package useractivity.utils;

import com.drew.imaging.ImageMetadataReader;
import com.drew.metadata.Directory;
import com.drew.metadata.Metadata;
import com.drew.metadata.exif.ExifDirectoryBase;
import org.apache.log4j.Logger;
import org.springframework.web.multipart.MultipartFile;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.HashMap;
import java.util.Map;

/**
 * @author leo
 * @version 2018/11/28 11:01
 * @Description 矯正手機拍攝圖片方向問題
 */
public class RotateImage {

    private static Logger logger = Logger.getLogger(RotateImage.class);

    /**
     * 調整手機上傳的圖片方向
     *
     * @param userHeadImage
     * @param userHeadImage
     * @return
     */
    public static Map rotate(MultipartFile userHeadImage) {
        Image src = null;
        int angel = 0;
        try {
            src = ImageIO.read(userHeadImage.getInputStream());
            File file = File.createTempFile("tmp", null);
            userHeadImage.transferTo(file);
            file.deleteOnExit();
            angel = getRotateAngleForPhoto(file);
        } catch (IOException e) {
            e.printStackTrace();
        }
        Map<String, Object> result = new HashMap<>();
        int src_width = src.getWidth(null);
        int src_height = src.getHeight(null);
        // calculate the new image size
        Rectangle rect_des = CalcRotatedSize(new Rectangle(new Dimension(
                src_width, src_height)), angel);

        BufferedImage res = null;
        res = new BufferedImage(rect_des.width, rect_des.height,
                BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = res.createGraphics();
        // transform
        g2.translate((rect_des.width - src_width) / 2,
                (rect_des.height - src_height) / 2);
        g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);
        g2.drawImage(src, null, null);
        ByteArrayOutputStream bs = new ByteArrayOutputStream();
        try {
            ImageOutputStream imOut = ImageIO.createImageOutputStream(bs);

            //scaledImage1為BufferedImage，jpg為影象的型別
            ImageIO.write(res, "jpg", imOut);
        } catch (IOException e) {
            e.printStackTrace();
        }
        logger.info("轉換工具類中圖片大小" + bs.size());
        InputStream is = new ByteArrayInputStream(bs.toByteArray());
        result.put("is", is);
        result.put("size", bs.size());
        return result;
    }

    public static Rectangle CalcRotatedSize(Rectangle src, int angel) {
        // if angel is greater than 90 degree, we need to do some conversion
        if (angel >= 90) {
            if (angel / 90 % 2 == 1) {
                int temp = src.height;
                src.height = src.width;
                src.width = temp;
            }
            angel = angel % 90;
        }
        double r = Math.sqrt(src.height * src.height + src.width * src.width) / 2;
        double len = 2 * Math.sin(Math.toRadians(angel) / 2) * r;
        double angel_alpha = (Math.PI - Math.toRadians(angel)) / 2;
        double angel_dalta_width = Math.atan((double) src.height / src.width);
        double angel_dalta_height = Math.atan((double) src.width / src.height);
        int len_dalta_width = (int) (len * Math.cos(Math.PI - angel_alpha
                - angel_dalta_width));
        int len_dalta_height = (int) (len * Math.cos(Math.PI - angel_alpha
                - angel_dalta_height));
        int des_width = src.width + len_dalta_width * 2;
        int des_height = src.height + len_dalta_height * 2;
        return new Rectangle(new Dimension(des_width, des_height));
    }

    public static int getRotateAngleForPhoto(File file) {
        int angle = 0;
        Metadata metadata;
        try {
            metadata = ImageMetadataReader.readMetadata(file);
            Directory directory = metadata.getFirstDirectoryOfType(ExifDirectoryBase.class);
            if (directory.containsTag(ExifDirectoryBase.TAG_ORIENTATION)) {

                // Exif資訊中方向　　
                int orientation = directory.getInt(ExifDirectoryBase.TAG_ORIENTATION);

                // 原圖片的方向資訊
                if (6 == orientation) {
                    //6旋轉90
                    angle = 90;
                } else if (3 == orientation) {
                    //3旋轉180
                    angle = 180;
                } else if (8 == orientation) {
                    //8旋轉90
                    angle = 270;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return angle;
    }
}