app.js

const express = require('express')
const path = require('path')
const fetch = require('cross-fetch')
const app = express()
var multer = require('multer');
var forms = multer({limits: { fieldSize: 10*1024*1024 }});
app.use(forms.array()); 

const bodyParser = require('body-parser')
app.use(bodyParser.json({limit : '50mb' }));  
app.use(bodyParser.urlencoded({ extended: true }));

const fetchSSE = require('./fetchsse.js');


app.all(`*`, async (req, res) => {
  const url = `https://api.openai.com${req.url}`;
  // 从 header 中取得 Authorization': 'Bearer 后的 token
  const token = req.headers.authorization?.split(' ')[1];
  if( !token ) return res.status(403).send('Forbidden');

  const openai_key = token.split(':')[0];
  if( !openai_key ) return res.status(403).send('Forbidden');

  const proxy_key = token.split(':')[1]||"";  
  if( process.env.PROXY_KEY && proxy_key !== process.env.PROXY_KEY ) 
    return res.status(403).send('Forbidden');

  
  const options = {
      method: req.method,
      timeout: process.env.TIMEOUT||5000,
      headers: {
        'Content-Type': 'application/json; charset=utf-8',
        'Authorization': 'Bearer '+ openai_key,
    },
  };
  
  if( req.method.toLocaleLowerCase() === 'post' && req.body ) options.body = JSON.stringify(req.body);
  console.log({url, options});

  try {
    const response = await myFetch(url, options);
    console.log(response);
    const data = await response.json();
    console.log( data );
    res.json(data);
  } catch (error) {
    console.error(error);
    res.status(500).json({"error":error.toString()});  
  }
})

async function myFetch(url, options) {
  const {timeout, ...fetchOptions} = options;
  const controller = new AbortController();
  const timeoutId = setTimeout(() => controller.abort(), timeout||5000)
  const res = await fetch(url, {...fetchOptions,signal:controller.signal});
  clearTimeout(timeoutId);
  return res;
}






// Error handler
app.use(function(err, req, res, next) {
  console.error(err)
  res.status(500).send('Internal Serverless Error')
})

const port = process.env.PORT||9000;
app.listen(port, () => {
  console.log(`Server start on http://localhost:${port}`);
})