class FiberBoundContextStorageExecutionAwareBC

final class FiberBoundContextStorageExecutionAwareBC implements ContextStorageInterface, ExecutionContextAwareInterface {
    private readonly FiberBoundContextStorage $storage;
    private ?ContextStorage $bc = null;
    public function __construct() {
        $this->storage = new FiberBoundContextStorage();
    }
    public function fork(int|string $id) : void {
        $this->bcStorage()
            ->fork($id);
    }
    public function switch(int|string $id) : void {
        $this->bcStorage()
            ->switch($id);
    }
    public function destroy(int|string $id) : void {
        $this->bcStorage()
            ->destroy($id);
    }
    private function bcStorage() : ContextStorage {
        if ($this->bc === null) {
            $this->bc = new ContextStorage();
            // Copy head into $this->bc storage to preserve already attached scopes
            
            /** @psalm-suppress PossiblyNullFunctionCall */
            $head = (static fn($storage) => $storage->heads[$storage])
                ->bindTo(null, FiberBoundContextStorage::class)($this->storage);
            $head->storage = $this->bc;
            
            /** @psalm-suppress PossiblyNullFunctionCall */
            (static fn($storage) => $storage->current = $storage->main = $head)
                ->bindTo(null, ContextStorage::class)($this->bc);
        }
        return $this->bc;
    }
    public function scope() : ?ContextStorageScopeInterface {
        return $this->bc ? $this->bc
            ->scope() : $this->storage
            ->scope();
    }
    public function current() : ContextInterface {
        return $this->bc ? $this->bc
            ->current() : $this->storage
            ->current();
    }
    public function attach(ContextInterface $context) : ContextStorageScopeInterface {
        return $this->bc ? $this->bc
            ->attach($context) : $this->storage
            ->attach($context);
    }

}