/*
    *
    * 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.yaml;
  
  import org.dbunit.database.AmbiguousTableNameException;
  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;
  import org.yaml.snakeyaml.LoaderOptions;
  import org.yaml.snakeyaml.Yaml;
  import org.yaml.snakeyaml.constructor.DuplicateKeyException;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.ArrayList;
  import java.util.LinkedHashMap;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  /**
   * @author Björn Beskow
   * @version $Revision$ $Date$
   */
  
  public class YamlProducer implements IDataSetProducer
  {
  
      private static final IDataSetConsumer EMPTY_CONSUMER = new DefaultConsumer();
  
      /**
       * The consumer which is responsible for creating the datasets and tables
       */
      private IDataSetConsumer _consumer = EMPTY_CONSUMER;
  
      private InputStream _inputStream;
  
      private Yaml _yaml;
  
      public YamlProducer(File file) throws IOException
      {
          this(new FileInputStream(file));
      }
  
      public YamlProducer(InputStream inputStream)
      {
          this._inputStream = inputStream;
          LoaderOptions options = new LoaderOptions();
          options.setAllowDuplicateKeys(false);
          _yaml = new Yaml(options);
      }
  
      ////////////////////////////////////////////////////////////////////////////
      // IDataSetProducer interface
  
      public void setConsumer(IDataSetConsumer consumer)
      {
          _consumer = consumer;
      }
  
      public void produce() throws DataSetException
      {
          _consumer.startDataSet();
          LinkedHashMap<String, Object> dataset;
          // get the base object tree from the stream
          try
          {
              dataset = (LinkedHashMap<String, Object>) _yaml.load(_inputStream);
          }
          catch (DuplicateKeyException e)
          {
              String problem = e.getProblem();
             String duplicateTable = problem.replace("found duplicate key ", "");
             throw new AmbiguousTableNameException(duplicateTable, e);
         }
         // iterate over the tables in the object tree
         for (String tableName : dataset.keySet())
         {
             // get the rows for the table
             List<Map<String, Object>> rows = (List<Map<String, Object>>) dataset.get(tableName);
             ITableMetaData meta = getMetaData(tableName, rows);
             _consumer.startTable(meta);
             if (rows != null)
             {
                 for (Map<String, Object> row : rows)
                 {
                     _consumer.row(getRow(meta, row));
                 }
             }
             _consumer.endTable();
         }
     }
 
 
     private ITableMetaData getMetaData(String tableName, List<Map<String, Object>> rows)
     {
         Set<String> columns = new LinkedHashSet<String>();
         if (rows != null)
         {
             // iterate through the dataset and add the column names to a set
             for (Map<String, Object> row : rows)
             {
                 for (Map.Entry<String, Object> column : row.entrySet())
                 {
                     columns.add(column.getKey());
                 }
             }
             List<Column> list = new ArrayList<Column>(columns.size());
             // create a list of DBUnit columns based on the column name set
             for (String s : columns)
             {
                 list.add(new Column(s, DataType.UNKNOWN));
             }
             return new DefaultTableMetaData(tableName, list.toArray(new Column[list.size()]));
         } else
         {
             return new DefaultTableMetaData(tableName, new Column[0]);
         }
     }
 
     private Object[] getRow(ITableMetaData meta, Map<String, Object> row) throws DataSetException
     {
         Object[] result = new Object[meta.getColumns().length];
         for (int i = 0; i < meta.getColumns().length; i++)
         {
             result[i] = row.get(meta.getColumns()[i].getColumnName());
         }
         return result;
     }
 
 }