/*
 * Copyright 2019 The Android Open Source Project
 *
 * 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
 *
 *      http://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.
 */

#include "hci/acl_manager.h"

#include <bluetooth/log.h>

#include <atomic>
#include <format>
#include <future>
#include <mutex>
#include <string>
#include <unordered_set>
#include <utility>
#include <vector>

#include "common/bidi_queue.h"
#include "common/byte_array.h"
#include "dumpsys_data_generated.h"
#include "hci/acl_manager/acl_scheduler.h"
#include "hci/acl_manager/classic_impl.h"
#include "hci/acl_manager/le_acceptlist_callbacks.h"
#include "hci/acl_manager/le_acl_connection.h"
#include "hci/acl_manager/le_impl.h"
#include "hci/acl_manager/round_robin_scheduler.h"
#include "hci/controller.h"
#include "hci/hci_layer.h"
#include "hci/remote_name_request.h"
#include "storage/config_keys.h"
#include "storage/storage_module.h"

namespace bluetooth {
namespace hci {

constexpr uint16_t kQualcommDebugHandle = 0xedc;
constexpr uint16_t kSamsungDebugHandle = 0xeef;

using acl_manager::AclConnection;
using common::Bind;
using common::BindOnce;

using acl_manager::classic_impl;
using acl_manager::ClassicAclConnection;
using acl_manager::ConnectionCallbacks;

using acl_manager::le_impl;
using acl_manager::LeAcceptlistCallbacks;
using acl_manager::LeAclConnection;
using acl_manager::LeConnectionCallbacks;

using acl_manager::RoundRobinScheduler;

using acl_manager::AclScheduler;

struct AclManager::impl {
  explicit impl(const AclManager& acl_manager) : acl_manager_(acl_manager) {}

  void Start() {
    hci_layer_ = acl_manager_.GetDependency<HciLayer>();
    handler_ = acl_manager_.GetHandler();
    controller_ = acl_manager_.GetDependency<Controller>();
    round_robin_scheduler_ =
            new RoundRobinScheduler(handler_, controller_, hci_layer_->GetAclQueueEnd());
    acl_scheduler_ = acl_manager_.GetDependency<AclScheduler>();

    remote_name_request_module_ = acl_manager_.GetDependency<RemoteNameRequestModule>();

    bool crash_on_unknown_handle = false;
    {
      const std::lock_guard<std::mutex> lock(dumpsys_mutex_);
      classic_impl_ = new classic_impl(hci_layer_, controller_, handler_, round_robin_scheduler_,
                                       crash_on_unknown_handle, acl_scheduler_,
                                       remote_name_request_module_);
      le_impl_ = new le_impl(hci_layer_, controller_, handler_, round_robin_scheduler_,
                             crash_on_unknown_handle);
    }

    hci_queue_end_ = hci_layer_->GetAclQueueEnd();
    hci_queue_end_->RegisterDequeue(handler_,
                                    common::Bind(&impl::dequeue_and_route_acl_packet_to_connection,
                                                 common::Unretained(this)));
  }

  void Stop() {
    hci_queue_end_->UnregisterDequeue();
    if (enqueue_registered_.exchange(false)) {
      hci_queue_end_->UnregisterEnqueue();
    }

    {
      const std::lock_guard<std::mutex> lock(dumpsys_mutex_);
      delete le_impl_;
      delete classic_impl_;
      le_impl_ = nullptr;
      classic_impl_ = nullptr;
    }

    unknown_acl_alarm_.reset();
    waiting_packets_.clear();

    delete round_robin_scheduler_;
    hci_queue_end_ = nullptr;
    handler_ = nullptr;
    hci_layer_ = nullptr;
    acl_scheduler_ = nullptr;
  }

  void retry_unknown_acl(bool timed_out) {
    std::vector<AclView> unsent_packets;
    for (const auto& itr : waiting_packets_) {
      auto handle = itr.GetHandle();
      if (!classic_impl_->send_packet_upward(handle,
                                             [itr](struct acl_manager::assembler* assembler) {
                                               assembler->on_incoming_packet(itr);
                                             }) &&
          !le_impl_->send_packet_upward(handle, [itr](struct acl_manager::assembler* assembler) {
            assembler->on_incoming_packet(itr);
          })) {
        if (!timed_out) {
          unsent_packets.push_back(itr);
        } else {
          log::error("Dropping packet of size {} to unknown connection 0x{:x}", itr.size(),
                     itr.GetHandle());
        }
      }
    }
    waiting_packets_ = std::move(unsent_packets);
  }

  static void on_unknown_acl_timer(struct AclManager::impl* impl) {
    log::info("Timer fired!");
    impl->retry_unknown_acl(/* timed_out = */ true);
    impl->unknown_acl_alarm_.reset();
  }

