/**********************************************************************

Audacity: A Digital Audio Editor

StretchHandle.cpp

Paul Licameli split from TrackPanel.cpp

**********************************************************************/

#include "../../../../Audacity.h" // for USE_* macros

#ifdef USE_MIDI
#include "StretchHandle.h"

#include "../../../../HitTestResult.h"
#include "../../../../NoteTrack.h"
#include "../../../../ProjectAudioIO.h"
#include "../../../../ProjectHistory.h"
#include "../../../../ProjectSettings.h"
#include "../../../../RefreshCode.h"
#include "../../../../TrackPanelMouseEvent.h"
#include "../../../../UndoManager.h"
#include "../../../../ViewInfo.h"
#include "../../../../../images/Cursors.h"

#include <algorithm>

StretchHandle::StretchHandle
( const std::shared_ptr<NoteTrack> &pTrack, const StretchState &stretchState )
   : mpTrack{ pTrack }
   , mStretchState{ stretchState }
{}

HitTestPreview StretchHandle::HitPreview( StretchEnum stretchMode, bool unsafe )
{
   static auto disabledCursor =
      ::MakeCursor(wxCURSOR_NO_ENTRY, DisabledCursorXpm, 16, 16);
   static auto stretchLeftCursor =
      ::MakeCursor(wxCURSOR_BULLSEYE, StretchLeftCursorXpm, 16, 16);
   static auto stretchRightCursor =
      ::MakeCursor(wxCURSOR_BULLSEYE, StretchRightCursorXpm, 16, 16);
   static auto stretchCursor =
      ::MakeCursor(wxCURSOR_BULLSEYE, StretchCursorXpm, 16, 16);

   if (unsafe) {
      return { {}, &*disabledCursor };
   }
   else {
      wxCursor *pCursor = NULL;
      switch (stretchMode) {
      default:
         wxASSERT(false);
      case stretchLeft:
         pCursor = &*stretchLeftCursor; break;
      case stretchCenter:
         pCursor = &*stretchCursor; break;
      case stretchRight:
         pCursor = &*stretchRightCursor; break;
      }
      return {
         XO("Click and drag to stretch selected region."),
         pCursor
      };
   }
}

UIHandlePtr StretchHandle::HitTest
(std::weak_ptr<StretchHandle> &holder,
 const TrackPanelMouseState &st, const AudacityProject *pProject,
 const std::shared_ptr<NoteTrack> &pTrack)
{
   StretchState stretchState;
   const wxMouseState &state = st.state;

   // later, we may want a different policy, but for now, stretch is
   // selected when the cursor is near the center of the track and
   // within the selection
   auto &viewInfo = ViewInfo::Get( *pProject );

   if (!pTrack || !pTrack->GetSelected())
      return {};

   const wxRect &rect = st.rect;
   int center = rect.y + rect.height / 2;
   int distance = abs(state.m_y - center);
   const int yTolerance = 10;
   wxInt64 leftSel = viewInfo.TimeToPosition(viewInfo.selectedRegion.t0(), rect.x);
   wxInt64 rightSel = viewInfo.TimeToPosition(viewInfo.selectedRegion.t1(), rect.x);
   // Something is wrong if right edge comes before left edge
   wxASSERT(!(rightSel < leftSel));
   if (!(leftSel <= state.m_x && state.m_x <= rightSel &&
         distance < yTolerance))
      return {};

   // find nearest beat to sel0, sel1
   static const double minPeriod = 0.05; // minimum beat period
   stretchState.mBeatCenter = { 0, 0 };

   auto t0 = GetT0(*pTrack, viewInfo);
   auto t1 = GetT1(*pTrack, viewInfo);

   if (t0 >= t1)
      return {};

   stretchState.mBeat0 = pTrack->NearestBeatTime( t0 );
   stretchState.mOrigSel0Quantized = stretchState.mBeat0.first;

   stretchState.mBeat1 = pTrack->NearestBeatTime( t1 );
   stretchState.mOrigSel1Quantized = stretchState.mBeat1.first;

