/*
 * Copyright (c) 2018-2019. 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.qrcode;

import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.EnumMap;
import java.util.Map;

import javax.imageio.ImageIO;

import com.google.zxing.EncodeHintType;
import com.google.zxing.WriterException;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import com.google.zxing.qrcode.encoder.ByteMatrix;
import com.google.zxing.qrcode.encoder.Encoder;
import com.google.zxing.qrcode.encoder.QRCode;

import org.hedgecode.chess.img.ImageFormat;

/**
 * Chess-specific QR Codes writer (image generator).
 *
 * @author Dmitry Samoshin aka gotty
 */
public class ChessQRCodeWriter {

    private static final int DEF_QUIET_ZONE_SIZE = 4;
    private static final int DEF_QRCODE_BIT_SIZE = 250;
    private static final int MIN_QRCODE_BIT_SIZE = 50;

    private static final ErrorCorrectionLevel DEF_ERR_CORR_LEVEL = ErrorCorrectionLevel.H; // todo: Q

    private static ChessQRCodeWriter _instance = new ChessQRCodeWriter();

    protected ChessQRCodeWriter() {
    }

    public void write(ChessQRCodeMode mode, String contents, ImageFormat format, String qrCodeFilePath)
            throws ChessQRCodeException
    {
        write(
                mode,
                contents,
                format,
                Paths.get(qrCodeFilePath)
        );
    }

    public void write(ChessQRCodeMode mode, String contents, ImageFormat format, Path qrCodeFile)
            throws ChessQRCodeException
    {
        write(
                mode,
                contents,
                format,
                DEF_QRCODE_BIT_SIZE,
                DEF_QRCODE_BIT_SIZE,
                qrCodeFile
        );
    }


    public void write(
            ChessQRCodeMode mode,
            String contents,
            ImageFormat format,
            int width, int height,
            Path qrCodeFile)
            throws ChessQRCodeException
    {
        try {
            BufferedImage image = generate(mode, contents, width, height);
            if (!ImageIO.write(image, format.name(), qrCodeFile.toFile())) {
                throw new ChessQRCodeException(
                        ChessQRCodeException.Type.WRITE, "write.output.qrcode.file", qrCodeFile.toFile().getName()
                );
            }
        } catch (IOException e) {
            throw new ChessQRCodeException(
                    ChessQRCodeException.Type.WRITE, "write.output.qrcode.file", e.getMessage()
            );
        }
    }

    public void write(ChessQRCodeMode mode, String contents, ImageFormat format, OutputStream stream)
            throws ChessQRCodeException
    {
        try {
            BufferedImage image = generate(mode, contents);
            if (!ImageIO.write(image, format.name(), stream)) {
                throw new ChessQRCodeException(
                        ChessQRCodeException.Type.WRITE, "write.output.qrcode.stream"
                );
            }
        } catch (IOException e) {
            throw new ChessQRCodeException(
                    ChessQRCodeException.Type.WRITE, "write.output.qrcode.stream", e.getMessage()
            );
        }
    }

    public BufferedImage generate(ChessQRCodeMode mode, String contents)
            throws ChessQRCodeException
    {
        return generate(mode, contents, DEF_QRCODE_BIT_SIZE, DEF_QRCODE_BIT_SIZE);
    }

    public BufferedImage generate(ChessQRCodeMode mode, String contents, int width, int height)
            throws ChessQRCodeException
    {
        BitMatrix bitMatrix = encode(
                mode, contents,
                width, height,
                null
        );

        return MatrixToImageWriter.toBufferedImage(
                bitMatrix
        );
    }

    protected BitMatrix encode(
            ChessQRCodeMode mode,
            String contents,
            int width, int height,
            Map<EncodeHintType,?> hints)
            throws ChessQRCodeException
    {
        if (mode == null) {
            throw new ChessQRCodeException(
                    ChessQRCodeException.Type.WRITE, "write.qrcode.mode.null"
            );
        }

        if (contents == null || contents.isEmpty()) {
            throw new ChessQRCodeException(
                    ChessQRCodeException.Type.WRITE, "write.qrcode.contents.empty"
            );
        }

        if (Math.min(width, height) < MIN_QRCODE_BIT_SIZE) { // todo: check for Version
            throw new ChessQRCodeException(
                    ChessQRCodeException.Type.WRITE, "write.qrcode.size.incorrect"
            );
        }

