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.Supplier;
  import java.util.function.UnaryOperator;
  
  import org.graalvm.polyglot.Context;
  import org.graalvm.polyglot.Value;
  import org.jsoup.Jsoup;
  import org.jsoup.nodes.Element;
  import org.jsoup.nodes.TextNode;
  
  /**
   * Processes a single {@literal <code>} node.
   */
  record PrismNodeHighlighter(
      PrismLanguage prismLanguage,
      /**
       * Expects the supplier to load the prism main JS and also the grammar JS associated with the given language.
       */
      Supplier<Context> contextSupplier
      ) implements UnaryOperator<Element> {
  
      @Override
      public Element apply(final Element codeNode) {
          try (Context context = contextSupplier.get()) {
              // get the highlight function and execute it later
              Value prism = context.getBindings("js").getMember("Prism");
              Value highlight = prism.getMember("highlight");
              Value language = prism.getMember("languages").getMember(prismLanguage.languageId());
  
              var html = new StringBuilder();
  
              codeNode.traverse((node, depth)->{
                  if(depth!=1) return;
                  if(node instanceof TextNode textNode) {
                      String highlightedCode = highlight.execute(textNode.getWholeText(), language, prismLanguage.languageId()).asString();
                      html.append(highlightedCode);
                  } else {
                      html.append(node.outerHtml());
                  }
              });
  
              var code = """
                      <code class="language-%s" data-lang="%s">%s</code>"""
                      .formatted(prismLanguage.languageId(), prismLanguage.languageId(), html.toString());
  
              var doc = Jsoup.parseBodyFragment(code);
              return doc.body().child(0);
          }
      }
  
  }
  