package com.example.sso.dao;

import net.coobird.thumbnailator.Thumbnails;
import net.coobird.thumbnailator.geometry.Positions;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.*;
import java.nio.file.Files;
import java.nio.file.Paths;

public class ThumbnailCompressor {

    private static final long MAX_SIZE = 300 * 1024; // 500KB

    /**
     * 使用Thumbnailator压缩图片
     */
    public static long compressWithThumbnailator(String inputPath, String outputPath) throws IOException {
        File inputFile = new File(inputPath);
        long fileSize = inputFile.length();

        System.out.println("原始大小: " + formatFileSize(fileSize));

        // 如果小于500KB，直接复制
        if (fileSize <= MAX_SIZE) {
            Files.copy(inputFile.toPath(), Paths.get(outputPath));
            return fileSize;
        }

        // 获取图片尺寸
        BufferedImage originalImage = ImageIO.read(inputFile);
        int width = originalImage.getWidth();
        int height = originalImage.getHeight();

        // 计算缩放比例
        float scale = 1.0f;
        if (width > 1920 || height > 1080) {
            float widthRatio = 1920f / width;
            float heightRatio = 1080f / height;
            scale = Math.min(widthRatio, heightRatio);
        }

        // 逐步压缩
        float quality = 0.9f;
        long compressedSize = Long.MAX_VALUE;
        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        while (quality > 0.1f && compressedSize > MAX_SIZE) {
            baos.reset();

            Thumbnails.of(inputFile)
                    .scale(scale)
                    .outputQuality(quality)
                    .outputFormat("jpg")
                    .toOutputStream(baos);

            compressedSize = baos.size();
            System.out.println("质量: " + quality + ", 大小: " + formatFileSize(compressedSize));

            quality -= 0.1f;
        }

        // 保存文件
        try (FileOutputStream fos = new FileOutputStream(outputPath)) {
            fos.write(baos.toByteArray());
        }

        return compressedSize;
    }

    /**
     * 批量压缩
     */
    public static void batchCompress(String inputDir, String outputDir, long maxSize) throws IOException {
        File dir = new File(inputDir);
        File[] imageFiles = dir.listFiles((d, name) ->
                name.toLowerCase().endsWith(".jpg") ||
                        name.toLowerCase().endsWith(".jpeg") ||
                        name.toLowerCase().endsWith(".png") ||
                        name.toLowerCase().endsWith(".bmp")
        );

        if (imageFiles == null) return;

        for (File imageFile : imageFiles) {
            String outputPath = outputDir + File.separator + "compressed_" + imageFile.getName();
            long compressedSize = compressWithThumbnailator(imageFile.getPath(), outputPath);

            System.out.println(imageFile.getName() +
                    " 压缩后: " + formatFileSize(compressedSize));
        }
    }

    private static String formatFileSize(long size) {
        if (size < 1024) return size + " B";
        if (size < 1024 * 1024) return String.format("%.2f KB", size / 1024.0);
        if (size < 1024 * 1024 * 1024) return String.format("%.2f MB", size / (1024.0 * 1024.0));
        return String.format("%.2f GB", size / (1024.0 * 1024.0 * 1024.0));
    }

    public static void main(String[] args) {
        try {
            // 压缩单个图片
            long size = compressWithThumbnailator("D:\\下载模板\\微信图片_20251224111834_4_27.jpg", "D:\\下载模板\\微信图片_20251224111834_4_27.jpg");
            System.out.println("最终大小: " + formatFileSize(size));

            // 批量压缩
            // batchCompress("input_images", "output_images", 500 * 1024);

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}