class DebugScope

final class DebugScope implements ScopeInterface {
    private static bool $shutdownHandlerInitialized = false;
    private static bool $finalShutdownPhase = false;
    private readonly ?int $fiberId;
    private readonly array $createdAt;
    private ?array $detachedAt = null;
    public function __construct(ContextStorageScopeInterface $scope) {
        $this->fiberId = self::currentFiberId();
        $this->createdAt = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
        if (!self::$shutdownHandlerInitialized) {
            self::$shutdownHandlerInitialized = true;
            register_shutdown_function('register_shutdown_function', static fn() => self::$finalShutdownPhase = true);
        }
    }
    public function detach() : int {
        $this->detachedAt ??= debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
        $flags = $this->scope
            ->detach();
        if (($flags & ScopeInterface::DETACHED) !== 0) {
            trigger_error(sprintf('Scope: unexpected call to Scope::detach() for scope #%d, scope was already detached %s', spl_object_id($this), self::formatBacktrace($this->detachedAt)));
        }
        elseif (($flags & ScopeInterface::MISMATCH) !== 0) {
            trigger_error(sprintf('Scope: unexpected call to Scope::detach() for scope #%d, scope successfully detached but another scope should have been detached first', spl_object_id($this)));
        }
        elseif (($flags & ScopeInterface::INACTIVE) !== 0) {
            trigger_error(sprintf('Scope: unexpected call to Scope::detach() for scope #%d, scope successfully detached from different execution context', spl_object_id($this)));
        }
        return $flags;
    }
    public function __destruct() {
        if (!$this->detachedAt) {
            // Handle destructors invoked during final shutdown
            // DebugScope::__destruct() might be called before fiber finally blocks run
            if (self::$finalShutdownPhase && $this->fiberId !== self::currentFiberId()) {
                return;
            }
            trigger_error(sprintf('Scope: missing call to Scope::detach() for scope #%d, created %s', spl_object_id($this->scope), self::formatBacktrace($this->createdAt)));
        }
    }
    
    /**
     * @phan-suppress PhanUndeclaredClassReference
     * @phan-suppress PhanUndeclaredClassMethod
     */
    private static function currentFiberId() : ?int {
        if (PHP_VERSION_ID < 80100) {
            return null;
        }
        assert(class_exists(Fiber::class, false));
        if (!($fiber = Fiber::getCurrent())) {
            return null;
        }
        return spl_object_id($fiber);
    }
    private static function formatBacktrace(array $trace) : string {
        $s = '';
        for ($i = 0, $n = count($trace) + 1; ++$i < $n;) {
            $s .= "\n\t";
            $s .= 'at ';
            if (isset($trace[$i]['class'])) {
                $s .= strtr($trace[$i]['class'], [
                    '\\' => '.',
                ]);
                $s .= '.';
            }
            $s .= strtr($trace[$i]['function'] ?? '{main}', [
                '\\' => '.',
            ]);
            $s .= '(';
            if (isset($trace[$i - 1]['file'])) {
                $s .= basename((string) $trace[$i - 1]['file']);
                if (isset($trace[$i - 1]['line'])) {
                    $s .= ':';
                    $s .= $trace[$i - 1]['line'];
                }
            }
            else {
                $s .= 'Unknown Source';
            }
            $s .= ')';
        }
        return $s . "\n";
    }

}