   // If there is not (almost) a beat to stretch that is slower
   // than 20 beats per second, don't stretch
   if ( within( stretchState.mBeat0.second,
                stretchState.mBeat1.second, 0.9 ) ||
       ( stretchState.mBeat1.first - stretchState.mBeat0.first ) /
          ( stretchState.mBeat1.second - stretchState.mBeat0.second )
            < minPeriod )
      return {};

   auto selStart = viewInfo.PositionToTime( state.m_x, rect.x );
   selStart = std::max(t0, std::min(t1, selStart));
   stretchState.mBeatCenter = pTrack->NearestBeatTime( selStart );
   if ( within( stretchState.mBeat0.second,
                stretchState.mBeatCenter.second, 0.1 ) ) {
      stretchState.mMode = stretchLeft;
      stretchState.mLeftBeats = 0;
      stretchState.mRightBeats =
         stretchState.mBeat1.second - stretchState.mBeat0.second;
   }
   else if ( within( stretchState.mBeat1.second,
                     stretchState.mBeatCenter.second, 0.1 ) ) {
      stretchState.mMode = stretchRight;
      stretchState.mLeftBeats =
         stretchState.mBeat1.second - stretchState.mBeat0.second;
      stretchState.mRightBeats = 0;
   }
   else {
      stretchState.mMode = stretchCenter;
      stretchState.mLeftBeats =
         stretchState.mBeat1.second - stretchState.mBeatCenter.second;
      stretchState.mRightBeats =
         stretchState.mBeatCenter.second - stretchState.mBeat0.second;
   }

   auto result = std::make_shared<StretchHandle>( pTrack, stretchState );
   result = AssignUIHandlePtr(holder, result);
   return result;
}

StretchHandle::~StretchHandle()
{
}

UIHandle::Result StretchHandle::Click
(const TrackPanelMouseEvent &evt, AudacityProject *pProject)
{
   using namespace RefreshCode;
   const bool unsafe = ProjectAudioIO::Get( *pProject ).IsAudioActive();
   if ( unsafe )
      return Cancelled;

   const wxMouseEvent &event = evt.event;

   if (event.LeftDClick() ||
       !event.LeftDown() ||
       evt.pCell == NULL)
      return Cancelled;


   mLeftEdge = evt.rect.GetLeft();
   auto &viewInfo = ViewInfo::Get( *pProject );

   viewInfo.selectedRegion.setTimes
      ( mStretchState.mBeat0.first, mStretchState.mBeat1.first );

   // Full refresh since the label area may need to indicate
   // newly selected tracks. (I'm really not sure if the label area
   // needs to be refreshed or how to just refresh non-label areas.-RBD)

   return RefreshAll;
}

UIHandle::Result StretchHandle::Drag
(const TrackPanelMouseEvent &evt, AudacityProject *pProject)
{
   using namespace RefreshCode;
   const bool unsafe = ProjectAudioIO::Get( *pProject ).IsAudioActive();
   if (unsafe) {
      this->Cancel(pProject);
      return RefreshAll | Cancelled;
   }

   const wxMouseEvent &event = evt.event;
   const int x = event.m_x;

   Track *clickedTrack=nullptr;
   if (evt.pCell)
      clickedTrack =
         static_cast<CommonTrackPanelCell*>(evt.pCell.get())->FindTrack().get();

   if (clickedTrack == nullptr && mpTrack != nullptr)
      clickedTrack = mpTrack.get();
   Stretch(pProject, x, mLeftEdge, clickedTrack);
   return RefreshAll;
}

HitTestPreview StretchHandle::Preview
(const TrackPanelMouseState &, AudacityProject *pProject)
{
   const bool unsafe = ProjectAudioIO::Get( *pProject ).IsAudioActive();
   return HitPreview( mStretchState.mMode, unsafe );
}

UIHandle::Result StretchHandle::Release
(const TrackPanelMouseEvent &, AudacityProject *pProject,
 wxWindow *)
{
   using namespace RefreshCode;

   const bool unsafe = ProjectAudioIO::Get( *pProject ).IsAudioActive();
   if (unsafe) {
      this->Cancel(pProject);
      return RefreshAll | Cancelled;
   }

