#include "dxftess.h"
#include "dxfdata.h"
#include "polyset.h"
#include "grid.h"
#include <stdio.h>

#include "system-gl.h"
#include "mathc99.h"

#include <QVector>
#include <QPair>
#include <QHash>

#ifdef WIN32
#  define STDCALL __stdcall
#else
#  define STDCALL
#endif

#undef DEBUG_TRIANGLE_SPLITTING

struct tess_vdata {
	GLdouble v[3];
};

struct tess_triangle {
	GLdouble *p[3];
	tess_triangle() { p[0] = NULL; p[1] = NULL; p[2] = NULL; }
	tess_triangle(double *p1, double *p2, double *p3) { p[0] = p1; p[1] = p2; p[2] = p3; }
};

static GLenum tess_type;
static int tess_count;
static QVector<tess_triangle> tess_tri;
static GLdouble *tess_p1, *tess_p2;

static void STDCALL tess_vertex(void *vertex_data)
{
	GLdouble *p = (double*)vertex_data;
#if 0
	printf("  %d: %f %f %f\n", tess_count, p[0], p[1], p[2]);
#endif
	if (tess_type == GL_TRIANGLE_FAN) {
		if (tess_count == 0) {
			tess_p1 = p;
		}
		if (tess_count == 1) {
			tess_p2 = p;
		}
		if (tess_count > 1) {
			tess_tri.append(tess_triangle(tess_p1, tess_p2, p));
			tess_p2 = p;
		}
	}
	if (tess_type == GL_TRIANGLE_STRIP) {
		if (tess_count == 0) {
			tess_p1 = p;
		}
		if (tess_count == 1) {
			tess_p2 = p;
		}
		if (tess_count > 1) {
			if (tess_count % 2 == 1) {
				tess_tri.append(tess_triangle(tess_p2, tess_p1, p));
			} else {
				tess_tri.append(tess_triangle(tess_p1, tess_p2, p));
			}
			tess_p1 = tess_p2;
			tess_p2 = p;
		}
	}
	if (tess_type == GL_TRIANGLES) {
		if (tess_count == 0) {
			tess_p1 = p;
		}
		if (tess_count == 1) {
			tess_p2 = p;
		}
		if (tess_count == 2) {
			tess_tri.append(tess_triangle(tess_p1, tess_p2, p));
			tess_count = -1;
		}
	}
	tess_count++;
}

static void STDCALL tess_begin(GLenum type)
{
#if 0
	if (type == GL_TRIANGLE_FAN) {
		printf("GL_TRIANGLE_FAN:\n");
	}
	if (type == GL_TRIANGLE_STRIP) {
		printf("GL_TRIANGLE_STRIP:\n");
	}
	if (type == GL_TRIANGLES) {
		printf("GL_TRIANGLES:\n");
	}
#endif
	tess_count = 0;
	tess_type = type;
}

static void STDCALL tess_end(void)
{
	/* nothing to be done here */
}

static void STDCALL tess_error(GLenum errno)
{
	fprintf(stderr, "GLU tesselation error %s", gluErrorString(errno));
	PRINTB("GLU tesselation error %s", gluErrorString(errno));
}

static void STDCALL tess_begin_data()
{
	PRINT("GLU tesselation BEGIN_DATA\n");
}

static void STDCALL tess_edge_flag(GLboolean flag)
{
//	PRINT("GLU tesselation EDGE_FLAG\n");
}

static void STDCALL tess_edge_flag_data(GLboolean flag, void *polygon_data)
{
	PRINT("GLU tesselation EDGE_FLAG_DATA\n");
}
static void STDCALL tess_vertex_data(void *vertex_data, void *polygon_data)
{
	PRINT("GLU tesselation VERTEX_DATA\n");
}
static void STDCALL tess_end_data(void *polygon_data)
{
	PRINT("GLU tesselation END_DATA\n");
}
static void STDCALL tess_combine(GLdouble coords[3], void *vertex_data[4],
                               GLfloat weight[4], void **outData )
{
	PRINT("GLU tesselation COMBINE\n");
}
static void STDCALL tess_combine_data(GLdouble coords[3], void *vertex_data[4],
                                    GLfloat weight[4], void **outData,
                                    void *polygon_data)
{
	PRINT("GLU tesselation COMBINE_DATA\n");
}
static void STDCALL tess_error_data(GLenum errno, void *polygon_data )
{
	PRINT("GLU tesselation ERROR_DATA\n");
}

