#include "prop_utils.h"

#include "../props/prop_data.h"
#include "../props/prop_data_entry.h"

#include "core/math/quick_hull.h"
#include "scene/3d/portal.h"
#include "scene/3d/room.h"
#include "scene/3d/room_manager.h"

#include "scene/3d/mesh_instance.h"
#include "scene/resources/mesh/mesh.h"

#include "modules/modules_enabled.gen.h"

#ifdef MODULE_MESH_DATA_RESOURCE_ENABLED
#include "../../mesh_data_resource/nodes/mesh_data_instance.h"
#endif

#include "core/config/engine.h"

PropUtils *PropUtils::_instance;
Vector<Ref<PropDataEntry>> PropUtils::_processors;

PropUtils *PropUtils::get_singleton() {
	return _instance;
}

Ref<PropData> PropUtils::convert_tree(Node *root) {
	ERR_FAIL_COND_V(!ObjectDB::instance_validate(root), Ref<PropData>());

	Ref<PropData> data;
	data.instance();
	Transform t;

	_convert_tree(data, root, t);

	return data;
}

void PropUtils::_convert_tree(Ref<PropData> prop_data, Node *node, const Transform &transform) {
	ERR_FAIL_COND(!ObjectDB::instance_validate(node));

	for (int i = 0; i < PropUtils::_processors.size(); ++i) {
		Ref<PropDataEntry> proc = PropUtils::_processors.get(i);

		ERR_CONTINUE(!proc.is_valid());

		if (proc->processor_handles(node)) {
			proc->processor_process(prop_data, node, transform);

			if (!proc->processor_evaluate_children()) {
				return;
			}

			break;
		}
	}

	Spatial *sp = Object::cast_to<Spatial>(node);

	if (!sp) {
		//reset transform
		Transform t;

		for (int i = 0; i < node->get_child_count(); ++i) {
			Node *child = node->get_child(i);

			if (Engine::get_singleton()->is_editor_hint()) {
				//Skip it if it's hidden from the tree
				if (child->get_owner() != NULL) {
					_convert_tree(prop_data, node->get_child(i), t);
				}
			} else {
				_convert_tree(prop_data, node->get_child(i), t);
			}
		}
	} else {
		//only handle the first encountered room per prop
		if (!prop_data->get_is_room()) {
			Room *r = Object::cast_to<Room>(sp);

			if (r) {
				prop_data->set_is_room(true);

				PoolVector3Array points = r->get_points();

				prop_data->set_room_bounds(points);
			}
		}

		for (int i = 0; i < node->get_child_count(); ++i) {
			Node *child = node->get_child(i);

			if (Engine::get_singleton()->is_editor_hint()) {
				//Skip it if it's hidden from the tree
				if (child->get_owner() != NULL) {
					_convert_tree(prop_data, node->get_child(i), transform * sp->get_transform());
				}
			} else {
				_convert_tree(prop_data, node->get_child(i), transform * sp->get_transform());
			}
		}
	}
}

bool PropUtils::generate_room_points_node(Node *node) {
	ERR_FAIL_COND_V(!ObjectDB::instance_validate(node), false);

	Room *r = Object::cast_to<Room>(node);

	if (r) {
		generate_room_points(r);

		return true;
	}

	for (int i = 0; i < node->get_child_count(); ++i) {
		if (generate_room_points_node(node->get_child(i))) {
			return true;
		}
	}

	return false;
}

void PropUtils::generate_room_points(Room *room) {
	ERR_FAIL_COND(!ObjectDB::instance_validate(room));

	Vector<PoolVector<Vector3>> mesh_arrays;

	get_mesh_arrays(room, &mesh_arrays);

	PoolVector<Plane> planes;
	Vector<Vector3> points;
	PoolVector<Face3> faces;

	for (int i = 0; i < mesh_arrays.size(); ++i) {
		PoolVector<Vector3> verts = mesh_arrays[i];

		for (int j = 0; j < verts.size(); j += 3) {
			Plane p(verts[j], verts[j + 1], verts[j + 2]);

			faces.push_back(Face3(verts[j], verts[j + 1], verts[j + 2]));

			//points.push_back(verts[j]);
			//points.push_back(verts[j + 1]);
			//points.push_back(verts[j + 2]);

			if (!is_plane_unique(planes, p)) {
				continue;
			}

			planes.push_back(p);

			//points.push_back(verts[j]);
			//points.push_back(verts[j + 1]);
			//points.push_back(verts[j + 2]);
		}
	}

	PoolVector<Face3> wrapped = Geometry::wrap_geometry(faces);

	for (int i = 0; i < wrapped.size(); ++i) {
		Face3 f = wrapped[i];

		points.push_back(f.vertex[0]);
		points.push_back(f.vertex[1]);
		points.push_back(f.vertex[2]);
	}

