package eu.dnetlib.pace.clustering;

import com.google.common.collect.Maps;
import eu.dnetlib.pace.config.Config;
import eu.dnetlib.pace.model.Document;
import eu.dnetlib.pace.model.Field;
import eu.dnetlib.pace.model.FieldListImpl;
import eu.dnetlib.pace.model.MapDocument;

import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.regex.Pattern;

public class BlacklistAwareClusteringCombiner extends ClusteringCombiner {

    public static Collection<String> filterAndCombine(final MapDocument a, final Config conf) {
        Document filtered = filter(a, conf.blacklists());
        return combine(filtered, conf);
    }

    private static MapDocument filter(final MapDocument a, final Map<String, List<Pattern>> blacklists) {
        if (blacklists == null || blacklists.isEmpty()) {
            return a;
        }

        final Map<String, Field> filtered = Maps.newHashMap(a.getFieldMap());

        for (final Entry<String, List<Pattern>> e : blacklists.entrySet()) {
            Field fields = a.getFieldMap().get(e.getKey());
            if (fields != null) {
                final FieldListImpl fl = new FieldListImpl();

                for (Field f : fields) {
                    if (!isBlackListed(f.stringValue(), e.getValue())) {
                        fl.add(f);
                    }
                }

                filtered.put(e.getKey(), fl);
            }
        }

        return new MapDocument(a.getIdentifier(), filtered);
    }

    private static boolean isBlackListed(String value, List<Pattern> blacklist) {
        for (Pattern pattern : blacklist) {
            if (pattern.matcher(value).matches()) {
                return true;
            }
        }

        return false;
    }

}