/*
 * Copyright (C) 2008-2020, Juick
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.juick.service;

import com.juick.model.Attachment;
import com.juick.model.Message;
import com.juick.model.Photo;
import org.apache.commons.imaging.ImageReadException;
import org.apache.commons.imaging.Imaging;
import org.apache.commons.imaging.common.ImageMetadata;
import org.apache.commons.imaging.formats.jpeg.JpegImageMetadata;
import org.apache.commons.imaging.formats.tiff.TiffField;
import org.apache.commons.imaging.formats.tiff.constants.TiffTagConstants;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.FilenameUtils;
import org.imgscalr.Scalr;
import org.imgscalr.Scalr.Rotation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.ResourceUtils;
import org.springframework.util.StringUtils;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import java.util.Iterator;

import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;

public class ImagesServiceImpl implements ImagesService {

    private static final Logger logger = LoggerFactory.getLogger(ImagesService.class);

    private final String imgDir;
    private final String tmpDir;

    public ImagesServiceImpl(String imgDir, String tmpDir) {
        this.imgDir = imgDir;
        this.tmpDir = tmpDir;
    }

    @Override
    public void setAttachmentMetadata(String baseUrl, Message msg) throws Exception {
        if (!StringUtils.isEmpty(msg.getAttachmentType())) {
            Photo photo = new Photo();
            if (msg.getRid() > 0) {
                photo.setSmall(String.format("%sphotos-512/%d-%d.%s", baseUrl, msg.getMid(), msg.getRid(),
                        msg.getAttachmentType()));
                photo.setMedium(String.format("%sphotos-1024/%d-%d.%s", baseUrl, msg.getMid(), msg.getRid(),
                        msg.getAttachmentType()));
                photo.setThumbnail(
                        String.format("%sps/%d-%d.%s", baseUrl, msg.getMid(), msg.getRid(), msg.getAttachmentType()));
            } else {
                photo.setSmall(String.format("%sphotos-512/%d.%s", baseUrl, msg.getMid(), msg.getAttachmentType()));
                photo.setMedium(String.format("%sphotos-1024/%d.%s", baseUrl, msg.getMid(), msg.getAttachmentType()));
                photo.setThumbnail(String.format("%sps/%d.%s", baseUrl, msg.getMid(), msg.getAttachmentType()));
            }
            msg.setPhoto(photo);
            String imageName = String.format("%s.%s", msg.getMid(), msg.getAttachmentType());
            if (msg.getRid() > 0) {
                imageName = String.format("%s-%s.%s", msg.getMid(), msg.getRid(), msg.getAttachmentType());
            }
            File fullImage = Paths.get(imgDir, "p", imageName).toFile();
            File mediumImage = Paths.get(imgDir, "photos-1024", imageName).toFile();
            File smallImage = Paths.get(imgDir, "photos-512", imageName).toFile();
            File thumbnailImage = Paths.get(imgDir, "ps", imageName).toFile();
            StringBuilder builder = new StringBuilder();
            builder.append(baseUrl);
            builder.append(msg.getAttachmentType().equals("mp4") ? "video" : "p");
            builder.append("/").append(msg.getMid());
            if (msg.getRid() > 0) {
                builder.append("-").append(msg.getRid());
            }
            builder.append(".").append(msg.getAttachmentType());
            String originalUrl = builder.toString();

            Attachment original = getAttachment(fullImage);
            original.setUrl(originalUrl);

            Attachment medium = getAttachment(mediumImage);
            medium.setUrl(photo.getMedium());
            original.setMedium(medium);

            Attachment small = getAttachment(smallImage);
            small.setUrl(photo.getSmall());
            original.setSmall(small);

            Attachment thumb = getAttachment(thumbnailImage);
            thumb.setUrl(photo.getMedium());
            original.setThumbnail(thumb);

            msg.setAttachment(original);
        }
    }

    @Override
    public Attachment getImageMetadata(String resourceLocation) throws FileNotFoundException, IOException {
        return getAttachment(ResourceUtils.getFile(resourceLocation));
    }

    /**
     * Returns <code>BufferedImage</code>, same as <code>ImageIO.read()</code> does.
     *
     * <p>
     * JPEG images with EXIF metadata are rotated according to Orientation tag.
     *
     * @param imageFile a <code>File</code> to read from.
     */
    private static BufferedImage readImageWithOrientation(File imageFile) throws IOException {

