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.wicket.ui.util;
  
  import java.nio.charset.StandardCharsets;
  import java.util.stream.Collectors;
  
  import org.apache.wicket.markup.head.CssHeaderItem;
  import org.apache.wicket.markup.head.CssReferenceHeaderItem;
  import org.apache.wicket.markup.head.HeaderItem;
  import org.apache.wicket.markup.head.IHeaderResponse;
  import org.apache.wicket.markup.head.JavaScriptReferenceHeaderItem;
  import org.apache.wicket.markup.head.OnDomReadyHeaderItem;
  import org.apache.wicket.markup.html.IHeaderContributor;
  import org.apache.wicket.request.resource.CssResourceReference;
  import org.apache.wicket.request.resource.JavaScriptResourceReference;
  
  import org.apache.causeway.commons.internal.base._Strings;
  import org.apache.causeway.commons.io.TextUtils;
  
  import lombok.Getter;
  import org.jspecify.annotations.NonNull;
  import lombok.RequiredArgsConstructor;
  import lombok.SneakyThrows;
  import lombok.experimental.UtilityClass;
  
  @UtilityClass
  public class WktHeaderItems {
  
      // -- FACTORIES
  
      /**
       * Reading JS from source, it (hardcoded) skips 18 license header lines
       * and any single line comments as well as empty lines.
       * @apiNote that could be done by the yui-compressor maven plugin as well,
       *      but at the time of writing did not look into it
       */
      public OnDomReadyHeaderItem forScriptReferenceAsOnDomReady(
              final @NonNull Class<?> resourceLocation,
              final @NonNull String resourceName) {
          return OnDomReadyHeaderItem.forScript(readJsResource(resourceLocation, resourceName));
      }
  
      public JavaScriptReferenceHeaderItem forScriptReference(
              final @NonNull Class<?> resourceLocation,
              final @NonNull String resourceName) {
          return JavaScriptReferenceHeaderItem.forReference(
                  new JavaScriptResourceReference(resourceLocation, resourceName));
      }
  
      public CssReferenceHeaderItem forCssReference(
              final @NonNull Class<?> resourceLocation,
              final @NonNull String resourceName) {
          return CssHeaderItem.forReference(
                  new CssResourceReference(resourceLocation, resourceName));
      }
  
      @RequiredArgsConstructor
      public class HeaderContributor
      implements IHeaderContributor {
          private static final long serialVersionUID = 1L;
          @Getter private final HeaderItem headerItem;
          @Override public void renderHead(final IHeaderResponse response) {
              response.render(headerItem);
          }
      }
  
      // -- HELPER
  
      /** skips 18 license header lines and any single line comments as well as empty lines */
      @SneakyThrows
      private String readJsResource(
              final @NonNull Class<?> resourceLocation,
              final @NonNull String resourceName) {
          return TextUtils.readLinesFromResource(
                  resourceLocation, resourceName, StandardCharsets.UTF_8)
                  .filter(_Strings::isNotEmpty)
                  .filter(line->!line.trim().startsWith("//"))
                  .stream()
                  .skip(18) // skip license header
                  .collect(Collectors.joining("\n"));
      }
  
  }
  