/*
    QGLView
    Copyright (C) 2019  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/>.
*/

#define GL_GLEXT_PROTOTYPES
#include <QOpenGLExtraFunctions>
#include "renderer_service.h"
#include "renderer.h"
#include "qglview.h"
#include "glmesh.h"
#include <qad_types.h>

using namespace QGLEngineShaders;


RendererService::RendererService(Renderer * r_): r(r_) {
	line_width = 1;
	current_action = haNoAction;
	current_handle = 0;
	mat_xyz.resize(3);   mat_ms2.resize(3);
	color_xyz.resize(3); color_ms2.resize(3);
	const QVector3D _rot [3] = {QVector3D(0,1,0), QVector3D(-1,0,0), QVector3D(0, 0,1)};
	const QVector3D _rot2[3] = {QVector3D(0,0,0), QVector3D( 1,0,0), QVector3D(0,-1,0)};
	for (int i = 0; i < 3; ++i) {
		QMatrix4x4 m;
		m.rotate(90., _rot[i]);
		mat_xyz[i] = m;
		m.setToIdentity();
		if (!_rot2[i].isNull())
			m.rotate(90., _rot2[i]);
		mat_ms2[i] = m;
		color_xyz[i] = color_ms2[i] = QVector4D(0,0,0,0.8);
		color_xyz[i][i] = 1.;
	}
	color_ms2[0] = (color_xyz[0] + color_xyz[1]) / 2.;
	color_ms2[1] = (color_xyz[0] + color_xyz[2]) / 2.;
	color_ms2[2] = (color_xyz[1] + color_xyz[2]) / 2.;
	axis_camera = new Camera();
	axis_camera->setAim(QVector3D());
	axis_camera->setFOV(45.);
	axis_mesh = Primitive::arrow(12);
	size_vp_scale = size_full_scale = 1.;
	box_mesh   = Primitive::cube();
	box_mesh_f = Primitive::cubeFrame();
	omni_mesh   = Primitive::ellipsoid(2, 1);
	omni_mesh_f = Primitive::ellipsoidFrame(2, 1);
	omni_mesh  ->scalePoints(1.5);
	omni_mesh_f->scalePoints(1.5);
	box_mesh   ->scalePoints(1.3);
	omni_mesh  ->scalePoints(1.3);

	handle_move_mesh = Primitive::arrow(12, 0.06);
	handle_ms_2_mesh = Primitive::torus(8, 12, 0.5, 0.025, 90);
	Mesh * m = Primitive::disc(8, 1., 1., true, 90);
	handle_ms_2_mesh->append(m);
	delete m;
	m = Primitive::disc(8, 1., 1., false, 90);
	handle_ms_2_mesh->append(m);
	delete m;

	handle_rotate_mesh = Primitive::arrow(12, 0.03);
	m = Primitive::torus(30, 12, 0.5, 0.06);
	m->translatePoints(QVector3D(0., 0., 0.75));
	handle_rotate_mesh->append(m);
	delete m;

	handle_scale_mesh = Primitive::cylinder(12, 0.06, 0.06, 0.85);
	m = Primitive::ellipsoid(12, 12, 0.3, 0.3, 0.3);
	m->translatePoints(QVector3D(0., 0., 0.85));
	handle_scale_mesh->append(m);
	delete m;
	handle_scale_3_mesh = Primitive::ellipsoid(12, 12, 0.4, 0.4, 0.4);

	handle_move_mesh    ->scalePoints(7.5);
	handle_ms_2_mesh    ->scalePoints(7.5);
	handle_rotate_mesh  ->scalePoints(7.5);
	handle_scale_mesh   ->scalePoints(7.5);
	handle_scale_3_mesh ->scalePoints(7.5);
}


