#include "routing_session.hpp"

#include "speed_camera.hpp"

#include "geometry/mercator.hpp"

#include "platform/location.hpp"
#include "platform/measurement_utils.hpp"
#include "platform/platform.hpp"

#include "coding/internal/file_data.hpp"

#include "3party/Alohalytics/src/alohalytics.h"

using namespace location;

namespace
{

int constexpr kOnRouteMissedCount = 5;

// @TODO(vbykoianko) The distance should depend on the current speed.
double constexpr kShowLanesDistInMeters = 500.;

// @todo(kshalnev) The distance may depend on the current speed.
double constexpr kShowPedestrianTurnInMeters = 5.;

double constexpr kRunawayDistanceSensitivityMeters = 0.01;

// Minimal distance to speed camera to make sound bell on overspeed.
double constexpr kSpeedCameraMinimalWarningMeters = 200.;
// Seconds to warning user before speed camera for driving with current speed.
double constexpr kSpeedCameraWarningSeconds = 30;

double constexpr kKmHToMps = 1000. / 3600.;

double constexpr kInvalidSpeedCameraDistance = -1;

// It limits depth of a speed camera point lookup along the route to avoid freezing.
size_t constexpr kSpeedCameraLookAheadCount = 50;

double constexpr kCompletionPercentAccuracy = 5;

uint32_t constexpr kMinimumETASec = 60;
}  // namespace

namespace routing
{
RoutingSession::RoutingSession()
  : m_router(nullptr)
  , m_route(string())
  , m_state(RoutingNotActive)
  , m_isFollowing(false)
  , m_endPoint(m2::PointD::Zero())
  , m_lastWarnedSpeedCameraIndex(0)
  , m_lastCheckedSpeedCameraIndex(0)
  , m_speedWarningSignal(false)
  , m_passedDistanceOnRouteMeters(0.0)
  , m_lastCompletionPercent(0.0)
{
}

void RoutingSession::Init(TRoutingStatisticsCallback const & routingStatisticsFn,
                          RouterDelegate::TPointCheckCallback const & pointCheckCallback)
{
  ASSERT(m_router == nullptr, ());
  m_router.reset(new AsyncRouter(routingStatisticsFn, pointCheckCallback));
}

void RoutingSession::BuildRoute(m2::PointD const & startPoint, m2::PointD const & endPoint,
                                TReadyCallback const & readyCallback,
                                TProgressCallback const & progressCallback,
                                uint32_t timeoutSec)
{
  ASSERT(m_router != nullptr, ());
  m_lastGoodPosition = startPoint;
  m_endPoint = endPoint;
  m_router->ClearState();
  m_isFollowing = false;
  m_routingRebuildCount = -1; // -1 for the first rebuild.
  RebuildRoute(startPoint, readyCallback, progressCallback, timeoutSec, RouteBuilding);
}

void RoutingSession::RebuildRoute(m2::PointD const & startPoint,
    TReadyCallback const & readyCallback,
    TProgressCallback const & progressCallback, uint32_t timeoutSec, State routeRebuildingState)
{
  ASSERT(m_router != nullptr, ());
  ASSERT_NOT_EQUAL(m_endPoint, m2::PointD::Zero(), ("End point was not set"));
  RemoveRoute();
  SetState(routeRebuildingState);
  m_routingRebuildCount++;
  m_lastCompletionPercent = 0;

  // Use old-style callback construction, because lambda constructs buggy function on Android
  // (callback param isn't captured by value).
  m_router->CalculateRoute(startPoint, startPoint - m_lastGoodPosition, m_endPoint,
                           DoReadyCallback(*this, readyCallback, m_routeSessionMutex),
                           progressCallback, timeoutSec);
}

void RoutingSession::DoReadyCallback::operator()(Route & route, IRouter::ResultCode e)
{
  threads::MutexGuard guard(m_routeSessionMutexInner);
  UNUSED_VALUE(guard);

  if (e != IRouter::NeedMoreMaps)
  {
    m_rs.AssignRoute(route, e);
  }
  else
  {
    for (string const & country : route.GetAbsentCountries())
      m_rs.m_route.AddAbsentCountry(country);
  }

  m_callback(m_rs.m_route, e);
}

void RoutingSession::RemoveRouteImpl()
{
  SetState(RoutingNotActive);
  m_lastDistance = 0.0;
  m_moveAwayCounter = 0;
  m_turnNotificationsMgr.Reset();

