/*
    * 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 javax.faces.convert;
  
  import javax.faces.component.UIComponent;
  import javax.faces.context.FacesContext;
  
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFConverter;
  
  import java.text.DecimalFormatSymbols;
  import java.util.Locale;
  
  /**
   * see Javadoc of <a href="http://java.sun.com/javaee/javaserverfaces/1.2/docs/api/index.html">JSF Specification</a>
   */
  @JSFConverter
  public class DoubleConverter
          implements Converter
  {
      // API FIELDS
      public static final String CONVERTER_ID = "javax.faces.Double";
      public static final String STRING_ID = "javax.faces.converter.STRING";
      public static final String DOUBLE_ID = "javax.faces.converter.DoubleConverter.DOUBLE";
  
      // CONSTRUCTORS
      public DoubleConverter()
      {
      }
  
      // METHODS
      public Object getAsObject(FacesContext facesContext, UIComponent uiComponent, String value)
      {
          if (facesContext == null)
          {
              throw new NullPointerException("facesContext");
          }
          if (uiComponent == null)
          {
              throw new NullPointerException("uiComponent");
          }
  
          if (value != null)
          {
              value = value.trim();
              if (value.length() > 0)
              {
                  try
                  {
                      value = fixLocale(facesContext, value);
                      return this.stringToDouble(value);
                  }
                  catch (NumberFormatException e)
                  {
                      throw new ConverterException(_MessageUtils.getErrorMessage(facesContext,
                                     DOUBLE_ID,
                                     new Object[]{value,"4214",_MessageUtils.getLabel(facesContext, uiComponent)}), e);
                  }
  
              }
          }
          return null;
      }
  
      /**
       * Since Double.valueOf is not Locale aware, and NumberFormatter
       * cannot parse E values correctly, we need to make a US Locale
       * string from our input value.
       * E.g. '34,383e3' will be translated to '34.383e3' if Locale.DE
       * is set in the {@link javax.faces.component.UIViewRoot#getLocale()}
       *
       * @param facesContext
       * @param value
       * @return the 'fixed' value String
       */
      private String fixLocale(FacesContext facesContext, String value)
      {
          Locale loc = facesContext.getViewRoot().getLocale();
          if (loc == null || loc == Locale.US)
          {
              // nothing to fix if we are already using the US Locale
              return value;
          }
  
         // TODO: DecimalFormatSymbols.getInstance exists only on JDK 1.6
         // change it on JSF 2.1
         //DecimalFormatSymbols dfs = DecimalFormatSymbols.getInstance(loc);
         DecimalFormatSymbols dfs = new DecimalFormatSymbols(loc);
 
         char decSep   = dfs.getDecimalSeparator();
 
 
         // replace decimal separators which are different to '.'
         if (decSep != '.' && value.lastIndexOf(decSep) >= 0)
         {
             StringBuffer sbVal = new StringBuffer();
 
             // remove all groupSeperators and change the decimalSeperator
             for (int i = 0; i < value.length(); i++)
             {
                 if (value.charAt(i) == decSep)
                 {
                     sbVal.append('.'); // we append the Locale.US decimal separator
                     continue;
                 }
 
                 // just append all other characters as usual
                 sbVal.append(value.charAt(i));
             }
 
             value = sbVal.toString();
         }
 
         // we need the formatter with the correct Locale of the user
         return value;
     }
 
     private Double stringToDouble(String value)
     {
         // this is a special hack for a jvm vulnerability with
         // converting some special double values.
         // e.g. "2.225073858507201200000e-308"
         // see MYFACES-3024 for further information
         // TODO we can remove this hack, once this got fixed in the jvm!
         if (value.length() >= 23)
         {
             StringBuffer normalized = new StringBuffer();
             for (int i=0; i< value.length(); i++)
             {
                 char c = value.charAt(i);
                 if ( c != '.')
                 {
                     normalized.append(c);
                 }
             }
 
             String normalizedString = normalized.toString();
             if (normalizedString.contains("22250738585072012") && normalizedString.contains("e-"))
             {
                 // oops, baaad value!
                throw new NumberFormatException("Not Allowed! This value could possibly kill the VM!");
             }
         }
 
 
         return Double.valueOf(value);
     }
 
     public String getAsString(FacesContext facesContext, UIComponent uiComponent, Object value)
     {
         if (facesContext == null)
         {
             throw new NullPointerException("facesContext");
         }
         if (uiComponent == null)
         {
             throw new NullPointerException("uiComponent");
         }
 
         if (value == null)
         {
             return "";
         }
         if (value instanceof String)
         {
             return (String)value;
         }
         try
         {
             return Double.toString(((Number)value).doubleValue());
         }
         catch (Exception e)
         {
             throw new ConverterException(_MessageUtils.getErrorMessage(facesContext, STRING_ID,
                     new Object[]{value,_MessageUtils.getLabel(facesContext, uiComponent)}),e);
         }
     }
 }