const express = require('express');
const sqlite3 = require('sqlite3').verbose();
const bcrypt = require('bcrypt');
const cors = require('cors');
const bodyParser = require('body-parser');

const app = express();
const port = 5000;

// Middleware
app.use(cors());
app.use(bodyParser.json());

// SQLite database setup
const db = new sqlite3.Database('./database.db', (err) => {
    if (err) {
        console.error(err.message);
    } else {
        console.log('Connected to SQLite database.');
    }
});

// Create users table if it doesn't exist
db.run(`CREATE TABLE IF NOT EXISTS users (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    username TEXT UNIQUE,
    email TEXT UNIQUE,
    password TEXT
)`);

// Create games table if it doesn't exist
db.run(`CREATE TABLE IF NOT EXISTS games (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT,
    description TEXT,
    game_master_id INTEGER,
    participants TEXT
)`);

// Registration route
app.post('/register', async (req, res) => {
    const { username, email, password } = req.body;
    try {
        const hashedPassword = await bcrypt.hash(password, 10);
        const stmt = db.prepare('INSERT INTO users (username, email, password) VALUES (?, ?, ?)');
        stmt.run([username, email, hashedPassword], function (err) {
            if (err) {
                return res.status(400).json({ error: 'User already exists or invalid data.' });
            }
            res.status(201).json({ message: 'User registered successfully!', userId: this.lastID });
        });
        stmt.finalize();
    } catch (error) {
        res.status(500).json({ error: 'Internal server error' });
    }
});

// Login route
app.post('/login', (req, res) => {
    const { username, password } = req.body;
    db.get('SELECT * FROM users WHERE username = ?', [username], async (err, row) => {
        if (err) {
            return res.status(500).json({ error: 'Internal server error' });
        }
        if (!row || !(await bcrypt.compare(password, row.password))) {
            return res.status(400).json({ error: 'Invalid username or password.' });
        }
        res.json({ message: 'Login successful!', userId: row.id });
    });
});

// Fetch games for a specific user
app.get('/games/:userId', (req, res) => {
    const userId = req.params.userId;
    db.all(
        `SELECT * FROM games WHERE game_master_id = ? OR participants LIKE ?`,
        [userId, `%${userId}%`],
        (err, rows) => {
            if (err) {
                return res.status(500).json({ error: 'Internal server error' });
            }
            res.json(rows);
        }
    );
});

// Create a new game
app.post('/games', (req, res) => {
    const { name, description, gameMasterId, participants } = req.body;
    const stmt = db.prepare('INSERT INTO games (name, description, game_master_id, participants) VALUES (?, ?, ?, ?)');
    stmt.run([name, description, gameMasterId, JSON.stringify(participants)], function (err) {
        if (err) {
            return res.status(400).json({ error: 'Failed to create game.' });
        }
        res.status(201).json({ message: 'Game created successfully!', gameId: this.lastID });
    });
    stmt.finalize();
});

// Start the server
app.listen(port, () => {
    console.log(`Server running on http://localhost:${port}`);
});