/*
    *
    * The DbUnit Database Testing Framework
    * Copyright (C)2002-2004, DbUnit.org
    *
    * This library is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public
    * License as published by the Free Software Foundation; either
    * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   */
  
  package org.dbunit.operation;
  
  import java.util.ArrayList;
  import java.util.BitSet;
  import java.util.List;
  
  import org.dbunit.database.IDatabaseConnection;
  import org.dbunit.dataset.Column;
  import org.dbunit.dataset.Columns;
  import org.dbunit.dataset.DataSetException;
  import org.dbunit.dataset.ITableMetaData;
  import org.dbunit.dataset.NoPrimaryKeyException;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Updates the database from the dataset contents. This operation assumes that
   * table data already exists in the database and fails if this is not the case.
  
   * @author Manuel Laflamme
   * @version $Revision$
   * @since Feb 19, 2002
   */
  public class UpdateOperation extends AbstractBatchOperation
  {
  
      /**
       * Logger for this class
       */
      private static final Logger logger = LoggerFactory.getLogger(UpdateOperation.class);
  
      UpdateOperation()
      {
      }
  
      ////////////////////////////////////////////////////////////////////////////
      // AbstractBatchOperation class
  
      public OperationData getOperationData(ITableMetaData metaData, BitSet ignoreMapping, IDatabaseConnection connection) throws DataSetException
      {
          if(logger.isDebugEnabled())
              logger.debug("getOperationData(metaData={}, ignoreMapping={}, connection={}) - start", 
                  new Object[]{metaData, ignoreMapping, connection});
  
          Column[] columns = metaData.getColumns();
          Column[] primaryKeys = metaData.getPrimaryKeys();
  
          // cannot construct where clause if no primary key
          if (primaryKeys.length == 0)
          {
              throw new NoPrimaryKeyException(metaData.getTableName());
          }
  
          // update table
          final StringBuilder sqlBuffer = new StringBuilder(128);
          sqlBuffer.append("update ");
          sqlBuffer.append(getQualifiedName(connection.getSchema(),
                  metaData.getTableName(), connection));
  
          // set
          boolean firstSet = true;
          List columnList = new ArrayList(columns.length);
          sqlBuffer.append(" set ");
          for (int i = 0; i < columns.length; i++)
          {
              Column column = columns[i];
  
              // set if not primary key
              if (Columns.getColumn(column.getColumnName(), primaryKeys) == null)
              {
                  if (!firstSet)
                  {
                      sqlBuffer.append(", ");
                  }
                  firstSet = false;
  
                  // escape column name
                  String columnName = getQualifiedName(null,
                         column.getColumnName(), connection);
                 sqlBuffer.append(columnName);
                 sqlBuffer.append(" = ?");
                 columnList.add(column);
             }
         }
 
         // where
         sqlBuffer.append(" where ");
         for (int i = 0; i < primaryKeys.length; i++)
         {
             Column column = primaryKeys[i];
 
             if (i > 0)
             {
                 sqlBuffer.append(" and ");
             }
 
             // escape column name
             String columnName = getQualifiedName(null,
                     column.getColumnName(), connection);
             sqlBuffer.append(columnName);
             sqlBuffer.append(" = ?");
             columnList.add(column);
         }
 
         return new OperationData(sqlBuffer.toString(),
                 (Column[])columnList.toArray(new Column[0]));
     }
 
 }