static bool point_on_line(double *p1, double *p2, double *p3)
{
	if (fabs(p1[0] - p2[0]) < 0.00001 && fabs(p1[1] - p2[1]) < 0.00001)
		return false;

	if (fabs(p3[0] - p2[0]) < 0.00001 && fabs(p3[1] - p2[1]) < 0.00001)
		return false;

	double v1[2] = { p2[0] - p1[0], p2[1] - p1[1] };
	double v2[2] = { p3[0] - p1[0], p3[1] - p1[1] };

	if (sqrt(v1[0]*v1[0] + v1[1]*v1[1]) > sqrt(v2[0]*v2[0] + v2[1]*v2[1]))
		return false;

	if (fabs(v1[0]) > fabs(v1[1])) {
		// y = x * dy/dx
		if (v2[0] == 0 || ((v1[0] > 0) != (v2[0] > 0)))
			return false;
		double v1_dy_dx = v1[1] / v1[0];
		double v2_dy_dx = v2[1] / v2[0];
		if (fabs(v1_dy_dx - v2_dy_dx) > 1e-15)
			return false;
	} else {
		// x = y * dx/dy
		if (v2[1] == 0 || ((v1[1] > 0) != (v2[1] > 0)))
			return false;
		double v1_dy_dx = v1[0] / v1[1];
		double v2_dy_dx = v2[0] / v2[1];
		if (fabs(v1_dy_dx - v2_dy_dx) > 1e-15)
			return false;
	}

#if 0
	printf("Point on line: %f/%f %f/%f %f/%f\n", p1[0], p1[1], p2[0], p2[1], p3[0], p3[1]);
#endif
	return true;
}

/*!
	up: true if the polygon is facing in the normal direction (i.e. normal = [0,0,1])
	rot: CLOCKWISE rotation around positive Z axis
 */

void dxf_tesselate(PolySet *ps, DxfData &dxf, double rot, bool up, bool do_triangle_splitting, double h)
{
	GLUtesselator *tobj = gluNewTess();

	gluTessCallback(tobj, GLU_TESS_VERTEX, (void(STDCALL *)())&tess_vertex);
	gluTessCallback(tobj, GLU_TESS_BEGIN, (void(STDCALL *)())&tess_begin);
	gluTessCallback(tobj, GLU_TESS_END, (void(STDCALL *)())&tess_end);
	gluTessCallback(tobj, GLU_TESS_ERROR, (void(STDCALL *)())&tess_error);

	gluTessCallback(tobj, GLU_TESS_EDGE_FLAG, (void(STDCALL *)())&tess_edge_flag);
//	gluTessCallback(tobj, GLU_TESS_COMBINE, (void(STDCALL *)())&tess_combine);

/* 	gluTessCallback(tobj, GLU_TESS_BEGIN_DATA, (void(STDCALL *)())&tess_begin_data); */
/* 	gluTessCallback(tobj, GLU_TESS_EDGE_FLAG_DATA, (void(STDCALL *)())&tess_edge_flag_data); */
/* 	gluTessCallback(tobj, GLU_TESS_VERTEX_DATA, (void(STDCALL *)())&tess_vertex_data); */
/* 	gluTessCallback(tobj, GLU_TESS_END_DATA, (void(STDCALL *)())&tess_end_data); */
/* 	gluTessCallback(tobj, GLU_TESS_COMBINE_DATA, (void(STDCALL *)())&tess_combine_data); */
/* 	gluTessCallback(tobj, GLU_TESS_ERROR_DATA, (void(STDCALL *)())&tess_error_data); */


	tess_tri.clear();
	QList<tess_vdata> vl;

	gluTessBeginPolygon(tobj, NULL);

	gluTessProperty(tobj, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_ODD);
	if (up) {
		gluTessNormal(tobj, 0, 0, -1);
	} else {
		gluTessNormal(tobj, 0, 0, +1);
	}

	Grid3d< QPair<int,int> > point_to_path(GRID_COARSE);

	for (int i = 0; i < dxf.paths.size(); i++) {
		if (!dxf.paths[i].is_closed)
			continue;
		gluTessBeginContour(tobj);
		for (int j = 1; j < dxf.paths[i].indices.size(); j++) {
			point_to_path.data(dxf.points[dxf.paths[i].indices[j]][0],
												 dxf.points[dxf.paths[i].indices[j]][1],
												 h) = QPair<int,int>(i, j);
			vl.append(tess_vdata());
			vl.last().v[0] = dxf.points[dxf.paths[i].indices[j]][0];
			vl.last().v[1] = dxf.points[dxf.paths[i].indices[j]][1];
			vl.last().v[2] = h;
			gluTessVertex(tobj, vl.last().v, vl.last().v);
		}
		gluTessEndContour(tobj);
	}

	gluTessEndPolygon(tobj);
	gluDeleteTess(tobj);

