package eu.dnetlib.dhp.schema.oaf.utils;

import java.util.HashSet;
import java.util.Objects;
import java.util.Optional;
import java.util.Set;

import org.apache.commons.lang3.StringUtils;

import eu.dnetlib.dhp.schema.oaf.StructuredProperty;

public class CleaningFunctions {

	public static final String DOI_PREFIX_REGEX = "(^10\\.|\\/10\\.)";
	public static final String DOI_PREFIX = "10.";

	public static final Set<String> PID_BLACKLIST = new HashSet<>();

	static {
		PID_BLACKLIST.add("none");
		PID_BLACKLIST.add("na");
	}

	public CleaningFunctions() {}

	/**
	 * Utility method that filter PID values on a per-type basis.
	 * @param s the PID whose value will be checked.
	 * @return false if the pid matches the filter criteria, true otherwise.
	 */
	public static boolean pidFilter(StructuredProperty s) {
		final String pidValue = s.getValue();
		if (Objects.isNull(s.getQualifier()) ||
			StringUtils.isBlank(pidValue) ||
			StringUtils.isBlank(pidValue.replaceAll("(?:\\n|\\r|\\t|\\s)", ""))) {
			return false;
		}
		if (CleaningFunctions.PID_BLACKLIST.contains(pidValue)) {
			return false;
		}
		return !PidBlacklistProvider.getBlacklist(s.getQualifier().getClassid()).contains(pidValue);
	}

	/**
	 * Utility method that normalises PID values on a per-type basis.
	 * @param pid the PID whose value will be normalised.
	 * @return the PID containing the normalised value.
	 */
	public static StructuredProperty normalizePidValue(StructuredProperty pid) {
		pid.setValue(
				normalizePidValue(
					pid.getQualifier().getClassid(),
					pid.getValue()));

		return pid;
	}

	public static String normalizePidValue(String pidType, String pidValue) {
		String value = Optional
				.ofNullable(pidValue)
				.map(String::trim)
				.orElseThrow(() -> new IllegalArgumentException("PID value cannot be empty"));

		switch (pidType) {

			// TODO add cleaning for more PID types as needed
			case "doi":
				return value.toLowerCase().replaceFirst(DOI_PREFIX_REGEX, DOI_PREFIX);
		}
		return value;
	}

}