org.graylog.plugins.pipelineprocessor.functions.dates.FlexParseDate.java Source code

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Here is the source code for org.graylog.plugins.pipelineprocessor.functions.dates.FlexParseDate.java

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/**
 * This file is part of Graylog Pipeline Processor.
 *
 * Graylog Pipeline Processor is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Graylog Pipeline Processor 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Graylog Pipeline Processor.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.graylog.plugins.pipelineprocessor.functions.dates;

import com.google.common.collect.ImmutableList;
import com.joestelmach.natty.DateGroup;
import com.joestelmach.natty.Parser;
import org.graylog.plugins.pipelineprocessor.EvaluationContext;
import org.graylog.plugins.pipelineprocessor.ast.functions.FunctionArgs;
import org.graylog.plugins.pipelineprocessor.ast.functions.ParameterDescriptor;
import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;

import java.util.List;
import java.util.Optional;

public class FlexParseDate extends TimezoneAwareFunction {

    public static final String VALUE = "value";
    public static final String NAME = "flex_parse_date";
    public static final String DEFAULT = "default";
    private final ParameterDescriptor<String, String> valueParam;
    private final ParameterDescriptor<DateTime, DateTime> defaultParam;

    public FlexParseDate() {
        valueParam = ParameterDescriptor.string(VALUE).description("Date string to parse").build();
        defaultParam = ParameterDescriptor.type(DEFAULT, DateTime.class).optional()
                .description("Used when 'value' could not be parsed, 'null' otherwise").build();
    }

    @Override
    protected DateTime evaluate(FunctionArgs args, EvaluationContext context, DateTimeZone timezone) {
        final String time = valueParam.required(args, context);

        final List<DateGroup> dates = new Parser(timezone.toTimeZone()).parse(time);
        if (dates.size() == 0) {
            final Optional<DateTime> defaultTime = defaultParam.optional(args, context);
            if (defaultTime.isPresent()) {
                return defaultTime.get();
            }
            // TODO really? this should probably throw an exception of some sort to be handled in the interpreter
            return null;
        }
        return new DateTime(dates.get(0).getDates().get(0), timezone);
    }

    @Override
    protected String description() {
        return "Parses a date string using natural language (see http://natty.joestelmach.com/)";
    }

    @Override
    protected String getName() {
        return NAME;
    }

    @Override
    protected ImmutableList<ParameterDescriptor> params() {
        return ImmutableList.of(valueParam, defaultParam);
    }
}