/*
    *  Copyright 2010, 2011 Christopher Pheby
    *
    *  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.jadira.usertype.spi.shared;
  
  import static org.jadira.usertype.spi.utils.reflection.ArrayUtils.copyOf;
  
  import java.io.Serializable;
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  
  import org.hibernate.HibernateException;
  import org.hibernate.engine.spi.SharedSessionContractImplementor;
  import org.hibernate.usertype.EnhancedUserType;
  import org.jadira.usertype.spi.utils.reflection.TypeHelper;
  
  public abstract class AbstractSingleColumnUserType<T, J, C extends ColumnMapper<T, J>> extends AbstractUserType implements EnhancedUserType, Serializable {
  
      private static final long serialVersionUID = -8258683760413283329L;
  
      private final C columnMapper;
      private final int[] sqlTypes;
  
      @SuppressWarnings("unchecked")
      public AbstractSingleColumnUserType() {
  
          try {
              columnMapper = (C) TypeHelper.getTypeArguments(AbstractSingleColumnUserType.class, getClass()).get(2).newInstance();
          } catch (InstantiationException ex) {
              throw new HibernateException("Could not initialise column mapper for " + getClass(), ex);
          } catch (IllegalAccessException ex) {
              throw new HibernateException("Could not access column mapper for " + getClass(), ex);
          }
          sqlTypes = new int[] { getColumnMapper().getSqlType() };
      }
  
      public final C getColumnMapper() {
          return columnMapper;
      }
  
      @Override
      public Class<T> returnedClass() {
          return getColumnMapper().returnedClass();
      }
  
      @Override
      public final int[] sqlTypes() {
          return copyOf(sqlTypes);
      }
  
      @Override
      public T nullSafeGet(ResultSet resultSet, String[] strings, SharedSessionContractImplementor session, Object object) throws SQLException {
          
      	beforeNullSafeOperation(session);
          	
      	final SharedSessionContractImplementor mySession = doWrapSession(session);
      	
      	try {
  	    	J converted = doNullSafeGet(resultSet, strings, mySession, object);
  	
  	        if (converted == null) {
  	            return null;
  	        }
  	
  	        return getColumnMapper().fromNonNullValue(converted);
  	        
      	} finally {
      		afterNullSafeOperation(session);
      	}
      }
  
      protected J doNullSafeGet(ResultSet resultSet, String[] strings, SharedSessionContractImplementor session, Object object) throws SQLException {
  		@SuppressWarnings("unchecked")
  		final J converted = (J) getColumnMapper().getHibernateType().nullSafeGet(resultSet, strings[0], session, object);
  		return converted;
  	}
  
  	@Override
      public void nullSafeSet(PreparedStatement preparedStatement, Object value, int index, SharedSessionContractImplementor session) throws SQLException {
  		
      	beforeNullSafeOperation(session);
      	    	
      	final SharedSessionContractImplementor mySession = doWrapSession(session);
      	
      	try {
  	        final J transformedValue;
 	        if (value == null) {
 	            transformedValue = null;
 	        } else {
 	            @SuppressWarnings("unchecked") T myValue = (T) value;
 	            transformedValue = getColumnMapper().toNonNullValue(myValue);
 	        }
 	
 	        doNullSafeSet(preparedStatement, transformedValue, index, mySession);
 	        
     	} finally {
     		afterNullSafeOperation(session);
     	}
     }
 
     protected void doNullSafeSet(PreparedStatement preparedStatement, J transformedValue, int index, SharedSessionContractImplementor session) throws SQLException {
     	getColumnMapper().getHibernateType().nullSafeSet(preparedStatement, transformedValue, index, session);
 	}
 
 	@Override
     public String objectToSQLString(Object object) {
         @SuppressWarnings("unchecked") final T myObject = (T) object;
         J convertedObject = myObject == null ? null : getColumnMapper().toNonNullValue(myObject);
         
         return getColumnMapper().getHibernateType().toString(convertedObject);
     }
 
     @Override
     public String toXMLString(Object object) {
         @SuppressWarnings("unchecked") final T myObject = (T) object;
         return getColumnMapper().toNonNullString(myObject);
     }
 
     @Override
     public T fromXMLString(String string) {
         return getColumnMapper().fromNonNullString(string);
     }
     
 	protected SharedSessionContractImplementor doWrapSession(SharedSessionContractImplementor session) {
 		return session;
 	}
 }