/*
    * 
    * 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();
   }
 
 }