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

  Audacity: A Digital Audio Editor

  EnvelopeEditor.cpp

  Paul Licameli split this from Envelope.cpp

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

#include "Audacity.h"
#include "EnvelopeEditor.h"

#include "Experimental.h"

#include <wx/dc.h>
#include <wx/event.h>

#include "AColor.h"
#include "Envelope.h"
#include "TrackArtist.h"
#include "TrackPanelDrawingContext.h"
#include "ViewInfo.h"

namespace {
void DrawPoint(wxDC & dc, const wxRect & r, int x, int y, bool top)
{
   if (y >= 0 && y <= r.height) {
      wxRect circle(r.x + x, r.y + (top ? y - 1: y - 2), 4, 4);
      dc.DrawEllipse(circle);
   }
}
}

void EnvelopeEditor::DrawPoints
(const Envelope &env,
 TrackPanelDrawingContext &context, const wxRect & r,
 bool dB, double dBRange,
 float zoomMin, float zoomMax, bool mirrored)
{
   auto &dc = context.dc;
   const auto artist = TrackArtist::Get( context );
   const auto &zoomInfo = *artist->pZoomInfo;

   bool highlight = false;
#ifdef EXPERIMENTAL_TRACK_PANEL_HIGHLIGHTING
   auto target = dynamic_cast<EnvelopeHandle*>(context.target.get());
   highlight = target && target->GetEnvelope() == this;
#endif
   wxPen &pen = highlight ? AColor::uglyPen : AColor::envelopePen;
   dc.SetPen( pen );
   dc.SetBrush(*wxWHITE_BRUSH);

   for (int i = 0; i < (int)env.GetNumberOfPoints(); i++) {
      const double time = env[i].GetT() + env.GetOffset();
      const wxInt64 position = zoomInfo.TimeToPosition(time);
      if (position >= 0 && position < r.width) {
         // Change colour if this is the draggable point...
         if (i == env.GetDragPoint()) {
            dc.SetPen( pen );
            dc.SetBrush(AColor::envelopeBrush);
         }

         double v = env[i].GetVal();
         int x = (int)(position);
         int y, y2;

         y = GetWaveYPos(v, zoomMin, zoomMax, r.height, dB,
            true, dBRange, false);
         if (!mirrored) {
            DrawPoint(dc, r, x, y, true);
         }
         else {
            y2 = GetWaveYPos(-v-.000000001, zoomMin, zoomMax, r.height, dB,
               true, dBRange, false);

            // This follows the same logic as the envelop drawing in
            // TrackArt::DrawEnvelope().
            // TODO: make this calculation into a reusable function.
            if (y2 - y < 9) {
               int value = (int)((zoomMax / (zoomMax - zoomMin)) * r.height);
               y = value - 4;
               y2 = value + 4;
            }

            DrawPoint(dc, r, x, y, true);
            DrawPoint(dc, r, x, y2, false);

            // Contour
            y = GetWaveYPos(v, zoomMin, zoomMax, r.height, dB,
               false, dBRange, false);
            y2 = GetWaveYPos(-v-.000000001, zoomMin, zoomMax, r.height, dB,
               false, dBRange, false);
            if (y <= y2) {
               DrawPoint(dc, r, x, y, true);
               DrawPoint(dc, r, x, y2, false);
            }
         }

         // Change colour back again if was the draggable point.
         if (i == env.GetDragPoint()) {
            dc.SetPen( pen );
            dc.SetBrush(*wxWHITE_BRUSH);
         }
      }
   }
}

EnvelopeEditor::EnvelopeEditor(Envelope &envelope, bool mirrored)
   : mEnvelope(envelope)
   , mMirrored(mirrored)
   , mContourOffset(-1)
   // , mInitialVal(-1.0)
   // , mInitialY(-1)
   , mUpper(false)
   , mButton(wxMOUSE_BTN_NONE)
   , mDirty(false)
{
}

