/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2011 by Rapid-I and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapid-i.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.operator.nio.model;

import java.util.LinkedList;
import java.util.List;

import javax.swing.table.AbstractTableModel;

import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.nio.ImportWizardUtils;
import com.rapidminer.tools.ProgressListener;

/**
 * Data container and table model for previews. Reads a few lines from a {@link DataResultSet} to display them.
 * This should be only used in case where no more efficient implementation for
 * the TableModel is available.
 * 
 * @author Simon Fischer
 * 
 */
public class DefaultPreview extends AbstractTableModel {

    private static final long serialVersionUID = 1L;

    private String[][] data;

    private String[] columnNames;

    private int previewSize = ImportWizardUtils.getPreviewLength();

    public DefaultPreview(DataResultSet resultSet, ProgressListener l) throws OperatorException, ParseException {
        read(resultSet, l);
    }

    public void read(DataResultSet resultSet, ProgressListener listener) throws OperatorException, ParseException {
        if (listener != null) {
            listener.setTotal(previewSize);
        }
        List<String[]> dataList = new LinkedList<String[]>();
        resultSet.reset(listener);
        while (resultSet.hasNext() && dataList.size() < previewSize) {
            resultSet.next(listener);
            String[] row = new String[resultSet.getNumberOfColumns()];
            for (int i = 0; i < row.length; i++) {
                row[i] = resultSet.getString(i);
            }
            dataList.add(row);
            if (listener != null) {
                listener.setCompleted(dataList.size());
            }
        }
        // copy to array since will be accessed by index
        this.data = dataList.toArray(new String[dataList.size()][]);
        columnNames = resultSet.getColumnNames();
        if (listener != null) {
            listener.complete();
        }
    }

    @Override
    public int getRowCount() {
        return data.length;
    }

    @Override
    public String getColumnName(int column) {
        return columnNames[column];
    }

    @Override
    public int getColumnCount() {
        if (columnNames != null) {
            return columnNames.length;
        } else {
            if (data != null && data.length > 0) {
                return data[0].length;
            } else {
                return 1;
            }
        }
    }

    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        final String[] row = data[rowIndex];
        if (row == null) {
            return null;
        } else if (columnIndex >= row.length) {
            return null;
        } else {
            return row[columnIndex];
        }
    }

}