const express = require('express');
const router = express.Router();
const { AccessToken } = require('livekit-server-sdk');
const db = require('../db');

// Middleware to check permissions?
// For now, simpler: assuming user is logged in (via x-user-id header check in frontend)
// Real implementation should use the checkPermission middleware or verify session

router.post('/token', async (req, res) => {
    const { channelId } = req.body;
    const userId = req.headers['x-user-id']; // Sent by frontend
    
    // Default fallback if no user (should rely on auth middleware ideally)
    if (!userId) {
        return res.status(401).json({ error: 'Unauthorized' });
    }

    try {
        // 1. Get Username (for display)
        const userRes = await db.query('SELECT username FROM users WHERE id = $1', [userId]);
        if (userRes.rows.length === 0) {
            return res.status(404).json({ error: 'User not found' });
        }
        const username = userRes.rows[0].username;

        // 2. Get Channel Name (Optional, for room name check)
        // Ensure channel exists and is of type 'voice'
        const channelRes = await db.query('SELECT id, type FROM channels WHERE id = $1', [channelId]);
        if (channelRes.rows.length === 0) {
            return res.status(404).json({ error: 'Channel not found' });
        }
        if (channelRes.rows[0].type !== 'voice') {
            return res.status(400).json({ error: 'Not a voice channel' });
        }

        // 3. Generate Token
        // API Key/Secret from env
        const apiKey = process.env.LIVEKIT_API_KEY || 'devkey';
        const apiSecret = process.env.LIVEKIT_API_SECRET || 'secret';
        
        const at = new AccessToken(apiKey, apiSecret, {
            identity: userId,
            name: username,
        });

        at.addGrant({
            roomJoin: true,
            room: channelId,
            canPublish: true,
            canSubscribe: true,
        });

        const token = await at.toJwt();

        res.json({ token });

    } catch (err) {
        console.error('Error creating voice token:', err);
        res.status(500).json({ error: 'Server error' });
    }
});

module.exports = router;