package com.dji.sample.media.util;

import java.awt.image.BufferedImage;
import java.io.*;
import java.net.URL;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;

public class ImageDownloaderAndCompressor {


    private static final int THREAD_POOL_SIZE = 10;

    public static void downloadAndSaveImages(List<String> urls, String outputFolder) {
        ExecutorService executorService = Executors.newFixedThreadPool(THREAD_POOL_SIZE);
        CountDownLatch latch = new CountDownLatch(urls.size());
        int count = 0;

        for (String imageUrl : urls) {
            final int index = count++;
            executorService.submit(() -> {
                try {
                    // 下载图片
                    URL url = new URL(imageUrl);
                    BufferedImage image = ImageIO.read(url);
                    // 保存图片
                    File outputfile = new File(outputFolder, "image_" + index + ".jpg");
                    ImageIO.write(image, "jpg", outputfile);
                    System.out.println("Saved: " + outputfile.getAbsolutePath());
                } catch (IOException e) {
                    System.err.println("Failed to download image: " + imageUrl);
                    e.printStackTrace();
                } finally {
                    latch.countDown();
                }
            });
        }

        try {
            latch.await();
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            System.err.println("Image downloading was interrupted.");
        } finally {
            executorService.shutdown();
        }
    }

    public static void zipAndSendFolder(String folderName, HttpServletResponse response) {
        File zipFile = new File(folderName + ".zip");
        try {
            zipFolder(folderName, zipFile.getPath());

            // 设置响应头
            response.setContentType("application/zip");
            response.setHeader("Content-Disposition", "attachment; filename=" + zipFile.getName());
            response.setContentLength((int) zipFile.length());

            // 将压缩文件写入响应
            try (InputStream is = new FileInputStream(zipFile);
                 OutputStream os = response.getOutputStream()) {
                byte[] buffer = new byte[1024];
                int length;
                while ((length = is.read(buffer)) > 0) {
                    os.write(buffer, 0, length);
                }
            }

        } catch (IOException e) {
            System.err.println("Failed to compress or send folder: " + folderName);
            e.printStackTrace();
            response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            try {
                response.getWriter().write("Failed to compress or send folder: " + folderName);
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        } finally {
            // 删除临时压缩文件
            if (zipFile.exists()) {
                zipFile.delete();
            }
        }
    }

    public static void zipFolder(String srcFolder, String destZipFile) throws IOException {
        try (FileOutputStream fos = new FileOutputStream(destZipFile);
             ZipOutputStream zos = new ZipOutputStream(fos)) {

            File srcFile = new File(srcFolder);
            for (File file : srcFile.listFiles()) {
                try (FileInputStream fis = new FileInputStream(file)) {
                    ZipEntry zipEntry = new ZipEntry(file.getName());
                    zos.putNextEntry(zipEntry);

                    byte[] bytes = new byte[1024];
                    int length;
                    while ((length = fis.read(bytes)) >= 0) {
                        zos.write(bytes, 0, length);
                    }
                    zos.closeEntry();
                }
            }
        }
    }

    public static void cleanUp(String folderName) {
        File folder = new File(folderName);
        deleteFolder(folder);
    }

    public static void deleteFolder(File folder) {
        File[] files = folder.listFiles();
        if (files != null) {
            for (File f : files) {
                if (f.isDirectory()) {
                    deleteFolder(f);
                } else {
                    f.delete();
                }
            }
        }
        folder.delete();
    }

}