config.php

<?php
// Database configuration
define('DB_HOST', 'localhost');
define('DB_USER', 'your_db_username');
define('DB_PASS', 'your_db_password');
define('DB_NAME', 'monthly_tombola');

// Site configuration
define('SITE_NAME', 'Monthly Tombola');
define('SITE_URL', 'https://yourdomain.com');
define('ADMIN_EMAIL', 'admin@yourdomain.com');

// Security settings
define('PEPPER', 'your-random-pepper-string-here'); // For password hashing
define('CSRF_TOKEN_SECRET', 'your-csrf-token-secret-here');

// Start session
session_start();

// Create database connection
try {
    $db = new PDO("mysql:host=".DB_HOST.";dbname=".DB_NAME, DB_USER, DB_PASS);
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
    $db->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
} catch(PDOException $e) {
    die("Database connection failed: " . $e->getMessage());
}

// Common functions
function sanitizeInput($data) {
    return htmlentities(strip_tags(trim($data)), ENT_QUOTES, 'UTF-8');
}

function redirect($url) {
    header("Location: $url");
    exit();
}

function isLoggedIn() {
    return isset($_SESSION['user_id']);
}

function generateCSRFToken() {
    if (empty($_SESSION['csrf_token'])) {
        $_SESSION['csrf_token'] = bin2hex(random_bytes(32));
    }
    return $_SESSION['csrf_token'];
}

function verifyCSRFToken($token) {
    return isset($_SESSION['csrf_token']) && hash_equals($_SESSION['csrf_token'], $token);
}

function hashPassword($password) {
    return password_hash($password . PEPPER, PASSWORD_BCRYPT);
}

function verifyPassword($password, $hash) {
    return password_verify($password . PEPPER, $hash);
}

function generateRandomString($length = 32) {
    return bin2hex(random_bytes($length));
}

function sendEmail($to, $subject, $message) {
    $headers = "From: " . ADMIN_EMAIL . "\r\n";
    $headers .= "Reply-To: " . ADMIN_EMAIL . "\r\n";
    $headers .= "Content-Type: text/html; charset=UTF-8\r\n";
    
    return mail($to, $subject, $message, $headers);
}

// Error handling
set_error_handler(function($errno, $errstr, $errfile, $errline) {
    error_log("Error [$errno] $errstr in $errfile on line $errline");
    if (defined('DEBUG') && DEBUG === true) {
        echo "<div class='alert alert-danger'>Error: $errstr in $errfile on line $errline</div>";
    }
});

// Set timezone
date_default_timezone_set('UTC');
?>