#include <tools/modifiers/modifiertest.h>

// std includes
#include <cmath>

//*****************************************************************************************
//    TModifierTest::Modifier implementation
//*****************************************************************************************


TModifierTest::Modifier::Modifier(
  TTrackHandler &handler,
  double angle,
  double radius,
  double speed
):
  TTrackModifier(handler),
  angle(angle),
  radius(radius),
  speed(speed)
{ }


TTrackPoint
TModifierTest::Modifier::calcPoint(double originalIndex) {
  TTrackPoint p = TTrackModifier::calcPoint(originalIndex);

  if (p.length > TConsts::epsilon) {
    double frac;
    int i0 = original.floorIndex(originalIndex, &frac);
    int i1 = original.ceilIndex(originalIndex);
    if (i0 < 0) return p;

    if (Handler *handler = dynamic_cast<Handler*>(&this->handler)) {
      double angle = this->angle + speed*TTrack::interpolationLinear(
        handler->angles[i0], handler->angles[i1], frac);
      double radius = 2.0*this->radius*p.pressure;
      double s = sin(angle);
      double c = cos(angle);

      TPointD tangent = original.calcTangent(originalIndex, fabs(2.0*this->radius/speed));
      p.position.x -= tangent.y*s*radius;
      p.position.y += tangent.x*s*radius;
      p.pressure   *= 1.0 - 0.5*c;
    }
  } else {
    p.pressure = 0.0;
  }

  return p;
}


//*****************************************************************************************
//    TModifierTest implementation
//*****************************************************************************************


TModifierTest::TModifierTest(int count, double radius):
  count(count),
  radius(radius)
{ }


void
TModifierTest::modifyTrack(
  const TTrack &track,
  const TInputSavePoint::Holder &savePoint,
  TTrackList &outTracks )
{
  const double segmentSize = 2.0*M_PI/10.0;

  if (!track.handler) {
    if (track.getKeyState(track.front().time).isPressed(TKey(Qt::Key_Alt))) {
      // TModifierTest::Handler for spiro
      track.handler = new Handler(track);
      for(int i = 0; i < count; ++i)
        track.handler->tracks.push_back(
          new TTrack(
            new Modifier(
              *track.handler,
              i*2.0*M_PI/(double)count,
              radius,
              0.25 )));
    }
  }

  Handler *handler = dynamic_cast<Handler*>(track.handler.getPointer());
  if (!handler) {
    TInputModifier::modifyTrack(track, savePoint, outTracks);
    return;
  }

  outTracks.insert(
    outTracks.end(),
    track.handler->tracks.begin(),
    track.handler->tracks.end() );
  if (!track.changed())
    return;

  int start = track.size() - track.pointsAdded;
  if (start < 0) start = 0;

  // remove angles
  double lastAngle = start < (int)handler->angles.size() ? handler->angles[start]
                   : handler->angles.empty() ? 0.0
                   : handler->angles.back();
  handler->angles.resize(start, lastAngle);

  // add angles
  for(int i = start; i < track.size(); ++i) {
    if (i > 0) {
      double dl = track[i].length - track[i-1].length;
      double da = track[i].pressure > TConsts::epsilon
                ? dl/(radius*track[i].pressure) : 0.0;
      handler->angles.push_back(handler->angles[i-1] + da);
    } else {
      handler->angles.push_back(0.0);
    }
  }

  // process sub-tracks
  for(TTrackList::const_iterator ti = handler->tracks.begin(); ti != handler->tracks.end(); ++ti) {
    TTrack &subTrack = **ti;
    double currentSegmentSize = segmentSize;
    if (const Modifier *modifier = dynamic_cast<const Modifier*>(subTrack.modifier.getPointer()))
      if (fabs(modifier->speed) > TConsts::epsilon)
        currentSegmentSize = segmentSize/fabs(modifier->speed);

    // remove points
    int subStart = subTrack.floorIndex(subTrack.indexByOriginalIndex(start-1)) + 1;
    subTrack.truncate(subStart);

    // add points
    for(int i = start; i < track.size(); ++i) {
      if (i > 0) {
        double prevAngle = handler->angles[i-1];
        double nextAngle = handler->angles[i];
        if (fabs(nextAngle - prevAngle) > 1.5*currentSegmentSize) {
          double step = currentSegmentSize/fabs(nextAngle - prevAngle);
          double end = 1.0 - 0.5*step;
          for(double frac = step; frac < end; frac += step)
            subTrack.push_back( subTrack.modifier->calcPoint((double)i - 1.0 + frac) );
        }
      }
      subTrack.push_back( subTrack.modifier->calcPoint(i) );
    }
  }

  track.resetChanges();
}