/*
    QGLView
    Copyright (C) 2020  Ivan Pelipenko peri4ko@yandex.ru

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "loader_3ds.h"


void Loader3DS::init3DSMesh(GLObjectBase * o, const QVector<uint> & smooth) {
	QVector<GLfloat> & vertices(o->VBO().vertices()), & normals(o->VBO().normals()), & uvs(o->VBO().texcoords());
	QVector<Vector3d> & points(o->points), & puvws(o->puvws), fnormals;
	QVector<Vector3i> & faces(o->faces);
	Vector3d pos = Vector3d(o->pos());
	bool has_uv = !puvws.isEmpty();
	Vector3i cf;
	Vector3d v0, v1, v2, cn0, cn1, cn2;
	fnormals.resize(faces.size());
	for (int i = 0; i < points.size(); ++i)
		points[i] -= pos;
	for (int i = 0; i < fnormals.size(); ++i) {
		cf = faces[i];
		v0 = points[cf.p0];
		v1 = points[cf.p1];
		v2 = points[cf.p2];
		fnormals[i] = ((v1 - v0) * (v2 - v0)).normalized();
	}
	int fcnt = faces.size() * 3;
	vertices.resize(fcnt * 3);
	normals.resize(vertices.size());
	if (has_uv) uvs.resize(fcnt * 2);
	int ind = 0, induv = 0, ncnt0, ncnt1, ncnt2, csg;
	//qDebug() << faces.size();
	if (smooth.isEmpty()) {
		for (int i = 0; i < faces.size(); ++i) {
			cf = faces[i];
			cn0 = fnormals[i];
			v0 = points[cf.p0];
			v1 = points[cf.p1];
			v2 = points[cf.p2];
			vertices[ind] = v0.x; normals[ind] = cn0.x; ++ind;
			vertices[ind] = v0.y; normals[ind] = cn0.y; ++ind;
			vertices[ind] = v0.z; normals[ind] = cn0.z; ++ind;
			vertices[ind] = v1.x; normals[ind] = cn0.x; ++ind;
			vertices[ind] = v1.y; normals[ind] = cn0.y; ++ind;
			vertices[ind] = v1.z; normals[ind] = cn0.z; ++ind;
			vertices[ind] = v2.x; normals[ind] = cn0.x; ++ind;
			vertices[ind] = v2.y; normals[ind] = cn0.y; ++ind;
			vertices[ind] = v2.z; normals[ind] = cn0.z; ++ind;
			if (has_uv) {
				uvs[induv] = puvws[cf.p0].x; ++induv;
				uvs[induv] = puvws[cf.p0].y; ++induv;
				uvs[induv] = puvws[cf.p1].x; ++induv;
				uvs[induv] = puvws[cf.p1].y; ++induv;
				uvs[induv] = puvws[cf.p2].x; ++induv;
				uvs[induv] = puvws[cf.p2].y; ++induv;
			}
		}
	} else {
		for (int i = 0; i < faces.size(); ++i) {
			cf = faces[i];
			csg = smooth[i];
			v0 = points[cf.p0];
			v1 = points[cf.p1];
			v2 = points[cf.p2];

			cn0 = cn1 = cn2 = fnormals[i];
			ncnt0 = ncnt1 = ncnt2 = 1;
			for (int j = 0; j < faces.size(); ++j) {
				if (csg != smooth[j] || j == i) continue;
				if (faces[j].p0 == cf.p0 || faces[j].p1 == cf.p0 || faces[j].p2 == cf.p0 ||
					points[faces[j].p0] == v0 || points[faces[j].p1] == v0 || points[faces[j].p2] == v0) {
					cn0 += fnormals[j];
					++ncnt0;
				}
				if (faces[j].p0 == cf.p1 || faces[j].p1 == cf.p1 || faces[j].p2 == cf.p1 ||
					points[faces[j].p0] == v1 || points[faces[j].p1] == v1 || points[faces[j].p2] == v1) {
					cn1 += fnormals[j];
					++ncnt1;
				}
				if (faces[j].p0 == cf.p2 || faces[j].p1 == cf.p2 || faces[j].p2 == cf.p2 ||
					points[faces[j].p0] == v2 || points[faces[j].p1] == v2 || points[faces[j].p2] == v2) {
					cn2 += fnormals[j];
					++ncnt2;
				}
			}
			cn0 /= ncnt0;
			cn1 /= ncnt1;
			cn2 /= ncnt2;
