const express = require('express');
const http = require('http');
const mysql = require('mysql');
const bodyParser = require('body-parser');
const cors = require('cors')
const WebSocket = require('ws');

const wss = new WebSocket.Server({ port: 8080 });
const app = express();
app.use(cors())
const server = http.createServer(app);

app.use(bodyParser.json());

// MySQL connection
const db = mysql.createConnection({
    host: 'localhost',
    port: 3306,
    user: 'root',
    database: 'mobile'
});

db.connect(err => {
    if (err) {
        console.error('Database connection failed:', err.stack);
        return;
    }
    console.log('Connected to database.');
});

app.get('/', (req, res) => {
    res.status(200).end();
});

// CRUD routes
app.get('/drug', (req, res) => {
    db.query('SELECT * FROM drug', (err, results) => {
        if (err) throw err;
        res.json(results);
    });
});

app.post('/drug', (req, res) => {
    const newItem = req.body;
    delete newItem.id;
    db.query('INSERT INTO drug SET ?', newItem, (err, result) => {
        if (err) throw err;
        emit('itemAdded', { id: parseInt(result.insertId), ...newItem });
        res.status(201).json({ id: parseInt(result.insertId), ...newItem });
    });
});

app.put('/drug', (req, res) => {
    const updatedItem = req.body;
    const id = parseInt(req.query.id);
    db.query('UPDATE drug SET ? WHERE id = ?', [updatedItem, id], (err) => {
        if (err) throw err;
        emit('itemUpdated', { id, ...updatedItem });
        res.status(200).json({ id, ...updatedItem });
    });
});

app.delete('/drug', (req, res) => {
    const id = parseInt(req.query.id);
    db.query('DELETE FROM drug WHERE id = ?', [id], (err) => {
        if (err) throw err;
        emit('itemDeleted', { id });
        res.status(204).end();
    });
});

// WebSocket connection
wss.on('connection', (socket) => {
    console.log('New client connected');
    socket.on('disconnect', () => {
        console.log('Client disconnected');
    });
    socket.on('message', (message) => {
        console.log('Message received:', message);
    });
    socket.on('close', () => {
        console.log('Client disconnected');
    });
    socket.on('error', (err) => {
        console.error('Error:', err);
    });

});

wss.on('close', () => {
    console.log('Client disconnected');
});

wss.on('error', (err) => {
    console.error('Error:', err);
});



const emit = (event, data) => {
    wss.clients.forEach(client => {
        if (client.readyState === WebSocket.OPEN) {
            client.send(JSON.stringify({ event, data }));
        }
    });
};


const PORT = process.env.PORT || 3000;
server.listen(PORT, () => {
    console.log(`Server is running on port ${PORT}`);
});