that gets the document root.
   * <p>
   * Based on the XPath 3.1
   * <a href= "https://www.w3.org/TR/xpath-31/#id-path-operator">path
   * operator</a>.
   * <p>
   * This class handles the root path expression "/", which selects the document
   * root node when evaluated. The evaluation follows the XPath specification for
   * absolute paths.
   */
  public class RootSlashOnlyPath
      extends AbstractPathExpression<INodeItem> {
  
    /**
     * Construct a new path expression.
     *
     * @param text
     *          the parsed text of the expression
     */
    public RootSlashOnlyPath(@NonNull String text) {
      super(text);
    }
  
    @Override
    public List<? extends IExpression> getChildren() {
      return CollectionUtil.emptyList();
    }
  
    @Override
    public Class<INodeItem> getBaseResultType() {
      return INodeItem.class;
    }
  
    @Override
    public <RESULT, CONTEXT> RESULT accept(IExpressionVisitor<RESULT, CONTEXT> visitor, CONTEXT context) {
      return visitor.visitRootSlashOnlyPath(this, context);
    }
  
    @Override
    protected ISequence<? extends INodeItem> evaluate(DynamicContext dynamicContext, ISequence<?> focus) {
      return ItemUtils.getDocumentNodeItems(dynamicContext, focus);
    }
  }