			vertices[ind] = v0.x; normals[ind] = cn0.x; ++ind;
			vertices[ind] = v0.y; normals[ind] = cn0.y; ++ind;
			vertices[ind] = v0.z; normals[ind] = cn0.z; ++ind;
			vertices[ind] = v1.x; normals[ind] = cn1.x; ++ind;
			vertices[ind] = v1.y; normals[ind] = cn1.y; ++ind;
			vertices[ind] = v1.z; normals[ind] = cn1.z; ++ind;
			vertices[ind] = v2.x; normals[ind] = cn2.x; ++ind;
			vertices[ind] = v2.y; normals[ind] = cn2.y; ++ind;
			vertices[ind] = v2.z; normals[ind] = cn2.z; ++ind;
			if (has_uv) {
				uvs[induv] = puvws[cf.p0].x; ++induv;
				uvs[induv] = puvws[cf.p0].y; ++induv;
				uvs[induv] = puvws[cf.p1].x; ++induv;
				uvs[induv] = puvws[cf.p1].y; ++induv;
				uvs[induv] = puvws[cf.p2].x; ++induv;
				uvs[induv] = puvws[cf.p2].y; ++induv;
			}
		}
	}
}


Material Loader3DS::materialByName(const QVector<Material> & materials, const QString & name) {
	foreach (const Material & m, materials)
		if (m.name == name)
			return m;
	return Material();
}


GLObjectBase * loadFrom3DSFile(const QString & filepath, float scale) {
	QFile f(filepath);
	if (!f.exists()) {
		qDebug() << "[Loader 3DS] Error: can`t open \"" + filepath + "\"";
		return nullptr;
	}
	f.open(QIODevice::ReadOnly);
	QDataStream stream(&f);
	QVector<Material> materials;
	QVector<uint> smooth;
	QVector<ushort> face_mats;
	GLObjectBase * root = new GLObjectBase(), * co = nullptr;
	Material mat;
	Loader3DS::Chunk cc;
	Loader3DS::Face face;
	Vector3d pos;
	QString str;
	ushort cnt;
	QString name;
	QByteArray ba;
	int cur_map = 0;
	float fl, fl1, matrix[3][3];
	uint col;
	root->setName(QFileInfo(f).baseName());
	while (!stream.atEnd()) {
		stream.readRawData((char * )&cc, sizeof(cc));
		switch (cc.id) {
			case LOADER_3DS_CHUNK_MAIN: /*qDebug() << "main" << cc.size;*/ break;
			case LOADER_3DS_CHUNK_OBJECTS: /*qDebug() << " objects" << cc.size;*/ break;
			case LOADER_3DS_CHUNK_OBJECT:
				if (co != nullptr) {
					Loader3DS::init3DSMesh(co, smooth);
					root->addChild(co);
				}
				co = new GLObjectBase();
				co->setName(readCharsUntilNull(stream));
				smooth.clear();
				//qDebug() << "  object" << co->name();
				break;
			case LOADER_3DS_CHUNK_MESH: /*qDebug() << "   mesh" << cc.size;*/ break;
			case LOADER_3DS_CHUNK_VERTLIST:
				stream.readRawData((char * )&cnt, sizeof(ushort));
				co->points.resize(cnt);
				//qDebug() << "    vertices" << cnt;
				for (int i = 0; i < cnt; ++i) {
					stream.readRawData((char * )&co->points[i].x, sizeof(float));
					stream.readRawData((char * )&co->points[i].y, sizeof(float));
					stream.readRawData((char * )&co->points[i].z, sizeof(float));
					co->points[i] *= scale;
				}
				break;
			case LOADER_3DS_CHUNK_FACELIST:
				stream.readRawData((char * )&cnt, sizeof(ushort));
				co->faces.resize(cnt);
				//qDebug() << "    faces" << cnt;
				for (int i = 0; i < cnt; ++i) {
					stream.readRawData((char * )&face, sizeof(Loader3DS::Face));
					co->faces[i].p0 = face.v0;
					co->faces[i].p1 = face.v1;
					co->faces[i].p2 = face.v2;
				}
				break;