RendererService::~RendererService() {
	delete box_mesh;
	delete box_mesh_f;
	delete omni_mesh;
	delete omni_mesh_f;
	delete axis_camera;
	delete axis_mesh;
	delete handle_move_mesh;
	delete handle_ms_2_mesh;
	delete handle_rotate_mesh;
	delete handle_scale_mesh;
	delete handle_scale_3_mesh;
}


void RendererService::init(int width, int height) {
	fillXYZObjects();
	axis_mesh->loadObjects(r->view, cur_objects);
	resize(width, height);
}


void RendererService::resize(int width, int height) {
	axis_viewport = preferredIconSize(10.);
	line_width = lineThickness();
	size_vp_scale = 25. * appScale() / qMax(qMin(width, height), 1);
	//qDebug() << axis_viewport;
}


QMatrix4x4 RendererService::invariantSizeMatrix(QVector3D p) {
	QVector4D pos = QVector4D(p, 1.);
	double dist = -(v_mat * pos).z();
	QMatrix4x4 m;
	m.translate(pos.toVector3D());
	m.scale(dist * size_full_scale);
	return m;
}


void RendererService::fillXYZObjects() {
	cur_objects.resize(3);
	for (int i = 0; i < 3; ++i) {
		cur_objects[i].color = color_xyz[i];
		mat_xyz[i].transposed().copyDataTo(cur_objects[i].modelmatrix);
	}
}


void RendererService::fillOmniObjects() {
	QList<Light*> ll = r->view->scene()->lights_used;
	Object o;
	cur_objects.clear();
	foreach (Light * l, ll) {
		QMatrix4x4 m = invariantSizeMatrix(l->worldPos());
		m.transposed().copyDataTo(o.modelmatrix);
		o.object_id = l->id_;
		cur_objects << o;
	}
}


void RendererService::fillHandleObjects(QVector3D center, HandleMesh ids[], const QVector<QMatrix4x4> & mats, const QVector<QVector4D> & colors, QMatrix4x4 add_mat, int count) {
	QMatrix4x4 m = invariantSizeMatrix(center) * add_mat;
	cur_objects.resize(count);
	for (int i = 0; i < count; ++i) {
		cur_objects[i].color = colors[i];
		QMatrix4x4 omat = m * mats[i];
		cur_objects[i].object_id = ids[i];
		if (current_handle.testFlag(ids[i])) {
			cur_objects[i].color = QVector4D(0,1,1,1);
		}
		omat.transposed().copyDataTo(cur_objects[i].modelmatrix);
	}
}


bool RendererService::calculateCenter() {
	QList<ObjectBase*> sol = r->view->scene()->selectedObjects(true);
	if (sol.isEmpty()) return false;
	selection_center = sol[0]->worldPos();
	if (sol.size() > 1) {
		Box3D bb;
		foreach (ObjectBase * o, sol) {
			o->calculateBoundingBox();
			bb |= o->boundingBox();
		}
		if (!bb.isEmpty())
			selection_center = bb.center();
	}
	axis_mat = QMatrix4x4();
	if ((sol.size() == 1) && (current_action != haMove)) {
		ObjectBase * o = sol[0];
		QMatrix4x4 pmat;
		if (o->parent()) {
			pmat = o->parent()->worldTransform();
			pmat.setColumn(3, QVector4D(0,0,0,1));
			double det = pmat.determinant();
			if (det > 0.) pmat /= sqrt(det);
		}
		axis_mat.rotate(o->angles_.z(), 0., 0., 1.);
		axis_mat.rotate(o->angles_.y(), 0., 1., 0.);
		axis_mat.rotate(o->angles_.x(), 1., 0., 0.);
		axis_mat = pmat * axis_mat;
	}
	return true;
}


