package eu.dnetlib.dhp.oa.dedup.model;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

import com.google.common.collect.Lists;

import eu.dnetlib.pace.model.MapDocument;

public class Block implements Serializable {

	private String key;

	private List<MapDocument> documents;

	public Block() {
		super();
	}

	public static Block from(String key, MapDocument doc) {
		Block block = new Block();
		block.setKey(key);
		block.setDocuments(Lists.newArrayList(doc));
		return block;
	}

	public static Block from(String key, Iterator<Block> blocks, String orderField, int maxSize) {
		Block block = new Block();
		block.setKey(key);

		Iterable<Block> it = () -> blocks;

		block
			.setDocuments(
				StreamSupport
					.stream(it.spliterator(), false)
					.flatMap(b -> b.getDocuments().stream())
					.sorted(Comparator.comparing(a -> a.getFieldMap().get(orderField).stringValue()))
					.limit(maxSize)
					.collect(Collectors.toCollection(ArrayList::new)));
		return block;
	}

	public static Block from(Block b1, Block b2, String orderField, int maxSize) {
		Block block = new Block();
		block.setKey(b1.getKey());
		block
			.setDocuments(
				Stream
					.concat(b1.getDocuments().stream(), b2.getDocuments().stream())
					.sorted(Comparator.comparing(a -> a.getFieldMap().get(orderField).stringValue()))
					.limit(maxSize)
					.collect(Collectors.toCollection(ArrayList::new)));

		return block;
	}

	public String getKey() {
		return key;
	}

	public void setKey(String key) {
		this.key = key;
	}

	public List<MapDocument> getDocuments() {
		return documents;
	}

	public void setDocuments(List<MapDocument> documents) {
		this.documents = documents;
	}
}