require('dotenv').config();
const express = require('express');
const socketIo = require('socket.io');
const multer = require('multer');
const pdfParse = require('pdf-parse');
const mammoth = require('mammoth');
const fetch = require('node-fetch');
const app = express(); // Initialize Express app

// Middleware
app.use(express.json());

// Multer for file uploads
const upload = multer({ dest: 'uploads/' });

// Socket.io setup (Passenger handles HTTP server)
const io = require('socket.io')(3000, {
  path: '/myapp/socket.io'
});

const sessions = {};

io.on('connection', (socket) => {
    socket.on('joinSession', (data) => {
        const { sessionId, mode } = data;
        socket.join(sessionId);
        if (!sessions[sessionId]) {
            sessions[sessionId] = { history: [{ role: 'system', content: getSystemPrompt(mode) }] };
        }
        socket.emit('chatHistory', sessions[sessionId].history);
    });

    socket.on('sendMessage', async ({ sessionId, message, mode }) => {
        const session = sessions[sessionId];
        session.history.push({ role: 'user', content: message });
        io.to(sessionId).emit('newMessage', { role: 'user', content: message });
        const response = await fetch('https://api.openai.com/v1/chat/completions', {
            method: 'POST',
            headers: {
                'Authorization': `Bearer ${process.env.OPENAI_API_KEY}`,
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({
                model: 'gpt-4o-mini',
                messages: session.history,
                temperature: 0.7,
                max_tokens: 1000
            })
        });
        const data = await response.json();
        const aiReply = data.choices[0].message.content;
        session.history.push({ role: 'assistant', content: aiReply });
        io.to(sessionId).emit('newMessage', { role: 'assistant', content: aiReply });
    });
});

app.post('/api/extract', upload.single('file'), async (req, res) => {
    const file = req.file;
    let text = '';
    if (file.mimetype === 'application/pdf') {
        const buffer = require('fs').readFileSync(file.path);
        const data = await pdfParse(buffer);
        text = data.text;
    } else if (file.mimetype === 'application/vnd.openxmlformats-officedocument.wordprocessingml.document') {
        const result = await mammoth.extractRawText({ path: file.path });
        text = result.value;
    }
    require('fs').unlinkSync(file.path);
    res.json({ text });
});

function getSystemPrompt(mode) {
    const prompts = {
        1: "You are a neutral mediator for non-legal roommate/family disputes. Guide users through empathetic dialogue, suggest compromises, and facilitate resolution without legal binding. Disclaim: This is not legal advice; consult a professional if needed.",
        2: "You are a legal mediator for binding agreements. Analyze uploaded documents, facilitate negotiation, and draft enforceable terms. Disclaim: This is not legal advice; ensure compliance with local laws and consult an attorney. Suggest e-signature if binding.",
        3: "You are a contract reviewer. Analyze uploaded documents for clauses, risks, fairness, and suggest revisions. Provide neutral, evidence-based feedback. Disclaim: This is not legal advice; consult a lawyer for final review."
    };
    return prompts[mode];
}

// Remove server.listen - Passenger handles this
// No need for http.createServer(app) since Passenger serves the app
module.exports = app; // Export app for Passenger (optional, depending on setup)