   bool left = mStretchState.mMode == stretchLeft;
   bool right = mStretchState.mMode == stretchRight;
   const auto &settings = ProjectSettings::Get( *pProject );
   auto &viewInfo = ViewInfo::Get( *pProject );
   if ( settings.IsSyncLocked() && ( left || right ) ) {
      for ( auto track :
           TrackList::SyncLockGroup( mpTrack.get() ) ) {
         if ( track != mpTrack.get() ) {
            if ( left ) {
               auto origT0 = mStretchState.mOrigSel0Quantized;
               auto diff = viewInfo.selectedRegion.t0() - origT0;
               if ( diff > 0)
                  track->SyncLockAdjust( origT0 + diff, origT0 );
               else
                  track->SyncLockAdjust( origT0, origT0 - diff );
               track->Offset( diff );
            }
            else {
               auto origT1 = mStretchState.mOrigSel1Quantized;
               auto diff = viewInfo.selectedRegion.t1() - origT1;
               track->SyncLockAdjust( origT1, origT1 + diff );
            }
         }
      }
   }

   /* i18n-hint: (noun) The track that is used for MIDI notes which can be
   dragged to change their duration.*/
   ProjectHistory::Get( *pProject ).PushState(XO("Stretch Note Track"),
      /* i18n-hint: In the history list, indicates a MIDI note has
      been dragged to change its duration (stretch it). Using either past
      or present tense is fine here.  If unsure, go for whichever is
      shorter.*/
      XO("Stretch"),
      UndoPush::CONSOLIDATE | UndoPush::AUTOSAVE);
   return RefreshAll;
}

UIHandle::Result StretchHandle::Cancel(AudacityProject *pProject)
{
   ProjectHistory::Get( *pProject ).RollbackState();
   return RefreshCode::RefreshNone;
}

double StretchHandle::GetT0(const Track &track, const ViewInfo &viewInfo)
{
   return std::max(track.GetStartTime(), viewInfo.selectedRegion.t0());
}

double StretchHandle::GetT1(const Track &track, const ViewInfo &viewInfo)
{
   return std::min(track.GetEndTime(), viewInfo.selectedRegion.t1());
}

void StretchHandle::Stretch(AudacityProject *pProject, int mouseXCoordinate, int trackLeftEdge,
   Track *pTrack)
{
   auto &viewInfo = ViewInfo::Get( *pProject );

   if (pTrack == NULL && mpTrack != NULL)
      pTrack = mpTrack.get();

  if (pTrack) pTrack->TypeSwitch( [&](NoteTrack *pNt) {
      double moveto =
        std::max(0.0, viewInfo.PositionToTime(mouseXCoordinate, trackLeftEdge));

      double dur, left_dur, right_dur;

      // check to make sure tempo is not higher than 20 beats per second
      // (In principle, tempo can be higher, but not infinity.)
      double minPeriod = 0.05; // minimum beat period

      // make sure target duration is not too short
      // Take quick exit if so, without changing the selection.
      auto t0 = mStretchState.mBeat0.first;
      auto t1 = mStretchState.mBeat1.first;
      switch ( mStretchState.mMode ) {
      case stretchLeft: {
         dur = t1 - moveto;
         if (dur < mStretchState.mRightBeats * minPeriod)
            return;
         pNt->StretchRegion
            ( mStretchState.mBeat0, mStretchState.mBeat1, dur );
         pNt->Offset( moveto - t0 );
         mStretchState.mBeat0.first = moveto;
         viewInfo.selectedRegion.setT0(moveto);
         break;
      }
      case stretchRight: {
         dur = moveto - t0;
         if (dur < mStretchState.mLeftBeats * minPeriod)
            return;
         pNt->StretchRegion
            ( mStretchState.mBeat0, mStretchState.mBeat1, dur );
         viewInfo.selectedRegion.setT1(moveto);
         mStretchState.mBeat1.first = moveto;
         break;
      }
      case stretchCenter: {
         moveto = std::max(t0, std::min(t1, moveto));
         left_dur = moveto - t0;
         right_dur = t1 - moveto;
         if ( left_dur < mStretchState.mLeftBeats * minPeriod ||
              right_dur < mStretchState.mRightBeats * minPeriod )
            return;
         pNt->StretchRegion
            ( mStretchState.mBeatCenter, mStretchState.mBeat1, right_dur );
         pNt->StretchRegion
            ( mStretchState.mBeat0, mStretchState.mBeatCenter, left_dur );
         mStretchState.mBeatCenter.first = moveto;
         break;
      }
      default:
         wxASSERT(false);
         break;
      }
  });
}
#endif
