/*************************************************************************/
/*  navigation_region_2d.cpp                                             */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
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/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
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/*************************************************************************/

#include "navigation_region_2d.h"

#include "core/config/engine.h"
#include "core/core_string_names.h"
#include "core/math/geometry_2d.h"
#include "core/os/mutex.h"
#include "navigation_2d.h"
#include "servers/navigation_server_2d.h"

#include "thirdparty/misc/polypartition.h"

#ifdef TOOLS_ENABLED
Rect2 NavigationPolygon::_edit_get_rect() const {
	if (rect_cache_dirty) {
		item_rect = Rect2();
		bool first = true;

		for (int i = 0; i < outlines.size(); i++) {
			const Vector<Vector2> &outline = outlines[i];
			const int outline_size = outline.size();
			if (outline_size < 3) {
				continue;
			}
			const Vector2 *p = outline.ptr();
			for (int j = 0; j < outline_size; j++) {
				if (first) {
					item_rect = Rect2(p[j], Vector2(0, 0));
					first = false;
				} else {
					item_rect.expand_to(p[j]);
				}
			}
		}

		rect_cache_dirty = false;
	}
	return item_rect;
}

bool NavigationPolygon::_edit_is_selected_on_click(const Point2 &p_point, double p_tolerance) const {
	for (int i = 0; i < outlines.size(); i++) {
		const Vector<Vector2> &outline = outlines[i];
		const int outline_size = outline.size();
		if (outline_size < 3) {
			continue;
		}
		if (Geometry2D::is_point_in_polygon(p_point, Variant(outline))) {
			return true;
		}
	}
	return false;
}
#endif

void NavigationPolygon::set_vertices(const Vector<Vector2> &p_vertices) {
	{
		MutexLock lock(navmesh_generation);
		navmesh.unref();
	}
	vertices = p_vertices;
	rect_cache_dirty = true;
}

Vector<Vector2> NavigationPolygon::get_vertices() const {
	return vertices;
}

void NavigationPolygon::_set_polygons(const TypedArray<Vector<int32_t>> &p_array) {
	{
		MutexLock lock(navmesh_generation);
		navmesh.unref();
	}
	polygons.resize(p_array.size());
	for (int i = 0; i < p_array.size(); i++) {
		polygons.write[i].indices = p_array[i];
	}
}

Array NavigationPolygon::_get_polygons() const {
	Array ret;
	ret.resize(polygons.size());
	for (int i = 0; i < ret.size(); i++) {
		ret[i] = polygons[i].indices;
	}

	return ret;
}

void NavigationPolygon::_set_outlines(const TypedArray<Vector<Vector2>> &p_array) {
	outlines.resize(p_array.size());
	for (int i = 0; i < p_array.size(); i++) {
		outlines.write[i] = p_array[i];
	}
	rect_cache_dirty = true;
}

Array NavigationPolygon::_get_outlines() const {
	Array ret;
	ret.resize(outlines.size());
	for (int i = 0; i < ret.size(); i++) {
		ret[i] = outlines[i];
	}

	return ret;
}

void NavigationPolygon::add_polygon(const Vector<int> &p_polygon) {
	Polygon polygon;
	polygon.indices = p_polygon;
	polygons.push_back(polygon);
	{
		MutexLock lock(navmesh_generation);
		navmesh.unref();
	}
}

void NavigationPolygon::add_outline_at_index(const Vector<Vector2> &p_outline, int p_index) {
	outlines.insert(p_index, p_outline);
	rect_cache_dirty = true;
}

int NavigationPolygon::get_polygon_count() const {
	return polygons.size();
}

Vector<int> NavigationPolygon::get_polygon(int p_idx) {
	ERR_FAIL_INDEX_V(p_idx, polygons.size(), Vector<int>());
	return polygons[p_idx].indices;
}

void NavigationPolygon::clear_polygons() {
	polygons.clear();
	{
		MutexLock lock(navmesh_generation);
		navmesh.unref();
	}
}

