<?php
// db/config.php

function db_connect() {
    static $pdo;

    if ($pdo) {
        return $pdo;
    }

    $host = '127.0.0.1';
    $db   = 'app';
    $user = 'root';
    $pass = '';
    $charset = 'utf8mb4';

    $dsn = "mysql:host=$host;dbname=$db;charset=$charset";
    $options = [
        PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
        PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
        PDO::ATTR_EMULATE_PREPARES   => false,
    ];

    try {
        $pdo = new PDO($dsn, $user, $pass, $options);
        return $pdo;
    } catch (\PDOException $e) {
        // In a real app, log this error and show a generic message
        throw new \PDOException($e->getMessage(), (int)$e->getCode());
    }
}

function run_migrations() {
    $pdo = db_connect();
    $migration_dir = __DIR__ . '/migrations';
    $files = glob($migration_dir . '/*.sql');
    sort($files);

    foreach ($files as $file) {
        try {
            $sql = file_get_contents($file);
            $pdo->exec($sql);
        } catch (\PDOException $e) {
            // Log error if needed, but continue
            // This might happen if the table already exists, which is fine for idempotent scripts
        }
    }
}