const axios = require('axios');
const FormData = require('form-data');
const Busboy = require('busboy');

module.exports = async (req, res) => {
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Methods', 'POST, OPTIONS');
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type');

  if (req.method === 'OPTIONS') return res.status(200).end();
  if (req.method !== 'POST') return res.status(405).json({ error: 'Method not allowed' });

  const CHEVERETO_URL = process.env.CHEVERETO_URL;
  const CHEVERETO_KEY = process.env.CHEVERETO_API_KEY;

  return new Promise((resolve) => {
    const busboy = Busboy({ headers: req.headers });
    let fileData = null;

    busboy.on('file', (fieldname, file, info) => {
      const { filename, mimeType } = info;
      const chunks = [];
      file.on('data', (chunk) => chunks.push(chunk));
      file.on('end', () => {
        fileData = {
          buffer: Buffer.concat(chunks),
          filename: filename || 'image.jpg',
          mimeType: mimeType || 'image/jpeg',
        };
      });
    });

    busboy.on('finish', async () => {
      if (!fileData) {
        res.status(400).json({ error: '没有收到文件' });
        return resolve();
      }

      try {
        // Chevereto V4 使用 multipart 直接传二进制
        const form = new FormData();
        form.append('source', fileData.buffer, {
          filename: fileData.filename,
          contentType: fileData.mimeType,
          knownLength: fileData.buffer.length,
        });
        form.append('format', 'json');

        const response = await axios.post(
          `${CHEVERETO_URL}/api/1/upload`,
          form,
          {
            headers: {
              ...form.getHeaders(),
              'X-API-Key': CHEVERETO_KEY, // V4 用 Header 认证
            },
            timeout: 20000,
            maxContentLength: Infinity,
            maxBodyLength: Infinity,
          }
        );

        const imageUrl = response.data?.image?.url;
        if (!imageUrl) {
          res.status(500).json({ error: '未返回图片URL', detail: response.data });
          return resolve();
        }

        res.status(200).json({ url: imageUrl });
        resolve();
      } catch (err) {
        if (err.response) {
          res.status(500).json({
            error: err.message,
            chevereto_status: err.response.status,
            chevereto_detail: err.response.data,
          });
        } else {
          res.status(500).json({ error: err.message });
        }
        resolve();
      }
    });

    busboy.on('error', (err) => {
      res.status(500).json({ error: 'Busboy错误: ' + err.message });
      resolve();
    });

    req.pipe(busboy);
  });
};

hexo.extend.injector.register('body_end', `
<script>
(function() {
  var UPLOAD_API = 'https://你的twikoo.vercel.app/api/upload';

  function hookVueComponent() {
    var input = document.querySelector('input.tk-input-image');
    if (!input) {
      setTimeout(hookVueComponent, 500);
      return;
    }

    // 向上遍历父元素，找到有 onSelectImage 方法的 Vue 实例
    var el = input;
    while (el) {
      var vue = el.__vue__;
      if (vue && typeof vue.onSelectImage === 'function') {
        console.log('找到 Vue 实例，准备 hook onSelectImage');

        vue.onSelectImage = async function(e) {
          var file = e.target.files[0];
          if (!file) return;

          try {
            var fd = new FormData();
            fd.append('file', file);
            var res = await fetch(UPLOAD_API, { method: 'POST', body: fd });
            var data = await res.json();
            if (!data.url) throw new Error(data.error || '未返回URL');

            // 将图片 Markdown 插入评论框
            var textarea = document.querySelector('.tk-input .el-textarea__inner')
                        || document.querySelector('.tk-input textarea');
            if (textarea) {
              var pos = textarea.selectionStart !== undefined
                ? textarea.selectionStart
                : textarea.value.length;
              var imgMd = '![](' + data.url + ')';
              var val = textarea.value;
              textarea.value = val.slice(0, pos) + imgMd + val.slice(pos);
              textarea.dispatchEvent(new Event('input', { bubbles: true }));
            }
            console.log('图片上传成功:', data.url);
          } catch(err) {
            console.error('上传失败:', err);
            alert('图片上传失败: ' + err.message);
          }

          e.target.value = '';
        };

        console.log('Twikoo Vue onSelectImage 已接管');
        return;
      }
      el = el.parentElement;
    }

    setTimeout(hookVueComponent, 500);
  }

  // 等待评论区 DOM 出现后再 hook
  var observer = new MutationObserver(function() {
    if (document.querySelector('input.tk-input-image')) {
      observer.disconnect();
      setTimeout(hookVueComponent, 300);
    }
  });
  observer.observe(document.body, { childList: true, subtree: true });
})();
</script>
`, 'default');