/*
 * Copyright (c) 2018. Developed by Hedgecode.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.hedgecode.chess.wiki;

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.hedgecode.chess.position.ParseException;
import org.hedgecode.chess.position.Parser;
import org.hedgecode.chess.position.Position;
import org.hedgecode.chess.position.Positions;
import org.hedgecode.chess.position.Square;

/**
 * Wikipedia chess diagram parser.
 *
 * @author Dmitry Samoshin aka gotty
 */
public final class WikiParser implements Parser {

    private static final String LINE_REGEX = "\\r?\\n";
    private static final String SQUARE_REGEX = String.format("[%s]", Wiki.SEPARATOR);

    private static final Pattern PATTERN =
            Pattern.compile(
                    String.format("^([%s][^%s]*){%d}$", Wiki.SEPARATOR, Wiki.SEPARATOR, Square.getSize())
            );

    private static Parser _instance = new WikiParser();

    private WikiParser() {
    }

    @Override
    public Position parse(String string) throws ParseException {
        return _parse(
                string.split(LINE_REGEX)
        );
    }

    private Position _parse(String[] strings) throws ParseException {
        List<String> lines = new ArrayList<>();
        for (String line : strings) {
            Matcher matcher = PATTERN.matcher(line);
            if (matcher.find()) {
                lines.add(
                        matcher.group(0)
                );
            }
        }
        if (lines.size() != Square.getSize())
            throw new ParseException("parse.wiki.incorrect.board");
        Position position = Positions.EMPTY.getPosition();
        _parsePieces(
                lines.toArray(
                        new String[lines.size()]
                ),
                position
        );
        return position;
    }

    private void _parsePieces(String[] lines, Position position) throws ParseException {
        for (int i = 0; i < lines.length; ++i) {
            int line = lines.length - i;
            String[] pieces = lines[i].split(SQUARE_REGEX, -1);
            if (pieces.length != Square.getSize() + 1)
                throw new ParseException("parse.wiki.incorrect.board");
            for (int j = 1; j < pieces.length; ++j) {
                position.setPiece(
                        Wiki.getColorPiece(pieces[j]),
                        Square.getSquare(j - 1, line - 1)
                );
            }
        }
    }

    public static Parser getInstance() {
        return _instance;
    }


    public static void main(String[] args) throws ParseException {
        Position position = getInstance().parse(
                "{{Шахматная диаграмма\n" +
                        "|\n" +
                        "|\n" +
                        "|rd|nd|bd|qd|kd|bd|nd|rd\n" +
                        "|pd|pd|  |pd|pd|pd|pd|pd\n" +
                        "|  |  |  |  |  |  |  |\n" +
                        "|  |  |  |  |  |  |  |\n" +
                        "|  |  |  |pd|pl|  |  |\r\n" +
                        "|  |  |pl|  |  |  |  |\n" +
                        "|pl|pl|  |  |  |pl|pl|pl\n" +
                        "|rl|nl|bl|ql|kl|bl|nl|rl\n" +
                        "| }}"
        );
        System.out.println(position);
    }

}