#ifndef WALLSVIACUTTEDQUADS_H
#define WALLSVIACUTTEDQUADS_H

#include "../../../geo/Line2.h"
#include "../../../geo/Polygon2.h"
#include "Walls.h"


namespace Ray3D {

	/**
	 * interpret walls als quads (polygons)
	 * intersect them with each other to prevent overlaps
	 */
	class WallsViaCuttedQuads : public Walls {

	private:

		struct Wall {

			const Floorplan::FloorObstacleLine* line;
			Line2 l1;
			Line2 l2;

			Wall(const Floorplan::FloorObstacleLine* line) : line(line) {

				const Point2 from = line->from;
				const Point2 to = line->to;
				const Point2 dir = (to-from).normalized();
				const Point2 dirP = dir.perpendicular();
				const float w = line->thickness_m;
				const float w2 = w/2;

				const Point2 p1 = from + dirP * w2;
				const Point2 p2 = from - dirP * w2;
				const Point2 p3 = to - dirP * w2;
				const Point2 p4 = to + dirP * w2;

				l1 = Line2(p1, p4);
				l2 = Line2(p2, p3);

			}

			Point2 getP1() const {return l1.p1;}
			Point2 getP2() const {return l1.p2;}
			Point2 getP3() const {return l2.p2;}
			Point2 getP4() const {return l2.p1;}

			struct CutRes {
				Point2 p;
				Line2* l1;	// within this wall
				Line2* l2;	// within the other wall
				CutRes(Point2 p, Line2* l1, Line2* l2) : p(p), l1(l1), l2(l2) {;}
			};

			std::vector<CutRes> getIntersections(Wall& o, bool limit = true) {
				std::vector<CutRes> res;
				Point2 p;
				if (intersects(l1, o.l1, limit, p)) {res.push_back(CutRes(p,&l1, &o.l1));}
				if (intersects(l1, o.l2, limit, p)) {res.push_back(CutRes(p,&l1, &o.l2));}
				if (intersects(l2, o.l1, limit, p)) {res.push_back(CutRes(p,&l2, &o.l1));}
				if (intersects(l2, o.l2, limit, p)) {res.push_back(CutRes(p,&l2, &o.l2));}
				return res;
			}

			bool containsPoint(const Point2 p) {
				return polygonContainsPoint({l1.p1, l1.p2, l2.p2, l2.p1}, p);
			}

		};

		void cropLine(Line2* l, Point2 p) {

			// determine which line-end to crop
			if (p.getDistance(l->p1) < p.getDistance(l->p2)) {
				l->p1 = p;
			} else {
				l->p2 = p;
			}

		}

		std::vector<Wall> walls;
		const Floorplan::Floor* floor;
		std::vector<Obstacle3D> obs;

	public:


		void clear() override {
			walls.clear();
		}

		void add(const Floorplan::Floor* f, const Floorplan::FloorObstacleLine* fol, const Floorplan::FloorObstacleDoor* aboveDoor) override {
			if (fol->type != Floorplan::ObstacleType::WALL) {return;}
			if (aboveDoor) {return;}
			this->floor = f;
			walls.push_back(Wall(fol));
		}

		virtual const std::vector<Obstacle3D>& get() override {
			std::vector<Wall> tmp = cut(walls);
			obs = toObs(tmp, floor);
			return obs;
		}

	private:

		/** convert all walls to obstacles */
		std::vector<Obstacle3D> toObs(const std::vector<Wall>& walls, const Floorplan::Floor* f) {
			std::vector<Obstacle3D> res;
			for (const Wall& w : walls) {
				res.push_back(toObs(w, f));
			}
			return res;
		}

//		bool isCW(Line2 l) {
//			float a = l.getAngle();
//			return a < 0 || a <= M_PI/2 || a >= M_PI*1.5;
//			//return a >= 0 && a <= M_PI;
//		}

		/** convert one wall into an obstacle */
		Obstacle3D toObs(const Wall& wall, const Floorplan::Floor* f) {

			Obstacle3D obs(getType(wall.line), wall.line->material);

			const float z1 = f->getStartingZ();
			const float z2 = f->getEndingZ();

//			Line2 l1(wall.getP1(), wall.getP2());
//			Line2 l2(wall.getP3(), wall.getP4());

//			float len1 = l1.getLength();
//			float a1 = l1.getAngle() * 180 / M_PI;
//			float a2 = l2.getAngle() * 180 / M_PI;

			const Point3 p1 = Point3(wall.getP1().x, wall.getP1().y, z1);
			const Point3 p2 = Point3(wall.getP2().x, wall.getP2().y, z1);
			const Point3 p3 = Point3(wall.getP3().x, wall.getP3().y, z1);
			const Point3 p4 = Point3(wall.getP4().x, wall.getP4().y, z1);

			const Point3 p1u = Point3(wall.getP1().x, wall.getP1().y, z2);
			const Point3 p2u = Point3(wall.getP2().x, wall.getP2().y, z2);
			const Point3 p3u = Point3(wall.getP3().x, wall.getP3().y, z2);
			const Point3 p4u = Point3(wall.getP4().x, wall.getP4().y, z2);

			obs.addQuad(p1, p2, p2u, p1u);
			obs.addQuad(p2, p3, p3u, p2u);
			obs.addQuad(p3, p4, p4u, p3u);
			obs.addQuad(p4, p1, p1u, p4u);

			obs.addQuad(p1u, p2u, p3u, p4u);
			obs.addQuad(p4, p3, p2, p1);

			obs.reverseFaces();

