// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_FUCHSIA_SCOPED_SERVICE_BINDING_H_
#define BASE_FUCHSIA_SCOPED_SERVICE_BINDING_H_

#include <lib/fidl/cpp/binding_set.h>

#include "base/bind.h"
#include "base/fuchsia/service_directory.h"

namespace base {
namespace fuchsia {

template <typename Interface>
class ScopedServiceBinding {
 public:
  // |service_directory| and |impl| must outlive the binding.
  ScopedServiceBinding(ServiceDirectory* service_directory, Interface* impl)
      : directory_(service_directory), impl_(impl) {
    directory_->AddService(
        Interface::Name_,
        BindRepeating(&ScopedServiceBinding::BindClient, Unretained(this)));
  }

  ~ScopedServiceBinding() { directory_->RemoveService(Interface::Name_); }

  void SetOnLastClientCallback(base::OnceClosure on_last_client_callback) {
    on_last_client_callback_ = std::move(on_last_client_callback);
    bindings_.set_empty_set_handler(
        fit::bind_member(this, &ScopedServiceBinding::OnBindingSetEmpty));
  }

 private:
  void BindClient(zx::channel channel) {
    bindings_.AddBinding(impl_,
                         fidl::InterfaceRequest<Interface>(std::move(channel)));
  }

  void OnBindingSetEmpty() {
    bindings_.set_empty_set_handler(nullptr);
    std::move(on_last_client_callback_).Run();
  }

  ServiceDirectory* const directory_;
  Interface* const impl_;
  fidl::BindingSet<Interface> bindings_;
  base::OnceClosure on_last_client_callback_;

  DISALLOW_COPY_AND_ASSIGN(ScopedServiceBinding);
};

}  // namespace fuchsia
}  // namespace base

#endif  // BASE_FUCHSIA_SCOPED_SERVICE_BINDING_H_