/*
    * Copyright 2007 Kasper B. Graversen
    * 
    * 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.supercsv.io;
  
  import java.io.IOException;
  import java.io.Reader;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.supercsv.cellprocessor.ift.CellProcessor;
  import org.supercsv.prefs.CsvPreference;
  import org.supercsv.util.Util;
  
  /**
   * CsvMapReader reads each CSV row into a Map with the column name as the map key, and the column value as the map
   * value.
   * 
   * @author Kasper B. Graversen
   * @author James Bassett
   */
  public class CsvMapReader extends AbstractCsvReader implements ICsvMapReader {
  	
  	/**
  	 * Constructs a new <tt>CsvMapReader</tt> with the supplied Reader and CSV preferences. Note that the
  	 * <tt>reader</tt> will be wrapped in a <tt>BufferedReader</tt> before accessed.
  	 * 
  	 * @param reader
  	 *            the reader
  	 * @param preferences
  	 *            the CSV preferences
  	 * @throws NullPointerException
  	 *             if reader or preferences are null
  	 */
  	public CsvMapReader(final Reader reader, final CsvPreference preferences) {
  		super(reader, preferences);
  	}
  	
  	/**
  	 * Constructs a new <tt>CsvMapReader</tt> with the supplied (custom) Tokenizer and CSV preferences. The tokenizer
  	 * should be set up with the Reader (CSV input) and CsvPreference beforehand.
  	 * 
  	 * @param tokenizer
  	 *            the tokenizer
  	 * @param preferences
  	 *            the CSV preferences
  	 * @throws NullPointerException
  	 *             if tokenizer or preferences are null
  	 */
  	public CsvMapReader(final ITokenizer tokenizer, final CsvPreference preferences) {
  		super(tokenizer, preferences);
  	}
  	
  	/**
  	 * {@inheritDoc}
  	 */
  	public Map<String, String> read(final String... nameMapping) throws IOException {
  		
  		if( nameMapping == null ) {
  			throw new NullPointerException("nameMapping should not be null");
  		}
  		
  		if( readRow() ) {
  			final Map<String, String> destination = new HashMap<String, String>();
  			Util.filterListToMap(destination, nameMapping, getColumns());
  			return destination;
  		}
  		
  		return null; // EOF
  	}
  	
  	/**
  	 * {@inheritDoc}
  	 */
  	public Map<String, Object> read(final String[] nameMapping, final CellProcessor[] processors) throws IOException {
  		
  		if( nameMapping == null ) {
  			throw new NullPointerException("nameMapping should not be null");
  		} else if( processors == null ) {
  			throw new NullPointerException("processors should not be null");
  		}
  		
  		if( readRow() ) {
  			// process the columns
  			final List<Object> processedColumns = executeProcessors(new ArrayList<Object>(getColumns().size()),
 				processors);
 			
 			// convert the List to a Map
 			final Map<String, Object> destination = new HashMap<String, Object>(processedColumns.size());
 			Util.filterListToMap((Map<String, Object>) destination, nameMapping, (List<Object>) processedColumns);
 			return destination;
 		}
 		
 		return null; // EOF
 	}
 }