#include "MapPresent.h"
#include "UnitDelegate.h"
#include <QVector2D>
#include <cmath>
#include <QVector3D>
#include <QPainter>

MapPresent::MapPresent(QWidget* parent /*= nullptr*/)
	:QWidget(parent)
{
	_center_index.row = 0;
	_center_index.col = 0;
}

PresentIndex MapPresent::indexGet(const QPointF& pos) const
{
	decltype(_visible_units) templist;
	for (auto& unit : _visible_units) {
		if (unit.outline.contains(pos)) {
			templist << unit;
		}
	}

	while (templist.size() > 1) {
		auto opta = templist[0];
		auto optb = templist[1];
		auto dista = QVector3D(opta.outline.center()).distanceToPoint(QVector3D(pos));
		auto distb = QVector3D(optb.outline.center()).distanceToPoint(QVector3D(pos));
		if (dista < distb) {
			templist.removeAt(1);
		}
		else {
			templist.removeAt(0);
		}
	}

	if (templist.size())
		return templist[0].index;

	return PresentIndex();
}

QRectF MapPresent::outlineGet(const PresentIndex& idx) const
{
	auto widget_rect = this->rect();
	auto widget_center = widget_rect.center();

	const float ap_len = _primitive_region_square_len / 2;
	auto a2_vec = ap_len * sqrt(3) / 2;
	auto n_yinc = QVector3D(a2_vec, ap_len * 3 / 2, 0);
	auto n_xinc = QVector3D(a2_vec, -ap_len * 3 / 2, 0);

	auto xinc = idx.row - _center_index.row;
	auto yinc = idx.col - _center_index.col;
	auto target_center = QVector3D(widget_center) + n_yinc * yinc + n_xinc * xinc;
	target_center -= QVector3D(ap_len, ap_len, 0);

	return QRectF(target_center.toPointF(), QSizeF(ap_len * 2, ap_len * 2));
}

void MapPresent::paintEvent(QPaintEvent* ev)
{
	QWidget::paintEvent(ev);
	BasicUnitDelegate t;

	QPainter p(this);
	for (auto opt : _visible_units) {
		p.save();

		auto rect = opt.outline;
		p.translate(rect.topLeft());
		rect.moveTo(0, 0);

		auto end_pts = t.endPointsGet(rect);
		QPainterPath clicp_path;
		clicp_path.moveTo(end_pts.first());
		for (auto idx = 0; idx < end_pts.size(); ++idx) {
			clicp_path.lineTo(end_pts[idx]);
		}
		p.setClipPath(clicp_path);

		opt.outline = rect;
		t.paint(&p, opt);

		p.restore();
	}
}

void MapPresent::resizeEvent(QResizeEvent* event)
{
	QWidget::resizeEvent(event);

	visibleUnitsTidy();
}

PresentOption AssumeOpt(PresentIndex index, QRectF rf) {
	PresentOption opt;
	opt.index = index;
	opt.outline = rf;
	return opt;
}

void MapPresent::visibleUnitsTidy() {
	_visible_units.clear();

	QRectF curr_outline = this->rect();
	_visible_units << AssumeOpt(_center_index, outlineGet(_center_index));

	int visible_count = 1, deduce_x = 1;
	while (visible_count) {
		visible_count = 0;

		auto siblings = siblingsGet(_center_index, deduce_x++);
		for (auto unit : siblings) {
			auto visible_rect = outlineGet(unit);
			if (curr_outline.intersects(visible_rect)) {
				_visible_units << AssumeOpt(unit, visible_rect);
				visible_count++;
			}
		}
	}

	// TODO 构建快速测试组织结构
}

QList<PresentIndex> MapPresent::siblingsGet(const PresentIndex& center, uint16_t dist) const
{
	QList<PresentIndex> e6_points;
	e6_points << PresentIndex{ center.row, center.col - dist };
	e6_points << PresentIndex{ center.row + dist, center.col };
	e6_points << PresentIndex{ center.row + dist, center.col + dist };
	e6_points << PresentIndex{ center.row, center.col + dist };
	e6_points << PresentIndex{ center.row - dist, center.col };
	e6_points << PresentIndex{ center.row - dist, center.col - dist };
	e6_points << PresentIndex{ center.row, center.col - dist };

	QList<PresentIndex> values;
	for (auto idx = 0; idx < 6; ++idx) {
		auto ap = e6_points[idx];
		auto bp = e6_points[idx + 1];
		values << itemFills(ap, bp);
	}
	return values;
}

QList<PresentIndex> MapPresent::itemFills(const PresentIndex& a, const PresentIndex& b) const
{
	QList<PresentIndex> items;
	auto sign_row = (a.row == b.row) ? 0 : ((b.row - a.row) / std::abs(a.row - b.row));
	auto sign_col = (a.col == b.col) ? 0 : ((b.col - a.col) / std::abs(a.col - b.col));

	auto temp_pt = a;
	while (temp_pt != b) {
		items << temp_pt;
		temp_pt += PresentIndex{ sign_row, sign_col };
	}

	return items;
}

PresentIndex& PresentIndex::operator+=(const PresentIndex& other)
{
	row += other.row;
	col += other.col;
	return *this;
}

bool PresentIndex::operator!=(const PresentIndex& other) const
{
	return row != other.row || col != other.col;
}

bool PresentIndex::isValid() const
{
	return row != INT_MAX && col != INT_MAX;
}