package eu.dnetlib.pace.common;

import com.google.common.base.Joiner;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import eu.dnetlib.pace.clustering.NGramUtils;
import eu.dnetlib.pace.distance.algo.JaroWinklerNormalizedName;
import eu.dnetlib.pace.model.Field;
import eu.dnetlib.pace.model.FieldList;
import eu.dnetlib.pace.model.FieldListImpl;
import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.math3.stat.descriptive.SummaryStatistics;

import java.text.Normalizer;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Set of common functions
 *
 * @author claudio
 *
 */
public abstract class AbstractPaceFunctions {

	protected static Set<String> stopwords = loadFromClasspath("/eu/dnetlib/pace/config/stopwords_en.txt");

	protected static Set<String> ngramBlacklist = loadFromClasspath("/eu/dnetlib/pace/config/ngram_blacklist.txt");

	private static final String alpha = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 ";
	private static final String aliases_from = "⁰¹²³⁴⁵⁶⁷⁸⁹⁺⁻⁼⁽⁾ⁿ₀₁₂₃₄₅₆₇₈₉₊₋₌₍₎àáâäæãåāèéêëēėęîïíīįìôöòóœøōõûüùúūßśšłžźżçćčñń";
	private static final String aliases_to = "0123456789+-=()n0123456789+-=()aaaaaaaaeeeeeeeiiiiiioooooooouuuuussslzzzcccnn";

	protected final static FieldList EMPTY_FIELD = new FieldListImpl();

	protected String concat(final List<String> l) {
		return Joiner.on(" ").skipNulls().join(l);
	}

	protected String cleanup(final String s) {
		final String s1 = nfd(s);
		final String s2 = fixAliases(s1);
		final String s3 = s2.replaceAll("&ndash;", " ");
		final String s4 = s3.replaceAll("&amp;", " ");
		final String s5 = s4.replaceAll("&quot;", " ");
		final String s6 = s5.replaceAll("&minus;", " ");
		final String s7 = s6.replaceAll("([0-9]+)", " $1 ");
		final String s8 = s7.replaceAll("[^\\p{ASCII}]|\\p{Punct}", " ");
		final String s9 = s8.replaceAll("\\n", " ");
		final String s10 = s9.replaceAll("(?m)\\s+", " ");
		final String s11 = s10.trim();
		return s11;
	}

	protected String finalCleanup(final String s) {
		return s.toLowerCase();
	}

	protected boolean checkNumbers(final String a, final String b) {
		final String numbersA = getNumbers(a);
		final String numbersB = getNumbers(b);
		final String romansA = getRomans(a);
		final String romansB = getRomans(b);
		return !numbersA.equals(numbersB) || !romansA.equals(romansB);
	}

	protected String getRomans(final String s) {
		final StringBuilder sb = new StringBuilder();
		for (final String t : s.split(" ")) {
			sb.append(isRoman(t) ? t : "");
		}
		return sb.toString();
	}

	protected boolean isRoman(final String s) {
		return s.replaceAll("^M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})$", "qwertyuiop").equals("qwertyuiop");
	}

	protected String getNumbers(final String s) {
		return s.replaceAll("\\D", "");
	}

	protected static String fixAliases(final String s) {
		final StringBuilder sb = new StringBuilder();
		for (final char ch : Lists.charactersOf(s)) {
			final int i = StringUtils.indexOf(aliases_from, ch);
			sb.append(i >= 0 ? aliases_to.charAt(i) : ch);
		}
		return sb.toString();
	}

	protected String removeSymbols(final String s) {
		final StringBuilder sb = new StringBuilder();

		for (final char ch : Lists.charactersOf(s)) {
			sb.append(StringUtils.contains(alpha, ch) ? ch : " ");
		}
		return sb.toString().replaceAll("\\s+", " ");
	}

	protected String getFirstValue(final Field values) {
		return (values != null) && !Iterables.isEmpty(values) ? Iterables.getFirst(values, EMPTY_FIELD).stringValue() : "";
	}

	protected boolean notNull(final String s) {
		return s != null;
	}

	// ///////////////////////

	protected String normalize(final String s) {
		return nfd(s).toLowerCase()
				// do not compact the regexes in a single expression, would cause StackOverflowError in case of large input strings
				.replaceAll("(\\W)+", " ")
				.replaceAll("(\\p{InCombiningDiacriticalMarks})+", " ")
				.replaceAll("(\\p{Punct})+", " ")
				.replaceAll("(\\d)+", " ")
				.replaceAll("(\\n)+", " ")
				.trim();
	}

