StringPeerHeaderDescriptor.java

/*
 * GovWay - A customizable API Gateway 
 * https://govway.org
 * 
 * Copyright (c) 2005-2025 Link.it srl (https://link.it). 
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3, as published by
 * the Free Software Foundation.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
package org.openspcoop2.pdd.core.integrazione.peer;

import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

/**
 * Classe che serve a descrivere un headers peer di tipo string
 * 
 *
 * @author Tommaso Burlon (tommaso.burlon@link.it)
 * @author $Author$
 * @version $Rev$, $Date$
 */
public class StringPeerHeaderDescriptor implements PeerHeaderDescriptor {
    private final Map<String, Integer> headerMap;
    private final String headerName;
    
    public StringPeerHeaderDescriptor(String key, String value) {
        this.headerName = key;
        
        List<String> headerList = Arrays.stream(value.split(","))
                .map(String::trim)
                .collect(Collectors.toList());
        this.headerMap = IntStream.range(0, headerList.size())
                .boxed()
                .collect(Collectors.toMap(headerList::get, i -> i, Math::min, HashMap::new));
    }
    
    @Override
    public Map<String, String> computeHeaders(Collection<String> headers) {
        Integer bestMatch = this.headerMap.size();
        String name = this.headerName;
        String match = null;
        for (String header : headers) {
            Integer priority = this.headerMap.get(header);
            
            if (priority != null && priority < bestMatch) {
                bestMatch = priority;
                match = header;
            }
        }
        
        if (match == null)
            return Map.of();
        return Map.of(name, match);
    }

}