			case LOADER_3DS_CHUNK_FACEMAT:
				name = readCharsUntilNull(stream);
				stream.readRawData((char * )&cnt, sizeof(ushort));
				face_mats.resize(cnt);
				for (int i = 0; i < cnt; ++i)
					stream.readRawData((char * )&(face_mats[i]), sizeof(ushort));
				//qDebug() << "   facemat name" << name << cnt;
				co->material().name = name;
				break;
			case LOADER_3DS_CHUNK_MAPLIST:
				stream.readRawData((char * )&cnt, sizeof(ushort));
				co->puvws.resize(cnt);
				//qDebug() << "    texcoords" << cnt;
				for (int i = 0; i < cnt; ++i) {
					stream.readRawData((char * )&co->puvws[i].x, sizeof(float));
					stream.readRawData((char * )&co->puvws[i].y, sizeof(float));
				}
				break;
			case LOADER_3DS_CHUNK_SMOOTH:
				cnt = co->faces.size();
				smooth.resize(cnt);
				//qDebug() << "    smooth" << cnt;
				for (int i = 0; i < cnt; ++i)
					stream.readRawData((char * )&smooth[i], sizeof(uint));
				break;
			case LOADER_3DS_CHUNK_TRMATRIX:
				//qDebug() << co->name();
				for (int i = 0; i < 3; ++i) {
					for (int j = 0; j < 3; ++j)
						stream.readRawData((char * )&(matrix[i][j]), sizeof(float));
					//qDebug() << matrix[i][0] << matrix[i][1] << matrix[i][2];
				}
				stream.readRawData((char * )&pos, sizeof(Vector3d));
				pos *= scale;
				//qDebug() << "pos =" << pos;
				co->setPos(pos.toQVector3D());
				break;
			case LOADER_3DS_CHUNK_LIGHT:
				//qDebug() << "   light" << cc.size;
				str = co->name();
				delete co;
				co = new Light();
				co->setName(str);
				stream.readRawData((char * )&pos, sizeof(Vector3d));
				pos *= scale;
				co->setPos(pos.toQVector3D());
				break;
			case LOADER_3DS_CHUNK_SPOTLIGHT:
				stream.readRawData((char * )&pos, sizeof(Vector3d));
				pos *= scale;
				globject_cast<Light * >(co)->light_type = Light::Cone;
				globject_cast<Light * >(co)->direction = (pos.toQVector3D() - co->pos()).normalized();
				stream.readRawData((char * )&fl1, sizeof(float));
				stream.readRawData((char * )&fl, sizeof(float));
				globject_cast<Light * >(co)->angle_start = fl1;
				globject_cast<Light * >(co)->angle_end = fl;
				//qDebug() << "spotlight" << globject_cast<Light * >(co)->direction << globject_cast<Light * >(co)->angle_spread;
				break;
			case LOADER_3DS_CHUNK_LIGHT_OFF:
				stream.skipRawData(cc.size - 6);
				co->hide();
				break;
			case LOADER_3DS_CHUNK_ATTENUATION_ON:
				stream.skipRawData(cc.size - 6);
				fl = globject_cast<Light * >(co)->decay_end;
				//fl1 = globject_cast<Light * >(co)->decay_start;
				globject_cast<Light * >(co)->decay_quadratic = 4.f / fl;
				//qDebug() << "decay" << globject_cast<Light * >(co)->decay_quadratic;
				break;
			case LOADER_3DS_CHUNK_COLOR_F:
				stream.readRawData((char * )&pos, sizeof(Vector3d));
				co->setColor(QColor::fromRgbF(pos.x, pos.y, pos.z));
				//qDebug() << "    color_f" << co->color();
				break;
			case LOADER_3DS_CHUNK_COLOR_B:
				stream.readRawData((char * )&col, 3);
				co->setColor(QColor::fromRgb(((uchar * )&col)[0], ((uchar * )&col)[1], ((uchar * )&col)[2]));
