/*
    * 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.commons.util;
  
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import java.text.DateFormat;
  import java.text.ParseException;
  import java.text.SimpleDateFormat;
  
  import java.util.Date;
  import java.util.Locale;
  
  import javax.faces.application.Application;
  import javax.faces.context.FacesContext;
  import javax.faces.el.ValueBinding;
  
  
  
  /**
   * Utility class for Tag classes
   *
   * @version $Name:  $ ($Revision: adfrt/faces/adf-faces-impl/src/main/java/oracle/adfinternal/view/faces/taglib/util/TagUtils.java#1 $) $Date: 11-nov-2005.14:59:38 $
   *
   */
  public final class TagUtils
  {
    private static final Log LOG = LogFactory.getLog(TagUtils.class);
  
    private TagUtils()
    {
    }
  
    public static ValueBinding getValueBinding(String valueBindingExpression)
    {
      FacesContext context = FacesContext.getCurrentInstance();
      Application app = context.getApplication();
      return app.createValueBinding(valueBindingExpression);
    }
  
    public static void assertNotNull(Object object)
    {
      if (null == object)
        throw new NullPointerException();
    }
  
    // Helpful with tag auto generation. Though this isn't really required.
    /**
     * Return the same string. It is there for convenience and makes life easy
     * while auto generating tags.
     * @param value
     * @return
     */
    public static String getString(
      String      value)
    {
      return value;
    }
  
    /**
     * String --> boolean
     * @param value
     * @return
     */
    public static boolean getBoolean(
      String      value)
    {
      return Boolean.valueOf(value).booleanValue();
    }
  
    /**
     * String --> int
     * @param value
     * @return
     */
    public static int getInteger(
      String      value)
    {
      return Integer.valueOf(value).intValue();
  
    }
 
   /**
    * String --> long
    * @param value
    * @return
    */
   public static long getLong(
     String      value)
   {
     return Long.valueOf(value).longValue();
 
   }
 
   /**
    * String --> long
    * @param value
    * @return
    */
   public static double getDouble(
     String      value)
   {
     return Double.valueOf(value).doubleValue();
 
   }
 
   /**
    * String --> long
    * @param value
    * @return
    */
   public static float getFloat(
     String      value)
   {
     return Float.valueOf(value).floatValue();
 
   }
 
   /**
    * These are normally NMTOKEN type in attributes
    * String --> String[]
    * @param value
    * @return
 
   public static String[] getStringArray(
     String      value) throws ParseException
   {
     return getTokensArray(value);
   }
   */
 
   /**
    *  ISO Date String --> Date
    * @param value
    * @return
    */
   public static Date getDate(
     String      value)
   {
      return parseISODate(value);
   }
 
   /**
    * String --> Locale
    * @param value
    * @return
    */
   public static Locale getLocale(
     String      value)
   {
     return getLocaleInternal(value);
   }
 
   /**
    * String --> TimeZone
    * @param value
    * @return
 
   public static TimeZone getTimeZone(
     String value)
   {
     return DateUtils.getSupportedTimeZone(value);
   }
    */
 
   public static boolean isValueReference(String expression)
   {
     if (null != expression)
     {
       int start = expression.indexOf("#{");
       if ((start >= 0) && (expression.indexOf('}', start + 1) >= 0))
         return true;
     }
 
     return false;
   }
 
 
 
   /**
    * Takes a string that is a composite of tokens, extracts tokens delimited
    *  by any whitespace character sequence combination and returns a String
    *  array of such tokens.
    * @throws ParseException In case of invalid character in the specified
    *           composite. The only invalid character is a comma (',').
 
   private static String[] _getTokensArray(String tokenComposite)
     throws ParseException
   {
     if (tokenComposite == null || "".equals(tokenComposite))
       return null;
 
     return XMLUtils.parseNameTokens(tokenComposite);
   }
   */
 
   /**
    * Parse a string into a java.util.Date object.  The
    * string must be in ISO 9601 format (yyyy-MM-dd).
    * @todo why not throw the exception in a different format?
    *       why do we kill it here and return null?
    */
   static private final Date parseISODate(String stringValue)
   {
     try
     {
       return getDateFormat().parse(stringValue);
     }
     catch (ParseException pe)
     {
       if (LOG.isInfoEnabled()) {
         LOG.info("CANNOT_PARSE_VALUE_INTO_DATE_WITH_YYYY_MM_DD_PATTERN "+ stringValue, pe);
       }
       return null;
     }
   }
 
   private static Locale getLocaleInternal(String locale)
   {
     String localeStr = locale.replace('-','_');
     String[] tokens = localeStr.split("[_]", 3);
     Locale locl = null;
 
     if ( tokens.length == 1)
     {
       locl = new Locale(tokens[0]); //lang
     }
     else if (tokens.length == 2)
     {
       locl = new Locale(tokens[0], tokens[1]); // lang + country
     }
     else if (tokens.length == 3 )
     {
       locl = new Locale(tokens[0], tokens[1], tokens[2]); // lang + country + variant
     }
     else
     {
       if(LOG.isWarnEnabled())
         LOG.warn("tokens length should not be greater than 3.");
     }
     return locl;
   }
 
   // We rely strictly on ISO 8601 formats
   private static DateFormat getDateFormat()
   {
     return new SimpleDateFormat("yyyy-MM-dd");
   }
 }