/*
 * 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.tcd;

import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;

/**
 * Tiny Chess Diagram (TCD) constants.
 *
 * @author Dmitry Samoshin aka gotty
 */
public final class TCD {

    public static final byte BYTE_MASK = 0b01000000;
    public static final byte FRAME_MASK = 0b111;
    public static final byte FRAME_LENGTH = 3;

    public static final byte WHITE = 0b000;
    public static final byte BLACK = 0b111;

    public static final byte END = 0b111;

    public static final byte PAWN   = 0b001;
    public static final byte KNIGHT = 0b010;
    public static final byte BISHOP = 0b011;
    public static final byte ROOK   = 0b100;
    public static final byte QUEEN  = 0b101;
    public static final byte KING   = 0b110;

    private static final byte SQUARE_A = 0b000, SQUARE_1 = SQUARE_A;
    private static final byte SQUARE_B = 0b001, SQUARE_2 = SQUARE_B;
    private static final byte SQUARE_C = 0b010, SQUARE_3 = SQUARE_C;
    private static final byte SQUARE_D = 0b011, SQUARE_4 = SQUARE_D;
    private static final byte SQUARE_E = 0b100, SQUARE_5 = SQUARE_E;
    private static final byte SQUARE_F = 0b101, SQUARE_6 = SQUARE_F;
    private static final byte SQUARE_G = 0b110, SQUARE_7 = SQUARE_G;
    private static final byte SQUARE_H = 0b111, SQUARE_8 = SQUARE_H;

    public static final byte SQUARE_SIZE = 8;

    public static final byte[][] SQUARE = {
            {SQUARE_A, SQUARE_1},
            {SQUARE_B, SQUARE_2},
            {SQUARE_C, SQUARE_3},
            {SQUARE_D, SQUARE_4},
            {SQUARE_E, SQUARE_5},
            {SQUARE_F, SQUARE_6},
            {SQUARE_G, SQUARE_7},
            {SQUARE_H, SQUARE_8},
    };

    public static final byte MOVE = 0b001;

    public static final byte CASTLE_WHITE = 0b000;
    public static final byte CASTLE_BLACK = 0b111;

    public static final byte CASTLE_NONE = 0b000;
    public static final byte CASTLE_KING = 0b001;
    public static final byte CASTLE_QUEEN = 0b010;
    public static final byte CASTLE_BOTH = 0b011;

    public static final byte[] CASTLE_OPTS = {CASTLE_NONE, CASTLE_KING, CASTLE_QUEEN, CASTLE_BOTH};

    public static final byte EN_PASSANT = 0b100;

    public static final byte HALFMOVE = 0b010;
    public static final byte FULLMOVE = 0b011;

    public static final byte MIN_BYTE = 0x40;
    public static final byte MAX_BYTE = 0x7F;

    private static final byte[] REPLACE_TO =
            {0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x2B, 0x2D};
    private static final byte[] REPLACE_FROM =
            {0x40, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F};

    public static final Charset OUTPUT_CHARSET = StandardCharsets.US_ASCII;

    private static boolean onlyDiagram = true;

    private TCD() {
    }

    public static void setDiagram(boolean isDiagram) {
        onlyDiagram = isDiagram;
    }

    public static boolean isDiagram() {
        return onlyDiagram;
    }

    public static void replaceTo(byte[] bytes) {
        for (int i = 0; i < bytes.length; ++i) {
            int j = frameSearch(REPLACE_FROM, bytes[i]);
            if (j >= 0)
                bytes[i] = REPLACE_TO[j];
        }
    }

    public static void replaceFrom(byte[] bytes) {
        for (int i = 0; i < bytes.length; ++i) {
            int j = frameSearch(REPLACE_TO, bytes[i]);
            if (j >= 0)
                bytes[i] = REPLACE_FROM[j];
        }
    }

    public static boolean isValid(byte[] bytes) {
        if (bytes.length < 1)
            return false;
        for (byte bite : bytes) {
            if (bite < MIN_BYTE)
                return false;
        }
        return true;
    }

    public static boolean isColor(byte frame) {
        return frame == WHITE || frame == BLACK;
    }

    public static boolean isNotColor(byte frame) {
        return !isColor(frame);
    }

    public static boolean isWhiteBlack(byte first, byte second) {
        return first == WHITE && second == BLACK;
    }

    public static boolean isBlackWhite(byte first, byte second) {
        return isWhiteBlack(second, first);
    }

    public static boolean isNotCastle(byte frame) {
        return frameSearch(CASTLE_OPTS, frame) < 0;
    }

    private static int frameSearch(byte[] bytes, byte frame) {
        for (int i = 0; i < bytes.length; ++i)
            if (bytes[i] == frame)
                return i;
        return -1;
    }

}