if ($_SERVER["REQUEST_METHOD"] === "POST")
{
    $title = $_POST["title"];
    $body = $_POST["body"];
    $slug = slugify($title);

    if (empty(trim($title))) {
        $errors[] = "No title. Please enter a title.";
    } elseif (strlen($title) > MAX_LENGTH_TITLE) {
        $errors[] = "Title too long. Please enter a title less than or equal to " . MAX_LENGTH_TITLE . " characters.";
    }
    if (strlen($body) > MAX_LENGTH_BODY) {
        $errors[] = "Body too long. Please enter a body less than or equal to " . MAX_LENGTH_BODY . " characters.";
    }

    if (!empty($_POST["edit-article"]))
    {
        if (slugify($title) !== $article["slug"]) {
            $errors[] = "Title may only change in capitalization or by having additional symbols added.";
        }
        if (empty($errors)) {
            $stmt = $pdo->prepare("UPDATE articles SET title = ?, body = ? WHERE id = ?");
            $stmt->execute([$title, $body, $article["id"]]);
            $_SESSION["message"] = "Article successfully updated.";
            header("Location: /wiki.php?title=" . $article["slug"]);
            exit();
        }
    } elseif (!empty($_POST["create-article"])) {

        $stmt = $pdo->prepare("SELECT title, slug FROM articles WHERE title = ? OR slug = ?");
        $stmt->execute([$title, $slug]);
        $article_exists = $stmt->fetch();

        if ($article_exists) {
            $errors[] = "An article by that title already exists. Please choose a different title.";
        }
        if (empty($errors)) {
            $stmt = $pdo->prepare("INSERT INTO articles (title, slug, body) VALUES (?, ?, ?)");
            $stmt->execute([$title, $slug, $body]);
            $_SESSION["message"] = "Article successfully created.";
            header("Location: /wiki.php?title=" . $slug);
            exit();
        }
    }
}
$title = $article["title"] ?? $title;
$template = "edit.php";
require_once "templates/layout.php";