  Route(string()).Swap(m_route);
}

void RoutingSession::RemoveRoute()
{
  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);

  RemoveRouteImpl();
}

void RoutingSession::Reset()
{
  ASSERT(m_router != nullptr, ());

  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);

  RemoveRouteImpl();
  m_router->ClearState();

  m_passedDistanceOnRouteMeters = 0.0;
  m_lastWarnedSpeedCameraIndex = 0;
  m_lastCheckedSpeedCameraIndex = 0;
  m_lastFoundCamera = SpeedCameraRestriction();
  m_speedWarningSignal = false;
  m_isFollowing = false;
  m_lastCompletionPercent = 0;
}

RoutingSession::State RoutingSession::OnLocationPositionChanged(GpsInfo const & info, Index const & index)
 {
  ASSERT(m_state != RoutingNotActive, ());
  ASSERT(m_router != nullptr, ());

  if (m_state == RouteNeedRebuild || m_state == RouteFinished
      || m_state == RouteBuilding || m_state == RouteRebuilding
      || m_state == RouteNotReady || m_state == RouteNoFollowing)
    return m_state;

  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);
  ASSERT(m_route.IsValid(), ());

  m_turnNotificationsMgr.SetSpeedMetersPerSecond(info.m_speed);

  if (m_route.MoveIterator(info))
  {
    m_moveAwayCounter = 0;
    m_lastDistance = 0.0;

    if (m_route.IsCurrentOnEnd())
    {
      m_passedDistanceOnRouteMeters += m_route.GetTotalDistanceMeters();
      SetState(RouteFinished);

      alohalytics::TStringMap params = {{"router", m_route.GetRouterId()},
                                        {"passedDistance", strings::to_string(m_passedDistanceOnRouteMeters)},
                                        {"rebuildCount", strings::to_string(m_routingRebuildCount)}};
      alohalytics::LogEvent("RouteTracking_ReachedDestination", params);
    }
    else
    {
      SetState(OnRoute);

      // Warning signals checks
      if (m_routingSettings.m_speedCameraWarning && !m_speedWarningSignal)
      {
        double const warningDistanceM = max(kSpeedCameraMinimalWarningMeters,
                                            info.m_speed * kSpeedCameraWarningSeconds);
        SpeedCameraRestriction cam(0, 0);
        double const camDistance = GetDistanceToCurrentCamM(cam, index);
        if (kInvalidSpeedCameraDistance != camDistance && camDistance < warningDistanceM)
        {
          if (cam.m_index > m_lastWarnedSpeedCameraIndex && info.m_speed > cam.m_maxSpeedKmH * kKmHToMps)
          {
            m_speedWarningSignal = true;
            m_lastWarnedSpeedCameraIndex = cam.m_index;
          }
        }
      }
    }
    m_lastGoodPosition = m_userCurrentPosition;
  }
  else
  {
    // Distance from the last known projection on route
    // (check if we are moving far from the last known projection).
    auto const & lastGoodPoint = m_route.GetFollowedPolyline().GetCurrentIter().m_pt;
    double const dist = MercatorBounds::DistanceOnEarth(lastGoodPoint,
                                                        MercatorBounds::FromLatLon(info.m_latitude, info.m_longitude));
    if (my::AlmostEqualAbs(dist, m_lastDistance, kRunawayDistanceSensitivityMeters))
        return m_state;
    if (dist > m_lastDistance)
    {
      ++m_moveAwayCounter;
      m_lastDistance = dist;
    }

