/*
    * Copyright (c) 2002-2025 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;
  
  import java.io.Serializable;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.htmlunit.cssparser.parser.CSSErrorHandler;
  import org.htmlunit.cssparser.parser.CSSParseException;
  
  /**
   * HtmlUnit's default implementation of {@link CSSErrorHandler}, which logs all CSS problems.
   *
   * @author Daniel Gredler
   * @author Ronald Brill
   * @see SilentCssErrorHandler
   */
  public class DefaultCssErrorHandler implements CSSErrorHandler, Serializable {
      /** Logging support. */
      private static final Log LOG = LogFactory.getLog(DefaultCssErrorHandler.class);
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void error(final CSSParseException exception) {
          if (LOG.isWarnEnabled()) {
              LOG.warn("CSS error: " + buildMessage(exception));
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void fatalError(final CSSParseException exception) {
          if (LOG.isWarnEnabled()) {
              LOG.warn("CSS fatal error: " + buildMessage(exception));
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void warning(final CSSParseException exception) {
          if (LOG.isWarnEnabled()) {
              LOG.warn("CSS warning: " + buildMessage(exception));
          }
      }
  
      /**
       * Builds a message for the specified CSS parsing exception.
       * @param exception the CSS parsing exception to build a message for
       * @return a message for the specified CSS parsing exception
       */
      private static String buildMessage(final CSSParseException exception) {
          final String uri = exception.getURI();
          final int line = exception.getLineNumber();
          final int col = exception.getColumnNumber();
  
          if (null == uri) {
              return "[" + line + ":" + col + "] " + exception.getMessage();
          }
          return "'" + uri + "' [" + line + ":" + col + "] " + exception.getMessage();
      }
  }