org.jboss.pnc.facade.rsql.ComparatorRSQLNodeTraveller Maven / Gradle / Ivy

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Common module for front-facing implementations like REST.

There is a newer version: 3.0.4

/**
 * JBoss, Home of Professional Open Source.
 * Copyright 2014-2022 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * Licensed 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.jboss.pnc.facade.rsql;

import static org.jboss.pnc.facade.rsql.RSQLProducerImpl.DESC;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.lang.invoke.MethodHandles;

import cz.jirutka.rsql.parser.ast.ComparisonNode;
import cz.jirutka.rsql.parser.ast.LogicalNode;
import java.lang.reflect.Method;
import java.util.Comparator;
import org.jboss.pnc.common.util.StringUtils;

/**
 *
 * @author Honza Brázdil <[email protected]>
 */
class ComparatorRSQLNodeTraveller extends RSQLNodeTraveller> {

    private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

    @Override
    public Comparator visit(LogicalNode logicalNode) {
        Comparator comparator = logicalNode.getChildren()
                .stream()
                .map(this::visit)
                .reduce(Comparator::thenComparing)
                .orElseThrow(() -> new RSQLException("No nodes for RSQL comparison found."));
        return comparator;
    }

    @Override
    public Comparator visit(ComparisonNode node) {
        logger.trace("Sorting direction - {}, arguments {}", node.getOperator(), node.getArguments());

        Comparator comparator = node.getArguments()
                .stream()
                .map(this::getComparator)
                .reduce(Comparator::thenComparing)
                .orElseThrow(() -> new RSQLException("No argument for RSQL comparison found."));

        if (node.getOperator().equals(DESC)) {
            comparator = comparator.reversed();
        }

        return comparator;
    }

    private Comparator getComparator(String argument) {
        return Comparator
                .comparing((DTO dto) -> getProperty(dto, argument), Comparator.nullsLast(Comparator.naturalOrder()));
    }

    private Comparable