package org.apache.onami.converters.i18n;
   
   /*
    * 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.
   */
  
  import java.text.DateFormat;
  import java.text.ParsePosition;
  import java.text.SimpleDateFormat;
  import java.util.ArrayList;
  import java.util.Calendar;
  import java.util.Date;
  import java.util.List;
  import java.util.Locale;
  import java.util.TimeZone;
  
  import org.apache.onami.converters.core.AbstractConverter;
  import org.kohsuke.MetaInfServices;
  
  import com.google.inject.Module;
  import com.google.inject.TypeLiteral;
  
  /**
   * Converter implementation for {@code java.util.Calendar} and {@code java.util.Date}.
   */
  @MetaInfServices( Module.class )
  public final class DateConverter
      extends AbstractConverter<Date>
  {
  
      private final List<String> patterns = new ArrayList<String>();
  
      private Locale locale;
  
      private TimeZone timeZone;
  
      public DateConverter()
      {
          // ISO date formats
          addPattern( "yyyy" );
          addPattern( "yyyy-MM" );
          addPattern( "yyyy-MM-dd" );
          addPattern( "yyyy-MM-dd'T'hh:mmZ" );
          addPattern( "yyyy-MM-dd'T'hh:mm:ssZ" );
          addPattern( "yyyy-MM-dd'T'hh:mm:ss.sZ" );
      }
  
      public void setLocale( Locale locale )
      {
          this.locale = locale;
      }
  
      public void setTimeZone( TimeZone timeZone )
      {
          this.timeZone = timeZone;
      }
  
      public void addPattern( String pattern )
      {
          this.patterns.add( pattern );
      }
  
      /**
       * {@inheritDoc}
       */
      public Object convert( String value, TypeLiteral<?> toType )
      {
          Exception firstEx = null;
          for ( String pattern : patterns )
          {
              try
              {
                  DateFormat format;
                  if ( locale != null )
                  {
                      format = new SimpleDateFormat( pattern, locale );
                  }
                  else
                  {
                      format = new SimpleDateFormat( pattern );
                  }
                  if ( timeZone != null )
                  {
                      format.setTimeZone( timeZone );
                 }
                 format.setLenient( false );
                 Date date = parse( value, format );
 
                 if ( Calendar.class == toType.getType() )
                 {
                     Calendar calendar = null;
                     if ( locale == null && timeZone == null )
                     {
                         calendar = Calendar.getInstance();
                     }
                     else if ( locale == null )
                     {
                         calendar = Calendar.getInstance( timeZone );
                     }
                     else if ( timeZone == null )
                     {
                         calendar = Calendar.getInstance( locale );
                     }
                     else
                     {
                         calendar = Calendar.getInstance( timeZone, locale );
                     }
                     calendar.setTime( date );
                     calendar.setLenient( false );
                     return calendar;
                 }
 
                 return date;
             }
             catch ( RuntimeException ex )
             {
                 if ( firstEx == null )
                 {
                     firstEx = ex;
                 }
             }
         }
 
         throw new IllegalArgumentException( "Error converting '"
                                             + value
                                             + "' using  patterns "
                                             + patterns,
                                             firstEx );
     }
 
     private Date parse( String value, DateFormat format )
     {
         ParsePosition pos = new ParsePosition( 0 );
         Date parsedDate = format.parse( value, pos ); // ignore the result (use the Calendar)
 
         if ( pos.getErrorIndex() >= 0 || pos.getIndex() != value.length() || parsedDate == null )
         {
             String msg = "Error converting '" + value + "'";
             if ( format instanceof SimpleDateFormat )
             {
                 msg += " using pattern '" + ( (SimpleDateFormat) format ).toPattern() + "'";
             }
             throw new IllegalArgumentException( msg );
         }
 
         return parsedDate;
     }
 
 }