/*
    * 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.myfaces.tobago.renderkit.css;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.el.ELContext;
  import javax.el.ValueExpression;
  import javax.faces.context.FacesContext;
  import java.lang.invoke.MethodHandles;
  import java.util.StringTokenizer;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  /**
   * Since Tobago 3.0.0
   */
  public class CustomClass implements CssItem {
  
    private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
  
    private static final Pattern CSS_CLASS_PATTERN = Pattern.compile("[\\w-]+");
  
    private String name;
    private ValueExpression valueExpression;
  
    public CustomClass(final String name) {
      this.name = name;
    }
  
    public CustomClass(final ValueExpression valueExpression) {
      this.valueExpression = valueExpression;
    }
  
    @Override
    public String getName() {
      final String string;
      if (name != null) {
        string = name;
      } else if (valueExpression != null) {
        final FacesContext facesContext = FacesContext.getCurrentInstance();
        final ELContext elContext = facesContext.getELContext();
        final Object valueExpressionValue = valueExpression.getValue(elContext);
        if (valueExpressionValue != null) {
          string = valueExpressionValue.toString();
        } else {
          return "";
        }
      } else {
        return "";
      }
  
      final StringTokenizer tokenizer = new StringTokenizer(string, " ");
      final StringBuilder result = new StringBuilder();
      boolean first = true;
      while (tokenizer.hasMoreTokens()) {
        final String token = tokenizer.nextToken();
        final Matcher matcher = CSS_CLASS_PATTERN.matcher(token);
        if (matcher.matches()) {
          if (!first) {
            result.append(' ');
          }
          result.append(token);
          first = false;
        } else {
          LOG.error("Invalid CSS class name: '{}' which is part of '{}'", token, string);
        }
      }
      return result.toString();
    }
  
    /**
     * @deprecated since 4.0.0
     */
    @Deprecated
    public static CustomClass valueOf(final String text) {
      return new CustomClass(text);
    }
  }