src/controllers/chatController.js

import { OpenAI } from "openai";

const client = new OpenAI({
  baseURL: "https://router.huggingface.co/novita/v3/openai",
  apiKey: process.env.NOVITA_API_KEY,
});

export const chatCompletion = async (req, res) => {
  try {
    const { messages } = req.body;

    // Default system message if not provided
    if (!messages.some(m => m.role === 'system')) {
      messages.unshift({
        role: 'system',
        content: 'Anda adalah asisten AI yang ramah, baik hati, dan selalu membantu. Gunakan bahasa Indonesia yang santun dan mudah dimengerti.'
      });
    }

    const stream = await client.chat.completions.create({
      model: process.env.MODEL,
      messages,
      stream: true,
    });

    res.setHeader('Content-Type', 'text/plain');

    for await (const chunk of stream) {
      const content = chunk.choices[0]?.delta?.content || '';
      res.write(content);
    }

    res.end();
  } catch (error) {
    console.error('Error:', error);
    res.status(500).json({ error: 'Internal server error' });
  }
};