package org.sxkj.resource.util;

import lombok.extern.slf4j.Slf4j;
import net.coobird.thumbnailator.Thumbnails;
import org.springframework.mock.web.MockMultipartFile;
import org.springframework.web.multipart.MultipartFile;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/**
 * 获取图片尺寸和截图 工具类
 *
 * @author zhangxiaoyan
 */
@Slf4j
public class ImageSizeUtil {


	/**
	 * 获取图片最长边长度
	 * @param params
	 * @return
	 */
	public static int getImageLengthOfSide(MultipartFile params){
		int lengthSize = 0;
		Map<String, Integer> result = new HashMap<>();
		long beginTime = new Date().getTime();
		// 获取图片格式
		String suffixName = getSuffixNameInfo(params);
		try {
			Iterator<ImageReader> readers = ImageIO.getImageReadersByFormatName(suffixName);
			ImageReader reader = (ImageReader) readers.next();
			ImageInputStream iis = ImageIO.createImageInputStream(params.getInputStream());
			reader.setInput(iis, true);
			result.put("width",reader.getWidth(0));
			result.put("height",reader.getHeight(0));
			if(reader.getWidth(0) > reader.getHeight(0)){
				lengthSize = reader.getWidth(0);
			}else{
				lengthSize = reader.getHeight(0);
			}
		} catch (IOException e) {
			e.printStackTrace();
		}

		return lengthSize;
	}

	/**
	 * 获取图片格式
	 * @param params
	 * @return
	 */
	public static String getSuffixNameInfo(MultipartFile params){
		String result = "";
		// 图片后缀
		String suffixName = params.getOriginalFilename().substring(
			params.getOriginalFilename().lastIndexOf("."));
		if(suffixName.indexOf("png")>0){
			result = "png";
		}else if(suffixName.indexOf("jpg")>0){
			result = "jpg";
		}else if(suffixName.indexOf("jpeg")>0){
			result = "jpeg";
		}

		return result;
	}




	/**
	 * 根据指定大小压缩图片
	 *
	 * @param imageBytes  源图片字节数组
	 * @param desFileSize 指定图片大小，单位kb
	 * @return 压缩质量后的图片字节数组
	 */
	public static byte[] compressPicForScale(byte[] imageBytes, long desFileSize) {
		if (imageBytes == null || imageBytes.length <= 0 || imageBytes.length < desFileSize * 1024) {
			return imageBytes;
		}
		long srcSize = imageBytes.length;
		double accuracy = getAccuracy(srcSize / 1024);
//        double accuracy = 0.85;
		try {
			while (imageBytes.length > desFileSize * 1024) {
				ByteArrayInputStream inputStream = new ByteArrayInputStream(imageBytes);
				ByteArrayOutputStream outputStream = new ByteArrayOutputStream(imageBytes.length);
				Thumbnails.of(inputStream)
					.scale(accuracy)
					.outputQuality(accuracy)
					.toOutputStream(outputStream);
				imageBytes = outputStream.toByteArray();
			}
			log.info("【图片压缩】imageId={} | 图片原大小={}kb | 压缩后大小={}kb",
				"", srcSize / 1024, imageBytes.length / 1024);
		} catch (Exception e) {
			log.error("【图片压缩】msg=图片压缩失败!", e);
		}finally {
		}
		return imageBytes;
	}

	/**
	 * 自动调节精度(经验数值)
	 *
	 * @param size 源图片大小，单位kb
	 * @return 图片压缩质量比
	 */
	private static double getAccuracy(long size) {
		double accuracy;
		if (size < 900) {
			accuracy = 0.85;
		} else if (size < 2047) {
//            accuracy = 0.6;
			accuracy = 0.8;
		} else if (size < 3275) {
//            accuracy = 0.44;
			accuracy = 0.7;
		} else {
			accuracy = 0.4;
		}
		return accuracy;
	}

	/**
	 * 压缩图片
	 * @return
	 */
	public static MultipartFile compressPic(MultipartFile multipartFile){
		// 获取图片最长边
		int imageLengthSize = ImageSizeUtil.getImageLengthOfSide(multipartFile);
		// 获取图片大小
		Long swd = multipartFile.getSize();
		try {
			InputStream inputStream = multipartFile.getInputStream();
			// 图片压缩并返回字节数组
			byte[] imgData = ImageSizeUtil.compressPicForScale(ToolsUtil.getByteArray(inputStream),2000);
			// 转换回 multipartFile 文件
			ByteArrayInputStream stream = new ByteArrayInputStream(imgData);
			String fileName = multipartFile.getOriginalFilename() + System.currentTimeMillis()  + ".jpg";
			// 使用MinIO客户端上传图片
			MockMultipartFile mockMultipartFile
				= new MockMultipartFile("__init__.py", fileName, "application/octet-stream", stream);
			// 关闭流
			stream.close();
			inputStream.close();
			// 赋值
			return mockMultipartFile;
		} catch (IOException e) {
			e.printStackTrace();
		}finally {
			// 流关闭
		}
		return null;
	}

}