	private String nfd(final String s) {
		return Normalizer.normalize(s, Normalizer.Form.NFD);
	}

	protected String filterStopWords(final String s, final Set<String> stopwords) {
		final StringTokenizer st = new StringTokenizer(s);
		final StringBuilder sb = new StringBuilder();
		while (st.hasMoreTokens()) {
			final String token = st.nextToken();
			if (!stopwords.contains(token)) {
				sb.append(token);
				sb.append(" ");
			}
		}
		return sb.toString().trim();
	}

	protected Collection<String> filterBlacklisted(final Collection<String> set, final Set<String> ngramBlacklist) {
		final Set<String> newset = Sets.newLinkedHashSet();
		for (final String s : set) {
			if (!ngramBlacklist.contains(s)) {
				newset.add(s);
			}
		}
		return newset;
	}

	// ////////////////////

	public static Set<String> loadFromClasspath(final String classpath) {
		final Set<String> h = Sets.newHashSet();
		try {
			for (final String s : IOUtils.readLines(NGramUtils.class.getResourceAsStream(classpath))) {
				h.add(s);
			}
		} catch (final Throwable e) {
			return Sets.newHashSet();
		}
		return h;
	}

	public static Map<String, String> loadMapFromClasspath(final String classpath) {
		final Map<String, String> m = new HashMap<>();
		try {
			for (final String s: IOUtils.readLines(JaroWinklerNormalizedName.class.getResourceAsStream(classpath))) {
				//string is like this: code;word1;word2;word3
				String[] line = s.split(";");
				String value = line[0];
				for (String key: line){
					m.put(fixAliases(key).toLowerCase(),value);
				}
			}
		} catch (final Throwable e){
			return new HashMap<>();
		}
		return m;
	}

	//translate the string: replace the keywords with the code
	public String translate(String s1, Map<String, String> translationMap){
		final StringTokenizer st = new StringTokenizer(s1);
		final StringBuilder sb = new StringBuilder();
		while (st.hasMoreTokens()){
			final String token = st.nextToken();
			sb.append(translationMap.getOrDefault(token,token) + " ");
		}
		return sb.toString().trim();
	}

	public String normalizeCities(String s1, Map<String,String> cityMap){
		for (String city : cityMap.keySet())
			s1 = s1.replaceAll(" " + city + " ", " " + cityMap.get(city) + " ");
		return s1;
	}

	public String removeCodes(String s) {
		final String regexKey = "\\bkey::[0-9]*\\b";
		final String regexCity = "\\bcity::[0-9]*\\b";
		return s.replaceAll(regexKey, "").replaceAll(regexCity, "").trim();

	}

	//check if 2 strings have same keywords
	public boolean sameKeywords(String s1, String s2){
		//at least 1 keyword in common
		if (getKeywords(s1).isEmpty() || getKeywords(s2).isEmpty())
			return true;
		else
			return CollectionUtils.intersection(getKeywords(s1),getKeywords(s2)).size()>0;
	}

	//returns true if at least 1 city is in common
	//returns true if a name has no cities
	public boolean sameCity(String s1, String s2){

		if (getCities(s1).isEmpty() || getCities(s2).isEmpty())
			return true;
		else
			return CollectionUtils.intersection(getCities(s1), getCities(s2)).size()>0;
	}

	//get the list of keywords in a string
	public List<String> getCities(String s) {

		final String regex = "\\bcity::[0-9]*\\b";

		Pattern p = Pattern.compile(regex, Pattern.MULTILINE);
		Matcher m = p.matcher(s);
		List<String> codes = new ArrayList<>();
		while (m.find()) {
			codes.add(m.group(0));
			for (int i = 1; i <= m.groupCount(); i++) {
				codes.add(m.group(0));
			}
		}
		return codes;
	}

	//get the list of keywords in a string
	public List<String> getKeywords(String s) {

		final String regex = "\\bkey::[0-9]*\\b";

		Pattern p = Pattern.compile(regex, Pattern.MULTILINE);
		Matcher m = p.matcher(s);
		List<String> codes = new ArrayList<>();
		while (m.find()) {
			codes.add(m.group(0));
			for (int i = 1; i <= m.groupCount(); i++) {
				codes.add(m.group(0));
			}
		}
		return codes;
	}

}