    if (m_moveAwayCounter > kOnRouteMissedCount)
    {
      m_passedDistanceOnRouteMeters += m_route.GetCurrentDistanceFromBeginMeters();
      SetState(RouteNeedRebuild);
      alohalytics::TStringMap params = {
          {"router", m_route.GetRouterId()},
          {"percent", strings::to_string(GetCompletionPercent())},
          {"passedDistance", strings::to_string(m_passedDistanceOnRouteMeters)},
          {"rebuildCount", strings::to_string(m_routingRebuildCount)}};
      alohalytics::LogEvent(
          "RouteTracking_RouteNeedRebuild", params,
          alohalytics::Location::FromLatLon(MercatorBounds::YToLat(lastGoodPoint.y),
                                            MercatorBounds::XToLon(lastGoodPoint.x)));
    }
  }

  return m_state;
}

void RoutingSession::GetRouteFollowingInfo(FollowingInfo & info) const
{
  auto formatDistFn = [](double dist, string & value, string & suffix)
  {
    /// @todo Make better formatting of distance and units.
    UNUSED_VALUE(measurement_utils::FormatDistance(dist, value));

    size_t const delim = value.find(' ');
    ASSERT(delim != string::npos, ());
    suffix = value.substr(delim + 1);
    value.erase(delim);
  };

  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);

  if (!m_route.IsValid())
  {
    // nothing should be displayed on the screen about turns if these lines are executed
    info = FollowingInfo();
    return;
  }

  if (!IsNavigable())
  {
    info = FollowingInfo();
    formatDistFn(m_route.GetTotalDistanceMeters(), info.m_distToTarget, info.m_targetUnitsSuffix);
    info.m_time = max(kMinimumETASec, m_route.GetCurrentTimeToEndSec());
    return;
  }

  formatDistFn(m_route.GetCurrentDistanceToEndMeters(), info.m_distToTarget, info.m_targetUnitsSuffix);

  double distanceToTurnMeters = 0.;
  turns::TurnItem turn;
  m_route.GetCurrentTurn(distanceToTurnMeters, turn);
  formatDistFn(distanceToTurnMeters, info.m_distToTurn, info.m_turnUnitsSuffix);
  info.m_turn = turn.m_turn;

  // The turn after the next one.
  if (m_routingSettings.m_showTurnAfterNext)
    info.m_nextTurn = m_turnNotificationsMgr.GetSecondTurnNotification();
  else
    info.m_nextTurn = routing::turns::TurnDirection::NoTurn;

  info.m_exitNum = turn.m_exitNum;
  info.m_time = max(kMinimumETASec, m_route.GetCurrentTimeToEndSec());
  m_route.GetCurrentStreetName(info.m_sourceName);
  m_route.GetStreetNameAfterIdx(turn.m_index, info.m_targetName);
  info.m_completionPercent = GetCompletionPercent();
  // Lane information.
  if (distanceToTurnMeters < kShowLanesDistInMeters)
  {
    // There are two nested loops below. Outer one is for lanes and inner one (ctor of
    // SingleLaneInfo) is
    // for each lane's directions. The size of turn.m_lanes is relatively small. Less than 10 in
    // most cases.
    info.m_lanes.clear();
    info.m_lanes.reserve(turn.m_lanes.size());
    for (size_t j = 0; j < turn.m_lanes.size(); ++j)
      info.m_lanes.emplace_back(turn.m_lanes[j]);
  }
  else
  {
    info.m_lanes.clear();
  }

  // Speedcam signal information.
  info.m_speedWarningSignal = m_speedWarningSignal;
  m_speedWarningSignal = false;

