001package ca.uhn.fhir.jpa.dao.predicate;
002
003/*-
004 * #%L
005 * HAPI FHIR JPA Server
006 * %%
007 * Copyright (C) 2014 - 2022 Smile CDR, Inc.
008 * %%
009 * Licensed under the Apache License, Version 2.0 (the "License");
010 * you may not use this file except in compliance with the License.
011 * You may obtain a copy of the License at
012 *
013 *      http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing, software
016 * distributed under the License is distributed on an "AS IS" BASIS,
017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
018 * See the License for the specific language governing permissions and
019 * limitations under the License.
020 * #L%
021 */
022
023import ca.uhn.fhir.rest.param.ParamPrefixEnum;
024
025import java.math.BigDecimal;
026
027public interface SearchFuzzUtil {
028        /**
029         * Figures out the tolerance for a search. For example, if the user is searching for <code>4.00</code>, this method
030         * returns <code>0.005</code> because we shold actually match values which are
031         * <code>4 (+/-) 0.005</code> according to the FHIR specs.
032         */
033        static BigDecimal calculateFuzzAmount(ParamPrefixEnum cmpValue, BigDecimal theValue) {
034                if (cmpValue == ParamPrefixEnum.APPROXIMATE) {
035                        return theValue.multiply(new BigDecimal(0.1));
036                } else {
037                        String plainString = theValue.toPlainString();
038                        int dotIdx = plainString.indexOf('.');
039                        if (dotIdx == -1) {
040                                return new BigDecimal(0.5);
041                        }
042
043                        int precision = plainString.length() - (dotIdx);
044                        double mul = Math.pow(10, -precision);
045                        double val = mul * 5.0d;
046                        return new BigDecimal(val);
047                }
048        }
049}