	Geometry::MeshData md = Geometry::build_convex_mesh(planes);
	md.optimize_vertices();

	QuickHull q;

	// calculate an epsilon based on the simplify value, and use this to build the hull
	real_t s = 0.5;

	// value between  0.3 (accurate) and 10.0 (very rough)
	// * UNIT_EPSILON
	s *= s;
	s *= 40.0;
	s += 0.3; // minimum
	s *= UNIT_EPSILON;

	q.build(points, md, s);

	md.optimize_vertices();

	PoolVector<Vector3> vs;
	vs.resize(md.vertices.size());
	for (int i = 0; i < md.vertices.size(); ++i) {
		vs.set(i, md.vertices[i]);
	}

	/*
	//It will probably have a few unnecessary vertices still
	//let's try to get rid of those as well
	PoolVector<int> remove_indices;
	int vssize = vs.size();
	for (int i = 0; i < vssize - 2; ++i) {
		Plane p(vs[i], vs[i + 1], vs[i + 2]);

		for (int j = 0; j < vssize; ++j) {
			if (i == j) {
				//skip this and the next 2
				j += 3;

				if (j >= vssize) {
					break;
				}
			}

			if (p.has_point(vs[j], 0.1)) {
				bool found = false;
				for (int k = 0; k < remove_indices.size(); ++k) {
					if (remove_indices[k] == j) {
						found = true;
						break;
					}
				}

				if (!found) {
					remove_indices.push_back(j);
				}
			}
		}
	}

	for (int i = 0; i < remove_indices.size(); ++i) {
		int rindex = remove_indices[i];

		vs.remove(rindex);

		for (int j = i + 1; j < remove_indices.size(); ++j) {
			int rij = remove_indices[j];

			if (rij > rindex) {
				remove_indices.set(j, rij - 1);
			}
		}
	}
*/

	room->set_points(vs);
}

//based on Room::SimplifyInfo::add_plane_if_unique
bool PropUtils::is_plane_unique(const PoolVector<Plane> &planes, const Plane &p) {
	for (int n = 0; n < planes.size(); n++) {
		const Plane &o = planes[n];

		// this is a fudge factor for how close planes can be to be considered the same ...
		// to prevent ridiculous amounts of planes
		const real_t d = 0.08f; //_plane_simplify_dist; // 0.08f

		if (Math::abs(p.d - o.d) > d) {
			continue;
		}

		real_t dot = p.normal.dot(o.normal);
		if (dot < 0.98f) //_plane_simplify_dot) // 0.98f
		{
			continue;
		}

		// match!
		return false;
	}

	return true;
}

void PropUtils::get_mesh_arrays(Node *node, Vector<PoolVector<Vector3>> *arrs) {
	ERR_FAIL_COND(!ObjectDB::instance_validate(node));

	for (int i = 0; i < node->get_child_count(); ++i) {
		get_mesh_arrays(node->get_child(i), arrs);
	}

	{
		Portal *pn = Object::cast_to<Portal>(node);

		if (pn) {
			if (!pn->get_portal_active()) {
				return;
			}

			if (!pn->is_visible_in_tree()) {
				return;
			}

			PoolVector<Vector2> points = pn->get_points();
			PoolVector<Vector3> v3p;
			v3p.resize(points.size());

			for (int i = 0; i < points.size(); ++i) {
				v3p.set(i, Vector3(points[i].x, points[i].y, 0));
			}

			Transform t = pn->get_global_transform();

			int fvertcount = (points.size() - 2) * 3;

			PoolVector<Vector3> tverts;
			tverts.resize(fvertcount);

			for (int i = 0; i < points.size() - 2; ++i) {
				int sindex = i * 3;

				tverts.set(sindex, t.xform(v3p[i]));
				tverts.set(sindex + 1, t.xform(v3p[i + 1]));
				tverts.set(sindex + 2, t.xform(v3p[i + 2]));
			}

			//portal planes need to take precedence
			arrs->insert(0, tverts);

			return;
		}
	}

#ifdef MODULE_MESH_DATA_RESOURCE_ENABLED
	{
		MeshDataInstance *mdi = Object::cast_to<MeshDataInstance>(node);

		if (mdi) {
			if (!mdi->is_visible_in_tree()) {
				return;
			}

			Ref<MeshDataResource> mdr = mdi->get_mesh_data();

			if (!mdr.is_valid()) {
				return;
			}

			Array arr = mdr->get_array();

			if (arr.size() != Mesh::ARRAY_MAX) {
				return;
			}

			Transform t = mdi->get_global_transform();

