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

Audacity: A Digital Audio Editor

TrackSelectHandle.cpp

Paul Licameli split from TrackPanel.cpp

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

#include "../../Audacity.h"
#include "TrackSelectHandle.h"

#include "TrackView.h"
#include "../../Project.h"
#include "../../ProjectAudioIO.h"
#include "../../ProjectHistory.h"
#include "../../RefreshCode.h"
#include "../../SelectUtilities.h"
#include "../../TrackPanel.h"
#include "../../TrackPanelMouseEvent.h"
#include "../../WaveTrack.h"

#include <wx/cursor.h>
#include <wx/translation.h>

#include "../../../images/Cursors.h"

#if defined(__WXMAC__)
/* i18n-hint: Command names a modifier key on Macintosh keyboards */
#define CTRL_CLICK _("Command-Click")
#else
/* i18n-hint: Ctrl names a modifier key on Windows or Linux keyboards */
#define CTRL_CLICK _("Ctrl-Click")
#endif

namespace {
   TranslatableString Message(unsigned trackCount) {
      if (trackCount > 1)
         // i18n-hint: %s is replaced by (translation of) 'Ctrl-Click' on windows, 'Command-Click' on Mac
         return XO(
"%s to select or deselect track. Drag up or down to change track order.")
            .Format( CTRL_CLICK );
      else
         // i18n-hint: %s is replaced by (translation of) 'Ctrl-Click' on windows, 'Command-Click' on Mac
         return XO("%s to select or deselect track.")
            .Format( CTRL_CLICK );
   }
}

TrackSelectHandle::TrackSelectHandle( const std::shared_ptr<Track> &pTrack )
   : mpTrack( pTrack )
{}

UIHandlePtr TrackSelectHandle::HitAnywhere
(std::weak_ptr<TrackSelectHandle> &holder,
 const std::shared_ptr<Track> &pTrack)
{
   auto result = std::make_shared<TrackSelectHandle>(pTrack);
   result = AssignUIHandlePtr(holder, result);
   return result;
}

TrackSelectHandle::~TrackSelectHandle()
{
}

UIHandle::Result TrackSelectHandle::Click
(const TrackPanelMouseEvent &evt, AudacityProject *pProject)
{
   // If unsafe to drag, still, it does harmlessly change the selected track
   // set on button down.

   using namespace RefreshCode;
   Result result = RefreshNone;

   const wxMouseEvent &event = evt.event;

   // AS: If not a click, ignore the mouse event.
   if (!event.ButtonDown() && !event.ButtonDClick())
      return Cancelled;
   if (!event.Button(wxMOUSE_BTN_LEFT))
      return Cancelled;

   const auto pTrack = mpTrack;
   if (!pTrack)
      return Cancelled;
   const bool unsafe = ProjectAudioIO::Get( *pProject ).IsAudioActive();

   // DM: If they weren't clicking on a particular part of a track label,
   //  deselect other tracks and select this one.

   // JH: also, capture the current track for rearranging, so the user
   //  can drag the track up or down to swap it with others
   if (unsafe)
      result |= Cancelled;
   else {
      mRearrangeCount = 0;
      CalculateRearrangingThresholds(event, pProject);
   }

   SelectUtilities::DoListSelection(*pProject,
      pTrack.get(), event.ShiftDown(), event.ControlDown(), !unsafe);

   mClicked = true;
   return result;
}

UIHandle::Result TrackSelectHandle::Drag
(const TrackPanelMouseEvent &evt, AudacityProject *pProject)
{
   using namespace RefreshCode;
   Result result = RefreshNone;

   const wxMouseEvent &event = evt.event;

   auto &tracks = TrackList::Get( *pProject );

   // probably harmless during play?  However, we do disallow the click, so check this too.
   bool unsafe = ProjectAudioIO::Get( *pProject ).IsAudioActive();
   if (unsafe)
      return result;

   if (event.m_y < mMoveUpThreshold || event.m_y < 0) {
      tracks.MoveUp(mpTrack.get());
      --mRearrangeCount;
   }
   else if ( event.m_y > mMoveDownThreshold
      || event.m_y > evt.whole.GetHeight() ) {
      tracks.MoveDown(mpTrack.get());
      ++mRearrangeCount;
   }
   else
      return result;

