#include <scwx/qt/map/alert_layer.hpp>
#include <scwx/qt/gl/draw/geo_lines.hpp>
#include <scwx/qt/manager/text_event_manager.hpp>
#include <scwx/qt/manager/timeline_manager.hpp>
#include <scwx/qt/settings/palette_settings.hpp>
#include <scwx/qt/util/color.hpp>
#include <scwx/qt/util/tooltip.hpp>
#include <scwx/util/logger.hpp>

#include <chrono>
#include <mutex>
#include <unordered_map>
#include <unordered_set>

#include <boost/algorithm/string/join.hpp>
#include <boost/container/stable_vector.hpp>
#include <boost/container_hash/hash.hpp>
#include <QEvent>

namespace scwx
{
namespace qt
{
namespace map
{

static const std::string logPrefix_ = "scwx::qt::map::alert_layer";
static const auto        logger_    = scwx::util::Logger::Create(logPrefix_);

static const boost::gil::rgba32f_pixel_t kBlack_ {0.0f, 0.0f, 0.0f, 1.0f};

template<class Key>
struct AlertTypeHash;

template<>
struct AlertTypeHash<std::pair<awips::Phenomenon, bool>>
{
   size_t operator()(const std::pair<awips::Phenomenon, bool>& x) const;
};

class AlertLayerHandler : public QObject
{
   Q_OBJECT
public:
   struct SegmentRecord
   {
      std::shared_ptr<const awips::Segment>            segment_;
      types::TextEventKey                              key_;
      std::shared_ptr<const awips::TextProductMessage> message_;
      std::chrono::system_clock::time_point            segmentBegin_;
      std::chrono::system_clock::time_point            segmentEnd_;

      SegmentRecord(
         const std::shared_ptr<const awips::Segment>&            segment,
         const types::TextEventKey&                              key,
         const std::shared_ptr<const awips::TextProductMessage>& message) :
          segment_ {segment},
          key_ {key},
          message_ {message},
          segmentBegin_ {segment->event_begin()},
          segmentEnd_ {segment->event_end()}
      {
      }
   };

   explicit AlertLayerHandler()
   {
      connect(textEventManager_.get(),
              &manager::TextEventManager::AlertUpdated,
              this,
              [this](const types::TextEventKey& key, std::size_t messageIndex)
              { HandleAlert(key, messageIndex); });
   }
   ~AlertLayerHandler()
   {
      disconnect(textEventManager_.get(), nullptr, this, nullptr);

      std::unique_lock lock(alertMutex_);
   }

   std::unordered_map<
      std::pair<awips::Phenomenon, bool>,
      boost::container::stable_vector<std::shared_ptr<SegmentRecord>>,
      AlertTypeHash<std::pair<awips::Phenomenon, bool>>>
      segmentsByType_ {};

   std::unordered_map<
      types::TextEventKey,
      boost::container::stable_vector<std::shared_ptr<SegmentRecord>>,
      types::TextEventHash<types::TextEventKey>>
      segmentsByKey_ {};

   void HandleAlert(const types::TextEventKey& key, size_t messageIndex);

   static AlertLayerHandler& Instance();

   std::shared_ptr<manager::TextEventManager> textEventManager_ {
      manager::TextEventManager::Instance()};

   std::shared_mutex alertMutex_ {};

signals:
   void AlertAdded(const std::shared_ptr<SegmentRecord>& segmentRecord,
                   awips::Phenomenon                     phenomenon);
   void AlertUpdated(const std::shared_ptr<SegmentRecord>& segmentRecord);
   void AlertsUpdated(awips::Phenomenon phenomenon, bool alertActive);
};

class AlertLayer::Impl
{
public:
   explicit Impl(AlertLayer*                 self,
                 std::shared_ptr<MapContext> context,
                 awips::Phenomenon           phenomenon) :
       self_ {self},
       phenomenon_ {phenomenon},
       geoLines_ {{false, std::make_shared<gl::draw::GeoLines>(context)},
                  {true, std::make_shared<gl::draw::GeoLines>(context)}}
   {
      auto& paletteSettings = settings::PaletteSettings::Instance();

      for (auto alertActive : {false, true})
      {
         lineColor_.emplace(
            alertActive,
            util::color::ToRgba32fPixelT(
               paletteSettings.alert_color(phenomenon_, alertActive)
                  .GetValue()));
      }

