<?php
// Database configuration
define('DB_HOST', getenv('DB_HOST') ?: '127.0.0.1');
define('DB_PORT', getenv('DB_PORT') ?: '3306');
define('DB_NAME', getenv('DB_NAME') ?: 'flatlogic');
define('DB_USER', getenv('DB_USER') ?: 'flatlogic');
define('DB_PASS', getenv('DB_PASS') ?: 'flatlogic');

function db() {
    static $pdo;
    if ($pdo) {
        return $pdo;
    }
    try {
        // Connect without specifying a database to create it if it doesn't exist
        $dsn_init = 'mysql:host=' . DB_HOST . ';port=' . DB_PORT . ';charset=utf8mb4';
        $pdo_init = new PDO($dsn_init, DB_USER, DB_PASS, [
            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES => false,
        ]);
        $pdo_init->exec('CREATE DATABASE IF NOT EXISTS `' . DB_NAME . '`');

        // Now connect to the specific database
        $dsn = 'mysql:host=' . DB_HOST . ';port=' . DB_PORT . ';dbname=' . DB_NAME . ';charset=utf8mb4';
        $pdo = new PDO($dsn, DB_USER, DB_PASS, [
            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES   => false,
        ]);

        run_migrations($pdo);

        return $pdo;
    } catch (PDOException $e) {
        // In a real app, you'd log this error and show a generic message
        throw new PDOException($e->getMessage(), (int)$e->getCode());
    }
}

function run_migrations($pdo) {
    $pdo->exec('CREATE TABLE IF NOT EXISTS `migrations` (`migration` VARCHAR(255) NOT NULL, PRIMARY KEY (`migration`))');
    $applied_migrations = $pdo->query('SELECT `migration` FROM `migrations`')->fetchAll(PDO::FETCH_COLUMN);

    $migration_files = glob(__DIR__ . '/migrations/*.sql');
    sort($migration_files);

    foreach ($migration_files as $file) {
        $migration_name = basename($file);
        if (!in_array($migration_name, $applied_migrations)) {
            $sql = file_get_contents($file);
            $pdo->exec($sql);
            $stmt = $pdo->prepare('INSERT INTO `migrations` (`migration`) VALUES (?)');
            $stmt->execute([$migration_name]);
        }
    }
}