/*
    * Copyright (c) 2002-2026 Gargoyle Software Inc.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * https://www.apache.org/licenses/LICENSE-2.0
    *
    * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.htmlunit.javascript.host.dom;
  
  import javax.xml.transform.TransformerException;
  
  import org.htmlunit.corejs.javascript.Context;
  import org.htmlunit.corejs.javascript.Function;
  import org.htmlunit.corejs.javascript.Scriptable;
  import org.htmlunit.corejs.javascript.VarScope;
  import org.htmlunit.html.DomNode;
  import org.htmlunit.html.xpath.HtmlUnitPrefixResolver;
  import org.htmlunit.html.xpath.XPathAdapter;
  import org.htmlunit.html.xpath.XPathHelper;
  import org.htmlunit.javascript.HtmlUnitScriptable;
  import org.htmlunit.javascript.JavaScriptEngine;
  import org.htmlunit.javascript.configuration.JsxClass;
  import org.htmlunit.javascript.configuration.JsxConstructor;
  import org.htmlunit.javascript.configuration.JsxFunction;
  import org.htmlunit.xpath.xml.utils.PrefixResolver;
  import org.w3c.dom.Node;
  
  /**
   * A JavaScript object for {@code XPathExpression}.
   *
   * @author Ahmed Ashour
   * @author Ronald Brill
   */
  @JsxClass
  public class XPathExpression extends HtmlUnitScriptable {
  
      private final XPathAdapter xpath_;
      private final PrefixResolver prefixResolver_;
  
      /**
       * Default constructor.
       */
      public XPathExpression() {
          super();
          xpath_ = null;
          prefixResolver_ = null;
      }
  
      /**
       * JavaScript constructor.
       */
      @JsxConstructor
      public void jsConstructor() {
          // nothing to do
      }
  
      XPathExpression(final String expression, final PrefixResolver prefixResolver,
              final DomNode node) throws TransformerException {
          super();
          PrefixResolver resolver = prefixResolver;
          if (resolver == null) {
              resolver = new HtmlUnitPrefixResolver(node);
          }
          prefixResolver_ = resolver;
          final boolean caseSensitive = node.getPage().hasCaseSensitiveTagNames();
          xpath_ = new XPathAdapter(expression, prefixResolver, caseSensitive);
      }
  
      /**
       * Executes an XPath expression on the given node or document and returns an XPathResult.
       * @param context the context
       * @param scope the scope
       * @param thisObj this object
       * @param args the arguments
       * @param function the function
       * @return the result of the evaluation of the XPath expression
       */
      @JsxFunction
      public static XPathResult evaluate(final Context context, final VarScope scope,
              final Scriptable thisObj, final Object[] args, final Function function) {
          if (args.length < 1) {
              throw JavaScriptEngine.reportRuntimeError("Missing 'contextNode' parameter");
          }
  
          int type = 0; // ANY
          if (args.length > 1) {
              type = (int) JavaScriptEngine.toInteger(args[1]);
          }
  
          Object result = null;
          if (args.length > 2) {
              result = args[2];
         }
 
         try {
             final Object contextNodeObj = args[0];
             if (!(contextNodeObj instanceof org.htmlunit.javascript.host.dom.Node)) {
                 throw JavaScriptEngine.reportRuntimeError("Illegal value for parameter 'context'");
             }
 
             final Node contextNode = ((org.htmlunit.javascript.host.dom.Node) contextNodeObj).getDomNodeOrDie();
             final XPathExpression expression = (XPathExpression) thisObj;
 
             final XPathResult xPathResult;
             if (result instanceof XPathResult pathResult) {
                 xPathResult = pathResult;
             }
             else {
                 xPathResult = new XPathResult();
                 xPathResult.setParentScope(expression.getParentScope());
                 xPathResult.setPrototype(expression.getPrototype(xPathResult.getClass()));
             }
 
             xPathResult.init(XPathHelper.getByXPath(contextNode, expression.xpath_, expression.prefixResolver_), type);
             return xPathResult;
         }
         catch (final Exception e) {
             throw JavaScriptEngine.reportRuntimeError("Failed to execute 'evaluate': " + e.getMessage());
         }
     }
 }