Ref<NavigationMesh> NavigationPolygon::get_mesh() {
	MutexLock lock(navmesh_generation);

	if (navmesh.is_null()) {
		navmesh.instance();
		Vector<Vector3> verts;
		{
			verts.resize(get_vertices().size());
			Vector3 *w = verts.ptrw();

			const Vector2 *r = get_vertices().ptr();

			for (int i(0); i < get_vertices().size(); i++) {
				w[i] = Vector3(r[i].x, 0.0, r[i].y);
			}
		}
		navmesh->set_vertices(verts);

		for (int i(0); i < get_polygon_count(); i++) {
			navmesh->add_polygon(get_polygon(i));
		}
	}

	return navmesh;
}

void NavigationPolygon::add_outline(const Vector<Vector2> &p_outline) {
	outlines.push_back(p_outline);
	rect_cache_dirty = true;
}

int NavigationPolygon::get_outline_count() const {
	return outlines.size();
}

void NavigationPolygon::set_outline(int p_idx, const Vector<Vector2> &p_outline) {
	ERR_FAIL_INDEX(p_idx, outlines.size());
	outlines.write[p_idx] = p_outline;
	rect_cache_dirty = true;
}

void NavigationPolygon::remove_outline(int p_idx) {
	ERR_FAIL_INDEX(p_idx, outlines.size());
	outlines.remove(p_idx);
	rect_cache_dirty = true;
}

Vector<Vector2> NavigationPolygon::get_outline(int p_idx) const {
	ERR_FAIL_INDEX_V(p_idx, outlines.size(), Vector<Vector2>());
	return outlines[p_idx];
}

void NavigationPolygon::clear_outlines() {
	outlines.clear();
	rect_cache_dirty = true;
}

void NavigationPolygon::make_polygons_from_outlines() {
	{
		MutexLock lock(navmesh_generation);
		navmesh.unref();
	}
	List<TPPLPoly> in_poly, out_poly;

	Vector2 outside_point(-1e10, -1e10);

	for (int i = 0; i < outlines.size(); i++) {
		Vector<Vector2> ol = outlines[i];
		int olsize = ol.size();
		if (olsize < 3) {
			continue;
		}
		const Vector2 *r = ol.ptr();
		for (int j = 0; j < olsize; j++) {
			outside_point.x = MAX(r[j].x, outside_point.x);
			outside_point.y = MAX(r[j].y, outside_point.y);
		}
	}

	outside_point += Vector2(0.7239784, 0.819238); //avoid precision issues

	for (int i = 0; i < outlines.size(); i++) {
		Vector<Vector2> ol = outlines[i];
		int olsize = ol.size();
		if (olsize < 3) {
			continue;
		}
		const Vector2 *r = ol.ptr();

		int interscount = 0;
		//test if this is an outer outline
		for (int k = 0; k < outlines.size(); k++) {
			if (i == k) {
				continue; //no self intersect
			}

			Vector<Vector2> ol2 = outlines[k];
			int olsize2 = ol2.size();
			if (olsize2 < 3) {
				continue;
			}
			const Vector2 *r2 = ol2.ptr();

			for (int l = 0; l < olsize2; l++) {
				if (Geometry2D::segment_intersects_segment(r[0], outside_point, r2[l], r2[(l + 1) % olsize2], nullptr)) {
					interscount++;
				}
			}
		}

		bool outer = (interscount % 2) == 0;

		TPPLPoly tp;
		tp.Init(olsize);
		for (int j = 0; j < olsize; j++) {
			tp[j] = r[j];
		}

		if (outer) {
			tp.SetOrientation(TPPL_ORIENTATION_CCW);
		} else {
			tp.SetOrientation(TPPL_ORIENTATION_CW);
			tp.SetHole(true);
		}

		in_poly.push_back(tp);
	}

	TPPLPartition tpart;
	if (tpart.ConvexPartition_HM(&in_poly, &out_poly) == 0) { //failed!
		ERR_PRINT("NavigationPolygon: Convex partition failed!");
		return;
	}

	polygons.clear();
	vertices.resize(0);

	Map<Vector2, int> points;
	for (List<TPPLPoly>::Element *I = out_poly.front(); I; I = I->next()) {
		TPPLPoly &tp = I->get();

		struct Polygon p;

		for (int64_t i = 0; i < tp.GetNumPoints(); i++) {
			Map<Vector2, int>::Element *E = points.find(tp[i]);
			if (!E) {
				E = points.insert(tp[i], vertices.size());
				vertices.push_back(tp[i]);
			}
			p.indices.push_back(E->get());
		}

		polygons.push_back(p);
	}

	emit_signal(CoreStringNames::get_singleton()->changed);
}

void NavigationPolygon::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_vertices", "vertices"), &NavigationPolygon::set_vertices);
	ClassDB::bind_method(D_METHOD("get_vertices"), &NavigationPolygon::get_vertices);