  // Invoked from some external Queue Reactable context 2
  void dequeue_and_route_acl_packet_to_connection() {
    // Retry any waiting packets first
    if (!waiting_packets_.empty()) {
      retry_unknown_acl(/* timed_out = */ false);
    }

    auto packet = hci_queue_end_->TryDequeue();
    log::assert_that(packet != nullptr, "assert failed: packet != nullptr");
    if (!packet->IsValid()) {
      log::info("Dropping invalid packet of size {}", packet->size());
      return;
    }
    uint16_t handle = packet->GetHandle();
    if (handle == kQualcommDebugHandle || handle == kSamsungDebugHandle) {
      return;
    }
    if (classic_impl_->send_packet_upward(handle,
                                          [&packet](struct acl_manager::assembler* assembler) {
                                            assembler->on_incoming_packet(*packet);
                                          })) {
      return;
    }
    if (le_impl_->send_packet_upward(handle, [&packet](struct acl_manager::assembler* assembler) {
          assembler->on_incoming_packet(*packet);
        })) {
      return;
    }
    if (unknown_acl_alarm_ == nullptr) {
      unknown_acl_alarm_.reset(new os::Alarm(handler_));
    }
    waiting_packets_.push_back(*packet);
    log::info("Saving packet of size {} to unknown connection 0x{:x}", packet->size(),
              packet->GetHandle());
    unknown_acl_alarm_->Schedule(BindOnce(&on_unknown_acl_timer, common::Unretained(this)),
                                 kWaitBeforeDroppingUnknownAcl);
  }

  template <typename OutputT>
  void dump(OutputT&& out) const;

  const AclManager& acl_manager_;

  classic_impl* classic_impl_ = nullptr;
  le_impl* le_impl_ = nullptr;
  AclScheduler* acl_scheduler_ = nullptr;
  RemoteNameRequestModule* remote_name_request_module_ = nullptr;
  os::Handler* handler_ = nullptr;
  Controller* controller_ = nullptr;
  HciLayer* hci_layer_ = nullptr;
  RoundRobinScheduler* round_robin_scheduler_ = nullptr;
  common::BidiQueueEnd<AclBuilder, AclView>* hci_queue_end_ = nullptr;
  std::atomic_bool enqueue_registered_ = false;
  uint16_t default_link_policy_settings_ = 0xffff;
  mutable std::mutex dumpsys_mutex_;
  std::unique_ptr<os::Alarm> unknown_acl_alarm_;
  std::vector<AclView> waiting_packets_;
  static constexpr std::chrono::seconds kWaitBeforeDroppingUnknownAcl{1};
};

AclManager::AclManager() : pimpl_(std::make_unique<impl>(*this)) {}

void AclManager::RegisterCallbacks(ConnectionCallbacks* callbacks, os::Handler* handler) {
  log::assert_that(callbacks != nullptr && handler != nullptr,
                   "assert failed: callbacks != nullptr && handler != nullptr");
  GetHandler()->Post(common::BindOnce(&classic_impl::handle_register_callbacks,
                                      common::Unretained(pimpl_->classic_impl_),
                                      common::Unretained(callbacks), common::Unretained(handler)));
}

void AclManager::UnregisterCallbacks(ConnectionCallbacks* callbacks, std::promise<void> promise) {
  log::assert_that(callbacks != nullptr, "assert failed: callbacks != nullptr");
  CallOn(pimpl_->classic_impl_, &classic_impl::handle_unregister_callbacks,
         common::Unretained(callbacks), std::move(promise));
}

void AclManager::RegisterLeCallbacks(LeConnectionCallbacks* callbacks, os::Handler* handler) {
  log::assert_that(callbacks != nullptr && handler != nullptr,
                   "assert failed: callbacks != nullptr && handler != nullptr");
  CallOn(pimpl_->le_impl_, &le_impl::handle_register_le_callbacks, common::Unretained(callbacks),
         common::Unretained(handler));
}

void AclManager::RegisterLeAcceptlistCallbacks(LeAcceptlistCallbacks* callbacks) {
  log::assert_that(callbacks != nullptr, "assert failed: callbacks != nullptr");
  CallOn(pimpl_->le_impl_, &le_impl::handle_register_le_acceptlist_callbacks,
         common::Unretained(callbacks));
}

void AclManager::UnregisterLeCallbacks(LeConnectionCallbacks* callbacks,
                                       std::promise<void> promise) {
  log::assert_that(callbacks != nullptr, "assert failed: callbacks != nullptr");
  CallOn(pimpl_->le_impl_, &le_impl::handle_unregister_le_callbacks, common::Unretained(callbacks),
         std::move(promise));
}

