// Copyright (c) 2012 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.

#include "device/bluetooth/bluetooth_adapter_win.h"

#include <memory>
#include <string>
#include <utility>

#include "base/feature_list.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/sequenced_task_runner.h"
#include "base/single_thread_task_runner.h"
#include "base/stl_util.h"
#include "base/threading/thread_task_runner_handle.h"
#include "base/win/windows_version.h"
#include "device/base/features.h"
#include "device/bluetooth/bluetooth_adapter_winrt.h"
#include "device/bluetooth/bluetooth_classic_win.h"
#include "device/bluetooth/bluetooth_device_win.h"
#include "device/bluetooth/bluetooth_discovery_session_outcome.h"
#include "device/bluetooth/bluetooth_socket_thread.h"
#include "device/bluetooth/bluetooth_socket_win.h"
#include "device/bluetooth/bluetooth_task_manager_win.h"
#include "device/bluetooth/bluetooth_uuid.h"

namespace device {

// static
base::WeakPtr<BluetoothAdapter> BluetoothAdapter::CreateAdapter(
    InitCallback init_callback) {
  return BluetoothAdapterWin::CreateAdapter(std::move(init_callback));
}

// static
base::WeakPtr<BluetoothAdapter> BluetoothAdapterWin::CreateAdapter(
    InitCallback init_callback) {
  if (UseNewBLEWinImplementation()) {
    auto* adapter = new BluetoothAdapterWinrt();
    adapter->Init(std::move(init_callback));
    return adapter->weak_ptr_factory_.GetWeakPtr();
  }

  auto* adapter = new BluetoothAdapterWin(std::move(init_callback));
  adapter->Init();
  return adapter->weak_ptr_factory_.GetWeakPtr();
}

// static
bool BluetoothAdapterWin::UseNewBLEWinImplementation() {
  return base::FeatureList::IsEnabled(kNewBLEWinImplementation) &&
         base::win::GetVersion() >= base::win::VERSION_WIN10;
}

BluetoothAdapterWin::BluetoothAdapterWin(InitCallback init_callback)
    : BluetoothAdapter(),
      init_callback_(std::move(init_callback)),
      initialized_(false),
      powered_(false),
      discovery_status_(NOT_DISCOVERING),
      num_discovery_listeners_(0),
      force_update_device_for_test_(false),
      weak_ptr_factory_(this) {}

BluetoothAdapterWin::~BluetoothAdapterWin() {
  if (task_manager_.get())
    task_manager_->RemoveObserver(this);
}

std::string BluetoothAdapterWin::GetAddress() const {
  return address_;
}

std::string BluetoothAdapterWin::GetName() const {
  return name_;
}

void BluetoothAdapterWin::SetName(const std::string& name,
                                  const base::Closure& callback,
                                  const ErrorCallback& error_callback) {
  NOTIMPLEMENTED();
}

// TODO(youngki): Return true when |task_manager_| initializes the adapter
// state.
bool BluetoothAdapterWin::IsInitialized() const {
  return initialized_;
}

bool BluetoothAdapterWin::IsPresent() const {
  return !address_.empty();
}

bool BluetoothAdapterWin::IsPowered() const {
  return powered_;
}

void BluetoothAdapterWin::SetPowered(
    bool powered,
    const base::Closure& callback,
    const ErrorCallback& error_callback) {
  task_manager_->PostSetPoweredBluetoothTask(powered, callback, error_callback);
}

bool BluetoothAdapterWin::IsDiscoverable() const {
  NOTIMPLEMENTED();
  return false;
}

void BluetoothAdapterWin::SetDiscoverable(
    bool discoverable,
    const base::Closure& callback,
    const ErrorCallback& error_callback) {
  NOTIMPLEMENTED();
}

bool BluetoothAdapterWin::IsDiscovering() const {
  return discovery_status_ == DISCOVERING ||
      discovery_status_ == DISCOVERY_STOPPING;
}

static void RunDiscoverySessionErrorCallback(
    base::OnceCallback<void(UMABluetoothDiscoverySessionOutcome)>
        error_callback,
    UMABluetoothDiscoverySessionOutcome outcome) {
  std::move(error_callback).Run(outcome);
}

void BluetoothAdapterWin::DiscoveryStarted(bool success) {
  discovery_status_ = success ? DISCOVERING : NOT_DISCOVERING;
  for (auto& callbacks : on_start_discovery_callbacks_) {
    if (success)
      ui_task_runner_->PostTask(FROM_HERE, callbacks.first);
    else
      ui_task_runner_->PostTask(
          FROM_HERE,
          base::BindOnce(&RunDiscoverySessionErrorCallback,
                         std::move(callbacks.second),
                         UMABluetoothDiscoverySessionOutcome::UNKNOWN));
  }
  num_discovery_listeners_ = on_start_discovery_callbacks_.size();
  on_start_discovery_callbacks_.clear();

  if (success) {
    for (auto& observer : observers_)
      observer.AdapterDiscoveringChanged(this, true);