//			// front
//			Triangle3 t1( Point3(0, 0, z1), Point3(len1, 0, z1), Point3(len1, 0, z2) );
//			t1.reverse(); t1.rotate_deg(Point3(0,0,a1));	t1 += Point3(l1.p1.x, l1.p1.y, 0);
//			Triangle3 t2( Point3(0, 0, z1), Point3(len1, 0, z2), Point3(0, 0, z2) );
//			t2.reverse(); t2.rotate_deg(Point3(0,0,a1));	t2 += Point3(l1.p1.x, l1.p1.y, 0);

//			// rear
//			Triangle3 t3( Point3(0, 0, z1), Point3(len1, 0, z1), Point3(len1, 0, z2) );
//			t3.reverse(); t3.rotate_deg(Point3(0,0,a2));	t3 += Point3(l2.p1.x, l2.p1.y, 0);
//			Triangle3 t4( Point3(0, 0, z1), Point3(len1, 0, z2), Point3(0, 0, z2) );
//			t4.reverse(); t4.rotate_deg(Point3(0,0,a2));	t4 += Point3(l2.p1.x, l2.p1.y, 0);


//			obs.triangles.push_back(t1);
//			obs.triangles.push_back(t2);
//			obs.triangles.push_back(t3);
//			obs.triangles.push_back(t4);
////			obs.triangles.push_back(t4);

			return obs;

		}

		std::vector<Wall> cut(std::vector<Wall> walls) {

			for (size_t i = 0; i < walls.size(); ++i) {
				Wall& w1 = walls[i];

				for (size_t j = i+1; j < walls.size(); ++j) {
					Wall& w2 = walls[j];

					if (i == j) {continue;}

					std::vector<Wall::CutRes> isect = w1.getIntersections(w2);

		//			for (const auto c : isect) {
		//				out << "<circle cx='" << ox+c.p.x*s << "' cy='" << oy+(h-c.p.y)*s << "' r='2.0'/>\n";
		//			}

					// check all detected intersections
					for (const auto c : isect) {

						// we have two polygons and need to decide which line to crop:
						// we want to cut-off the polygon, that has ending points within the other polygon!
						// -> check which line (that contains the intersection point) ends within the other polygon
						const bool p1EndsWithinP2 = w2.containsPoint(c.l1->p1) || w2.containsPoint(c.l1->p2);
						const bool p2EndsWithinP1 = w1.containsPoint(c.l2->p1) || w1.containsPoint(c.l2->p2);

						// if both polygons end within the other one (this is the case for edges where two lines are conencted) -> ignore
						if (p1EndsWithinP2 && p2EndsWithinP1) {

							isect = w1.getIntersections(w2, false);
							if (isect.size() != 4) {continue;}

							// center of the 4 intersections
							Point2 isectCen;
							for (const auto c2 : isect) {isectCen += c2.p;}
							isectCen /= isect.size();

							// 2 vectors along the two walls, both pointing AWAY from the center of intersection
							const Point2 dir1 = isectCen.getDistance(w1.line->from) < isectCen.getDistance(w1.line->to) ? (w1.line->to - w1.line->from) : (w1.line->from - w1.line->to);
							const Point2 dir2 = isectCen.getDistance(w2.line->from) < isectCen.getDistance(w2.line->to) ? (w2.line->to - w2.line->from) : (w2.line->from - w2.line->to);

							// average between both, after normalization
							const Point2 dirFromCen = (dir1.normalized()+dir2.normalized()) / 2;

							// pointing INWARDS (between both walls) away from the intersection center
							const Point2 innerCenter = isectCen + dirFromCen * 10;

							// sort the 4 intersections by distance from innerCenter
							// we want to know the farthest and the nearest of the 4
							auto comp = [innerCenter] (const Wall::CutRes& a, const Wall::CutRes& b) {
								return a.p.getDistance(innerCenter) < b.p.getDistance(innerCenter);
							};
							std::sort(isect.begin(), isect.end(), comp);

							// w1 will be made longer
							// w2 will be made shorter

							bool use45 = false;

							if (use45) {

								// farthest from center
								cropLine(isect[3].l1, isect[3].p);
								cropLine(isect[3].l2, isect[3].p);

								// nearest to center
								cropLine(isect[0].l2, isect[0].p);
								cropLine(isect[0].l1, isect[0].p);

							} else {

								// farthest from center
								cropLine(isect[3].l1, isect[3].p);

								// nearest to center
								cropLine(isect[0].l2, isect[0].p);

								//cropLine(isect[2].l2, isect[2].p);

								// shared point
								if (isect[3].l1 != isect[2].l1) {
									cropLine(isect[2].l2, isect[2].p);
									cropLine(isect[2].l1, isect[2].p);
								} else {
									cropLine(isect[1].l2, isect[1].p);
									cropLine(isect[1].l1, isect[1].p);
								}

							}

						} else if (p1EndsWithinP2) {
							// crop the intersecting line within polygon 1
							cropLine(c.l1, c.p);
						} else if (p2EndsWithinP1) {
							// crop the intersecting line within polygon 2
							cropLine(c.l2, c.p);
						}

					}

				}

			}

			return walls;

		}

	};

}

#endif // WALLSVIACUTTEDQUADS_H