/*
    * Copyright 2009 The Kuali Foundation
    * 
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    * 
   * 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.kuali.ole.sys.batch.dataaccess.impl;
  
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.kuali.ole.sys.batch.dataaccess.PreparedStatementCachingDao;
  import org.kuali.rice.core.framework.persistence.jdbc.dao.PlatformAwareDaoBaseJdbc;
  
  public abstract class AbstractPreparedStatementCachingDaoJdbc extends PlatformAwareDaoBaseJdbc implements PreparedStatementCachingDao {
      protected static final String RETRIEVE_PREFIX = "retrieve-";
      protected static final String INSERT_PREFIX = "insert-";
      protected static final String UPDATE_PREFIX = "update-";
  
      protected abstract class JdbcWrapper<T> {
          protected abstract void populateStatement(PreparedStatement preparedStatement) throws SQLException;
  
          void update(Class<T> type, PreparedStatement preparedStatement) {
              try {
                  populateStatement(preparedStatement);
                  preparedStatement.executeUpdate();
              }
              catch (SQLException e) {
                  throw new RuntimeException("AbstractUpdatingPreparedStatementCachingDaoJdbc.UpdatingJdbcWrapper encountered exception during getObject method for type: " + type, e);
              }
          }
      }
  
      protected abstract class RetrievingJdbcWrapper<T> extends JdbcWrapper {
          protected abstract T extractResult(ResultSet resultSet) throws SQLException;
  
          public T get(Class<T> type) {
              T value = null;
              PreparedStatement statement = preparedStatementCache.get(RETRIEVE_PREFIX + type);
              try {
                  populateStatement(statement);
                  ResultSet resultSet = statement.executeQuery();
                  if (resultSet.next()) {
                      value = extractResult(resultSet);
                      if (resultSet.next()) {
                          throw new RuntimeException("More that one row returned when selecting by primary key in AbstractRetrievingPreparedStatementCachingDaoJdbc.RetrievingJdbcWrapper for: " + type);
                      }
                  }
                  resultSet.close();
              }
              catch (SQLException e) {
                  throw new RuntimeException("AbstractRetrievingPreparedStatementCachingDaoJdbc.RetrievingJdbcWrapper encountered exception during getObject method for type: " + type, e);
              }
              return (T) value;
          }
      }
      
      /**
       * Retrieve list jdbc objects 
       */
      protected abstract class RetrievingListJdbcWrapper<T> extends JdbcWrapper {
          protected abstract T extractResult(ResultSet resultSet) throws SQLException;
  
          public List<T> get(Class<T> type) {
              List<T> resultList = new ArrayList<T>();
              PreparedStatement statement = preparedStatementCache.get(RETRIEVE_PREFIX + type);
              try {
                  populateStatement(statement);
                  ResultSet resultSet = statement.executeQuery();
                  while (resultSet.next()) {
                      resultList.add(extractResult(resultSet));
                  }
                  resultSet.close();
              }
              catch (SQLException e) {
                  throw new RuntimeException("AbstractRetrievingPreparedStatementCachingDaoJdbc.RetrievingListJdbcWrapper encountered exception during getObject method for type: " + type, e);
              }
              return resultList;
          }
      }
  
      protected abstract class InsertingJdbcWrapper<T> extends JdbcWrapper {
          public void execute(Class<T> type) {
              update(type, preparedStatementCache.get(INSERT_PREFIX + type));
          }
     }
 
     protected abstract class UpdatingJdbcWrapper<T> extends JdbcWrapper {
         public void execute(Class<T> type) {
             update(type, preparedStatementCache.get(UPDATE_PREFIX + type));
         }
     }
 
     protected Map<String, PreparedStatement> preparedStatementCache;
 
     protected abstract Map<String, String> getSql();
 
     public void initialize() {
         preparedStatementCache = new HashMap<String, PreparedStatement>();
         try {
             for (String statementKey : getSql().keySet()) {
                 preparedStatementCache.put(statementKey, getConnection().prepareStatement(getSql().get(statementKey)));
             }
         }
         catch (SQLException e) {
             throw new RuntimeException("Caught exception preparing statements in CachingDaoJdbc initialize method", e);
         }
     }
 
     public void destroy() {
         try {
             for (PreparedStatement preparedStatement : preparedStatementCache.values()) {
                 preparedStatement.close();
             }
             preparedStatementCache = null;
         }
         catch (SQLException e) {
             throw new RuntimeException("Caught exception closing statements in CachingDaoJdbc destroy method", e);
         }
     }
 
 }