void RendererService::drawCurrentHandleObjects() {
	if (current_action == haNoAction) return;
	if (calculateCenter()) {
		HandleMesh ids[3];
		switch (current_action) {
		case haMove  : ids[0] = hmMoveX  ; ids[1] = hmMoveY  ; ids[2] = hmMoveZ  ; break;
		case haRotate: ids[0] = hmRotateX; ids[1] = hmRotateY; ids[2] = hmRotateZ; break;
		case haScale : ids[0] = hmScaleX ; ids[1] = hmScaleY ; ids[2] = hmScaleZ ; break;
		default: break;
		}
		fillHandleObjects(selection_center, ids, mat_xyz, color_xyz, axis_mat);
		Mesh * hm = currentHandleMesh();
		QVector<uchar> sel;
		sel.fill(0, 3);
		if (hm) {
			hm->loadObjects(r->view, cur_objects);
			hm->loadSelections(r->view, sel);
			hm->draw(r->view, 3);
		}
		if (current_action == haMove || current_action == haScale) {
			switch (current_action) {
			case haMove  : ids[0] = hmMoveXY  ; ids[1] = hmMoveXZ  ; ids[2] = hmMoveYZ  ; break;
			case haScale : ids[0] = hmScaleXY ; ids[1] = hmScaleXZ ; ids[2] = hmScaleYZ ; break;
			default: break;
			}
			hm = handle_ms_2_mesh;
			fillHandleObjects(selection_center, ids, mat_ms2, color_ms2, axis_mat);
			hm->loadObjects(r->view, cur_objects);
			hm->loadSelections(r->view, sel);
			hm->draw(r->view, 3);
			if (current_action == haScale) {
				hm = handle_scale_3_mesh;
				QVector<QMatrix4x4> mv; mv.resize(1);
				QVector<QVector4D> cv; cv.fill(QVector4D(0.9, 0.9, 0.7, 1), 1);
				ids[0] = hmMaxScale;
				fillHandleObjects(selection_center, ids, mv, cv, axis_mat, 1);
				hm->loadObjects(r->view, cur_objects);
				hm->loadSelections(r->view, sel);
				hm->draw(r->view, 1);
			}
		}
	}
}


void RendererService::setObjectsColor(QVector<Object> & ol, QColor col) {
	QVector4D cv = QColor2QVector(col);
	for (int i = 0; i < ol.size(); ++i)
		ol[i].color = cv;
}


void RendererService::renderService() {
	QOpenGLShaderProgram * prog = 0;
	QOpenGLExtraFunctions * f = r->view;
	size_full_scale = tan(r->view->camera()->FOV() / 2. * deg2rad) * size_vp_scale;
	v_mat = r->view->camera()->fullViewMatrix();
	f->glEnable(GL_MULTISAMPLE);
	glEnableDepth();
	f->glClear(GL_DEPTH_BUFFER_BIT);
	if (r->bindShader(Renderer::srServiceFrame, &prog)) {
		prog->setUniformValue("qgl_ProjMatrix", r->view->camera()->projectionMatrix(r->view->aspect));

		/// lights
		//glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
		glDisable(GL_CULL_FACE);
		r->setUniformCamera(prog, r->view->camera());
		fillOmniObjects();

		setObjectsColor(cur_objects, Qt::white);
		prog->setUniformValue("line_width", 2.f);
		prog->setUniformValue("z_offset", 0.f);
		omni_mesh_f->loadObjects(f, cur_objects);
		omni_mesh_f->draw(f, cur_objects.size());

		setObjectsColor(cur_objects, Qt::black);
		prog->setUniformValue("line_width", 1.f);
		prog->setUniformValue("z_offset", -1.E-3f);
		omni_mesh_f->loadObjects(f, cur_objects);
		omni_mesh_f->draw(f, cur_objects.size());

		glEnable(GL_CULL_FACE);
		//glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

	}
	if (r->bindShader(Renderer::srServiceFill, &prog)) {
		r->setUniformCamera(prog, r->view->camera());

		/// handles
		f->glEnable(GL_BLEND);
		f->glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
		drawCurrentHandleObjects();
		f->glDisable(GL_BLEND);

		/// axis
		f->glViewport(0, 0, axis_viewport.width(), axis_viewport.height());
		axis_camera->setPos(-r->view->camera()->direction() * 3.);
		r->setUniformCamera(prog, axis_camera, true, axis_viewport);
		axis_mesh->draw(f, 3);
		f->glViewport(0, 0, r->view->width(), r->view->height());

	}
	f->glDisable(GL_MULTISAMPLE);
}


Mesh * RendererService::currentHandleMesh() {
	switch (current_action) {
	case haMove  : return handle_move_mesh;
	case haRotate: return handle_rotate_mesh;
	case haScale : return handle_scale_mesh;
	default: break;
	}
	return 0;
}