      ConnectSignals();
   }
   ~Impl()
   {
      receiver_ = nullptr;

      std::unique_lock lock(linesMutex_);
   };

   void AddAlert(
      const std::shared_ptr<AlertLayerHandler::SegmentRecord>& segmentRecord);
   void UpdateAlert(
      const std::shared_ptr<AlertLayerHandler::SegmentRecord>& segmentRecord);
   void ConnectAlertHandlerSignals();
   void ConnectSignals();
   void HandleGeoLinesEvent(std::shared_ptr<gl::draw::GeoLineDrawItem>& di,
                            QEvent*                                     ev);
   void HandleGeoLinesHover(std::shared_ptr<gl::draw::GeoLineDrawItem>& di,
                            const QPointF& mouseGlobalPos);

   void AddLine(std::shared_ptr<gl::draw::GeoLines>&        geoLines,
                std::shared_ptr<gl::draw::GeoLineDrawItem>& di,
                const common::Coordinate&                   p1,
                const common::Coordinate&                   p2,
                boost::gil::rgba32f_pixel_t                 color,
                float                                       width,
                std::chrono::system_clock::time_point       startTime,
                std::chrono::system_clock::time_point       endTime,
                bool                                        enableHover);
   void AddLines(std::shared_ptr<gl::draw::GeoLines>&   geoLines,
                 const std::vector<common::Coordinate>& coordinates,
                 boost::gil::rgba32f_pixel_t            color,
                 float                                  width,
                 std::chrono::system_clock::time_point  startTime,
                 std::chrono::system_clock::time_point  endTime,
                 bool                                   enableHover,
                 boost::container::stable_vector<
                    std::shared_ptr<gl::draw::GeoLineDrawItem>>& drawItems);

   AlertLayer* self_;

   const awips::Phenomenon phenomenon_;

   std::unique_ptr<QObject> receiver_ {std::make_unique<QObject>()};

   std::unordered_map<bool, std::shared_ptr<gl::draw::GeoLines>> geoLines_;

   std::unordered_map<std::shared_ptr<const AlertLayerHandler::SegmentRecord>,
                      boost::container::stable_vector<
                         std::shared_ptr<gl::draw::GeoLineDrawItem>>>
      linesBySegment_ {};
   std::unordered_map<std::shared_ptr<const gl::draw::GeoLineDrawItem>,
                      std::shared_ptr<const AlertLayerHandler::SegmentRecord>>
              segmentsByLine_;
   std::mutex linesMutex_ {};

   std::unordered_map<bool, boost::gil::rgba32f_pixel_t> lineColor_;

   std::chrono::system_clock::time_point selectedTime_ {};

   std::shared_ptr<const gl::draw::GeoLineDrawItem> lastHoverDi_ {nullptr};
   std::string                                      tooltip_ {};
};

AlertLayer::AlertLayer(std::shared_ptr<MapContext> context,
                       awips::Phenomenon           phenomenon) :
    DrawLayer(context), p(std::make_unique<Impl>(this, context, phenomenon))
{
   for (auto alertActive : {false, true})
   {
      auto& geoLines = p->geoLines_.at(alertActive);

      AddDrawItem(geoLines);
   }
}

AlertLayer::~AlertLayer() = default;

void AlertLayer::InitializeHandler()
{
   static bool ftt = true;

   if (ftt)
   {
      logger_->debug("Initializing handler");
      AlertLayerHandler::Instance();
      ftt = false;
   }
}

void AlertLayer::Initialize()
{
   logger_->debug("Initialize: {}", awips::GetPhenomenonText(p->phenomenon_));