    // If there are stop discovery requests, post the stop discovery again.
    MaybePostStopDiscoveryTask();
  } else if (!on_stop_discovery_callbacks_.empty()) {
    // If there are stop discovery requests but start discovery has failed,
    // notify that stop discovery has been complete.
    DiscoveryStopped();
  }
}

void BluetoothAdapterWin::DiscoveryStopped() {
  discovered_devices_.clear();
  bool was_discovering = IsDiscovering();
  discovery_status_ = NOT_DISCOVERING;
  for (std::vector<base::Closure>::const_iterator iter =
           on_stop_discovery_callbacks_.begin();
       iter != on_stop_discovery_callbacks_.end();
       ++iter) {
    ui_task_runner_->PostTask(FROM_HERE, *iter);
  }
  num_discovery_listeners_ = 0;
  on_stop_discovery_callbacks_.clear();
  if (was_discovering)
    for (auto& observer : observers_)
      observer.AdapterDiscoveringChanged(this, false);

  // If there are start discovery requests, post the start discovery again.
  MaybePostStartDiscoveryTask();
}

BluetoothAdapter::UUIDList BluetoothAdapterWin::GetUUIDs() const {
  NOTIMPLEMENTED();
  return UUIDList();
}

void BluetoothAdapterWin::CreateRfcommService(
    const BluetoothUUID& uuid,
    const ServiceOptions& options,
    const CreateServiceCallback& callback,
    const CreateServiceErrorCallback& error_callback) {
  scoped_refptr<BluetoothSocketWin> socket =
      BluetoothSocketWin::CreateBluetoothSocket(
          ui_task_runner_, socket_thread_);
  socket->Listen(this, uuid, options,
                 base::Bind(callback, socket),
                 error_callback);
}

void BluetoothAdapterWin::CreateL2capService(
    const BluetoothUUID& uuid,
    const ServiceOptions& options,
    const CreateServiceCallback& callback,
    const CreateServiceErrorCallback& error_callback) {
  // TODO(keybuk): implement.
  NOTIMPLEMENTED();
}

void BluetoothAdapterWin::RegisterAdvertisement(
    std::unique_ptr<BluetoothAdvertisement::Data> advertisement_data,
    const CreateAdvertisementCallback& callback,
    const AdvertisementErrorCallback& error_callback) {
  NOTIMPLEMENTED();
  error_callback.Run(BluetoothAdvertisement::ERROR_UNSUPPORTED_PLATFORM);
}

BluetoothLocalGattService* BluetoothAdapterWin::GetGattService(
    const std::string& identifier) const {
  return nullptr;
}

void BluetoothAdapterWin::RemovePairingDelegateInternal(
    BluetoothDevice::PairingDelegate* pairing_delegate) {
}

void BluetoothAdapterWin::AdapterStateChanged(
    const BluetoothTaskManagerWin::AdapterState& state) {
  DCHECK(thread_checker_.CalledOnValidThread());
  name_ = state.name;
  bool was_present = IsPresent();
  bool is_present = !state.address.empty();
  address_ = BluetoothDevice::CanonicalizeAddress(state.address);
  if (was_present != is_present) {
    for (auto& observer : observers_)
      observer.AdapterPresentChanged(this, is_present);
  }
  if (powered_ != state.powered) {
    powered_ = state.powered;
    for (auto& observer : observers_)
      observer.AdapterPoweredChanged(this, powered_);
  }
  if (!initialized_) {
    initialized_ = true;
    std::move(init_callback_).Run();
  }
}

void BluetoothAdapterWin::DevicesPolled(
    const std::vector<std::unique_ptr<BluetoothTaskManagerWin::DeviceState>>&
        devices) {
  DCHECK(thread_checker_.CalledOnValidThread());

  // We are receiving a new list of all devices known to the system. Merge this
  // new list with the list we know of (|devices_|) and raise corresponding
  // DeviceAdded, DeviceRemoved and DeviceChanged events.

  using DeviceAddressSet = std::set<std::string>;
  DeviceAddressSet known_devices;
  for (const auto& device : devices_)
    known_devices.insert(device.first);

  DeviceAddressSet new_devices;
  for (const auto& device_state : devices)
    new_devices.insert(device_state->address);

  // Process device removal first.
  DeviceAddressSet removed_devices =
      base::STLSetDifference<DeviceAddressSet>(known_devices, new_devices);
  for (const auto& device : removed_devices) {
    auto it = devices_.find(device);
    std::unique_ptr<BluetoothDevice> device_win = std::move(it->second);
    devices_.erase(it);
    for (auto& observer : observers_)
      observer.DeviceRemoved(this, device_win.get());
  }