	ClassDB::bind_method(D_METHOD("add_polygon", "polygon"), &NavigationPolygon::add_polygon);
	ClassDB::bind_method(D_METHOD("get_polygon_count"), &NavigationPolygon::get_polygon_count);
	ClassDB::bind_method(D_METHOD("get_polygon", "idx"), &NavigationPolygon::get_polygon);
	ClassDB::bind_method(D_METHOD("clear_polygons"), &NavigationPolygon::clear_polygons);

	ClassDB::bind_method(D_METHOD("add_outline", "outline"), &NavigationPolygon::add_outline);
	ClassDB::bind_method(D_METHOD("add_outline_at_index", "outline", "index"), &NavigationPolygon::add_outline_at_index);
	ClassDB::bind_method(D_METHOD("get_outline_count"), &NavigationPolygon::get_outline_count);
	ClassDB::bind_method(D_METHOD("set_outline", "idx", "outline"), &NavigationPolygon::set_outline);
	ClassDB::bind_method(D_METHOD("get_outline", "idx"), &NavigationPolygon::get_outline);
	ClassDB::bind_method(D_METHOD("remove_outline", "idx"), &NavigationPolygon::remove_outline);
	ClassDB::bind_method(D_METHOD("clear_outlines"), &NavigationPolygon::clear_outlines);
	ClassDB::bind_method(D_METHOD("make_polygons_from_outlines"), &NavigationPolygon::make_polygons_from_outlines);

	ClassDB::bind_method(D_METHOD("_set_polygons", "polygons"), &NavigationPolygon::_set_polygons);
	ClassDB::bind_method(D_METHOD("_get_polygons"), &NavigationPolygon::_get_polygons);

	ClassDB::bind_method(D_METHOD("_set_outlines", "outlines"), &NavigationPolygon::_set_outlines);
	ClassDB::bind_method(D_METHOD("_get_outlines"), &NavigationPolygon::_get_outlines);

	ADD_PROPERTY(PropertyInfo(Variant::PACKED_VECTOR2_ARRAY, "vertices", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR | PROPERTY_USAGE_INTERNAL), "set_vertices", "get_vertices");
	ADD_PROPERTY(PropertyInfo(Variant::ARRAY, "polygons", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR | PROPERTY_USAGE_INTERNAL), "_set_polygons", "_get_polygons");
	ADD_PROPERTY(PropertyInfo(Variant::ARRAY, "outlines", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR | PROPERTY_USAGE_INTERNAL), "_set_outlines", "_get_outlines");
}

void NavigationRegion2D::set_enabled(bool p_enabled) {
	if (enabled == p_enabled) {
		return;
	}
	enabled = p_enabled;

	if (!is_inside_tree()) {
		return;
	}

	if (!enabled) {
		NavigationServer2D::get_singleton()->region_set_map(region, RID());
	} else {
		if (navigation) {
			NavigationServer2D::get_singleton()->region_set_map(region, navigation->get_rid());
		}
	}

	if (Engine::get_singleton()->is_editor_hint() || get_tree()->is_debugging_navigation_hint()) {
		update();
	}
}

bool NavigationRegion2D::is_enabled() const {
	return enabled;
}

/////////////////////////////
#ifdef TOOLS_ENABLED
Rect2 NavigationRegion2D::_edit_get_rect() const {
	return navpoly.is_valid() ? navpoly->_edit_get_rect() : Rect2();
}

bool NavigationRegion2D::_edit_is_selected_on_click(const Point2 &p_point, double p_tolerance) const {
	return navpoly.is_valid() ? navpoly->_edit_is_selected_on_click(p_point, p_tolerance) : false;
}
#endif

void NavigationRegion2D::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_ENTER_TREE: {
			Node2D *c = this;
			while (c) {
				navigation = Object::cast_to<Navigation2D>(c);
				if (navigation) {
					if (enabled) {
						NavigationServer2D::get_singleton()->region_set_map(region, navigation->get_rid());
					}
					break;
				}

				c = Object::cast_to<Node2D>(c->get_parent());
			}

		} break;
		case NOTIFICATION_TRANSFORM_CHANGED: {
			NavigationServer2D::get_singleton()->region_set_transform(region, get_global_transform());