#if 0
	for (int i = 0; i < tess_tri.size(); i++) {
		printf("~~~\n");
		printf("  %f %f %f\n", tess_tri[i].p[0][0], tess_tri[i].p[0][1], tess_tri[i].p[0][2]);
		printf("  %f %f %f\n", tess_tri[i].p[1][0], tess_tri[i].p[1][1], tess_tri[i].p[1][2]);
		printf("  %f %f %f\n", tess_tri[i].p[2][0], tess_tri[i].p[2][1], tess_tri[i].p[2][2]);
	}
#endif

	// GLU tessing sometimes generates degenerated triangles. We must find and remove
	// them so we can use the triangle array with CGAL..
	for (int i = 0; i < tess_tri.size(); i++) {
		if (point_on_line(tess_tri[i].p[0], tess_tri[i].p[1], tess_tri[i].p[2]) ||
				point_on_line(tess_tri[i].p[1], tess_tri[i].p[2], tess_tri[i].p[0]) ||
				point_on_line(tess_tri[i].p[2], tess_tri[i].p[0], tess_tri[i].p[1])) {
			// printf("DEBUG: Removed triangle\n");
			tess_tri.remove(i--);
		}
	}

	// GLU tessing creates T-junctions. This is ok for GL displaying but creates
	// invalid polyhedrons for CGAL. So we split this tirangles up again in order
	// to create polyhedrons that are also accepted by CGAL..
	// All triangle edges are sorted by their atan2 and only edges with a simmilar atan2
	// value are compared. This speeds up this code block dramatically (compared to the
	// n^2 compares that are neccessary in the trivial implementation).
#if 1
	if (do_triangle_splitting)
	{
		bool added_triangles = true;
		typedef QPair<int,int> QPair_ii;
		QHash<int, QPair_ii> tri_by_atan2;
		for (int i = 0; i < tess_tri.size(); i++)
		for (int j = 0; j < 3; j++) {
			int ai = (int)round(atan2(fabs(tess_tri[i].p[(j+1)%3][0] - tess_tri[i].p[j][0]),
					fabs(tess_tri[i].p[(j+1)%3][1] - tess_tri[i].p[j][1])) / 0.001);
			tri_by_atan2.insertMulti(ai, QPair<int,int>(i, j));
		}
		while (added_triangles)
		{
			added_triangles = false;
#ifdef DEBUG_TRIANGLE_SPLITTING
			printf("*** Triangle splitting (%d) ***\n", tess_tri.size()+1);
#endif
			for (int i = 0; i < tess_tri.size(); i++)
			for (int k = 0; k < 3; k++)
			{
				QHash<QPair_ii, QPair_ii> possible_neigh;
				int ai = (int)floor(atan2(fabs(tess_tri[i].p[(k+1)%3][0] - tess_tri[i].p[k][0]),
						fabs(tess_tri[i].p[(k+1)%3][1] - tess_tri[i].p[k][1])) / 0.001 - 0.5);
				for (int j = 0; j < 2; j++) {
					foreach (const QPair_ii &jl, tri_by_atan2.values(ai+j))
						if (i != jl.first)
							possible_neigh[jl] = jl;
				}
#ifdef DEBUG_TRIANGLE_SPLITTING
				printf("%d/%d: %d\n", i, k, possible_neigh.size());
#endif
				foreach (const QPair_ii &jl, possible_neigh) {
					int j = jl.first;
					for (int l = jl.second; l != (jl.second + 2) % 3; l = (l + 1) % 3)
					if (point_on_line(tess_tri[i].p[k], tess_tri[j].p[l], tess_tri[i].p[(k+1)%3])) {
#ifdef DEBUG_TRIANGLE_SPLITTING
						printf("%% %f %f %f %f %f %f [%d %d]\n",
								tess_tri[i].p[k][0], tess_tri[i].p[k][1],
								tess_tri[j].p[l][0], tess_tri[j].p[l][1],
								tess_tri[i].p[(k+1)%3][0], tess_tri[i].p[(k+1)%3][1],
								i, j);
#endif
						tess_tri.append(tess_triangle(tess_tri[j].p[l],
								tess_tri[i].p[(k+1)%3], tess_tri[i].p[(k+2)%3]));
						for (int m = 0; m < 2; m++) {
							int ai = (int)round(atan2(fabs(tess_tri.last().p[(m+1)%3][0] - tess_tri.last().p[m][0]),
									fabs(tess_tri.last().p[(m+1)%3][1] - tess_tri.last().p[m][1])) / 0.001 );
							tri_by_atan2.insertMulti(ai, QPair<int,int>(tess_tri.size()-1, m));
						}
						tess_tri[i].p[(k+1)%3] = tess_tri[j].p[l];
						for (int m = 0; m < 2; m++) {
							int ai = (int)round(atan2(fabs(tess_tri[i].p[(m+1)%3][0] - tess_tri[i].p[m][0]),
									fabs(tess_tri[i].p[(m+1)%3][1] - tess_tri[i].p[m][1])) / 0.001 );
							tri_by_atan2.insertMulti(ai, QPair<int,int>(i, m));
						}
						added_triangles = true;
					}
				}
			}
		}
	}
#endif

