content: /*
   *  Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you 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
   *
   *        http://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.apache.causeway.viewer.commons.prism;
  
  import java.util.function.UnaryOperator;
  
  import org.jsoup.Jsoup;
  import org.jsoup.nodes.Element;
  import org.jsoup.nodes.Node;
  
  import lombok.extern.log4j.Log4j2;
  @Log4j2
  public record PrismHighlighter(
          ) implements UnaryOperator<String> {
  
      /**
       * Returns the highlighted HTML.
       * @param htmlContent code to be highlighted
       */
      @Override
      public String apply(final String htmlContent) {
  
          var doc = Jsoup.parseBodyFragment(htmlContent);
  
          //var tt = org.apache.causeway.commons.internal.base._Timing.now();
  
          doc.traverse((final Node node, final int depth)->{
              if(node instanceof Element element
                  && "code".equals(node.nodeName())) {
  
                  var prismLanguage = PrismLanguage.parseFromCssClass(node.attr("class")).orElse(null);
                  if(prismLanguage==null) return;
  
                  var grammarJs = PrismUtils.jsResource(prismLanguage).orElse(null);
                  if(grammarJs==null) {
                      log.warn("grammarJs not found for {}", prismLanguage);
                      return;
                  }
  
                  var newNode = new PrismNodeHighlighter(prismLanguage, ()->{
                      var context = PrismUtils.createPrismContext();
                      context.eval("js", grammarJs);
                      return context;
                  }).apply(element);
  
                  //<pre class="highlight language-%s">
                  node.parent().attr("class", "highlight language-%s".formatted(prismLanguage.languageId()));
  
                  node.replaceWith(newNode);
              }
          });
  
          //tt.stop();System.err.printf("context took %s%n", tt);
  
          return doc.body().html();
      }
  
  }
  