/*
 * JasperReports - Free Java Reporting Library.
 * Copyright (C) 2001 - 2016 TIBCO Software Inc. All rights reserved.
 * http://www.jaspersoft.com
 *
 * Unless you have purchased a commercial license agreement from Jaspersoft,
 * the following license terms apply:
 *
 * This program is part of JasperReports.
 *
 * JasperReports 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 3 of the License, or
 * (at your option) any later version.
 *
 * JasperReports 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 JasperReports. If not, see <http://www.gnu.org/licenses/>.
 */
package net.sf.jasperreports.engine.data;

import java.util.Collection;
import java.util.Iterator;
import java.util.Map;

import net.sf.jasperreports.engine.JRField;
import net.sf.jasperreports.engine.JRRewindableDataSource;

/**
 * @author Teodor Danciu (teodord@users.sourceforge.net)
 */
public class JRMapCollectionDataSource implements JRRewindableDataSource
{

	/**
	 *
	 */
	private Collection<Map<String,?>> records;
	private Iterator<Map<String,?>> iterator;
	private Map<String,?> currentRecord;
	

	/**
	 *
	 */
	public JRMapCollectionDataSource(Collection<Map<String,?>> col)
	{
		records = col;

		if (records != null)
		{
			iterator = records.iterator();
		}
	}
	

	@Override
	public boolean next()
	{
		boolean hasNext = false;
		
		if (iterator != null)
		{
			hasNext = iterator.hasNext();
			
			if (hasNext)
			{
				currentRecord = iterator.next();
			}
		}
		
		return hasNext;
	}
	
	
	@Override
	public Object getFieldValue(JRField field)
	{
		Object value = null;
		
		if (currentRecord != null)
		{
			value = currentRecord.get(field.getName());
		}

		return value;
	}

	
	@Override
	public void moveFirst()
	{
		if (records != null)
		{
			iterator = records.iterator();
		}
	}

	/**
	 * Returns the underlying map collection used by this data source.
	 * 
	 * @return the underlying map collection
	 */
	public Collection<Map<String,?>> getData()
	{
		return records;
	}

	/**
	 * Returns the total number of records/maps that this data source
	 * contains.
	 * 
	 * @return the total number of records of this data source
	 */
	public int getRecordCount()
	{
		return records == null ? 0 : records.size();
	}
	
	/**
	 * Clones this data source by creating a new instance that reuses the same
	 * underlying map collection.
	 * 
	 * @return a clone of this data source
	 */
	public JRMapCollectionDataSource cloneDataSource()
	{
		return new JRMapCollectionDataSource(records);
	}


}