  // Pedestrian info
  m2::PointD pos;
  m_route.GetCurrentDirectionPoint(pos);
  info.m_pedestrianDirectionPos = MercatorBounds::ToLatLon(pos);
  info.m_pedestrianTurn =
      (distanceToTurnMeters < kShowPedestrianTurnInMeters) ? turn.m_pedestrianTurn : turns::PedestrianDirection::None;
}

double RoutingSession::GetCompletionPercent() const
{
  // Uncreated route can't have completion percents.
  if (!m_route.IsValid())
    return 0;

  double const percent = 100.0 *
    (m_passedDistanceOnRouteMeters + m_route.GetCurrentDistanceFromBeginMeters()) /
    (m_passedDistanceOnRouteMeters + m_route.GetTotalDistanceMeters());
  if (percent - m_lastCompletionPercent > kCompletionPercentAccuracy)
  {
    auto const lastGoodPoint =
        MercatorBounds::ToLatLon(m_route.GetFollowedPolyline().GetCurrentIter().m_pt);
    alohalytics::Stats::Instance().LogEvent(
        "RouteTracking_PercentUpdate", {{"percent", strings::to_string(percent)}},
        alohalytics::Location::FromLatLon(lastGoodPoint.lat, lastGoodPoint.lon));
    m_lastCompletionPercent = percent;
  }
  return percent;
}

void RoutingSession::GenerateTurnNotifications(vector<string> & turnNotifications)
{
  turnNotifications.clear();

  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);
  // Voice turn notifications.
  if (!m_routingSettings.m_soundDirection)
    return;

  if (!m_route.IsValid() || !IsNavigable())
    return;

  vector<turns::TurnItemDist> turns;
  if (m_route.GetNextTurns(turns))
    m_turnNotificationsMgr.GenerateTurnNotifications(turns, turnNotifications);
}

void RoutingSession::AssignRoute(Route & route, IRouter::ResultCode e)
{
  if (e != IRouter::Cancelled)
  {
    if (route.IsValid())
      SetState(RouteNotStarted);
    else
      SetState(RoutingNotActive);

    if (e != IRouter::NoError)
      SetState(RouteNotReady);
  }
  else
  {
    SetState(RoutingNotActive);
  }

  route.SetRoutingSettings(m_routingSettings);
  m_route.Swap(route);
  m_lastWarnedSpeedCameraIndex = 0;
  m_lastCheckedSpeedCameraIndex = 0;
  m_lastFoundCamera = SpeedCameraRestriction();
}

void RoutingSession::SetRouter(unique_ptr<IRouter> && router,
                               unique_ptr<OnlineAbsentCountriesFetcher> && fetcher)
{
  ASSERT(m_router != nullptr, ());
  Reset();
  m_router->SetRouter(move(router), move(fetcher));
}

void RoutingSession::MatchLocationToRoute(location::GpsInfo & location,
                                          location::RouteMatchingInfo & routeMatchingInfo) const
{
  if (!IsOnRoute())
    return;

  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);
  m_route.MatchLocationToRoute(location, routeMatchingInfo);
}

bool RoutingSession::DisableFollowMode()
{
  LOG(LINFO, ("Routing disables a following mode. State: ", m_state));
  if (m_state == RouteNotStarted || m_state == OnRoute)
  {
    SetState(RouteNoFollowing);
    m_isFollowing = false;
    return true;
  }
  return false;
}

bool RoutingSession::EnableFollowMode()
{
  LOG(LINFO, ("Routing enables a following mode. State: ", m_state));
  if (m_state == RouteNotStarted || m_state == OnRoute)
  {
    SetState(OnRoute);
    m_isFollowing = true;
  }
  return m_isFollowing;
}

void RoutingSession::SetRoutingSettings(RoutingSettings const & routingSettings)
{
  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);
  m_routingSettings = routingSettings;
}

void RoutingSession::SetUserCurrentPosition(m2::PointD const & position)
{
  m_userCurrentPosition = position;
}

m2::PointD const & RoutingSession::GetUserCurrentPosition() const
{
  return m_userCurrentPosition;
}

void RoutingSession::EnableTurnNotifications(bool enable)
{
  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);
  m_turnNotificationsMgr.Enable(enable);
}