   DrawLayer::Initialize();

   auto& alertLayerHandler = AlertLayerHandler::Instance();

   // Take a shared lock to prevent handling additional alerts while populating
   // initial lists
   std::shared_lock lock {alertLayerHandler.alertMutex_};

   for (auto alertActive : {false, true})
   {
      auto& geoLines = p->geoLines_.at(alertActive);

      geoLines->StartLines();

      // Populate initial segments
      auto segmentsIt =
         alertLayerHandler.segmentsByType_.find({p->phenomenon_, alertActive});
      if (segmentsIt != alertLayerHandler.segmentsByType_.cend())
      {
         for (auto& segment : segmentsIt->second)
         {
            p->AddAlert(segment);
         }
      }

      geoLines->FinishLines();
   }

   p->ConnectAlertHandlerSignals();
}

void AlertLayer::Render(const QMapLibre::CustomLayerRenderParameters& params)
{
   gl::OpenGLFunctions& gl = context()->gl();

   for (auto alertActive : {false, true})
   {
      p->geoLines_.at(alertActive)->set_selected_time(p->selectedTime_);
   }

   DrawLayer::Render(params);

   SCWX_GL_CHECK_ERROR();
}

void AlertLayer::Deinitialize()
{
   logger_->debug("Deinitialize: {}", awips::GetPhenomenonText(p->phenomenon_));

   DrawLayer::Deinitialize();
}

void AlertLayerHandler::HandleAlert(const types::TextEventKey& key,
                                    size_t                     messageIndex)
{
   logger_->trace("HandleAlert: {}", key.ToString());

   std::unordered_set<std::pair<awips::Phenomenon, bool>,
                      AlertTypeHash<std::pair<awips::Phenomenon, bool>>>
      alertsUpdated {};

   auto message = textEventManager_->message_list(key).at(messageIndex);

   // Determine start time for first segment
   std::chrono::system_clock::time_point segmentBegin {};
   if (message->segment_count() > 0)
   {
      segmentBegin = message->segment(0)->event_begin();
   }

   // Take a unique mutex before modifying segments
   std::unique_lock lock {alertMutex_};

   // Update any existing segments with new end time
   auto& segmentsForKey = segmentsByKey_[key];
   for (auto& segmentRecord : segmentsForKey)
   {
      if (segmentRecord->segmentEnd_ > segmentBegin)
      {
         segmentRecord->segmentEnd_ = segmentBegin;

         Q_EMIT AlertUpdated(segmentRecord);
      }
   }

   // Process new segments
   for (auto& segment : message->segments())
   {
      if (!segment->codedLocation_.has_value())
      {
         // Cannot handle a segment without a location
         continue;
      }

      auto&             vtec       = segment->header_->vtecString_.front();
      auto              action     = vtec.pVtec_.action();
      awips::Phenomenon phenomenon = vtec.pVtec_.phenomenon();
      bool alertActive             = (action != awips::PVtec::Action::Canceled);

      auto& segmentsForType = segmentsByType_[{key.phenomenon_, alertActive}];

      // Insert segment into lists
      std::shared_ptr<SegmentRecord> segmentRecord =
         std::make_shared<SegmentRecord>(segment, key, message);

      segmentsForKey.push_back(segmentRecord);
      segmentsForType.push_back(segmentRecord);

      Q_EMIT AlertAdded(segmentRecord, phenomenon);

      alertsUpdated.emplace(phenomenon, alertActive);
   }

   // Release the lock after completing segment updates
   lock.unlock();

   for (auto& alert : alertsUpdated)
   {
      // Emit signal for each updated alert type
      Q_EMIT AlertsUpdated(alert.first, alert.second);
   }
}

void AlertLayer::Impl::ConnectAlertHandlerSignals()
{
   auto& alertLayerHandler = AlertLayerHandler::Instance();

