/*
    * 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;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.myfaces.tobago.component.Attributes;
  import org.apache.myfaces.tobago.component.RendererTypes;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.faces.component.UIComponent;
  import java.util.Locale;
  
  public final class LabelWithAccessKey {
  
    private static final Logger LOG = LoggerFactory.getLogger(LabelWithAccessKey.class);
  
    private String text;
    private Character accessKey;
    private int pos = -1;
    public static final char INDICATOR = '_';
    public static final String ESCAPED_INDICATOR = "__";
  
    public LabelWithAccessKey(String label) {
      text = label;
      setup(text);
    }
  
    public LabelWithAccessKey(UIComponent component) {
      Object value;
      if (RendererTypes.LABEL.equals(component.getRendererType())) {
        value = component.getAttributes().get(Attributes.VALUE);
      } else {
        value = component.getAttributes().get(Attributes.LABEL);
      }
      text = (value == null) ? null : String.valueOf(value);
      setup(text);
    }
  
    private void findIndicator(String label, int index, int escapedIndicatorCount) {
      index = label.indexOf(INDICATOR, index);
      if (index == -1) {
        text = label;
      } else if (index == label.length() - 1) {
        LOG.warn(INDICATOR + " in label is last char, this is not allowed"
            + "label='" + label + "'.");
        text = label.substring(0, label.length() - 1);
        pos = -1;
      } else if (label.charAt(index + 1) == INDICATOR) {
        escapedIndicatorCount++;
        findIndicator(label, index + 2, escapedIndicatorCount);
      } else {
        text = label.substring(0, index)
            + label.substring(index + 1);
        setAccessKey(text.charAt(index));
        pos = index - escapedIndicatorCount;
      }
    }
  
    public void setup(String label) {
      if (label != null) {
        findIndicator(label, 0, 0);
        text = StringUtils.replace(text, ESCAPED_INDICATOR, String.valueOf(INDICATOR));
      } else {
        if (accessKey != null && text != null) {
          pos = text.toLowerCase(Locale.ENGLISH).indexOf(
              Character.toLowerCase(accessKey.charValue()));
        }
      }
    }
  
    public void reset() {
      text = null;
      accessKey = null;
      pos = -1;
    }
  
    public String getText() {
      return text;
    }
  
    public Character getAccessKey() {
     return accessKey;
   }
 
   public int getPos() {
     return pos;
   }
 
   public void setText(String text) {
     this.text = text;
   }
 
   public void setAccessKey(Character accessKey) {
     if (!isPermitted(accessKey)) {
       LOG.warn("Ignoring illegal access key: " + accessKey);
     }
     this.accessKey = accessKey;
   }
 
   /**
    * Ensures, that no illegal character will be write out.
    * (If this is changed from only allowing letters, the renderers may change the escaping)
    */
   private boolean isPermitted(Character accessKey) {
     return accessKey >= 'a' && accessKey <= 'z' || accessKey >= 'A' && accessKey <= 'Z';
   }
 }