/*
   
    * Copyright 2005 Philipp Erlacher
    *
    * Licensed 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.exolab.castor.xml.parsing.primitive.objects;
  
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  /**
   * This class is used as a factory to get an instance of a class with a given
   * value.
   */
  public class PrimitiveObjectFactory {
  
      private Map<Class<?>, Class<? extends PrimitiveObject>> typeHandlers = new HashMap<Class<?>, Class<? extends PrimitiveObject>>();
  
      private final Log logger = LogFactory.getLog(this.getClass());
      
      private static PrimitiveObjectFactory primitiveObjectFactory;
      
      public static synchronized PrimitiveObjectFactory getInstance() {
         if (primitiveObjectFactory == null) {
            primitiveObjectFactory = new PrimitiveObjectFactory();
         }
         return primitiveObjectFactory;
      }
      
      private PrimitiveObjectFactory() {
          typeHandlers.put(String.class, PrimitiveString.class);
  
          typeHandlers.put(Enum.class, PrimitiveEnum.class);
  
          typeHandlers.put(Integer.TYPE, PrimitiveInteger.class);
          typeHandlers.put(Integer.class, PrimitiveInteger.class);
  
          typeHandlers.put(Boolean.TYPE, PrimitiveBoolean.class);
          typeHandlers.put(Boolean.class, PrimitiveBoolean.class);
  
          typeHandlers.put(Double.TYPE, PrimitiveDouble.class);
          typeHandlers.put(Double.class, PrimitiveDouble.class);
  
          typeHandlers.put(Long.TYPE, PrimitiveLong.class);
          typeHandlers.put(Long.class, PrimitiveLong.class);
  
          typeHandlers.put(Character.TYPE, PrimitiveChar.class);
          typeHandlers.put(Character.class, PrimitiveChar.class);
  
          typeHandlers.put(Short.TYPE, PrimitiveShort.class);
          typeHandlers.put(Short.class, PrimitiveShort.class);
  
          typeHandlers.put(Float.TYPE, PrimitiveFloat.class);
          typeHandlers.put(Float.class, PrimitiveFloat.class);
  
          typeHandlers.put(Byte.TYPE, PrimitiveByte.class);
          typeHandlers.put(Byte.class, PrimitiveByte.class);
  
          typeHandlers.put(BigInteger.class, PrimitiveBigInteger.class);
  
          typeHandlers.put(BigDecimal.class, PrimitiveBigDecimal.class);
      }
      
      /**
       * returns an instantiated Object
       * 
       * @return
       */
      public Object getObject(Class<?> type, String value) {
  
          PrimitiveObject handler = lookupHandler(type);
  
          if (handler == null) {
              handler = getDefaultHandler();
          }
  
          if (type != String.class) {
              value = trimNumericValues(value);
          }
  
          return handler.getObject(type, value);
      }
  
     /**
      * Looks up a handler from the map for the given type. <br>
      * Returns null if there isn't any suitable handler.
      * 
      * @param type
      * @return a handler to instantiate the given class
      */
     private PrimitiveObject lookupHandler(Class<?> type) {
        
        PrimitiveObject instance = null;
 
         if (type == null) {
             return null;
         }
 
         Class<? extends PrimitiveObject> result = typeHandlers.get(type);
 
         if (result == null) {
             result = typeHandlers.get(type.getSuperclass());
         }
 
         if (result != null) {
            try {
               instance = result.newInstance();
            } catch (InstantiationException e) {
               this.logger.error("Problem instantiating an instance of " + result.getName());
               e.printStackTrace();
            } catch (IllegalAccessException e) {
               this.logger.error("Problem accessing default constructor of " + result.getName());
               e.printStackTrace();
            }
         }
         
         return instance;
     }
 
     /**
      * Trim any numeric values
      * 
      * @param value
      *            Value to be trimmed, can be null
      * @return trimmed value or null
      */
     private String trimNumericValues(String value) {
         if (value == null) {
             return null;
         }
 
         return value.trim();
     }
 
     /**
      * returns a default Handler for Object instantiation
      * 
      * @return primitiveObject Primitive
      */
     private PrimitiveObject getDefaultHandler() {
         return new PrimitiveObject();
     }
 
 }