#pragma once

#ifndef RASTER_EDGE_ITERATOR_HPP
#define RASTER_EDGE_ITERATOR_HPP

#include "raster_edge_iterator.h"

namespace TRop
{
namespace borders
{

template <typename PixelSelector>
RasterEdgeIterator<PixelSelector>::RasterEdgeIterator(
	const raster_typeP &rin, const selector_type &selector,
	const TPoint &pos, const TPoint &dir, int adherence)
	: m_ras(rin), m_lx_1(rin->getLx() - 1), m_ly_1(rin->getLy() - 1), m_wrap(rin->getWrap()), m_selector(selector), m_pos(pos), m_dir(dir), m_elbowColor(selector.transparent()), m_rightSide(adherence == RIGHT), m_turn(UNKNOWN)
{
	pixels(m_leftPix, m_rightPix);
	colors(m_leftColor, m_rightColor);
}

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

template <typename PixelSelector>
void RasterEdgeIterator<PixelSelector>::setEdge(const TPoint &pos, const TPoint &dir)
{
	m_pos = pos, m_dir = dir;
	pixels(m_leftPix, m_rightPix);
	colors(m_leftColor, m_rightColor);
}

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

template <typename PixelSelector>
inline void RasterEdgeIterator<PixelSelector>::pixels(
	pixel_type *&pixLeft, pixel_type *&pixRight)
{
	pixel_type *pix = m_ras->pixels(0) + m_pos.y * m_wrap + m_pos.x;
	if (m_dir.y)
		if (m_dir.y > 0)
			pixLeft = pix - 1, pixRight = pix;
		else
			pixLeft = pix - m_wrap, pixRight = pixLeft - 1;
	else if (m_dir.x > 0)
		pixLeft = pix, pixRight = pix - m_wrap;
	else
		pixRight = pix - 1, pixLeft = pixRight - m_wrap;
}

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

template <typename PixelSelector>
inline void RasterEdgeIterator<PixelSelector>::colors(
	value_type &leftColor, value_type &rightColor)
{
	if (m_dir.y)
		if (m_dir.y > 0) {
			if (m_pos.y > m_ly_1)
				leftColor = rightColor = m_selector.transparent();
			else {
				leftColor = (m_pos.x > 0) ? m_selector.value(*m_leftPix) : m_selector.transparent();
				rightColor = (m_pos.x <= m_lx_1) ? m_selector.value(*m_rightPix) : m_selector.transparent();
			}
		} else {
			if (m_pos.y < 1)
				leftColor = rightColor = m_selector.transparent();
			else {
				leftColor = (m_pos.x <= m_lx_1) ? m_selector.value(*m_leftPix) : m_selector.transparent();
				rightColor = (m_pos.x > 0) ? m_selector.value(*m_rightPix) : m_selector.transparent();
			}
		}
	else if (m_dir.x > 0) {
		if (m_pos.x > m_lx_1)
			leftColor = rightColor = m_selector.transparent();
		else {
			leftColor = (m_pos.y <= m_ly_1) ? m_selector.value(*m_leftPix) : m_selector.transparent();
			rightColor = (m_pos.y > 0) ? m_selector.value(*m_rightPix) : m_selector.transparent();
		}
	} else {
		if (m_pos.x < 1)
			leftColor = rightColor = m_selector.transparent();
		else {
			leftColor = (m_pos.y > 0) ? m_selector.value(*m_leftPix) : m_selector.transparent();
			rightColor = (m_pos.y <= m_ly_1) ? m_selector.value(*m_rightPix) : m_selector.transparent();
		}
	}
}

