шаг 1 сделан

app/Core/Database.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Core;
+
+use PDO;
+
+final class Database
+{
+    private static ?PDO $pdo = null;
+
+    public static function pdo(): PDO
+    {
+        if (self::$pdo !== null) {
+            return self::$pdo;
+        }
+
+        $host = app_env('DB_HOST', 'localhost');
+        $port = app_env('DB_PORT', '3306');
+        $database = app_env('DB_DATABASE', '');
+        $charset = app_env('DB_CHARSET', 'utf8mb4');
+        $username = app_env('DB_USERNAME', '');
+        $password = app_env('DB_PASSWORD', '');
+
+        $dsn = "mysql:host={$host};port={$port};dbname={$database};charset={$charset}";
+
+        self::$pdo = new PDO($dsn, $username, $password, [
+            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
+            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
+            PDO::ATTR_EMULATE_PREPARES => false,
+        ]);
+
+        return self::$pdo;
+    }
+}

app/Core/Env.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Core;
+
+final class Env
+{
+    public static function load(string $path): void
+    {
+        if (!is_file($path)) {
+            return;
+        }
+
+        $lines = file($path, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
+
+        if ($lines === false) {
+            return;
+        }
+
+        foreach ($lines as $line) {
+            $line = trim($line);
+
+            if ($line === '' || str_starts_with($line, '#')) {
+                continue;
+            }
+
+            [$key, $value] = array_pad(explode('=', $line, 2), 2, '');
+            $key = trim($key);
+            $value = self::normalizeValue(trim($value));
+
+            if ($key === '') {
+                continue;
+            }
+
+            $_ENV[$key] = $value;
+            putenv($key . '=' . $value);
+        }
+    }
+
+    private static function normalizeValue(string $value): string
+    {
+        if (
+            strlen($value) >= 2
+            && (($value[0] === '"' && $value[-1] === '"') || ($value[0] === "'" && $value[-1] === "'"))
+        ) {
+            return substr($value, 1, -1);
+        }
+
+        return $value;
+    }
+}

app/Core/View.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Core;
+
+final class View
+{
+    public static function render(string $template, array $data = []): void
+    {
+        $templatePath = base_path('views/' . trim($template, '/') . '.php');
+
+        if (!is_file($templatePath)) {
+            http_response_code(500);
+            echo 'Template not found';
+            return;
+        }
+
+        extract($data, EXTR_SKIP);
+
+        require base_path('views/layouts/main.php');
+    }
+}

app/bootstrap.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+spl_autoload_register(static function (string $class): void {
+    $prefix = 'App\\';
+
+    if (!str_starts_with($class, $prefix)) {
+        return;
+    }
+
+    $relativeClass = substr($class, strlen($prefix));
+    $path = __DIR__ . '/' . str_replace('\\', '/', $relativeClass) . '.php';
+
+    if (is_file($path)) {
+        require_once $path;
+    }
+});
+
+require_once __DIR__ . '/helpers.php';
+
+App\Core\Env::load(dirname(__DIR__) . '/.env');

app/helpers.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Core\View;
+
+function app_env(string $key, ?string $default = null): ?string
+{
+    $value = $_ENV[$key] ?? getenv($key);
+
+    if ($value === false || $value === null) {
+        return $default;
+    }
+
+    return (string) $value;
+}
+
+function base_path(string $path = ''): string
+{
+    $base = dirname(__DIR__);
+
+    return $path === '' ? $base : $base . '/' . ltrim($path, '/');
+}
+
+function view(string $template, array $data = []): void
+{
+    View::render($template, $data);
+}