#pragma once

#ifndef RASTER_EDGE_EVALUATOR_HPP
#define RASTER_EDGE_EVALUATOR_HPP

#include "raster_edge_evaluator.h"

//*******************************************************************************
//    Raster Edge Evaluator implementation
//*******************************************************************************

template <typename RanIt>
RasterEdgeEvaluator<RanIt>::RasterEdgeEvaluator(
	const iterator_type &begin, const iterator_type &end,
	double tolerance, double maxLength)
	: tcg::polyline_ops::StandardDeviationEvaluator<RanIt>(begin, end), m_tolerance(tolerance), m_maxLength(maxLength)
{
}

//--------------------------------------------------------------------------

template <typename RanIt>
typename RasterEdgeEvaluator<RanIt>::penalty_type
RasterEdgeEvaluator<RanIt>::penalty(const iterator_type &a, const iterator_type &b)
{
	return tcg::point_ops::norm(*b - *a) * tcg::polyline_ops::StandardDeviationEvaluator<RanIt>::penalty(a, b);
}

//--------------------------------------------------------------------------

template <typename RanIt>
typename RasterEdgeEvaluator<RanIt>::iterator_type
RasterEdgeEvaluator<RanIt>::furthestFrom(const iterator_type &start)
{
	//Build the furthest possible forward difference for every vertex between begin and end.
	point_type displace, oldDisplace;
	point_type leftConstraint, rightConstraint;
	point_type newLeftConstraint, newRightConstraint;
	point_type leftDirConstr, rightDirConstr, dir, oldDir;
	iterator_type it = start, jt;

	const double sqMaxLength = sq(m_maxLength);

	//Initialize search
	leftConstraint = rightConstraint = point_type();
	leftDirConstr = rightDirConstr = point_type();
	oldDir = oldDisplace = point_type();

	if (it != this->m_begin)
		--it; //Chop left

	jt = it;
	for (++jt; jt != this->m_end; ++jt) {
		//Retrieve displacement from *it
		displace = point_type(jt->x - it->x, jt->y - it->y);
		dir = point_type(displace.x - oldDisplace.x, displace.y - oldDisplace.y);

		//Max length
		if (oldDir.x != 0 || oldDir.y != 0) {
			if (sq(displace.x) + sq(displace.y) > sqMaxLength)
				break;
		} else
			leftDirConstr = rightDirConstr = dir;

		//Test displacement against the oldDisplacement. If it's reversing the
		//direction, make it invalid.

		if (cross(oldDir, dir) > 0)
			leftDirConstr = dir;

		if (cross(oldDir, dir) < 0)
			rightDirConstr = dir;

		//Test constraints

		/*if(cross(rightDirConstr, leftDirConstr) <= 0 &&
       leftDirConstr * rightDirConstr < 0)
      break;*/
		if (cross(rightDirConstr, leftDirConstr) < 0)
			break;

		if (cross(displace, leftConstraint) < 0)
			break;
		if (cross(displace, rightConstraint) > 0)
			break;

		if (std::max({displace.x, -displace.x, displace.y, -displace.y}) > m_tolerance) {
			//Update m_tolerance constraints
			newLeftConstraint.x = displace.x +
								  (displace.y < 0 || (displace.y == 0 && displace.x < 0) ? m_tolerance : -m_tolerance);
			newLeftConstraint.y = displace.y +
								  (displace.x > 0 || (displace.x == 0 && displace.y < 0) ? m_tolerance : -m_tolerance);

			if (cross(newLeftConstraint, leftConstraint) >= 0)
				leftConstraint = newLeftConstraint;

			newRightConstraint.x = displace.x +
								   (displace.y > 0 || (displace.y == 0 && displace.x < 0) ? m_tolerance : -m_tolerance);

			newRightConstraint.y = displace.y +
								   (displace.x < 0 || (displace.x == 0 && displace.y < 0) ? m_tolerance : -m_tolerance);

			if (cross(newRightConstraint, rightConstraint) <= 0)
				rightConstraint = newRightConstraint;
		}

		oldDisplace = displace;
		oldDir = dir;
	}

	if (jt != this->m_end)
		--jt; //Chop Right

	return start + std::max((int)std::min(jt - start - 1, this->m_end - this->m_begin - 2), 1);
}

#endif // RASTER_EDGE_EVALUATOR_HPP