const express = require('express');
const multer = require('multer');
const JSZip = require('jszip');
const { createCanvas } = require('canvas');
const fs = require('fs');
const app = express();

// 设置 multer 用于处理文件上传
const storage = multer.memoryStorage();
const upload = multer({ storage: storage });

app.use(express.json());
app.use(express.urlencoded({ extended: true }));

app.post('/upload', upload.single('file'), async (req, res) => {
  try {
    const file = req.file;
    const fileName = file.originalname;
    const fileType = file.mimetype;
    const fileBuffer = file.buffer;

    // 输出接收到的文件信息
    console.log(`File Name: ${fileName}`);
    console.log(`File Type: ${fileType}`);
    console.log(`File Size: ${fileBuffer.length} bytes`);

    // 压缩文件成 zip 格式
    const zip = new JSZip();
    zip.file(fileName, fileBuffer);
    const zipBuffer = await zip.generateAsync({ type: 'nodebuffer' });

    // 创建包含文件信息的表格图片
    const width = 800;
    const height = 600;
    const canvas = createCanvas(width, height);
    const ctx = canvas.getContext('2d');

    // 设置背景为白色
    ctx.fillStyle = '#FFFFFF';
    ctx.fillRect(0, 0, width, height);

    // 设置文本颜色为黑色，并绘制文本
    ctx.fillStyle = '#000000';
    ctx.font = '20px Arial';
    const text = `
      File Name: ${fileName}
      File Type: ${fileType}
      File Size: ${fileBuffer.length} bytes
      Created At: ${new Date().toLocaleString()}
      Modified At: ${new Date().toLocaleString()}
    `;
    ctx.fillText(text.trim(), 50, 100);

    // 将 canvas 转换为 JPEG 图片
    const rawImageData = canvas.toBuffer('image/jpeg', { quality: 0.75 });

    // 将包含信息的图片和生成的 zip 打包
    const finalBuffer = Buffer.concat([rawImageData, zipBuffer]);

    // 生成新的文件名，添加后缀 -piczip
    const outputFileName = fileName.replace(/\.[^/.]+$/, "") + '-piczip.jpg';

    // 返回新的隐藏 zip 文件的新图片文件
    res.setHeader('Content-Type', 'image/jpeg');
    res.setHeader('Content-Disposition', `attachment; filename="${outputFileName}"`);
    res.send(finalBuffer);
  } catch (error) {
    console.error(error);
    res.status(500).send('An error occurred');
  }
});

const PORT = process.env.PORT || 7860;
app.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});