				//qDebug() << "    color_b" << co->color();
				break;
			case LOADER_3DS_CHUNK_MULTIPLIER:
				stream.readRawData((char * )&fl, sizeof(float));
				globject_cast<Light * >(co)->intensity = fl;
				//qDebug() << "    multiplier" << fl;
				break;
			case LOADER_3DS_CHUNK_RANGE_START:
				stream.readRawData((char * )&fl, sizeof(float));
				globject_cast<Light * >(co)->decay_start = fl;
				//qDebug() << "    range start" << fl;
				break;
			case LOADER_3DS_CHUNK_RANGE_END:
				stream.readRawData((char * )&fl, sizeof(float));
				globject_cast<Light * >(co)->decay_end = fl;
				//qDebug() << "    range end" << fl;
				break;
			case LOADER_3DS_CHUNK_MATERIAL:
				//stream.skipRawData(cc.size - 6);
				if (!mat.name.isEmpty())
					materials << mat;
				mat = Material();
				break;
			case LOADER_3DS_CHUNK_MATERIAL_NAME:
				mat.name = readCharsUntilNull(stream);
				//qDebug() << "matname" << mat.name;
				break;
			case LOADER_3DS_CHUNK_AMBIENT_COLOR:
				stream.skipRawData(cc.size - 9);
				stream.readRawData((char * )&col, 3);
				mat.color_self_illumination = QColor::fromRgb(((uchar * )&col)[0], ((uchar * )&col)[1], ((uchar * )&col)[2]);
				//qDebug() << "mat diffuse" << mat.color_diffuse;
				break;
			case LOADER_3DS_CHUNK_DIFFUSE_COLOR:
				stream.skipRawData(cc.size - 9);
				stream.readRawData((char * )&col, 3);
				mat.color_diffuse = QColor::fromRgb(((uchar * )&col)[0], ((uchar * )&col)[1], ((uchar * )&col)[2]);
				//qDebug() << "mat diffuse" << mat.color_diffuse;
				break;
			case LOADER_3DS_CHUNK_SPECULAR_COLOR:
				stream.skipRawData(cc.size - 9);
				stream.readRawData((char * )&col, 3);
				mat.color_specular = QColor::fromRgb(((uchar * )&col)[0], ((uchar * )&col)[1], ((uchar * )&col)[2]);
				//qDebug() << "mat diffuse" << mat.color_diffuse;
				break;
			case LOADER_3DS_CHUNK_TEXTURE_MAP:
				cur_map = LOADER_3DS_CHUNK_TEXTURE_MAP;
				break;
			case LOADER_3DS_CHUNK_BUMP_MAP:
				cur_map = LOADER_3DS_CHUNK_BUMP_MAP;
				break;
			case LOADER_3DS_CHUNK_REFLECTION_MAP:
				cur_map = LOADER_3DS_CHUNK_REFLECTION_MAP;
				break;
			case LOADER_3DS_CHUNK_MAP_FILENAME:
				name = readCharsUntilNull(stream);
				//qDebug() << "  mat map" << QString::number(cur_map, 16) << name;
				switch (cur_map) {
					case LOADER_3DS_CHUNK_TEXTURE_MAP: mat.map_diffuse.bitmap_path = name; break;
					case LOADER_3DS_CHUNK_BUMP_MAP: mat.map_normal.bitmap_path = name; break;
				}
				break;
			default: /*qDebug() << "???" << QString::number(cc.id, 16).rightJustified(4, '0') << cc.size;*/ stream.skipRawData(cc.size - 6);
		}
	}
	if (!mat.name.isEmpty())
		materials << mat;
	foreach (const Material & m, materials)
		qDebug() << m.name;
	if (co != nullptr) {
		Loader3DS::init3DSMesh(co, smooth);
		root->addChild(co);
	}
	for (int i = 0; i < root->childCount(); ++i)
		root->child(i)->material() = Loader3DS::materialByName(materials, root->child(i)->material().name);
	qDebug() << "[Loader 3DS] Loaded" << root->childCount() << "objects from" << filepath;
	return root;
}