  // Process added and (maybe) changed devices in one pass.
  DeviceAddressSet added_devices =
      base::STLSetDifference<DeviceAddressSet>(new_devices, known_devices);
  DeviceAddressSet changed_devices =
      base::STLSetIntersection<DeviceAddressSet>(known_devices, new_devices);
  for (const auto& device_state : devices) {
    if (added_devices.find(device_state->address) != added_devices.end()) {
      auto device_win = std::make_unique<BluetoothDeviceWin>(
          this, *device_state, ui_task_runner_, socket_thread_);
      BluetoothDeviceWin* device_win_raw = device_win.get();
      devices_[device_state->address] = std::move(device_win);
      for (auto& observer : observers_)
        observer.DeviceAdded(this, device_win_raw);
    } else if (changed_devices.find(device_state->address) !=
               changed_devices.end()) {
      auto iter = devices_.find(device_state->address);
      DCHECK(iter != devices_.end());
      BluetoothDeviceWin* device_win =
          static_cast<BluetoothDeviceWin*>(iter->second.get());
      if (!device_win->IsEqual(*device_state)) {
        device_win->Update(*device_state);
        for (auto& observer : observers_)
          observer.DeviceChanged(this, device_win);
      }
      // Above IsEqual returns true if device name, address, status and services
      // (primary services of BLE device) are the same. However, in BLE tests,
      // we may simulate characteristic, descriptor and secondary GATT service
      // after device has been initialized.
      if (force_update_device_for_test_) {
        device_win->Update(*device_state);
      }
    }
  }
}

// BluetoothAdapterWin should override SetPowered() instead.
bool BluetoothAdapterWin::SetPoweredImpl(bool powered) {
  NOTREACHED();
  return false;
}

// If the method is called when |discovery_status_| is DISCOVERY_STOPPING,
// starting again is handled by BluetoothAdapterWin::DiscoveryStopped().
void BluetoothAdapterWin::AddDiscoverySession(
    BluetoothDiscoveryFilter* discovery_filter,
    const base::Closure& callback,
    DiscoverySessionErrorCallback error_callback) {
  if (discovery_status_ == DISCOVERING) {
    num_discovery_listeners_++;
    callback.Run();
    return;
  }
  on_start_discovery_callbacks_.push_back(
      std::make_pair(callback, std::move(error_callback)));
  MaybePostStartDiscoveryTask();
}

void BluetoothAdapterWin::RemoveDiscoverySession(
    BluetoothDiscoveryFilter* discovery_filter,
    const base::Closure& callback,
    DiscoverySessionErrorCallback error_callback) {
  if (discovery_status_ == NOT_DISCOVERING) {
    std::move(error_callback)
        .Run(UMABluetoothDiscoverySessionOutcome::NOT_ACTIVE);
    return;
  }
  on_stop_discovery_callbacks_.push_back(callback);
  MaybePostStopDiscoveryTask();
}

void BluetoothAdapterWin::SetDiscoveryFilter(
    std::unique_ptr<BluetoothDiscoveryFilter> discovery_filter,
    const base::Closure& callback,
    DiscoverySessionErrorCallback error_callback) {
  NOTIMPLEMENTED();
  std::move(error_callback)
      .Run(UMABluetoothDiscoverySessionOutcome::NOT_IMPLEMENTED);
}

void BluetoothAdapterWin::Init() {
  ui_task_runner_ = base::ThreadTaskRunnerHandle::Get();
  socket_thread_ = BluetoothSocketThread::Get();
  task_manager_ =
      base::MakeRefCounted<BluetoothTaskManagerWin>(ui_task_runner_);
  task_manager_->AddObserver(this);
  task_manager_->Initialize();
}

void BluetoothAdapterWin::InitForTest(
    std::unique_ptr<win::BluetoothClassicWrapper> classic_wrapper,
    std::unique_ptr<win::BluetoothLowEnergyWrapper> le_wrapper,
    scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner,
    scoped_refptr<base::SequencedTaskRunner> bluetooth_task_runner) {
  ui_task_runner_ = ui_task_runner;
  if (!ui_task_runner_)
    ui_task_runner_ = base::ThreadTaskRunnerHandle::Get();
  task_manager_ = BluetoothTaskManagerWin::CreateForTesting(
      std::move(classic_wrapper), std::move(le_wrapper), ui_task_runner_);
  task_manager_->AddObserver(this);
  task_manager_->InitializeWithBluetoothTaskRunner(bluetooth_task_runner);
}

void BluetoothAdapterWin::MaybePostStartDiscoveryTask() {
  if (discovery_status_ == NOT_DISCOVERING &&
      !on_start_discovery_callbacks_.empty()) {
    discovery_status_ = DISCOVERY_STARTING;
    task_manager_->PostStartDiscoveryTask();
  }
}

void BluetoothAdapterWin::MaybePostStopDiscoveryTask() {
  if (discovery_status_ != DISCOVERING)
    return;

  if (on_stop_discovery_callbacks_.size() < num_discovery_listeners_) {
    for (std::vector<base::Closure>::const_iterator iter =
             on_stop_discovery_callbacks_.begin();
         iter != on_stop_discovery_callbacks_.end();
         ++iter) {
      ui_task_runner_->PostTask(FROM_HERE, *iter);
    }
    num_discovery_listeners_ -= on_stop_discovery_callbacks_.size();
    on_stop_discovery_callbacks_.clear();
    return;
  }

  discovery_status_ = DISCOVERY_STOPPING;
  task_manager_->PostStopDiscoveryTask();
}

}  // namespace device