	for (int i = 0; i < tess_tri.size(); i++)
	{
#if 0
		printf("---\n");
		printf("  %f %f %f\n", tess_tri[i].p[0][0], tess_tri[i].p[0][1], tess_tri[i].p[0][2]);
		printf("  %f %f %f\n", tess_tri[i].p[1][0], tess_tri[i].p[1][1], tess_tri[i].p[1][2]);
		printf("  %f %f %f\n", tess_tri[i].p[2][0], tess_tri[i].p[2][1], tess_tri[i].p[2][2]);
#endif
		double x, y;
		ps->append_poly();

		x = tess_tri[i].p[0][0] *  cos(rot*M_PI/180) + tess_tri[i].p[0][1] * sin(rot*M_PI/180);
		y = tess_tri[i].p[0][0] * -sin(rot*M_PI/180) + tess_tri[i].p[0][1] * cos(rot*M_PI/180);
		ps->insert_vertex(x, y, tess_tri[i].p[0][2]);

		x = tess_tri[i].p[1][0] *  cos(rot*M_PI/180) + tess_tri[i].p[1][1] * sin(rot*M_PI/180);
		y = tess_tri[i].p[1][0] * -sin(rot*M_PI/180) + tess_tri[i].p[1][1] * cos(rot*M_PI/180);
		ps->insert_vertex(x, y, tess_tri[i].p[1][2]);

		x = tess_tri[i].p[2][0] *  cos(rot*M_PI/180) + tess_tri[i].p[2][1] * sin(rot*M_PI/180);
		y = tess_tri[i].p[2][0] * -sin(rot*M_PI/180) + tess_tri[i].p[2][1] * cos(rot*M_PI/180);
		ps->insert_vertex(x, y, tess_tri[i].p[2][2]);

		int i0 = point_to_path.data(tess_tri[i].p[0][0], tess_tri[i].p[0][1], tess_tri[i].p[0][2]).first;
		int j0 = point_to_path.data(tess_tri[i].p[0][0], tess_tri[i].p[0][1], tess_tri[i].p[0][2]).second;

		int i1 = point_to_path.data(tess_tri[i].p[1][0], tess_tri[i].p[1][1], tess_tri[i].p[1][2]).first;
		int j1 = point_to_path.data(tess_tri[i].p[1][0], tess_tri[i].p[1][1], tess_tri[i].p[1][2]).second;

		int i2 = point_to_path.data(tess_tri[i].p[2][0], tess_tri[i].p[2][1], tess_tri[i].p[2][2]).first;
		int j2 = point_to_path.data(tess_tri[i].p[2][0], tess_tri[i].p[2][1], tess_tri[i].p[2][2]).second;

		if (i0 == i1 && j0 == 1 && j1 == 2)
			dxf.paths[i0].is_inner = !up;
		if (i0 == i1 && j0 == 2 && j1 == 1)
			dxf.paths[i0].is_inner = up;

		if (i1 == i2 && j1 == 1 && j2 == 2)
			dxf.paths[i1].is_inner = !up;
		if (i1 == i2 && j1 == 2 && j2 == 1)
			dxf.paths[i1].is_inner = up;

		if (i2 == i0 && j2 == 1 && j0 == 2)
			dxf.paths[i2].is_inner = !up;
		if (i2 == i0 && j2 == 2 && j0 == 1)
			dxf.paths[i2].is_inner = up;
	}

	tess_tri.clear();
}