void AclManager::UnregisterLeAcceptlistCallbacks(LeAcceptlistCallbacks* callbacks,
                                                 std::promise<void> promise) {
  log::assert_that(callbacks != nullptr, "assert failed: callbacks != nullptr");
  CallOn(pimpl_->le_impl_, &le_impl::handle_unregister_le_acceptlist_callbacks,
         common::Unretained(callbacks), std::move(promise));
}

void AclManager::CreateConnection(Address address) {
  CallOn(pimpl_->classic_impl_, &classic_impl::create_connection, address);
}

void AclManager::CreateLeConnection(AddressWithType address_with_type, bool is_direct) {
  if (!is_direct) {
    CallOn(pimpl_->le_impl_, &le_impl::add_device_to_background_connection_list, address_with_type);
  }
  CallOn(pimpl_->le_impl_, &le_impl::create_le_connection, address_with_type, true, is_direct);
}

void AclManager::IsOnBackgroundList(AddressWithType address_with_type, std::promise<bool> promise) {
  CallOn(pimpl_->le_impl_, &le_impl::is_on_background_connection_list, address_with_type,
         std::move(promise));
}

void AclManager::SetLeSuggestedDefaultDataParameters(uint16_t octets, uint16_t time) {
  CallOn(pimpl_->le_impl_, &le_impl::set_le_suggested_default_data_parameters, octets, time);
}

void AclManager::LeSetDefaultSubrate(uint16_t subrate_min, uint16_t subrate_max,
                                     uint16_t max_latency, uint16_t cont_num, uint16_t sup_tout) {
  CallOn(pimpl_->le_impl_, &le_impl::LeSetDefaultSubrate, subrate_min, subrate_max, max_latency,
         cont_num, sup_tout);
}

void AclManager::SetPrivacyPolicyForInitiatorAddress(
        LeAddressManager::AddressPolicy address_policy, AddressWithType fixed_address,
        std::chrono::milliseconds minimum_rotation_time,
        std::chrono::milliseconds maximum_rotation_time) {
  Octet16 rotation_irk{};
  auto irk_prop = GetDependency<storage::StorageModule>()->GetProperty(
          BTIF_STORAGE_SECTION_ADAPTER, BTIF_STORAGE_KEY_LE_LOCAL_KEY_IRK);
  if (irk_prop.has_value()) {
    auto irk = common::ByteArray<16>::FromString(irk_prop.value());
    if (irk.has_value()) {
      rotation_irk = irk->bytes;
    }
  }
  CallOn(pimpl_->le_impl_, &le_impl::set_privacy_policy_for_initiator_address, address_policy,
         fixed_address, rotation_irk, minimum_rotation_time, maximum_rotation_time);
}

// TODO(jpawlowski): remove once we have config file abstraction in cert tests
void AclManager::SetPrivacyPolicyForInitiatorAddressForTest(
        LeAddressManager::AddressPolicy address_policy, AddressWithType fixed_address,
        Octet16 rotation_irk, std::chrono::milliseconds minimum_rotation_time,
        std::chrono::milliseconds maximum_rotation_time) {
  CallOn(pimpl_->le_impl_, &le_impl::set_privacy_policy_for_initiator_address_for_test,
         address_policy, fixed_address, rotation_irk, minimum_rotation_time, maximum_rotation_time);
}

void AclManager::CancelConnect(Address address) {
  CallOn(pimpl_->classic_impl_, &classic_impl::cancel_connect, address);
}

void AclManager::CancelLeConnect(AddressWithType address_with_type) {
  CallOn(pimpl_->le_impl_, &le_impl::remove_device_from_background_connection_list,
         address_with_type);
  CallOn(pimpl_->le_impl_, &le_impl::cancel_connect, address_with_type);
}

void AclManager::RemoveFromBackgroundList(AddressWithType address_with_type) {
  CallOn(pimpl_->le_impl_, &le_impl::remove_device_from_background_connection_list,
         address_with_type);
}

void AclManager::ClearFilterAcceptList() {
  CallOn(pimpl_->le_impl_, &le_impl::clear_filter_accept_list);
}

void AclManager::AddDeviceToResolvingList(AddressWithType address_with_type,
                                          const std::array<uint8_t, 16>& peer_irk,
                                          const std::array<uint8_t, 16>& local_irk) {
  CallOn(pimpl_->le_impl_, &le_impl::add_device_to_resolving_list, address_with_type, peer_irk,
         local_irk);
}

void AclManager::RemoveDeviceFromResolvingList(AddressWithType address_with_type) {
  CallOn(pimpl_->le_impl_, &le_impl::remove_device_from_resolving_list, address_with_type);
}

void AclManager::ClearResolvingList() { CallOn(pimpl_->le_impl_, &le_impl::clear_resolving_list); }

