# Metoda POST
if ($_SERVER['REQUEST_METHOD'] === 'POST' && $_SERVER['REQUEST_URI'] === '/api/categories/') {
    $name  = $_POST['name'] ?? null;
    $color = $_POST['color'] ?? null;

    # 400 Bad Request - pusta nazwa, pusty kolor lub zły format koloru
    if (empty($name) || empty($color) || !preg_match('/^#[0-9A-Fa-f]{6}$/', $color)) {
        http_response_code(400);
        echo json_encode(['error' => 'Bad request']);
        exit();
    }

    $stmt = $conn->prepare("SELECT id FROM categories WHERE name = :name");
    $stmt->execute(['name' => $name]);

    # 409 Conflict - nazwa istnieje w bazie
    if ($stmt->rowCount() > 0) {
        http_response_code(409);
        echo json_encode(['error' => 'Conflict']);
        exit();
    }

    $stmt = $conn->prepare("INSERT INTO categories (name, color) VALUES (:name, :color)");
    $stmt->execute(['name' => $name, 'color' => $color]);

    # 201 Created
    $newId = $conn->lastInsertId();
    http_response_code(201);
    echo json_encode(['id' => $newId, 'name' => $name, 'color' => $color]);
    exit();
}

# Metoda PUT
if ($_SERVER['REQUEST_METHOD'] === 'PUT' && preg_match('#^/api/categories/(\d+)/$#', $_SERVER['REQUEST_URI'], $matches)) {
    $categoryId = $matches[1];

    $input = json_decode(file_get_contents("php://input"), true);
    $name  = $input['name'] ?? null;
    $color = $input['color'] ?? null;


   if ($name === null || $color === null) {
    http_response_code(400); // Bad Request
    echo json_encode(['error' => 'Bad Request']);
    exit();
    }

    // Sprawdź, czy kategoria o podanym ID istnieje
    $stmt = $conn->prepare("SELECT id FROM categories WHERE id = :id");
    $stmt->execute(['id' => $categoryId]);
    $category = $stmt->fetch(PDO::FETCH_ASSOC);

    if (!$category) {
        http_response_code(404); // Not Found
        echo json_encode(['error' => 'Not Found']);
        exit();
    }

    // Czy już istnieje taka nazwa kategorii dla innego id w bazie danych
    $stmt = $conn->prepare("SELECT id FROM categories WHERE name = :name AND id != :id");
    $stmt->execute(['name' => $name, 'id' => $categoryId]);

    if ($stmt->rowCount() > 0) {
        http_response_code(409); // Conflict
        echo json_encode(['error' => 'Conflict']);
        exit();
    }

    // Sprawdzenie czy nazwa lub kolor są puste / kolor ma # i 6 znaków
    if (empty($name) || empty($color) || !preg_match('/^#[0-9A-Fa-f]{6}$/', $color)) {
        http_response_code(400);
        echo json_encode(['error' => 'Bad Request']);
        exit();
    }

    // Aktualizacja danych
    $stmt = $conn->prepare("UPDATE categories SET name = :name, color = :color WHERE id = :id");
    $stmt->execute(['name' => $name, 'color' => $color]);

    http_response_code(204);
    exit();
}