   QObject::connect(
      &alertLayerHandler,
      &AlertLayerHandler::AlertAdded,
      receiver_.get(),
      [this](
         const std::shared_ptr<AlertLayerHandler::SegmentRecord>& segmentRecord,
         awips::Phenomenon                                        phenomenon)
      {
         if (phenomenon == phenomenon_)
         {
            AddAlert(segmentRecord);
         }
      });
   QObject::connect(
      &alertLayerHandler,
      &AlertLayerHandler::AlertUpdated,
      receiver_.get(),
      [this](
         const std::shared_ptr<AlertLayerHandler::SegmentRecord>& segmentRecord)
      {
         if (segmentRecord->key_.phenomenon_ == phenomenon_)
         {
            UpdateAlert(segmentRecord);
         }
      });
}

void AlertLayer::Impl::ConnectSignals()
{
   auto timelineManager = manager::TimelineManager::Instance();

   QObject::connect(timelineManager.get(),
                    &manager::TimelineManager::SelectedTimeUpdated,
                    receiver_.get(),
                    [this](std::chrono::system_clock::time_point dateTime)
                    { selectedTime_ = dateTime; });
}

void AlertLayer::Impl::AddAlert(
   const std::shared_ptr<AlertLayerHandler::SegmentRecord>& segmentRecord)
{
   auto& segment = segmentRecord->segment_;

   auto& vtec        = segment->header_->vtecString_.front();
   auto  action      = vtec.pVtec_.action();
   bool  alertActive = (action != awips::PVtec::Action::Canceled);
   auto& startTime   = segmentRecord->segmentBegin_;
   auto& endTime     = segmentRecord->segmentEnd_;

   auto& lineColor = lineColor_.at(alertActive);
   auto& geoLines  = geoLines_.at(alertActive);

   const auto& coordinates = segment->codedLocation_->coordinates();

   // Take a mutex before modifying lines by segment
   std::unique_lock lock {linesMutex_};

   // Add draw items only if the segment has not already been added
   auto drawItems = linesBySegment_.try_emplace(
      segmentRecord,
      boost::container::stable_vector<
         std::shared_ptr<gl::draw::GeoLineDrawItem>> {});

   // If draw items were added
   if (drawItems.second)
   {
      // Add border
      AddLines(geoLines,
               coordinates,
               kBlack_,
               5.0f,
               startTime,
               endTime,
               true,
               drawItems.first->second);

      // Add only border to segmentsByLine_
      for (auto& di : drawItems.first->second)
      {
         segmentsByLine_.insert({di, segmentRecord});
      }

      // Add line
      AddLines(geoLines,
               coordinates,
               lineColor,
               3.0f,
               startTime,
               endTime,
               false,
               drawItems.first->second);
   }
}

void AlertLayer::Impl::UpdateAlert(
   const std::shared_ptr<AlertLayerHandler::SegmentRecord>& segmentRecord)
{
   // Take a mutex before referencing lines iterators and stable vector
   std::unique_lock lock {linesMutex_};

   auto it = linesBySegment_.find(segmentRecord);
   if (it != linesBySegment_.cend())
   {
      auto& segment = segmentRecord->segment_;

      auto& vtec        = segment->header_->vtecString_.front();
      auto  action      = vtec.pVtec_.action();
      bool  alertActive = (action != awips::PVtec::Action::Canceled);

      auto& geoLines = geoLines_.at(alertActive);

      auto& lines = it->second;
      for (auto& line : lines)
      {
         geoLines->SetLineStartTime(line, segmentRecord->segmentBegin_);
         geoLines->SetLineEndTime(line, segmentRecord->segmentEnd_);
      }
   }
}

void AlertLayer::Impl::AddLines(
   std::shared_ptr<gl::draw::GeoLines>&   geoLines,
   const std::vector<common::Coordinate>& coordinates,
   boost::gil::rgba32f_pixel_t            color,
   float                                  width,
   std::chrono::system_clock::time_point  startTime,
   std::chrono::system_clock::time_point  endTime,
   bool                                   enableHover,
   boost::container::stable_vector<std::shared_ptr<gl::draw::GeoLineDrawItem>>&
      drawItems)
{
   for (std::size_t i = 0, j = 1; i < coordinates.size(); ++i, ++j)
   {
      if (j >= coordinates.size())
      {
         j = 0;

