server.js

const express = require('express');
const cors = require('cors');
const dotenv = require('dotenv');
const path = require('path');

dotenv.config();

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

// Middleware
app.use(cors());
app.use(express.json());
app.use(express.static(path.join(__dirname, 'public')));

// In-memory storage for chat history (in production, use a database)
const chatHistory = [];

// DeepSeek API configuration
const DEEPSEEK_API_KEY = process.env.DEEPSEEK_API_KEY || 'sk-e789f2f01936430b843d08ea81c13c6d';
const DEEPSEEK_API_URL = 'https://api.deepseek.com/chat/completions';

// Language options
const LANGUAGES = {
  english: 'English',
  pidgin: 'Nigerian Pidgin',
  yoruba: 'Yoruba',
  igbo: 'Igbo',
  hausa: 'Hausa'
};

// System prompt for the Qwen model
const SYSTEM_PROMPT = `You are Compatriot, a helpful assistant that explains constitutional and legal rights in Nigeria.
You should respond in the language selected by the user. The available languages are:
- English
- Nigerian Pidgin
- Yoruba
- Igbo
- Hausa

Focus on providing accurate information about Nigerian constitutional and legal rights. If you're unsure about specific legal details, 
acknowledge the limitation and suggest consulting with a legal professional. Always be respectful and helpful.`;

// Chat endpoint
app.post('/api/chat', async (req, res) => {
  try {
    const { message, language } = req.body;
    
    // Validate language
    if (!LANGUAGES[language]) {
      return res.status(400).json({ error: 'Invalid language selected' });
    }
    
    // Add user message to history
    chatHistory.push({ role: 'user', content: message, language });
    
    // Prepare the prompt with language context
    const prompt = `Respond in ${LANGUAGES[language]}: ${message}`;
    
    // Call DeepSeek API
    const response = await fetch(DEEPSEEK_API_URL, {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${DEEPSEEK_API_KEY}`,
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({
        model: 'deepseek-chat',
        messages: [
          { role: 'system', content: SYSTEM_PROMPT },
          { role: 'user', content: prompt }
        ],
        temperature: 0.7
      })
    });
    
    if (!response.ok) {
      const errorData = await response.json();
      throw new Error(`DeepSeek API error: ${errorData.error?.message || response.statusText}`);
    }
    
    const data = await response.json();
    const botResponse = data.choices[0].message.content;
    
    // Add bot response to history
    chatHistory.push({ role: 'assistant', content: botResponse, language });
    
    res.json({ response: botResponse });
  } catch (error) {
    console.error('Chat error:', error);
    res.status(500).json({ error: 'Failed to get response from AI model' });
  }
});

// Get supported languages
app.get('/api/languages', (req, res) => {
  res.json(LANGUAGES);
});

// Get chat history
app.get('/api/history', (req, res) => {
  res.json(chatHistory);
});

// Serve the frontend
app.get('/', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

// Serve all other routes to support React Router
app.get('*', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

app.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});