/**
 * DataCleaner (community edition)
 * Copyright (C) 2014 Neopost - Customer Information Management
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.datacleaner.extension.networktools;

import javax.inject.Named;

import org.datacleaner.api.Categorized;
import org.datacleaner.api.Configured;
import org.datacleaner.api.Description;
import org.datacleaner.api.InputColumn;
import org.datacleaner.api.InputRow;
import org.datacleaner.api.OutputColumns;
import org.datacleaner.api.Transformer;
import org.datacleaner.util.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Named("Convert IP to number")
@Categorized(NetworkToolsCategory.class)
@Description(
        "Converts an IPv4 string to a number value, which makes it appropriate for eg. persisting in a number column.")
public class IpToNumberConverter implements Transformer {
    private static final Logger logger = LoggerFactory.getLogger(IpToNumberConverter.class);

    @Configured("IP string column")
    InputColumn<String> ipColumn;

    @Override
    public OutputColumns getOutputColumns() {
        return new OutputColumns(Number.class, ipColumn.getName() + " (IP as number)");
    }

    @Override
    public Number[] transform(final InputRow inputRow) {
        final Number[] result = new Number[1];
        final String addr = inputRow.getValue(ipColumn);
        if (StringUtils.isNullOrEmpty(addr)) {
            return result;
        }

        try {
            final String[] addrArray = addr.split("\\.");
            if (addrArray.length != 4) {
                throw new IllegalStateException("Found " + addrArray.length + " tokens, expected 4");
            }
            long num = 0;

            for (int i = 0; i < addrArray.length; i++) {
                final int power = 3 - i;
                final int ipPart = Integer.parseInt(addrArray[i]);
                if (ipPart < 0 || ipPart > 255) {
                    throw new IllegalStateException("Illegal IP part: " + ipPart);
                }
                num += (ipPart * Math.pow(256, power));
            }

            result[0] = num;
        } catch (final Exception e) {
            logger.warn("Could not convert ip: {} - {}", addr, e.getMessage());
        }

        return result;
    }
}