/*
   *
   * 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.dataset.csv;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.net.URL;
  import java.util.Iterator;
  import java.util.List;
  
  import org.dbunit.dataset.Column;
  import org.dbunit.dataset.DataSetException;
  import org.dbunit.dataset.DefaultTableMetaData;
  import org.dbunit.dataset.ITableMetaData;
  import org.dbunit.dataset.datatype.DataType;
  import org.dbunit.dataset.stream.DefaultConsumer;
  import org.dbunit.dataset.stream.IDataSetConsumer;
  import org.dbunit.dataset.stream.IDataSetProducer;
  
  /**
   * A {@link IDataSetProducer Data Set Producer} that produces datasets from 
   * CVS files found at a base URL.
   * 
   * Based HEAVILY on {@link org.dbunit.dataset.csv.CsvProducer}.
   *  
   * @author Dion Gillard
   * @author Federico Spinazzi
   * @author Last changed by: $Author: gommma $
   * @version $Revision: 766 $ $Date: 2008-08-01 13:05:20 +0200 (ven, 01 ago 2008) $
   * @since Sep 12, 2004 (pre 2.3)
   */
  public class CsvURLProducer implements IDataSetProducer {
  
      /**
       * Logger for this class
       */
      private static final Logger logger = LoggerFactory.getLogger(CsvURLProducer.class);
  
  	/** the default consumer - does nothing */
      private static final IDataSetConsumer EMPTY_CONSUMER = new DefaultConsumer();
  
      /**
       * the consumer of the produced datasets, by default a 
       * {@link DefaultConsumer}
       */
      private IDataSetConsumer _consumer = EMPTY_CONSUMER;
      
      /** the base url to retrieve data from */
      private URL base;
  
      /** the offset from the base url where the list of tables can be found */
      private String tableList;
      
      /**
       * Create a CSV Data Set Producer which uses the base URL to retrieve 
       * a list of tables and the data.
       * @param base the URL where the tableList and data can be found. 
       * @param tableList the relative location of the list of tables.
       */
      public CsvURLProducer(URL base, String tableList)
      {
      	this.base = base;
      	this.tableList = tableList;
      }
      
      /*
  	 * @see IDataSetProducer#setConsumer(org.dbunit.dataset.stream.IDataSetConsumer)
  	 */
  	public void setConsumer(IDataSetConsumer consumer) throws DataSetException {
          logger.debug("setConsumer(consumer) - start");
  
  		_consumer = consumer;
  	}
  
  	/*
  	 * @see IDataSetProducer#produce()
  	 */
  	public void produce() throws DataSetException {
          logger.debug("produce() - start");
 
         _consumer.startDataSet();
         try {
         	List tableSpecs = CsvProducer.getTables(base, tableList);
         	for (Iterator tableIter = tableSpecs.iterator(); tableIter.hasNext();) {
 				String table = (String) tableIter.next();
 	            try {
 	                produceFromURL(new URL(base, table + ".csv"));
 	            } catch (CsvParserException e) {
 	                throw new DataSetException("error producing dataset for table '" + table + "'", e);
 	            }
 
 			}
             _consumer.endDataSet();
         } catch (IOException e) {
         	throw new DataSetException("error getting list of tables", e);
         }
 	}
 
 	/**
 	 * Produce a dataset from a URL. 
 	 * The URL is assumed to contain data in CSV format.
 	 * @param url a url containing CSV data.
 	 */
 	private void produceFromURL(URL url) throws DataSetException {
         logger.debug("produceFromURL(url=" + url + ") - start");
 
         try {
             CsvParser parser = new CsvParserImpl();
             List readData = parser.parse(url);
             List readColumns = (List) readData.get(0);
             Column[] columns = new Column[readColumns.size()];
 
             for (int i = 0; i < readColumns.size(); i++) {
                 columns[i] = new Column((String) readColumns.get(i), DataType.UNKNOWN);
             }
 
             String tableName = url.getFile();
             tableName = tableName.substring(tableName.lastIndexOf("/")+1, tableName.indexOf(".csv"));
             ITableMetaData metaData = new DefaultTableMetaData(tableName, columns);
             _consumer.startTable(metaData);
             for (int i = 1 ; i < readData.size(); i++) {
                 List rowList = (List)readData.get(i);
                 Object[] row = rowList.toArray();
                 for(int col = 0; col < row.length; col++) {
                 	if (CsvDataSetWriter.NULL.equals(row[col])) {
                 		row[col] = null;
                 	}
                 }
                 _consumer.row(row);
             }
             _consumer.endTable();
         } catch (CsvParserException e) {
         	throw new DataSetException("error parsing CSV for URL: '" + url + "'");
 		} catch (IOException e) {
         	throw new DataSetException("I/O error parsing CSV for URL: '" + url + "'");
 		}
 	}
 }