bool RoutingSession::AreTurnNotificationsEnabled() const
{
  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);
  return m_turnNotificationsMgr.IsEnabled();
}

void RoutingSession::SetTurnNotificationsUnits(measurement_utils::Units const units)
{
  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);
  m_turnNotificationsMgr.SetLengthUnits(units);
}

void RoutingSession::SetTurnNotificationsLocale(string const & locale)
{
  LOG(LINFO, ("The language for turn notifications is", locale));
  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);
  m_turnNotificationsMgr.SetLocale(locale);
}

string RoutingSession::GetTurnNotificationsLocale() const
{
  threads::MutexGuard guard(m_routeSessionMutex);
  UNUSED_VALUE(guard);
  return m_turnNotificationsMgr.GetLocale();
}

double RoutingSession::GetDistanceToCurrentCamM(SpeedCameraRestriction & camera, Index const & index)
{
  auto const & m_poly = m_route.GetFollowedPolyline();
  auto const & currentIter = m_poly.GetCurrentIter();
  if (currentIter.m_ind < m_lastFoundCamera.m_index &&
      m_lastFoundCamera.m_index < m_poly.GetPolyline().GetSize())
  {
    camera = m_lastFoundCamera;
    return m_poly.GetDistanceM(currentIter, m_poly.GetIterToIndex(camera.m_index));
  }
  size_t const currentIndex = max(currentIter.m_ind, m_lastCheckedSpeedCameraIndex + 1);
  size_t const upperBound = min(m_poly.GetPolyline().GetSize(), currentIndex + kSpeedCameraLookAheadCount);
  for (m_lastCheckedSpeedCameraIndex = currentIndex; m_lastCheckedSpeedCameraIndex < upperBound; ++m_lastCheckedSpeedCameraIndex)
  {
    uint8_t speed = CheckCameraInPoint(m_poly.GetPolyline().GetPoint(m_lastCheckedSpeedCameraIndex), index);
    if (speed != kNoSpeedCamera)
    {
      camera = SpeedCameraRestriction(static_cast<uint32_t>(m_lastCheckedSpeedCameraIndex), speed);
      m_lastFoundCamera = camera;
      return m_poly.GetDistanceM(currentIter, m_poly.GetIterToIndex(m_lastCheckedSpeedCameraIndex));
    }
  }
  return kInvalidSpeedCameraDistance;
}

void RoutingSession::EmitCloseRoutingEvent() const
{
  if (!m_route.IsValid())
  {
    ASSERT(false, ());
    return;
  }
  auto const lastGoodPoint =
      MercatorBounds::ToLatLon(m_route.GetFollowedPolyline().GetCurrentIter().m_pt);
  alohalytics::Stats::Instance().LogEvent(
      "RouteTracking_RouteClosing",
      {{"percent", strings::to_string(GetCompletionPercent())},
       {"distance", strings::to_string(m_passedDistanceOnRouteMeters +
                                       m_route.GetCurrentDistanceToEndMeters())},
       {"router", m_route.GetRouterId()},
       {"rebuildCount", strings::to_string(m_routingRebuildCount)}},
      alohalytics::Location::FromLatLon(lastGoodPoint.lat, lastGoodPoint.lon));
}

string DebugPrint(RoutingSession::State state)
{
  switch (state)
  {
  case RoutingSession::RoutingNotActive: return "RoutingNotActive";
  case RoutingSession::RouteBuilding: return "RouteBuilding";
  case RoutingSession::RouteNotReady: return "RouteNotReady";
  case RoutingSession::RouteNotStarted: return "RouteNotStarted";
  case RoutingSession::OnRoute: return "OnRoute";
  case RoutingSession::RouteNeedRebuild: return "RouteNeedRebuild";
  case RoutingSession::RouteFinished: return "RouteFinished";
  case RoutingSession::RouteNoFollowing: return "RouteNoFollowing";
  case RoutingSession::RouteRebuilding: return "RouteRebuilding";
  }
}
}  // namespace routing