		} break;
		case NOTIFICATION_EXIT_TREE: {
			if (navigation) {
				NavigationServer2D::get_singleton()->region_set_map(region, RID());
			}
			navigation = nullptr;
		} break;
		case NOTIFICATION_DRAW: {
			if (is_inside_tree() && (Engine::get_singleton()->is_editor_hint() || get_tree()->is_debugging_navigation_hint()) && navpoly.is_valid()) {
				Vector<Vector2> verts = navpoly->get_vertices();
				int vsize = verts.size();
				if (vsize < 3) {
					return;
				}

				Color color;
				if (enabled) {
					color = get_tree()->get_debug_navigation_color();
				} else {
					color = get_tree()->get_debug_navigation_disabled_color();
				}
				Vector<Color> colors;
				Vector<Vector2> vertices;
				vertices.resize(vsize);
				colors.resize(vsize);
				{
					const Vector2 *vr = verts.ptr();
					for (int i = 0; i < vsize; i++) {
						vertices.write[i] = vr[i];
						colors.write[i] = color;
					}
				}

				Vector<int> indices;

				for (int i = 0; i < navpoly->get_polygon_count(); i++) {
					Vector<int> polygon = navpoly->get_polygon(i);

					for (int j = 2; j < polygon.size(); j++) {
						int kofs[3] = { 0, j - 1, j };
						for (int k = 0; k < 3; k++) {
							int idx = polygon[kofs[k]];
							ERR_FAIL_INDEX(idx, vsize);
							indices.push_back(idx);
						}
					}
				}
				RS::get_singleton()->canvas_item_add_triangle_array(get_canvas_item(), indices, vertices, colors);
			}
		} break;
	}
}

void NavigationRegion2D::set_navigation_polygon(const Ref<NavigationPolygon> &p_navpoly) {
	if (p_navpoly == navpoly) {
		return;
	}

	if (navpoly.is_valid()) {
		navpoly->disconnect(CoreStringNames::get_singleton()->changed, callable_mp(this, &NavigationRegion2D::_navpoly_changed));
	}

	navpoly = p_navpoly;
	NavigationServer2D::get_singleton()->region_set_navpoly(region, p_navpoly);

	if (navpoly.is_valid()) {
		navpoly->connect(CoreStringNames::get_singleton()->changed, callable_mp(this, &NavigationRegion2D::_navpoly_changed));
	}
	_navpoly_changed();

	update_configuration_warning();
}

Ref<NavigationPolygon> NavigationRegion2D::get_navigation_polygon() const {
	return navpoly;
}

void NavigationRegion2D::_navpoly_changed() {
	if (is_inside_tree() && (Engine::get_singleton()->is_editor_hint() || get_tree()->is_debugging_navigation_hint())) {
		update();
	}
}

String NavigationRegion2D::get_configuration_warning() const {
	if (!is_visible_in_tree() || !is_inside_tree()) {
		return String();
	}

	String warning = Node2D::get_configuration_warning();

	if (!navpoly.is_valid()) {
		if (!warning.is_empty()) {
			warning += "\n\n";
		}
		warning += TTR("A NavigationPolygon resource must be set or created for this node to work. Please set a property or draw a polygon.");
	}
	const Node2D *c = this;
	while (c) {
		if (Object::cast_to<Navigation2D>(c)) {
			return warning;
		}

		c = Object::cast_to<Node2D>(c->get_parent());
	}
	if (!warning.is_empty()) {
		warning += "\n\n";
	}
	return warning + TTR("NavigationRegion2D must be a child or grandchild to a Navigation2D node. It only provides navigation data.");
}

void NavigationRegion2D::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_navigation_polygon", "navpoly"), &NavigationRegion2D::set_navigation_polygon);
	ClassDB::bind_method(D_METHOD("get_navigation_polygon"), &NavigationRegion2D::get_navigation_polygon);

	ClassDB::bind_method(D_METHOD("set_enabled", "enabled"), &NavigationRegion2D::set_enabled);
	ClassDB::bind_method(D_METHOD("is_enabled"), &NavigationRegion2D::is_enabled);

	ClassDB::bind_method(D_METHOD("_navpoly_changed"), &NavigationRegion2D::_navpoly_changed);

	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "navpoly", PROPERTY_HINT_RESOURCE_TYPE, "NavigationPolygon"), "set_navigation_polygon", "get_navigation_polygon");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "enabled"), "set_enabled", "is_enabled");
}

NavigationRegion2D::NavigationRegion2D() {
	set_notify_transform(true);
	region = NavigationServer2D::get_singleton()->region_create();
}

NavigationRegion2D::~NavigationRegion2D() {
	NavigationServer2D::get_singleton()->free(region);
}