<?php
// db/config.php

// --- Database Credentials ---
// Replace with your actual database credentials
define('DB_HOST', '127.0.0.1');
define('DB_NAME', 'mymecha'); // Changed from 'default_db'
define('DB_USER', 'root');      // Changed from 'user'
define('DB_PASS', '');          // Assuming empty password for local dev

// --- PDO Connection Function ---
/**
 * Creates a PDO database connection.
 *
 * @return PDO|null A PDO connection object on success, or null on failure.
 */
function db_connect() {
    static $pdo = null; // Static variable to hold the connection

    if ($pdo === null) {
        $dsn = 'mysql:host=' . DB_HOST . ';dbname=' . DB_NAME . ';charset=utf8mb4';
        $options = [
            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES   => false,
        ];

        try {
            // Create the database if it doesn't exist
            $temp_pdo = new PDO('mysql:host=' . DB_HOST, DB_USER, DB_PASS, $options);
            $temp_pdo->exec("CREATE DATABASE IF NOT EXISTS " . DB_NAME);

            // Now connect to the specific database
            $pdo = new PDO($dsn, DB_USER, DB_PASS, $options);

        } catch (PDOException $e) {
            // In a real application, you would log this error, not display it
            // For development, it's useful to see the error
            error_log('Database Connection Error: ' . $e->getMessage());
            // Return null or handle the error as appropriate for your application
            return null;
        }
    }

    return $pdo;
}
?>