         // Ignore repeated coordinates at the end
         if (coordinates[i] == coordinates[j])
         {
            break;
         }
      }

      auto di = geoLines->AddLine();
      AddLine(geoLines,
              di,
              coordinates[i],
              coordinates[j],
              color,
              width,
              startTime,
              endTime,
              enableHover);

      drawItems.push_back(di);
   }
}

void AlertLayer::Impl::AddLine(std::shared_ptr<gl::draw::GeoLines>& geoLines,
                               std::shared_ptr<gl::draw::GeoLineDrawItem>& di,
                               const common::Coordinate&                   p1,
                               const common::Coordinate&                   p2,
                               boost::gil::rgba32f_pixel_t           color,
                               float                                 width,
                               std::chrono::system_clock::time_point startTime,
                               std::chrono::system_clock::time_point endTime,
                               bool enableHover)
{
   geoLines->SetLineLocation(
      di, p1.latitude_, p1.longitude_, p2.latitude_, p2.longitude_);
   geoLines->SetLineModulate(di, color);
   geoLines->SetLineWidth(di, width);
   geoLines->SetLineStartTime(di, startTime);
   geoLines->SetLineEndTime(di, endTime);

   if (enableHover)
   {
      geoLines->SetLineHoverCallback(
         di,
         std::bind(&AlertLayer::Impl::HandleGeoLinesHover,
                   this,
                   std::placeholders::_1,
                   std::placeholders::_2));

      gl::draw::GeoLines::RegisterEventHandler(
         di,
         std::bind(&AlertLayer::Impl::HandleGeoLinesEvent,
                   this,
                   di,
                   std::placeholders::_1));
   }
}

void AlertLayer::Impl::HandleGeoLinesEvent(
   std::shared_ptr<gl::draw::GeoLineDrawItem>& di, QEvent* ev)
{
   switch (ev->type())
   {
   case QEvent::Type::MouseButtonPress:
      auto it = segmentsByLine_.find(di);
      if (it != segmentsByLine_.cend())
      {
         // Display alert dialog
         logger_->debug("Selected alert: {}", it->second->key_.ToString());
         Q_EMIT self_->AlertSelected(it->second->key_);
      }
      break;
   }
}

void AlertLayer::Impl::HandleGeoLinesHover(
   std::shared_ptr<gl::draw::GeoLineDrawItem>& di,
   const QPointF&                              mouseGlobalPos)
{
   if (di != lastHoverDi_)
   {
      auto it = segmentsByLine_.find(di);
      if (it != segmentsByLine_.cend())
      {
         tooltip_ =
            boost::algorithm::join(it->second->segment_->productContent_, "\n");
      }
      else
      {
         tooltip_.clear();
      }

      lastHoverDi_ = di;
   }

   if (!tooltip_.empty())
   {
      util::tooltip::Show(tooltip_, mouseGlobalPos);
   }
}

AlertLayerHandler& AlertLayerHandler::Instance()
{
   static AlertLayerHandler alertLayerHandler_ {};
   return alertLayerHandler_;
}

size_t AlertTypeHash<std::pair<awips::Phenomenon, bool>>::operator()(
   const std::pair<awips::Phenomenon, bool>& x) const
{
   size_t seed = 0;
   boost::hash_combine(seed, x.first);
   boost::hash_combine(seed, x.second);
   return seed;
}

} // namespace map
} // namespace qt
} // namespace scwx

#include "alert_layer.moc"