package eu.dnetlib.pace.tree;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.function.BiFunction;
import java.util.stream.Collectors;

import com.wcohen.ss.AbstractStringDistance;

import eu.dnetlib.pace.config.Config;
import eu.dnetlib.pace.model.Person;
import eu.dnetlib.pace.tree.support.AbstractListComparator;
import eu.dnetlib.pace.tree.support.ComparatorClass;
import eu.dnetlib.pace.util.AuthorMatchers;

@ComparatorClass("authorsMatch")
public class AuthorsMatch extends AbstractListComparator {

	Map<String, String> params;

	private double SURNAME_THRESHOLD;
	private double NAME_THRESHOLD;
	private double FULLNAME_THRESHOLD;
	private String MODE; // full or surname
	private int SIZE_THRESHOLD;
	private String TYPE; // count or percentage

	public AuthorsMatch(Map<String, String> params) {
		super(params, new com.wcohen.ss.JaroWinkler());
		this.params = params;

		MODE = params.getOrDefault("mode", "full");
		SURNAME_THRESHOLD = Double.parseDouble(params.getOrDefault("surname_th", "0.95"));
		NAME_THRESHOLD = Double.parseDouble(params.getOrDefault("name_th", "0.95"));
		FULLNAME_THRESHOLD = Double.parseDouble(params.getOrDefault("fullname_th", "0.9"));
		SIZE_THRESHOLD = Integer.parseInt(params.getOrDefault("size_th", "20"));
		TYPE = params.getOrDefault("type", "percentage");
	}

	protected AuthorsMatch(double w, AbstractStringDistance ssalgo) {
		super(w, ssalgo);
	}

	@Override
	public double compare(final List<String> left, final List<String> right, final Config conf) {
		if (left.isEmpty() || right.isEmpty())
			return -1;

		if (left.size() > SIZE_THRESHOLD || right.size() > SIZE_THRESHOLD)
			return 1.0;

		Double threshold = getDoubleParam("threshold");
		int maxMiss = Integer.MAX_VALUE;

		if (threshold != null && threshold >= 0.0 && threshold <= 1.0 && left.size() == right.size()) {
			maxMiss = (int) Math.floor((1 - threshold) * Math.max(left.size(), right.size()));
		}

		int common = 0;

		List<String> a = new ArrayList<>(left);
		List<String> b = new ArrayList<>(right);

		common += AuthorMatchers
			.removeMatches(a, b, (BiFunction<String, String, Object>) AuthorMatchers::matchEqualsIgnoreCase)
			.size() / 2;
		common += AuthorMatchers
			.removeMatches(a, b, (BiFunction<String, String, Object>) AuthorMatchers::matchOrderedTokenAndAbbreviations)
			.size() / 2;

		List<Person> bList = b.stream().map(author -> new Person(author, false)).collect(Collectors.toList());

		// compare each element of List1 with each element of List2
		int alreadyMatched = common;
		for (int i = 0; i < a.size(); i++) {
			Person p1 = new Person(a.get(i), false);

			for (Person p2 : bList) {
				// both persons are inaccurate
				if (!p1.isAccurate() && !p2.isAccurate()) {
					// compare just normalized fullnames
					String fullname1 = normalization(
						p1.getNormalisedFullname().isEmpty() ? p1.getOriginal() : p1.getNormalisedFullname());
					String fullname2 = normalization(
						p2.getNormalisedFullname().isEmpty() ? p2.getOriginal() : p2.getNormalisedFullname());

					if (ssalgo.score(fullname1, fullname2) > FULLNAME_THRESHOLD) {
						common += 1;
						break;
					}
				}

				// one person is inaccurate
				if (p1.isAccurate() ^ p2.isAccurate()) {
					// prepare data
					// data for the accurate person
					String name = normalization(
						p1.isAccurate() ? p1.getNormalisedFirstName() : p2.getNormalisedFirstName());
					String surname = normalization(
						p1.isAccurate() ? p1.getNormalisedSurname() : p2.getNormalisedSurname());

					// data for the inaccurate person
					String fullname = normalization(
						p1.isAccurate()
							? ((p2.getNormalisedFullname().isEmpty()) ? p2.getOriginal() : p2.getNormalisedFullname())
							: (p1.getNormalisedFullname().isEmpty() ? p1.getOriginal() : p1.getNormalisedFullname()));

					if (fullname.contains(surname)) {
						if (MODE.equals("full")) {
							if (fullname.contains(name)) {
								common += 1;
								break;
							}
						} else { // MODE equals "surname"
							common += 1;
							break;
						}
					}
				}

				// both persons are accurate
				if (p1.isAccurate() && p2.isAccurate()) {

					if (compareSurname(p1, p2)) {
						if (MODE.equals("full")) {
							if (compareFirstname(p1, p2)) {
								common += 1;
								break;
							}
						} else { // MODE equals "surname"
							common += 1;
							break;
						}
					}

				}
			}

			if (i - common - alreadyMatched > maxMiss) {
				return 0.0;
			}
		}

		// normalization factor to compute the score
		int normFactor = left.size() == right.size() ? left.size() : (left.size() + right.size() - common);

		if (TYPE.equals("percentage")) {
			return (double) common / normFactor;
		} else {
			return (double) common;
		}
	}

	public boolean compareSurname(Person p1, Person p2) {
		return ssalgo
			.score(
				normalization(p1.getNormalisedSurname()), normalization(p2.getNormalisedSurname())) > SURNAME_THRESHOLD;
	}

	public boolean compareFirstname(Person p1, Person p2) {

		if (p1.getNormalisedFirstName().length() <= 2 || p2.getNormalisedFirstName().length() <= 2) {
			if (firstLC(p1.getNormalisedFirstName()).equals(firstLC(p2.getNormalisedFirstName())))
				return true;
		}

		return ssalgo
			.score(
				normalization(p1.getNormalisedFirstName()),
				normalization(p2.getNormalisedFirstName())) > NAME_THRESHOLD;
	}

	public String normalization(String s) {
		return normalize(utf8(cleanup(s)));
	}
}