EnvelopeEditor::~EnvelopeEditor()
{
}

namespace
{
inline int SQR(int x) { return x * x; }
}

/// ValueOfPixel() converts a y position on screen to an envelope value.
/// @param y - y position, usually of the mouse.relative to the clip.
/// @param height - height of the rectangle we are in.
/// @upper - true if we are on the upper line, false if on lower.
/// @dB - display mode either linear or log.
/// @zoomMin - vertical scale, typically -1.0
/// @zoomMax - vertical scale, typically +1.0
float EnvelopeEditor::ValueOfPixel( int y, int height, bool upper,
                              bool dB, double dBRange,
                              float zoomMin, float zoomMax)
{
   float v = ::ValueOfPixel(y, height, 0 != mContourOffset, dB, dBRange, zoomMin, zoomMax);

   // MB: this is mostly equivalent to what the old code did, I'm not sure
   // if anything special is needed for asymmetric ranges
   if(upper)
      return mEnvelope.ClampValue(v);
   else
      return mEnvelope.ClampValue(-v);
}

/// HandleMouseButtonDown either finds an existing control point or adds a NEW one
/// which is then recorded as the point to drag.
/// This is slightly complicated by there possibly being four control points for
/// a given time value:
/// We have an upper and lower envelope line.
/// Also we may be showing an inner envelope (at 0.5 the range).
bool EnvelopeEditor::HandleMouseButtonDown(const wxMouseEvent & event, wxRect & r,
                                     const ZoomInfo &zoomInfo,
                                     bool dB, double dBRange,
                                     float zoomMin, float zoomMax)
{
   int ctr = (int)(r.height * zoomMax / (zoomMax - zoomMin));
   bool upper = !mMirrored || (zoomMin >= 0.0) || (event.m_y - r.y < ctr);

   int clip_y = event.m_y - r.y;
   if(clip_y < 0) clip_y = 0; //keeps point in rect r, even if mouse isn't
   if(clip_y > r.GetBottom()) clip_y = r.GetBottom();

   int bestNum = -1;
   int bestDistSqr = 100; // Must be within 10 pixel radius.

   // Member variables hold state that will be needed in dragging.
   mButton        = event.GetButton();
   mContourOffset = false;

   //   wxLogDebug(wxT("Y:%i Height:%i Offset:%i"), y, height, mContourOffset );
   int len = mEnvelope.GetNumberOfPoints();

   // TODO: extract this into a function FindNearestControlPoint()
   // TODO: also fix it so that we can drag the last point on an envelope.
   for (int i = 0; i < len; i++) { //search for control point nearest click
      const double time = mEnvelope[i].GetT() + mEnvelope.GetOffset();
      const wxInt64 position = zoomInfo.TimeToPosition(time);
      if (position >= 0 && position < r.width) {

         int x = (int)(position);
         int y[4];
         int numControlPoints;

         // Outer control points
         double value = mEnvelope[i].GetVal();
         y[0] = GetWaveYPos(value, zoomMin, zoomMax, r.height,
                                dB, true, dBRange, false);
         y[1] = GetWaveYPos(-value, zoomMin, zoomMax, r.height,
                                dB, true, dBRange, false);

         // Inner control points(contour)
         y[2] = GetWaveYPos(value, zoomMin, zoomMax, r.height,
                                dB, false, dBRange, false);
         y[3] = GetWaveYPos(-value -.00000001, zoomMin, zoomMax,
                                r.height, dB, false, dBRange, false);

         numControlPoints = 4;

         if (y[2] > y[3])
            numControlPoints = 2;

         if (!mMirrored)
            numControlPoints = 1;

         const int deltaXSquared = SQR(x - (event.m_x - r.x));
         for(int j=0; j<numControlPoints; j++){

            const int dSqr = deltaXSquared + SQR(y[j] - (event.m_y - r.y));
            if (dSqr < bestDistSqr) {
               bestNum = i;
               bestDistSqr = dSqr;
               mContourOffset = (bool)(j > 1);
            }
         }
      }
   }

   if (bestNum >= 0) {
      mEnvelope.SetDragPoint(bestNum);
   }
   else {
      // TODO: Extract this into a function CreateNewPoint
      const double when = zoomInfo.PositionToTime(event.m_x, r.x);

