/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.apache.jmeter.functions;

import java.time.Duration;
import java.time.Instant;
import java.time.LocalDateTime;
import java.time.Year;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeFormatterBuilder;
import java.time.format.DateTimeParseException;
import java.time.temporal.ChronoField;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;

import org.apache.commons.lang3.StringUtils;
import org.apache.jmeter.engine.util.CompoundVariable;
import org.apache.jmeter.samplers.SampleResult;
import org.apache.jmeter.samplers.Sampler;
import org.apache.jmeter.threads.JMeterVariables;
import org.apache.jmeter.util.JMeterUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.github.benmanes.caffeine.cache.Cache;
import com.github.benmanes.caffeine.cache.Caffeine;

/**
 * timeShifting Function permit to shift a date
 *
 * Parameters: - format date @see
 * https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html
 * (optional - defaults to epoch time in millisecond) - date to shift formated
 * as first param (optional - defaults now) - amount of (seconds, minutes,
 * hours, days ) to add (optional - default nothing is add ) -
 * variable name ( optional )
 *
 * Returns: a formatted date with the specified number of (seconds, minutes,
 * hours, days or months ) added. - value is also saved in the variable for
 * later re-use.
 *
 * @since 3.3
 */
public class TimeShift extends AbstractFunction {
    private static final Logger log = LoggerFactory.getLogger(TimeShift.class);

    private static final String KEY = "__timeShift"; // $NON-NLS-1$

    private static final List<String> desc = Arrays.asList(JMeterUtils.getResString("time_format_shift"),
            JMeterUtils.getResString("date_to_shift"), JMeterUtils.getResString("value_to_shift"),
            JMeterUtils.getResString("function_name_paropt"));

    // Ensure that these are set, even if no paramters are provided
    private String format = ""; //$NON-NLS-1$
    private String dateToShift = ""; //$NON-NLS-1$
    private String amountToShift = ""; //$NON-NLS-1$
    private String variableName = ""; //$NON-NLS-1$
    private ZoneId systemDefaultZoneID = ZoneId.systemDefault();

    /** Date time format cache handler **/
    private Cache<String, DateTimeFormatter> dateTimeFormatterCache = null;

    public TimeShift() {
        super();
    }

    /** {@inheritDoc} */
    @Override
    public String execute(SampleResult previousResult, Sampler currentSampler) throws InvalidVariableException {
        String dateString;
        LocalDateTime localDateTimeToShift = LocalDateTime.now(systemDefaultZoneID);
        DateTimeFormatter formatter = null;
        if (!StringUtils.isEmpty(format)) {
            try {
                formatter = (DateTimeFormatter) dateTimeFormatterCache.get(format, key -> createFormatter((String)key));
            } catch (IllegalArgumentException ex) {
                log.error("Format date pattern '{}' is invalid (see https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html)", format, ex); // $NON-NLS-1$
                return "";
            }
        }

        if (!dateToShift.isEmpty()) {
            try {
                if (formatter != null) {
                    localDateTimeToShift = LocalDateTime.parse(dateToShift, formatter);
                } else {
                    localDateTimeToShift = LocalDateTime.ofInstant(Instant.ofEpochMilli(Long.parseLong(dateToShift)),
                            ZoneId.systemDefault());
                }
            } catch (DateTimeParseException | NumberFormatException ex) {
                log.error("Failed to parse the date '{}' to shift", dateToShift, ex); // $NON-NLS-1$
            }
        }

        // Check amount value to shift
        if (!StringUtils.isEmpty(amountToShift)) {
            try {
                Duration duration = Duration.parse(amountToShift);
                localDateTimeToShift = localDateTimeToShift.plus(duration);
            } catch (DateTimeParseException ex) {
                log.error("Failed to parse the amount duration '{}' to shift (see https://docs.oracle.com/javase/8/docs/api/java/time/Duration.html#parse-java.lang.CharSequence-) ", amountToShift, ex); // $NON-NLS-1$
            }
        }

        if (formatter != null) {
            dateString = localDateTimeToShift.format(formatter);
        } else {
            ZoneOffset offset = ZoneOffset.systemDefault().getRules().getOffset(localDateTimeToShift);
            dateString = String.valueOf(localDateTimeToShift.toInstant(offset).toEpochMilli());
        }

        if (!StringUtils.isEmpty(variableName)) {
            JMeterVariables vars = getVariables();
            if (vars != null) {// vars will be null on TestPlan
                vars.put(variableName, dateString);
            }
        }
        return dateString;
    }

    private DateTimeFormatter createFormatter(String format) throws IllegalArgumentException {

        log.debug("Create a new instance of DateTimeFormatter for format '{}' in the cache", format);
        return new DateTimeFormatterBuilder().appendPattern(format).parseDefaulting(ChronoField.NANO_OF_SECOND, 0)
                .parseDefaulting(ChronoField.MILLI_OF_SECOND, 0).parseDefaulting(ChronoField.SECOND_OF_MINUTE, 0)
                .parseDefaulting(ChronoField.MINUTE_OF_HOUR, 0).parseDefaulting(ChronoField.HOUR_OF_DAY, 0)
                .parseDefaulting(ChronoField.DAY_OF_MONTH, 1).parseDefaulting(ChronoField.MONTH_OF_YEAR, 1)
                .parseDefaulting(ChronoField.YEAR_OF_ERA, Year.now().getValue()).toFormatter(JMeterUtils.getLocale());
    }

    protected static Cache<String, DateTimeFormatter> buildCache() {
        Caffeine<Object, Object> cacheBuilder = Caffeine.newBuilder();
        cacheBuilder.maximumSize(100);
        return cacheBuilder.build();
    }

    /** {@inheritDoc} */
    @Override
    public void setParameters(Collection<CompoundVariable> parameters) throws InvalidVariableException {

        checkParameterCount(parameters, 0, 4);
        Object[] values = parameters.toArray();

        format = ((CompoundVariable) values[0]).execute().trim();
        dateToShift = ((CompoundVariable) values[1]).execute().trim();
        amountToShift = ((CompoundVariable) values[2]).execute().trim();
        variableName = ((CompoundVariable) values[3]).execute().trim();

        // Create the cache
        if (dateTimeFormatterCache == null) {
            dateTimeFormatterCache =  buildCache();
        }

    }

    /** {@inheritDoc} */
    @Override
    public String getReferenceKey() {
        return KEY;
    }

    /** {@inheritDoc} */
    @Override
    public List<String> getArgumentDesc() {
        return desc;
    }
}

@@ -3689,28 +3689,8 @@
 er =
- (DateTimeFormatter)
  dat

Remove cast. It is not needed here.