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

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Here is the source code for org.graylog.plugins.pipelineprocessor.functions.dates.TimezoneAwareFunction.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.google.common.collect.ImmutableMap;
import com.google.common.collect.Maps;
import org.graylog.plugins.pipelineprocessor.EvaluationContext;
import org.graylog.plugins.pipelineprocessor.ast.functions.AbstractFunction;
import org.graylog.plugins.pipelineprocessor.ast.functions.FunctionArgs;
import org.graylog.plugins.pipelineprocessor.ast.functions.FunctionDescriptor;
import org.graylog.plugins.pipelineprocessor.ast.functions.ParameterDescriptor;
import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;

import java.util.Locale;

public abstract class TimezoneAwareFunction extends AbstractFunction<DateTime> {

    private static final String TIMEZONE = "timezone";
    private static final ImmutableMap<String, String> UPPER_ZONE_MAP = Maps.uniqueIndex(
            DateTimeZone.getAvailableIDs(), input -> input != null ? input.toUpperCase(Locale.ENGLISH) : "UTC");
    private final ParameterDescriptor<String, DateTimeZone> timeZoneParam;

    protected TimezoneAwareFunction() {
        timeZoneParam = ParameterDescriptor.string(TIMEZONE, DateTimeZone.class)
                .transform(id -> DateTimeZone
                        .forID(UPPER_ZONE_MAP.getOrDefault(id.toUpperCase(Locale.ENGLISH), "UTC")))
                .optional().description("The timezone to apply to the date, defaults to UTC").build();
    }

    @Override
    public DateTime evaluate(FunctionArgs args, EvaluationContext context) {
        final DateTimeZone timezone = timeZoneParam.optional(args, context).orElse(DateTimeZone.UTC);

        return evaluate(args, context, timezone);
    }

    protected abstract DateTime evaluate(FunctionArgs args, EvaluationContext context, DateTimeZone timezone);

    @Override
    public FunctionDescriptor<DateTime> descriptor() {
        return FunctionDescriptor.<DateTime>builder().name(getName()).returnType(DateTime.class)
                .params(ImmutableList.<ParameterDescriptor>builder().addAll(params()).add(timeZoneParam).build())
                .description(description()).build();
    }

    protected abstract String description();

    protected abstract String getName();

    protected abstract ImmutableList<ParameterDescriptor> params();
}