void AclManager::CentralLinkKey(KeyFlag key_flag) {
  CallOn(pimpl_->classic_impl_, &classic_impl::central_link_key, key_flag);
}

void AclManager::SwitchRole(Address address, Role role) {
  CallOn(pimpl_->classic_impl_, &classic_impl::switch_role, address, role);
}

uint16_t AclManager::ReadDefaultLinkPolicySettings() {
  log::assert_that(pimpl_->default_link_policy_settings_ != 0xffff, "Settings were never written");
  return pimpl_->default_link_policy_settings_;
}

void AclManager::WriteDefaultLinkPolicySettings(uint16_t default_link_policy_settings) {
  pimpl_->default_link_policy_settings_ = default_link_policy_settings;
  CallOn(pimpl_->classic_impl_, &classic_impl::write_default_link_policy_settings,
         default_link_policy_settings);
}

void AclManager::OnAdvertisingSetTerminated(ErrorCode status, uint16_t conn_handle,
                                            uint8_t adv_set_id, hci::AddressWithType adv_address,
                                            bool is_discoverable) {
  if (status == ErrorCode::SUCCESS) {
    CallOn(pimpl_->le_impl_, &le_impl::OnAdvertisingSetTerminated, conn_handle, adv_set_id,
           adv_address, is_discoverable);
  }
}

void AclManager::OnClassicSuspendInitiatedDisconnect(uint16_t handle, ErrorCode reason) {
  CallOn(pimpl_->classic_impl_, &classic_impl::on_classic_disconnect, handle, reason);
}

void AclManager::OnLeSuspendInitiatedDisconnect(uint16_t handle, ErrorCode reason) {
  CallOn(pimpl_->le_impl_, &le_impl::on_le_disconnect, handle, reason);
}

void AclManager::SetSystemSuspendState(bool suspended) {
  CallOn(pimpl_->le_impl_, &le_impl::set_system_suspend_state, suspended);
}

LeAddressManager* AclManager::GetLeAddressManager() {
  return pimpl_->le_impl_->le_address_manager_;
}

uint16_t AclManager::HACK_GetHandle(Address address) {
  return pimpl_->classic_impl_->HACK_get_handle(address);
}

uint16_t AclManager::HACK_GetLeHandle(Address address) {
  return pimpl_->le_impl_->HACK_get_handle(address);
}

Address AclManager::HACK_GetLeAddress(uint16_t connection_handle) {
  return pimpl_->le_impl_->HACK_get_address(connection_handle);
}

void AclManager::HACK_SetAclTxPriority(uint8_t handle, bool high_priority) {
  CallOn(pimpl_->round_robin_scheduler_, &RoundRobinScheduler::SetLinkPriority, handle,
         high_priority);
}

void AclManager::ListDependencies(ModuleList* list) const {
  list->add<HciLayer>();
  list->add<Controller>();
  list->add<storage::StorageModule>();
  list->add<AclScheduler>();
  list->add<RemoteNameRequestModule>();
}

void AclManager::Start() { pimpl_->Start(); }

void AclManager::Stop() { pimpl_->Stop(); }

std::string AclManager::ToString() const { return "Acl Manager"; }

const ModuleFactory AclManager::Factory = ModuleFactory([]() { return new AclManager(); });

AclManager::~AclManager() = default;

template <typename OutputT>
void AclManager::impl::dump(OutputT&& out) const {
  const std::lock_guard<std::mutex> lock(dumpsys_mutex_);
  const auto accept_list =
          (le_impl_ != nullptr) ? le_impl_->accept_list : std::unordered_set<AddressWithType>();
  const auto le_connectability_state_text =
          (le_impl_ != nullptr) ? connectability_state_machine_text(le_impl_->connectability_state_)
                                : "INDETERMINATE";
  const auto le_create_connection_timeout_alarms_count =
          (le_impl_ != nullptr)
                  ? static_cast<int>(le_impl_->create_connection_timeout_alarms_.size())
                  : 0;

  std::format_to(out, "\nACL Manager Dumpsys:\n");
  std::format_to(out,
                 "    le_connectability_state: \"{}\"\n"
                 "    le_create_connection_timeout_alarms_count: {}\n"
                 "    le_filter_accept_list_count: {}\n"
                 "    le_filter_accept_list: [",
                 le_connectability_state_text, le_create_connection_timeout_alarms_count,
                 accept_list.size());
  for (const auto& it : accept_list) {
    std::format_to(out, "\n        \"{}\",", it.ToString());
  }
  std::format_to(out, "\n    ]\n");
}

void AclManager::Dump(int fd) const {
  std::string out;
  pimpl_->dump(std::back_inserter(out));
  dprintf(fd, "%s", out.c_str());
}

}  // namespace hci
}  // namespace bluetooth