   // JH: if we moved up or down, recalculate the thresholds and make sure the
   // track is fully on-screen.
   CalculateRearrangingThresholds(event, pProject);

   result |= EnsureVisible | RefreshAll;
   return result;
}

HitTestPreview TrackSelectHandle::Preview
(const TrackPanelMouseState &, AudacityProject *project)
{
   static auto disabledCursor =
      ::MakeCursor(wxCURSOR_NO_ENTRY, DisabledCursorXpm, 16, 16);
   //static wxCursor rearrangeCursor{ wxCURSOR_HAND };
   static auto rearrangingCursor =
      ::MakeCursor(wxCURSOR_HAND, RearrangingCursorXpm, 16, 16);
   static wxCursor arrowCursor{ wxCURSOR_ARROW };

   //static auto hoverCursor =
   //   ::MakeCursor(wxCURSOR_HAND, RearrangeCursorXpm, 16, 16);
   //static auto clickedCursor =
   //   ::MakeCursor(wxCURSOR_HAND, RearrangingCursorXpm, 16, 16);

   const auto trackCount = TrackList::Get( *project ).Leaders().size();
   auto message = Message(trackCount);
   if (mClicked) {
      const bool unsafe =
         ProjectAudioIO::Get( *project ).IsAudioActive();
      const bool canMove = TrackList::Get( *project ).Leaders().size() > 1;
      return {
         message,
         (unsafe
          ? &*disabledCursor
          : canMove
             ? &*rearrangingCursor
             : &arrowCursor)
         // , message // Stop showing the tooltip after the click
      };
   }
   else {
      // Only mouse-over
      // Don't test safety, because the click to change selection is allowed
      return {
         message,
         &arrowCursor,
         message
      };
   }
}

UIHandle::Result TrackSelectHandle::Release
(const TrackPanelMouseEvent &, AudacityProject *project, wxWindow *)
{
   // If we're releasing, surely we are dragging a track?
   wxASSERT( mpTrack );
   if (mRearrangeCount != 0) {
      ProjectHistory::Get( *project ).PushState(
         /* i18n-hint: will substitute name of track for %s */
         ( mRearrangeCount < 0 ? XO("Moved '%s' up") : XO("Moved '%s' down") )
            .Format( mpTrack->GetName() ),
         XO("Move Track"));
   }
   // Bug 1677
   // Holding on to the reference to the track was causing it to be released far later
   // than necessary, on shutdown, and so causing a crash as a dialog about cleaning
   // out files could not show at that time.
   mpTrack.reset();
   // No need to redraw, that was done when drag moved the track
   return RefreshCode::RefreshNone;
}

UIHandle::Result TrackSelectHandle::Cancel(AudacityProject *pProject)
{
   ProjectHistory::Get( *pProject ).RollbackState();
   // Bug 1677
   mpTrack.reset();
   return RefreshCode::RefreshAll;
}

/// Figure out how far the user must drag the mouse up or down
/// before the track will swap with the one above or below
void TrackSelectHandle::CalculateRearrangingThresholds(
   const wxMouseEvent & event, AudacityProject *project)
{
   // JH: this will probably need to be tweaked a bit, I'm just
   //   not sure what formula will have the best feel for the
   //   user.

   auto &tracks = TrackList::Get( *project );

   if (tracks.CanMoveUp(mpTrack.get()))
      mMoveUpThreshold =
         event.m_y -
            TrackView::GetChannelGroupHeight(
               * -- tracks.FindLeader( mpTrack.get() ) );
   else
      mMoveUpThreshold = INT_MIN;

   if (tracks.CanMoveDown(mpTrack.get()))
      mMoveDownThreshold =
         event.m_y +
            TrackView::GetChannelGroupHeight(
               * ++ tracks.FindLeader( mpTrack.get() ) );
   else
      mMoveDownThreshold = INT_MAX;
}
