server.js

const express = require('express');
const { OpenAI } = require('openai');
const cors = require('cors');
require('dotenv').config({ path: '.env.js' });

const app = express();
const port = process.env.PORT || 3000;

// Configure OpenAI client for DeepSeek
const client = new OpenAI({
  apiKey: process.env.DEEPSEEK_API_KEY,
  baseURL: process.env.DEEPSEEK_BASE_URL || "https://api.deepseek.com"
});

// Middleware
app.use(cors());
app.use(express.json());
app.use(express.static('public'));

// Serve index.html
app.get('/', (req, res) => {
  res.sendFile(__dirname + '/templates/index.html');
});

// Stream response route
app.post('/stream', async (req, res) => {
  const { message } = req.body;

  // Set headers for server-sent events
  res.setHeader('Content-Type', 'text/event-stream');
  res.setHeader('Cache-Control', 'no-cache');
  res.setHeader('Connection', 'keep-open');

  try {
    const stream = await client.chat.completions.create({
      model: "deepseek-chat",
      messages: [
        { role: "system", content: "You are a helpful assistant." },
        { role: "user", content: message }
      ],
      stream: true
    });

    for await (const chunk of stream) {
      const content = chunk.choices[0]?.delta?.content;
      if (content) {
        // Send data with 'data:' prefix for SSE
        res.write(`data: ${content}\n\n`);
      }
    }

    res.end();
  } catch (error) {
    console.error('Streaming error:', error);
    res.status(500).json({ error: 'Streaming failed' });
  }
});

// Start server
app.listen(port, () => {
  console.log(`Server running at http://localhost:${port}`);
});