      //      if (when <= 0 || when >= mTrackLen)
      //         return false;

      const double v = mEnvelope.GetValue( when );

      int ct = GetWaveYPos( v, zoomMin, zoomMax, r.height, dB,
                               false, dBRange, false) ;
      int cb = GetWaveYPos( -v-.000000001, zoomMin, zoomMax, r.height, dB,
                               false, dBRange, false) ;
      if (ct <= cb || !mMirrored) {
         int t = GetWaveYPos( v, zoomMin, zoomMax, r.height, dB,
                                 true, dBRange, false) ;
         int b = GetWaveYPos( -v, zoomMin, zoomMax, r.height, dB,
                                 true, dBRange, false) ;

         ct = (t + ct) / 2;
         cb = (b + cb) / 2;

         if (mMirrored &&
            (event.m_y - r.y) > ct &&
            ((event.m_y - r.y) < cb))
            mContourOffset = true;
         else
            mContourOffset = false;
      }

      double newVal = ValueOfPixel(clip_y, r.height, upper, dB, dBRange,
                                   zoomMin, zoomMax);

      mEnvelope.SetDragPoint(mEnvelope.InsertOrReplace(when, newVal));
      mDirty = true;
   }

   mUpper = upper;

   // const int dragPoint = mEnvelope.GetDragPoint();
   // mInitialVal = mEnvelope[dragPoint].GetVal();
   // mInitialY = event.m_y+mContourOffset;

   return true;
}

void EnvelopeEditor::MoveDragPoint(const wxMouseEvent & event, wxRect & r,
                               const ZoomInfo &zoomInfo, bool dB, double dBRange,
                               float zoomMin, float zoomMax)
{
   int clip_y = event.m_y - r.y;
   if(clip_y < 0) clip_y = 0;
   if(clip_y > r.height) clip_y = r.height;
   double newVal = ValueOfPixel(clip_y, r.height, mUpper, dB, dBRange,
                                zoomMin, zoomMax);

   // We no longer tolerate multiple envelope points at the same t.
   // epsilon is less than the time offset of a single sample
   // TODO: However because mTrackEpsilon assumes 200KHz this use
   // of epsilon is a tad bogus.  What we need to do instead is DELETE
   // a duplicated point on a mouse up.
   double newWhen = zoomInfo.PositionToTime(event.m_x, r.x) - mEnvelope.GetOffset();
   mEnvelope.MoveDragPoint(newWhen, newVal);
}

bool EnvelopeEditor::HandleDragging(const wxMouseEvent & event, wxRect & r,
                               const ZoomInfo &zoomInfo, bool dB, double dBRange,
                               float zoomMin, float zoomMax,
                               float WXUNUSED(eMin), float WXUNUSED(eMax))
{
   mDirty = true;

   wxRect larger = r;
   larger.Inflate(10, 10);

   if (larger.Contains(event.m_x, event.m_y))
   {
      // IF we're in the rect THEN we're not deleting this point (anymore).
      // ...we're dragging it.
      MoveDragPoint( event, r, zoomInfo, dB, dBRange, zoomMin, zoomMax);
      return true;
   }

   if(!mEnvelope.GetDragPointValid())
      // IF we already know we're deleting THEN no envelope point to update.
      return false;

   // Invalidate the point
   mEnvelope.SetDragPointValid(false);
   return true;
}

// Exit dragging mode and delete dragged point if necessary.
bool EnvelopeEditor::HandleMouseButtonUp()
{
   mEnvelope.ClearDragPoint();
   mButton = wxMOUSE_BTN_NONE;
   return true;
}

// Returns true if parent needs to be redrawn
bool EnvelopeEditor::MouseEvent(const wxMouseEvent & event, wxRect & r,
                          const ZoomInfo &zoomInfo, bool dB, double dBRange,
                          float zoomMin, float zoomMax)
{
   if (event.ButtonDown() && mButton == wxMOUSE_BTN_NONE)
      return HandleMouseButtonDown( event, r, zoomInfo, dB, dBRange,
                                    zoomMin, zoomMax);
   if (event.Dragging() && mEnvelope.GetDragPoint() >= 0)
      return HandleDragging( event, r, zoomInfo, dB, dBRange,
                             zoomMin, zoomMax);
   if (event.ButtonUp() && event.GetButton() == mButton)
      return HandleMouseButtonUp();
   return false;
}