const fetch = require('node-fetch');
const FormData = require('form-data');
const sharp = require('sharp');

async function onRequest(req, res) {
  const url = new URL(req.url, `http://${req.headers.host}`);
  const imageUrl = url.searchParams.get('q');

  if (!imageUrl) {
    return res.status(400).send('');
  }

  try {
    const response = await fetch(imageUrl);
    if (!response.ok) {
      throw new Error(`获取图像失败: ${response.statusText}`);
    }
    const imageBuffer = await response.buffer();
    console.log('原始图像大小:', imageBuffer.byteLength);

    // 使用 sharp 库来调整图像大小
    const resizedImageBuffer = await sharp(imageBuffer).resize(40).toBuffer();
    console.log('压缩后的图像大小:', resizedImageBuffer.byteLength);

    // 创建一个 FormData 对象并添加压缩后的图像
    const formData = new FormData();
    formData.append('file', resizedImageBuffer, { filename: 'compressed.jpg', contentType: 'image/jpeg' });

    // 使用提供的API地址和方法上传文件
    const uploadResponse = await fetch('https://telegra.ph/upload', {
      method: 'POST',
      body: formData
    });

    if (!uploadResponse.ok) {
      throw new Error(`上传图像失败: ${uploadResponse.statusText}`);
    }

    const uploadResult = await uploadResponse.json();
    console.log('上传结果:', uploadResult);
    const uploadedImageUrl = uploadResult[0].src;

    res.setHeader('Content-Type', 'text/plain');
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');
    res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
    res.setHeader('Access-Control-Max-Age', '86400');
    res.send(uploadedImageUrl);
  } catch (error) {
    console.error('压缩图像时出错:', error);
    res.status(500).send('');
  }
}

module.exports = { onRequest };