#ifndef MV2DELEMENTFLOORUNDERLAY_H
#define MV2DELEMENTFLOORUNDERLAY_H


#include "MV2DElement.h"
#include "MapViewElementHelper.h"

#include <Indoor/floorplan/v2/Floorplan.h>

/**
 * display e.g. a PNG-file below the map [as reference]
 */
class MV2DElementFloorUnderlay : public MV2DElement {

private:

	QImage img;
	QImage imgScaled;

	std::string tmpFile;
	Floorplan::UnderlayImage* underlay;
	BBox2 bbox;

	int selPoint = -1;

public:

	/** ctor */
	MV2DElementFloorUnderlay(Floorplan::UnderlayImage* underlay) : underlay(underlay) {
		missing();
	}

	void missing() {
		//img = QImage(QSize(64, 64), QImage::Format_ARGB32);
		//img.fill(0xFF000000);
		img = QImage("://res/icons/cross.png");
	}

	/** get the element's 3D bounding box */
	BBox2 getBoundingBox() const override {
		return bbox;
	}

	/** get the element's minimal distance (nearest whatsoever) to the given point */
	float getMinDistanceXY(const Point2 p) const override {
		(void) p;
		return CFG::SEL_THRESHOLD_SIZE_PX;	// we do not know the distance from the image
	}

	virtual void onFocus() override {

	}

	virtual void onUnfocus() override {
		selPoint = -1;	// clear selection
	}

	void paint(Painter& p) override {
		(void) p;

		if (tmpFile != underlay->filename) {
			img = QImage(underlay->filename.c_str());
			if (img.size().width() == 0) { missing(); }
			img = img.convertToFormat(QImage::Format_Grayscale8);		// saves a huge amount of memory and should suffice
			tmpFile = underlay->filename;
		}



		// map coordinates
		float mx1 = underlay->anchor.x;
		float my1 = underlay->anchor.y;
		float mw = img.width() * underlay->scaleX;
		float mh = img.height() * underlay->scaleY;
		float mx2 = mx1+mw;
		float my2 = my1+mh;

		// screen coordinates
		float sx1 = p.s.xms(mx1);
		float sy1 = p.s.yms(my1);
		float sx2 = p.s.xms(mx2);
		float sy2 = p.s.yms(my2);
		float sw = std::round(std::abs(sx1-sx2));
		float sh = std::round(std::abs(sy1-sy2));

		const float origArea = img.width() * img.height();
		const float scaledArea = sw*sh;

		bbox = BBox2();
		bbox.add(Point2(mx1, my1));
		bbox.add(Point2(mx2, my2));


		// if the to-be-displayed image is smaller than the input-one, use a pre-computed downscaled version
		if (scaledArea < origArea) {
			// does the cached downscaled image needs rebuild? (size changed)
			if (imgScaled.width() != sw || imgScaled.height() != sh) {
				imgScaled = img.scaled(sw, sh, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
			}
		} else {
			imgScaled = QImage();
		}


		float opacity = p.p->opacity();
		p.p->setOpacity(0.50f);

		// render downscaled image from cache? or use live-upscaling (faster, eats up less memory, ...)
		if (imgScaled.width() > 0) {
			p.p->drawImage(sx1, sy1-sh, imgScaled);
		} else {
			p.p->setRenderHint(QPainter::SmoothPixmapTransform, true);
			p.p->drawImage(QRectF(sx1, sy1-sh, sw, sh), img, QRectF(0,0,img.width(),img.height()));
		}

		p.p->setOpacity(opacity);

		// selected endpoint(s)?
		if (hasFocus()) {
			p.setPenBrush(Qt::NoPen, CFG::SEL_COLOR);
			if (selPoint == 0) {p.drawCircle(bbox.getMin());}
		}

		// just focused?
		if (hasFocus()) {
			p.setPenBrush(Qt::black, Qt::NoBrush);
			p.drawRect(mx1,my1,mx2,my2);
			p.drawCircle(bbox.getMin());
		}

	}

	virtual void mousePressed(MapView2D* v, const Point2 p) override {
		(void) v;
		(void) p;
	}

	virtual void mouseMove(MapView2D* v, const Point2 _p) override {
		(void) v;
		if (selPoint == -1) {return;}
		const Point2 p = v->getScaler().snap(_p);
		if (selPoint == 0) {underlay->anchor = p;}
	}

	virtual void mouseReleased(MapView2D* v, const Point2 _p) override {
		// select a new point on mouse-release (more robust than on mouse-press)
		const float t = v->getScaler().sm(CFG::SEL_THRESHOLD_SIZE_PX);
		const float l1 = _p.getDistance(bbox.getMin());
		if		(l1 <= t)	{selPoint = 0;}
		else				{selPoint = -1;}
	}

	virtual bool keyPressEvent(MapView2D* v, QKeyEvent *e) override {

		(void) v;

		const float s = (e->modifiers() & Qt::ShiftModifier) ? (1.0f) : (0.1f);

		if (e->key() == Qt::Key_Up) {underlay->anchor += Point2(0, +s); return true;}
		if (e->key() == Qt::Key_Down) {underlay->anchor += Point2(0, -s); return true;}

		if (e->key() == Qt::Key_Left) {underlay->anchor += Point2(-s, 0); return true;}
		if (e->key() == Qt::Key_Right) {underlay->anchor += Point2(+s, 0); return true;}

		return false;

	}


};

#endif // MV2DELEMENTFLOORUNDERLAY_H