D-Net

package eu.dnetlib.data.transform;

import java.util.Arrays;

import java.util.Set;

import java.util.stream.Collectors;

import java.util.stream.Stream;

import com.google.common.base.Function;

import com.google.common.base.Predicate;

import com.google.common.collect.Iterables;

import com.google.common.collect.Sets;

import com.google.protobuf.Descriptors.Descriptor;

import com.google.protobuf.Descriptors.FieldDescriptor;

import eu.dnetlib.data.mapreduce.util.OafDecoder;

import eu.dnetlib.data.proto.FieldTypeProtos.StructuredProperty;

import eu.dnetlib.data.proto.TypeProtos.Type;

public class OafUtils {

	private static Stream<String> types() {

		return Arrays.stream(Type.values())

				.map(Enum::toString);

	}

	public static Set<String> entities() {

		return types()

				.collect(Collectors.toSet());

	}

	public static Function<OafDecoder, String> idDecoder() {

		return input -> input.getEntityId();

	}

	public static Predicate<StructuredProperty> mainTitleFilter() {

		return sp -> (sp.getQualifier() != null) && sp.getQualifier().getClassname().equals("main title");

	}

	public static Set<String> getFieldNames(final Descriptor d, final Integer... tag) {

		return Sets.newHashSet(Iterables.transform(Arrays.asList(tag), i -> {

			final FieldDescriptor fd = d.findFieldByNumber(i);

			if (fd == null) throw new IllegalArgumentException("undefined tag: " + i + " for type: " + d.getFullName());

			return fd.getName();

		}));

	}

}