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

template <typename PixelSelector>
inline void RasterEdgeIterator<PixelSelector>::turn(const value_type &newLeftColor, const value_type &newRightColor)
{
	if (m_rightSide) {
		if (newLeftColor == m_rightColor) {
			if (newRightColor == m_leftColor)
				turnAmbiguous(newLeftColor, newRightColor);
			else
				turnLeft();
		} else {
			if (newRightColor != m_rightColor)
				turnRight();
			else
				m_turn = STRAIGHT;
		}

		m_elbowColor = newLeftColor;
	} else {
		if (newRightColor == m_leftColor) {
			if (newLeftColor == m_rightColor)
				turnAmbiguous(newLeftColor, newRightColor);
			else
				turnRight();
		} else {
			if (newLeftColor != m_leftColor)
				turnLeft();
			else
				m_turn = STRAIGHT;
		}

		m_elbowColor = newRightColor;
	}

	pixels(m_leftPix, m_rightPix);
}

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

template <typename PixelSelector>
inline void RasterEdgeIterator<PixelSelector>::turnAmbiguous(
	const value_type &newLeftColor, const value_type &newRightColor)
{
	pixel_type *pix = m_ras->pixels(0) + m_pos.y * m_wrap + m_pos.x;
	UCHAR count1 = 0, count2 = 0;

	value_type val;

	// Check the 4x4 neighbourhood and connect the minority color
	if (m_pos.x > 2) {
		val = m_selector.value(*(pix - 2));
		if (val == m_leftColor)
			++count1;
		else if (val == m_rightColor)
			++count2;

		val = m_selector.value(*(pix - 2 - m_wrap));
		if (val == m_leftColor)
			++count1;
		else if (val == m_rightColor)
			++count2;
	}

	if (m_pos.x < m_lx_1) {
		val = m_selector.value(*(pix + 1));
		if (val == m_leftColor)
			++count1;
		else if (val == m_rightColor)
			++count2;

		val = m_selector.value(*(pix + 1 - m_wrap));
		if (val == m_leftColor)
			++count1;
		else if (val == m_rightColor)
			++count2;
	}

	if (m_pos.y > 2) {
		int wrap2 = m_wrap << 1;

		val = m_selector.value(*(pix - wrap2));
		if (val == m_leftColor)
			++count1;
		else if (val == m_rightColor)
			++count2;

		val = m_selector.value(*(pix - wrap2 - 1));
		if (val == m_leftColor)
			++count1;
		else if (val == m_rightColor)
			++count2;
	}

	if (m_pos.y < m_ly_1) {
		val = m_selector.value(*(pix + m_wrap));
		if (val == m_leftColor)
			++count1;
		else if (val == m_rightColor)
			++count2;

		val = m_selector.value(*(pix + m_wrap - 1));
		if (val == m_leftColor)
			++count1;
		else if (val == m_rightColor)
			++count2;
	}

	// Minority connection - join the one with less count
	if (count1 < count2)
		turnRight(); // Join m_leftColor == newRightColor
	else if (count1 > count2)
		turnLeft(); // Join m_rightColor == newLeftColor
	else if (m_rightColor < m_leftColor)
		turnLeft();
	else
		turnRight();

	m_turn |= AMBIGUOUS;
}

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

template <typename PixelSelector>
RasterEdgeIterator<PixelSelector> &RasterEdgeIterator<PixelSelector>::operator++()
{
	value_type newLeftColor = m_leftColor, newRightColor = m_rightColor;

	int pixAdd = m_dir.y * m_wrap + m_dir.x;
	if (m_rightSide) {
		do {
			m_pos.x += m_dir.x, m_pos.y += m_dir.y;
			m_leftPix += pixAdd, m_rightPix += pixAdd;
			m_leftColor = newLeftColor;

			colors(newLeftColor, newRightColor);
		} while ((newRightColor == m_rightColor) && (newLeftColor != newRightColor) &&
				 m_selector.skip(m_leftColor, newLeftColor));
	} else {
		do {
			m_pos.x += m_dir.x, m_pos.y += m_dir.y;
			m_leftPix += pixAdd, m_rightPix += pixAdd;
			m_rightColor = newRightColor;

			colors(newLeftColor, newRightColor);
		} while ((newLeftColor == m_leftColor) && (newLeftColor != newRightColor) &&
				 m_selector.skip(m_rightColor, newRightColor));
	}

	turn(newLeftColor, newRightColor);
	colors(m_leftColor, m_rightColor);

	return *this;
}
}
} //  namespace TRop::borders

#endif // RASTER_EDGE_ITERATOR_HPP