/*
 * 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.ascii;

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

import org.hedgecode.chess.Builders;
import org.hedgecode.chess.position.Color;
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;

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

    private static final String LINE_REGEX = "\\r?\\n";
    private static final String BAR_SQUARE_REGEX = String.format("[%s]", ASCII.BAR_REGEX);
    private static final String DOT_SQUARE_REGEX = String.format("[^%s]+", ASCII.DOT_PIECE_REGEX);

    private static final Pattern BAR_PATTERN =
            Pattern.compile(
                    String.format(
                            "^.*[%s](([^%s]+[%s]){%d}[^%s]+)[%s].*$",
                            ASCII.EDGE_REGEX, ASCII.BAR_REGEX, ASCII.BAR_REGEX,
                            Square.getSize() - 1, ASCII.EDGE_REGEX, ASCII.EDGE_REGEX
                    )
            );

    private static final Pattern DOT_PATTERN =
            Pattern.compile(
                    String.format(
                            "^.*[%s](([^%s]+[%s]){%d}[^%s]+)[%s].*$",
                            ASCII.DOT_EDGE, ASCII.DOT_PIECE_REGEX, ASCII.DOT_PIECE_REGEX,
                            Square.getSize(), ASCII.DOT_PIECE_REGEX, ASCII.DOT_EDGE
                    )
            );

    private static Parser _instance = new ASCIIParser();

    private ASCIIParser() {
    }

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

    private Position _parse(String[] strings) throws ParseException {
        String[] lines;
        String squareRegex = BAR_SQUARE_REGEX;
        lines = _parseLines(strings, BAR_PATTERN);
        if (lines.length != Square.getSize()) {
            squareRegex = DOT_SQUARE_REGEX;
            lines = _parseLines(strings, DOT_PATTERN);
            if (lines.length != Square.getSize())
                throw new ParseException("parse.ascii.incorrect.board");
        }
        Position position = Positions.EMPTY.getPosition();
        _parsePieces(
                lines,
                position,
                squareRegex
        );
        return position;
    }

    private String[] _parseLines(String[] strings, Pattern linePattern) {
        List<String> lines = new ArrayList<>();
        for (String line : strings) {
            Matcher matcher = linePattern.matcher(line);
            if (matcher.find()) {
                lines.add(
                        matcher.group(1).trim()
                );
            }
        }
        return lines.toArray(
                new String[lines.size()]
        );
    }

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

    public static Parser getInstance() {
        return _instance;
    }


    public static void main(String[] args) throws ParseException {
        ASCII.setType(ASCIIBoardType.DOT);
        ASCII.setNotation(false);

        // Position position = Positions.INITIAL.getPosition();
        Position position = Positions.EMPTY.getPosition();
        position.setKing(Color.WHITE, Square.A1);
        position.setPawn(Color.WHITE, Square.A2);
        position.setPawn(Color.WHITE, Square.E4);
        position.setQueen(Color.WHITE, Square.A7);
        position.setKing(Color.BLACK, Square.H8);
        position.setPawn(Color.BLACK, Square.G7);
        position.setPawn(Color.BLACK, Square.H7);
        position.setKnight(Color.BLACK, Square.G2);
        position.setBishop(Color.BLACK, Square.D4);
        position.setRook(Color.BLACK, Square.E2);

        String ascii = Builders.ASCII.builder().build(position);
        System.out.println(
                ascii
        );

        position = getInstance().parse(ascii);

        ASCII.setType(ASCIIBoardType.HYPHEN);
        ascii = Builders.ASCII.builder().build(position);
        System.out.println(
                ascii
        );
    }

}