// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SERVICES_DEVICE_SERIAL_BLUETOOTH_SERIAL_DEVICE_ENUMERATOR_H_
#define SERVICES_DEVICE_SERIAL_BLUETOOTH_SERIAL_DEVICE_ENUMERATOR_H_

#include <string>
#include <string_view>
#include <utility>

#include "base/containers/flat_map.h"
#include "base/memory/scoped_refptr.h"
#include "base/memory/weak_ptr.h"
#include "base/sequence_checker.h"
#include "base/task/single_thread_task_runner.h"
#include "base/threading/sequence_bound.h"
#include "device/bluetooth/bluetooth_adapter.h"
#include "services/device/public/mojom/serial.mojom-forward.h"
#include "services/device/serial/bluetooth_serial_port_impl.h"
#include "services/device/serial/serial_device_enumerator.h"

namespace device {

class BluetoothUUID;

class BluetoothSerialDeviceEnumerator : public SerialDeviceEnumerator {
 public:
  // `adapter_runner` is the task runner with which to access the Bluetooth
  // adapter.
  explicit BluetoothSerialDeviceEnumerator(
      scoped_refptr<base::SingleThreadTaskRunner> adapter_runner);
  BluetoothSerialDeviceEnumerator(const BluetoothSerialDeviceEnumerator&) =
      delete;
  BluetoothSerialDeviceEnumerator& operator=(
      const BluetoothSerialDeviceEnumerator&) = delete;
  ~BluetoothSerialDeviceEnumerator() override;

  // Invokes `callback` with the result of GetDevices(). Runs synchronously if
  // the enumerator has already completed its initial enumeration, otherwise
  // waits until enumeration is complete.
  void GetDevicesAfterInitialEnumeration(
      mojom::SerialPortManager::GetDevicesCallback callback);

  void DeviceAddedOrChanged(std::string_view device_address,
                            std::u16string_view device_name,
                            BluetoothDevice::UUIDSet service_class_ids,
                            bool is_connected);
  void DeviceRemoved(const std::string& device_address);

  void OpenPort(const std::string& address,
                const BluetoothUUID& service_class_id,
                mojom::SerialConnectionOptionsPtr options,
                mojo::PendingRemote<mojom::SerialPortClient> client,
                mojo::PendingRemote<mojom::SerialPortConnectionWatcher> watcher,
                BluetoothSerialPortImpl::OpenCallback callback);

  // This method will search the map of Bluetooth ports and find the
  // address with the matching token.
  std::optional<std::string> GetAddressFromToken(
      const base::UnguessableToken& token) const;

  // Return the service class ID for the port's `token`. If `token` is not found
  // then an empty (invalid) id will be returned.
  BluetoothUUID GetServiceClassIdFromToken(
      const base::UnguessableToken& token) const;

  void DeviceAddedForTesting(BluetoothAdapter* adapter,
                             BluetoothDevice* device);
  void DeviceChangedForTesting(BluetoothAdapter* adapter,
                               BluetoothDevice* device);
  void SynchronouslyResetHelperForTesting();

 private:
  class AdapterHelper;

  // Contains <Device address, Bluetooth service class ID>.
  using DeviceServiceInfo = std::pair<std::string, BluetoothUUID>;

  // Map BluetoothDevice address to port token.
  using DevicePortsMap =
      base::flat_map<DeviceServiceInfo, base::UnguessableToken>;

  void AddOrUpdateService(std::string_view device_address,
                          std::u16string_view device_name,
                          const BluetoothUUID& service_class_id,
                          bool is_connected);
  void OnInitialEnumerationComplete();

  // A flag indicating whether the initial enumeration has completed.
  bool initial_enumeration_completed_ = false;

  // Pending callbacks for calls to GetDevicesAfterInitialEnumeration, to be
  // invoked once the initial enumeration is complete.
  std::vector<mojom::SerialPortManager::GetDevicesCallback>
      pending_get_devices_;

  DevicePortsMap device_ports_;
  base::SequenceBound<AdapterHelper> helper_;
  SEQUENCE_CHECKER(sequence_checker_);
  base::WeakPtrFactory<BluetoothSerialDeviceEnumerator> weak_ptr_factory_{this};
};

}  // namespace device

#endif  // SERVICES_DEVICE_SERIAL_BLUETOOTH_SERIAL_DEVICE_ENUMERATOR_H_