<?php
declare (strict_types = 1);

// Interdit l’accès direct au fichier (pas de HTML ici)
if (isset($_SERVER['SCRIPT_FILENAME']) && realpath(__FILE__) === realpath($_SERVER['SCRIPT_FILENAME'])) {
    http_response_code(403);
    exit('Forbidden');
}

/** Est-ce que l'utilisateur est connecté ? */
function is_logged_in(): bool
{
    return isset($_SESSION['compte_id'], $_SESSION['reference_id'])
        && $_SESSION['compte_id'] !== ''
        && $_SESSION['reference_id'] !== '';
}

/** Timeout inactivité (2h) */
function enforce_session_timeout(int $maxIdleSeconds = 7200): void
{
    $now  = time();
    $last = (int) ($_SESSION['last_activity'] ?? 0);

    if ($last > 0 && ($now - $last) > $maxIdleSeconds) {
        logout_and_redirect_to_login($_SERVER['REQUEST_URI'] ?? '/');
    }
    $_SESSION['last_activity'] = $now;
}

/** Anti open-redirect : n’autorise que les chemins internes commençant par '/' */
function next_safe(?string $u): ?string
{
    if (! $u) {
        return null;
    }

    if (! preg_match('#^/[^\\r\\n]*$#', $u)) {
        return null;
    }

    if (strpos($u, '//') === 0) {
        return null;
    }

    return $u;
}

function redirect_forbidden(?string $requestUri = null): void
{
    $u = $requestUri ?: ($_SERVER['REQUEST_URI'] ?? '/');
    $u = next_safe($u) ?? '/';
    header('Location: /403.php?next=' . rawurlencode($u), true, 303);
    exit;
}

function redirect_to_login_with_next(?string $requestUri = null): void
{
    $u = $requestUri ?: ($_SERVER['REQUEST_URI'] ?? '/');
    $u = next_safe($u) ?? '/';

    $_SESSION['redirect_to'] = $u;
    header('Location: /connexion.php?next=' . rawurlencode($u), true, 303);
    exit;
}

function logout_and_redirect_to_login(): void
{
    $_SESSION = [];

    if (session_status() === PHP_SESSION_ACTIVE) {
        $params = session_get_cookie_params();

        setcookie(session_name(), '', [
            'expires'  => time() - 42000,
            'path'     => $params['path'] ?? '/',
            'domain'   => $params['domain'] ?? '',
            'secure'   => (bool) ($params['secure'] ?? false),
            'httponly' => (bool) ($params['httponly'] ?? true),
            'samesite' => $params['samesite'] ?? 'Lax',
        ]);

        session_destroy();
    }

    header('Location: /index.php', true, 303);
    exit;
}

/**
 * 🔒 Re-check rôle depuis DB (optionnel) + hydrate $_SESSION['role'] si absent.
 * Retourne le rôle (string) ou '' si introuvable.
 */
function refresh_role_from_db(PDO $pdo): string
{
    $compteId = (int) ($_SESSION['compte_id'] ?? 0);
    if ($compteId <= 0) {
        return '';
    }

    $stmt = $pdo->prepare("SELECT role FROM compte WHERE id=? LIMIT 1");
    $stmt->execute([$compteId]);
    $role = (string) ($stmt->fetchColumn() ?: '');
    if ($role !== '') {
        $_SESSION['role'] = $role;
    }
    return strtolower($role);
}

/**
 * ✅ À appeler en haut des pages protégées.
 * - $allowedRoles = null => tous rôles
 * - options:
 *   - 'pdo' => PDO (pour re-check DB si demandé)
 *   - 'recheck_db_role' => true/false
 *   - 'admin_strict_reference' => int|null (ex: 88888888)
 */
function require_login_or_redirect(?array $allowedRoles = null, array $options = []): void
{
    if (! is_logged_in()) {
        redirect_to_login_with_next($_SERVER['REQUEST_URI'] ?? '/');
    }

    enforce_session_timeout(7200);

    $pdo     = $options['pdo'] ?? ($GLOBALS['pdo'] ?? null);
    $recheck = (bool) ($options['recheck_db_role'] ?? false);

    // Rôle: session d'abord, DB si demandé (ou si role manquant)
    $userRole = strtolower((string) ($_SESSION['role'] ?? ''));
    if (($userRole === '' || $recheck) && ($pdo instanceof PDO)) {
        $userRole = refresh_role_from_db($pdo);
    }

    if ($allowedRoles) {
        $allowed = array_map(static fn($r) => strtolower((string) $r), $allowedRoles);

        if (! in_array($userRole, $allowed, true)) {
            redirect_forbidden($_SERVER['REQUEST_URI'] ?? '/');
        }

        // 🔥 Renfort admin optionnel : role + reference_id
        if (in_array('admin', $allowed, true)) {
            $strictRef = $options['admin_strict_reference'] ?? null;
            if ($strictRef !== null) {
                $refId = (int) ($_SESSION['reference_id'] ?? 0);
                if ($refId !== (int) $strictRef) {
                    redirect_forbidden($_SERVER['REQUEST_URI'] ?? '/');
                }
            }
        }
    }
}

/* =========================
   Admin helpers (CSRF + logs)
   ========================= */

/** Token CSRF session */
function ensure_csrf_token(): string
{
    if (empty($_SESSION['csrf_token'])) {
        $_SESSION['csrf_token'] = bin2hex(random_bytes(32));
    }
    return (string) $_SESSION['csrf_token'];
}

/** Exige POST + CSRF (supporte aussi header X-CSRF-Token si tu veux fetch/AJAX) */
function require_post_csrf(): void
{
    if (($_SERVER['REQUEST_METHOD'] ?? '') !== 'POST') {
        http_response_code(405);
        exit('Méthode non autorisée');
    }

    $token = $_POST['csrf_token'] ?? '';
    if ($token === '' && ! empty($_SERVER['HTTP_X_CSRF_TOKEN'])) {
        $token = (string) $_SERVER['HTTP_X_CSRF_TOKEN'];
    }

    if ($token === '' || ! hash_equals((string) ($_SESSION['csrf_token'] ?? ''), (string) $token)) {
        http_response_code(419);
        exit('CSRF invalide');
    }
}

/** Log admin minimal */
function log_admin_action(PDO $pdo, int $userId, string $action, string $details = ''): void
{
    // limite simple pour éviter d'exploser la table
    if (strlen($details) > 2000) {
        $details = substr($details, 0, 2000);
    }

    $pdo->prepare(
        "INSERT INTO admin_actions_log (user_id, action, details, ip) VALUES (?,?,?,?)"
    )->execute([
        $userId,
        $action,
        $details,
        $_SERVER['REMOTE_ADDR'] ?? '',
    ]);
}