<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

if (file_exists(__DIR__ . '/vendor/autoload.php')) {
    require_once __DIR__ . '/vendor/autoload.php';
}

function get_db_config() {
    $config = [
        'host' => getenv('DB_HOST') ?: '127.0.0.1',
        'port' => getenv('DB_PORT') ?: '3306',
        'name' => getenv('DB_NAME') ?: 'default_db',
        'user' => getenv('DB_USER') ?: 'default_user',
        'pass' => getenv('DB_PASS') ?: 'default_pass',
    ];
    if (empty($config['name'])) die('DB_NAME is not set');
    if (empty($config['user'])) die('DB_USER is not set');
    return $config;
}

function db() {
    static $pdo;
    if ($pdo) {
        return $pdo;
    }
    try {
        $c = get_db_config();
        $dsn = sprintf('mysql:host=%s;port=%d;dbname=%s;charset=utf8mb4', $c['host'], $c['port'], $c['name']);
        $pdo = new PDO($dsn, $c['user'], $c['pass'], [
            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES => false,
        ]);
        return $pdo;
    } catch (PDOException $e) {
        error_log($e->getMessage());
        http_response_code(500);
        die('Database connection failed. Check server logs.');
    }
}