        String qrCodeContents = mode.name().concat(contents);

        int quietZone = DEF_QUIET_ZONE_SIZE;
        ErrorCorrectionLevel errorCorrectionLevel = DEF_ERR_CORR_LEVEL;

        Map<EncodeHintType,Object> newHints = new EnumMap<>(EncodeHintType.class);
        if (hints != null) {
            newHints.putAll(hints);
            if (!hints.containsKey(EncodeHintType.CHARACTER_SET)) {
                newHints.put(EncodeHintType.CHARACTER_SET, ChessQRCodeConstants.CHARSET.name());
            }
            if (hints.containsKey(EncodeHintType.ERROR_CORRECTION)) {
                errorCorrectionLevel = ErrorCorrectionLevel.valueOf(
                        hints.get(EncodeHintType.ERROR_CORRECTION).toString()
                );
            }
            if (hints.containsKey(EncodeHintType.MARGIN)) {
                quietZone = Integer.parseInt(
                        hints.get(EncodeHintType.MARGIN).toString()
                );
            }
        } else {
            newHints.put(EncodeHintType.CHARACTER_SET, ChessQRCodeConstants.CHARSET.name());
        }
        hints = newHints;

        QRCode qrCode;
        try {
            qrCode = Encoder.encode(
                    qrCodeContents, errorCorrectionLevel, hints
            );
        } catch (WriterException e) {
            throw new ChessQRCodeException(
                    ChessQRCodeException.Type.WRITE, "write.zxing.qrcode.error", e.getMessage()
            );
        }

        return renderMatrix(
                qrCode, width, height, quietZone
        );
    }

    private BitMatrix renderMatrix(QRCode qrCode, int width, int height, int quietZone)
            throws ChessQRCodeException
    {
        ByteMatrix byteMatrix =
                ChessQRMatrixUtils.embedChessLogoPattern(
                        qrCode.getMatrix()
                );

        if (byteMatrix == null) {
            throw new ChessQRCodeException(
                    ChessQRCodeException.Type.WRITE, "write.qrcode.chess.incorrect"
            );
        }

        return ChessQRMatrixUtils.renderMatrix(
                byteMatrix,
                width,
                height,
                quietZone
        );
    }

    public static ChessQRCodeWriter getInstance() {
        return _instance;
    }


    public static void main(String[] args) {
        try {
            ChessQRCodeWriter.getInstance().write(
                    ChessQRCodeMode.FEN,
                    "rnbqkbnr/ppp1pppp/8/3p4/4P3/8/PPPP1PPP/RNBQKBNR w KQkq d6 0 2",
                    ImageFormat.PNG,
                    "./qrcode.png"
            );
/*
            ChessQRCodeWriter.getInstance().write(
                    ChessQRCodeMode.PGN,
                    "1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Ng5 Ngf6 6.Bd3 e6 7.N1f3 h6\n" +
                            "8.Nxe6 Qe7 9.O-O fxe6 10.Bg6+ Kd8 {Каспаров встряхнул головой} \n" +
                            "11.Bf4 b5 12.a4 Bb7 13.Re1 Nd5 14.Bg3 Kc8 15.axb5 cxb5 16.Qd3 Bc6 \n" +
                            "17.Bf5 exf5 18.Rxe7 Bxe7 19.c4 1-0",
                    ImageFormat.PNG,
                    "./qrcode.png"
            );
*/
        } catch (ChessQRCodeException e) {
            System.out.println("Could not generate QR Code, Exception: " + e.getMessage());
        }
    }

}