        BufferedImage image = ImageIO.read(imageFile);
        if (!FilenameUtils.getExtension(imageFile.getName()).equals("jpg")) {
            return image;
        }

        try {
            ImageMetadata metadata = Imaging.getMetadata(imageFile);

            if (metadata instanceof JpegImageMetadata) {
                JpegImageMetadata jpegMetadata = (JpegImageMetadata) metadata;
                TiffField orientationField = jpegMetadata.findEXIFValue(TiffTagConstants.TIFF_TAG_ORIENTATION);

                if (orientationField != null) {
                    int orientation = orientationField.getIntValue();
                    switch (orientation) {
                    case TiffTagConstants.ORIENTATION_VALUE_ROTATE_90_CW:
                        image = Scalr.rotate(image, Rotation.CW_90);
                        break;
                    case TiffTagConstants.ORIENTATION_VALUE_ROTATE_180:
                        image = Scalr.rotate(image, Rotation.CW_180);
                        break;
                    case TiffTagConstants.ORIENTATION_VALUE_ROTATE_270_CW:
                        image = Scalr.rotate(image, Rotation.CW_270);
                        break;
                    case TiffTagConstants.ORIENTATION_VALUE_MIRROR_HORIZONTAL:
                        image = Scalr.rotate(image, Rotation.FLIP_HORZ);
                        break;
                    case TiffTagConstants.ORIENTATION_VALUE_MIRROR_VERTICAL:
                        image = Scalr.rotate(image, Rotation.FLIP_VERT);
                        break;
                    case TiffTagConstants.ORIENTATION_VALUE_MIRROR_HORIZONTAL_AND_ROTATE_90_CW:
                        image = Scalr.rotate(Scalr.rotate(image, Rotation.FLIP_HORZ), Rotation.CW_90);
                        break;
                    case TiffTagConstants.ORIENTATION_VALUE_MIRROR_HORIZONTAL_AND_ROTATE_270_CW:
                        image = Scalr.rotate(Scalr.rotate(image, Rotation.FLIP_HORZ), Rotation.CW_270);
                        break;
                    case TiffTagConstants.ORIENTATION_VALUE_HORIZONTAL_NORMAL:
                    default:
                        // do nothing
                        break;
                    }
                }
            }
        } catch (ImageReadException | IOException e) {
            // failed to read metadata.
            // nothing to do here, return image as is.
        }

        return image;
    }

    @Override
    public void saveImageWithPreviews(String tempFilename, String outputFilename) throws IOException {
        String ext = FilenameUtils.getExtension(outputFilename);

        Path outputImagePath = Paths.get(imgDir, "p", outputFilename);
        // this throws strange exceptions
        // Files.move(Paths.get(tmpDir, tempFilename), outputImagePath);
        FileUtils.moveFile(Paths.get(tmpDir, tempFilename).toFile(), outputImagePath.toFile());
        BufferedImage originalImage = readImageWithOrientation(outputImagePath.toFile());

        int width = originalImage.getWidth();
        int height = originalImage.getHeight();
        int maxDimension = Math.max(width, height);
        BufferedImage image1024 = (maxDimension > 1024) ? Scalr.resize(originalImage, 1024) : originalImage;
        BufferedImage image0512 = (maxDimension > 512) ? Scalr.resize(originalImage, 512) : originalImage;
        BufferedImage image0160 = (maxDimension > 160) ? Scalr.resize(originalImage, 160) : originalImage;
        ImageIO.write(image1024, ext, Paths.get(imgDir, "photos-1024", outputFilename).toFile());
        ImageIO.write(image0512, ext, Paths.get(imgDir, "photos-512", outputFilename).toFile());
        ImageIO.write(image0160, ext, Paths.get(imgDir, "ps", outputFilename).toFile());
    }

    public void saveAvatar(String tempFilename, int uid) throws IOException {
        String ext = FilenameUtils.getExtension(tempFilename);
        String originalName = String.format("%s.%s", uid, ext);
        Path originalPath = Paths.get(imgDir, "ao", originalName);
        Files.move(Paths.get(tmpDir, tempFilename), originalPath, StandardCopyOption.REPLACE_EXISTING);
        BufferedImage originalImage = ImageIO.read(originalPath.toFile());

        String targetExt = "png";
        String targetName = String.format("%s.%s", uid, targetExt);
        ImageIO.write(Scalr.resize(originalImage, 96), targetExt, Paths.get(imgDir, "a", targetName).toFile());
        ImageIO.write(Scalr.resize(originalImage, 32), targetExt, Paths.get(imgDir, "as", targetName).toFile());
    }

    public Attachment getAttachment(File imgFile) throws IOException {
        Attachment attachment = new Attachment();
        if (imgFile.exists()) {
            try (ImageInputStream stream = ImageIO.createImageInputStream(imgFile)) {
                Iterator<ImageReader> iter = ImageIO.getImageReaders(stream);
                while (iter.hasNext()) {
                    ImageReader reader = iter.next();
                    try {
                        reader.setInput(stream);
                        attachment.setWidth(reader.getWidth(reader.getMinIndex()));
                        attachment.setHeight(reader.getHeight(reader.getMinIndex()));
                        return attachment;
                    } catch (Exception e) {
                        logger.debug("Error reading {}, trying next reader", imgFile.getAbsolutePath());
                    } finally {
                        reader.dispose();
                    }
                }
            }
        } else {
            logger.warn("File not exists yet: {}", imgFile.getAbsolutePath());
            return attachment;
        }

        logger.warn("Not a known image file {}", imgFile.getAbsolutePath());
        return attachment;
    }

    @Override
    public String getImageDirectory() {
        return imgDir;
    }

    @Override
    public String getTemporaryDirectory() {
        return tmpDir;
    }
}