// Copyright 2024 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.

#pragma once

#include <fidl/fuchsia.driver.framework/cpp/fidl.h>
#include <fidl/fuchsia.hardware.bluetooth/cpp/fidl.h>
#include <lib/driver/component/cpp/driver_base.h>
#include <lib/driver/devfs/cpp/connector.h>

#include "pw_bluetooth_sapphire/fuchsia/bt_hci_virtual/emulator.h"
#include "pw_bluetooth_sapphire/fuchsia/bt_hci_virtual/loopback.h"

namespace bt_hci_virtual {

// The VirtualController class implements the
// fuchsia.hardware.bluetooth.VirtualController API. It is used to created two
// devices: the EmulatorDevice and/or the LoopbackDevice. The EmulatorDevice is
// used for Bluetooth integration tests, and the LoopbackDevice is used by
// RootCanal for PTS-bot.
//
// VirtualController publishes itself as a DFv2 driver and starts a device node
// to bind to said driver. It can create a EmulatorDevice/LoopbackDevice which
// can then use the VirtualController's child node
// |virtual_controller_child_node_| to publish its own children node that would
// represent the EmulatorDevice/LoopbackDevice.
//
// EmulatorDevice/LoopbackDevice then implements and serves the FIDL protocols
// that their client needs. For more details, refer to
// go/bluetooth-virtual-driver-doc.
class VirtualController
    : public fdf::DriverBase,
      public fidl::WireAsyncEventHandler<
          fuchsia_driver_framework::NodeController>,
      public fidl::WireAsyncEventHandler<fuchsia_driver_framework::Node>,
      public fidl::WireServer<fuchsia_hardware_bluetooth::VirtualController> {
 public:
  explicit VirtualController(
      fdf::DriverStartArgs start_args,
      fdf::UnownedSynchronizedDispatcher driver_dispatcher);

  // fdf::DriverBase overrides:
  zx::result<> Start() override;

  void handle_unknown_event(
      fidl::UnknownEventMetadata<fuchsia_driver_framework::Node> metadata)
      override {}
  void handle_unknown_event(
      fidl::UnknownEventMetadata<fuchsia_driver_framework::NodeController>
          metadata) override {}

 private:
  // fuchsia_hardware_bluetooth::VirtualController overrides:
  void CreateEmulator(CreateEmulatorCompleter::Sync& completer) override;
  void CreateLoopbackDevice(
      CreateLoopbackDeviceRequestView request,
      CreateLoopbackDeviceCompleter::Sync& completer) override;
  void handle_unknown_method(
      fidl::UnknownMethodMetadata<fuchsia_hardware_bluetooth::VirtualController>
          metadata,
      fidl::UnknownMethodCompleter::Sync& completer) override;

  void Connect(
      fidl::ServerEnd<fuchsia_hardware_bluetooth::VirtualController> request);

  // Helpers functions to add DFv2 device nodes
  zx_status_t AddVirtualControllerChildNode(
      fuchsia_driver_framework::wire::NodeAddArgs args);
  zx_status_t AddLoopbackChildNode(
      fuchsia_driver_framework::wire::NodeAddArgs args);
  zx_status_t AddEmulatorChildNode(
      fuchsia_driver_framework::wire::NodeAddArgs args,
      EmulatorDevice* emulator_device);

  std::unique_ptr<EmulatorDevice> emulator_device_;
  std::unique_ptr<LoopbackDevice> loopback_device_;

  // VirtualController
  fidl::WireClient<fuchsia_driver_framework::Node> node_;
  fidl::WireClient<fuchsia_driver_framework::NodeController> node_controller_;
  fidl::WireClient<fuchsia_driver_framework::Node>
      virtual_controller_child_node_;
  driver_devfs::Connector<fuchsia_hardware_bluetooth::VirtualController>
      devfs_connector_;
  fidl::ServerBindingGroup<fuchsia_hardware_bluetooth::VirtualController>
      virtual_controller_binding_group_;

  // LoopbackDevice
  fidl::WireClient<fuchsia_driver_framework::NodeController>
      loopback_node_controller_;
  fidl::WireClient<fuchsia_driver_framework::Node> loopback_child_node_;

  // EmulatorDevice
  fidl::WireClient<fuchsia_driver_framework::NodeController>
      emulator_node_controller_;
  fidl::WireClient<fuchsia_driver_framework::Node> emulator_child_node_;
};

}  // namespace bt_hci_virtual