			PoolVector<Vector3> verts = arr[Mesh::ARRAY_VERTEX];
			PoolVector<Vector3> tverts;
			tverts.resize(verts.size());

			for (int i = 0; i < verts.size(); ++i) {
				tverts.set(i, t.xform(verts[i]));
			}

			PoolVector<int> indices = arr[Mesh::ARRAY_INDEX];

			if (indices.size() == 0) {
				arrs->push_back(tverts);
				return;
			}

			PoolVector<Vector3> fverts;
			fverts.resize(indices.size());

			for (int i = 0; i < indices.size(); ++i) {
				fverts.set(i, tverts[indices[i]]);
			}

			arrs->push_back(fverts);

			return;
		}
	}
#endif

	{
		MeshInstance *min = Object::cast_to<MeshInstance>(node);

		if (min) {
			if (!min->is_visible_in_tree()) {
				return;
			}

			Ref<ArrayMesh> am = min->get_mesh();

			if (!am.is_valid()) {
				return;
			}

			Transform t = min->get_global_transform();

			for (int si = 0; si < am->get_surface_count(); ++si) {
				Array arr = am->surface_get_arrays(si);

				if (arr.size() != Mesh::ARRAY_MAX) {
					continue;
				}

				PoolVector<Vector3> verts = arr[Mesh::ARRAY_VERTEX];
				PoolVector<Vector3> tverts;
				tverts.resize(verts.size());

				for (int i = 0; i < verts.size(); ++i) {
					tverts.set(i, t.xform(verts[i]));
				}

				PoolVector<int> indices = arr[Mesh::ARRAY_INDEX];

				if (indices.size() == 0) {
					arrs->push_back(tverts);
					continue;
				}

				PoolVector<Vector3> fverts;
				fverts.resize(indices.size());

				for (int i = 0; i < indices.size(); ++i) {
					fverts.set(i, tverts[indices[i]]);
				}

				arrs->push_back(fverts);
			}

			return;
		}
	}
}

int PropUtils::add_processor(const Ref<PropDataEntry> &processor) {
	ERR_FAIL_COND_V(!processor.is_valid(), 0);

	PropUtils::_processors.push_back(processor);

	return PropUtils::_processors.size() - 1;
}
Ref<PropDataEntry> PropUtils::get_processor(const int index) {
	ERR_FAIL_INDEX_V(index, PropUtils::_processors.size(), Ref<PropDataEntry>());

	return PropUtils::_processors[index];
}
void PropUtils::swap_processors(const int index1, const int index2) {
	ERR_FAIL_INDEX(index1, PropUtils::_processors.size());
	ERR_FAIL_INDEX(index2, PropUtils::_processors.size());

	Ref<PropDataEntry> a = PropUtils::_processors.get(index1);
	PropUtils::_processors.set(index1, PropUtils::_processors.get(index2));
	PropUtils::_processors.set(index2, a);
}
void PropUtils::remove_processor(const int index) {
	ERR_FAIL_INDEX(index, PropUtils::_processors.size());

	PropUtils::_processors.remove(index);
}
int PropUtils::get_processor_count() {
	return PropUtils::_processors.size();
}

PropUtils::PropUtils() {
	_instance = this;
}

PropUtils::~PropUtils() {
	_instance = NULL;

	PropUtils::_processors.clear();
}

void PropUtils::_bind_methods() {
	ClassDB::bind_method(D_METHOD("convert_tree", "root"), &PropUtils::convert_tree);

	ClassDB::bind_method(D_METHOD("add_processor", "processor"), &PropUtils::_add_processor_bind);
	ClassDB::bind_method(D_METHOD("get_processor", "index"), &PropUtils::_get_processor_bind);
	ClassDB::bind_method(D_METHOD("swap_processors", "index1", "index2"), &PropUtils::_swap_processors_bind);
	ClassDB::bind_method(D_METHOD("remove_processor", "index"), &PropUtils::_remove_processor_bind);
	ClassDB::bind_method(D_METHOD("get_processor_count"), &PropUtils::_get_processor_count_bind);
}

int PropUtils::_add_processor_bind(const Ref<PropDataEntry> &processor) {
	return PropUtils::add_processor(processor);
}
Ref<PropDataEntry> PropUtils::_get_processor_bind(const int index) {
	return PropUtils::get_processor(index);
}
void PropUtils::_swap_processors_bind(const int index1, const int index2) {
	PropUtils::swap_processors(index1, index2);
}
void PropUtils::_remove_processor_bind(const int index) {
	PropUtils::remove_processor(index);
}
int PropUtils::_get_processor_count_bind() {
	return PropUtils::get_processor_count();
}