/* ========================================================================
 * PlantUML : a free UML diagram generator
 * ========================================================================
 *
 * (C) Copyright 2009-2024, Arnaud Roques
 *
 * Project Info:  https://plantuml.com
 * 
 * If you like this project or if you find it useful, you can support us at:
 * 
 * https://plantuml.com/patreon (only 1$ per month!)
 * https://plantuml.com/paypal
 * 
 * This file is part of PlantUML.
 *
 * PlantUML is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * PlantUML distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
 * License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 *
 * Original Author:  Arnaud Roques
 * 
 *
 */
package net.sourceforge.plantuml.regex;

import java.util.Collections;
import java.util.Iterator;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import net.sourceforge.plantuml.text.FoxSignature;
import net.sourceforge.plantuml.text.StringLocated;

public class RegexLeaf implements IRegex {

	private static final RegexLeaf END = new RegexLeaf("$");
	private static final RegexLeaf START = new RegexLeaf("^");
	private final String pattern;
	private final String name;

	private int count = -1;

	public RegexLeaf(String regex) {
		this(0, null, regex);
	}

	public RegexLeaf(int count, String regex) {
		this(count, null, regex);
	}

	public RegexLeaf(int count, String name, String regex) {
		this.pattern = regex;
		this.name = name;
		this.count = count;
		assert internalSlowCount() == count : "Bad count number for " + name;
	}

	public static RegexLeaf spaceZeroOrMore() {
		return new RegexLeaf("[%s]*");
	}

	public static RegexLeaf spaceOne() {
		return new RegexLeaf("[%s]");
	}

	public static RegexOptional spaceZeroOrOne() {
		return new RegexOptional(spaceOne());
	}

	public static RegexLeaf spaceOneOrMore() {
		return new RegexLeaf("[%s]+");
	}

	public static RegexLeaf start() {
		return START;
	}

	public static RegexLeaf end() {
		return END;
	}

	@Override
	public String toString() {
		return super.toString() + " " + name + " " + pattern;
	}

	public String getName() {
		return name;
	}

	@Override
	public String getPatternAsString() {
		return pattern;
	}

	public int count() {
		return count;
	}

	private int internalSlowCount() {
		return Pattern2.compileInternal(pattern).matcher("").groupCount();
	}

	public Map<String, RegexPartialMatch> createPartialMatch(Iterator<String> it) {
		final RegexPartialMatch m = new RegexPartialMatch(name);
		for (int i = 0; i < count(); i++) {
			final String group = it.next();
			m.add(group);
		}
		if (name == null)
			return Collections.emptyMap();

		return Collections.singletonMap(name, m);
	}

	public boolean match(StringLocated full) {
		throw new UnsupportedOperationException();
	}

	public RegexResult matcher(String full) {
		throw new UnsupportedOperationException();
	}

	// static private final Set<String> UNKNOWN = new HashSet<>();

	static private final Pattern p1 = Pattern.compile(
			"^\\(?((?:[-0A-Za-z_!:@;/=,\"\' ][?+*]?|\\\\[b$(){}<>|*.+^\\[\\]][?+*]?|\\.\\*|\\.\\+)+)(?:\\)\\+|\\))?$");

	static private final Pattern p2 = Pattern.compile("^\\([-?a-z ]+(\\|[-?a-z ]+)+\\)$");

	static private final Pattern p3 = Pattern.compile("^\\(?\\[[-=.~]+\\]\\+\\)?$");

	private static long getSignatureP2(String s) {
		long result = -1L;
		for (StringTokenizer st = new StringTokenizer(s, "()|"); st.hasMoreTokens();) {
			final String val = st.nextToken();
			result = result & FoxSignature.getFoxSignatureFromRegex(val);
		}
		return result;
	}

	private static final Pattern PATTERN_TO_REMOVE = Pattern
			.compile("\\[%s\\][+*?]?|\\(\\[([^\\\\\\[\\]])+\\]\\)[+*?]?");

	public long getFoxSignature() {
		if (pattern.equals("[%s]+"))
			return FoxSignature.getSpecialSpaces();
		if (pattern.equals("[%s]*"))
			return 0;
		final String pattern2 = PATTERN_TO_REMOVE.matcher(pattern).replaceAll("");

		final Matcher m1 = p1.matcher(pattern2);
		if (m1.matches())
			return FoxSignature.getFoxSignatureFromRegex(m1.group(1));

		final Matcher m2 = p2.matcher(pattern2);
		if (m2.matches())
			return getSignatureP2(pattern2);

		final Matcher m3 = p3.matcher(pattern2);
		if (m3.matches())
			return FoxSignature.getSpecial1();

//		synchronized (UNKNOWN) {
//			final boolean changed = UNKNOWN.add(pattern2);
//			if (changed) {
//				if (pattern.equals(pattern2))
//					System.err.println("unknow=" + UNKNOWN.size() + " " + pattern);
//				else
//					System.err.println("unknow=" + UNKNOWN.size() + " " + pattern2 + "        " + pattern);
//				// Thread.dumpStack();
//			}
//		}
		return 0;
	}

}
