<?php

declare(strict_types=1);

namespace Steuerkram;

use PDO;
use PDOException;

class Database
{
    private static ?PDO $instance = null;
    private static int $txDepth = 0;

    public static function get(): PDO
    {
        if (self::$instance === null) {
            $host = Config::get('db_host');
            $name = Config::get('db_name');
            $user = Config::get('db_user');
            $pass = Config::get('db_pass');

            $dsn = "mysql:host={$host};dbname={$name};charset=utf8mb4";

            self::$instance = new PDO($dsn, $user, $pass, [
                PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
                PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
                PDO::ATTR_EMULATE_PREPARES   => false,
            ]);
        }

        return self::$instance;
    }

    // Convenience wrappers
    public static function query(string $sql, array $params = []): \PDOStatement
    {
        $stmt = self::get()->prepare($sql);
        $stmt->execute($params);
        return $stmt;
    }

    public static function fetchAll(string $sql, array $params = []): array
    {
        return self::query($sql, $params)->fetchAll();
    }

    public static function fetchOne(string $sql, array $params = []): array|false
    {
        return self::query($sql, $params)->fetch();
    }

    public static function execute(string $sql, array $params = []): int
    {
        $stmt = self::query($sql, $params);
        return $stmt->rowCount();
    }

    public static function lastInsertId(): string
    {
        return self::get()->lastInsertId();
    }

    public static function beginTransaction(): void
    {
        if (self::$txDepth === 0) {
            self::get()->beginTransaction();
        }
        self::$txDepth++;
    }

    public static function commit(): void
    {
        if (self::$txDepth > 0) {
            self::$txDepth--;
        }
        if (self::$txDepth === 0 && self::get()->inTransaction()) {
            self::get()->commit();
        }
    }

    public static function rollBack(): void
    {
        self::$txDepth = 0;
        if (self::get()->inTransaction()) {
            self::get()->rollBack();
        }
    }
}