/*************************************************************************/
/*  navigation_polygon.cpp                                               */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
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/* Permission is hereby granted, free of charge, to any person obtaining */
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/* The above copyright notice and this permission notice shall be        */
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/*************************************************************************/

#include "navigation_polygon_instance.h"

#include "core/config/engine.h"
#include "core/core_string_names.h"
#include "core/object/func_ref.h"
#include "core/os/mutex.h"
#include "core/os/os.h"
#include "navigation_2d.h"
#include "scene/resources/navigation_mesh.h"
#include "scene/resources/navigation_mesh_source_geometry_data_2d.h"
#include "scene/resources/navigation_polygon.h"
#include "scene/resources/world_2d.h"
#include "servers/navigation/navigation_mesh_generator.h"
#include "servers/navigation_2d_server.h"
#include "servers/navigation_server.h"

#include "thirdparty/misc/triangulator.h"

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

	if (!is_inside_tree()) {
		return;
	}

	if (!enabled) {
		Navigation2DServer::get_singleton()->region_set_map(region, RID());
	} else {
		if (navigation != nullptr) {
			Navigation2DServer::get_singleton()->region_set_map(region, navigation->get_rid());
		} else {
			if (map_override.is_valid()) {
				Navigation2DServer::get_singleton()->region_set_map(region, map_override);
			} else {
				Navigation2DServer::get_singleton()->region_set_map(region, get_world_2d()->get_navigation_map());
			}
		}
	}

#ifdef DEBUG_ENABLED
	if (Engine::get_singleton()->is_editor_hint() || Navigation2DServer::get_singleton()->get_debug_enabled()) {
		update();
	}
#endif // DEBUG_ENABLED
}

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

void NavigationPolygonInstance::set_navigation_layers(uint32_t p_navigation_layers) {
	navigation_layers = p_navigation_layers;
	Navigation2DServer::get_singleton()->region_set_navigation_layers(region, navigation_layers);
}

uint32_t NavigationPolygonInstance::get_navigation_layers() const {
	return navigation_layers;
}

void NavigationPolygonInstance::set_navigation_layer_value(int p_layer_number, bool p_value) {
	ERR_FAIL_COND_MSG(p_layer_number < 1, "Navigation layer number must be between 1 and 32 inclusive.");
	ERR_FAIL_COND_MSG(p_layer_number > 32, "Navigation layer number must be between 1 and 32 inclusive.");
	uint32_t _navigation_layers = get_navigation_layers();
	if (p_value) {
		_navigation_layers |= 1 << (p_layer_number - 1);
	} else {
		_navigation_layers &= ~(1 << (p_layer_number - 1));
	}
	set_navigation_layers(_navigation_layers);
}

bool NavigationPolygonInstance::get_navigation_layer_value(int p_layer_number) const {
	ERR_FAIL_COND_V_MSG(p_layer_number < 1, false, "Navigation layer number must be between 1 and 32 inclusive.");
	ERR_FAIL_COND_V_MSG(p_layer_number > 32, false, "Navigation layer number must be between 1 and 32 inclusive.");
	return get_navigation_layers() & (1 << (p_layer_number - 1));
}

void NavigationPolygonInstance::set_enter_cost(real_t p_enter_cost) {
	ERR_FAIL_COND_MSG(p_enter_cost < 0.0, "The enter_cost must be positive.");
	if (Math::is_equal_approx(enter_cost, p_enter_cost)) {
		return;
	}

	enter_cost = p_enter_cost;

	Navigation2DServer::get_singleton()->region_set_enter_cost(region, p_enter_cost);
}

real_t NavigationPolygonInstance::get_enter_cost() const {
	return enter_cost;
}

void NavigationPolygonInstance::set_travel_cost(real_t p_travel_cost) {
	ERR_FAIL_COND_MSG(p_travel_cost < 0.0, "The travel_cost must be positive.");
	if (Math::is_equal_approx(travel_cost, p_travel_cost)) {
		return;
	}

	travel_cost = p_travel_cost;

	Navigation2DServer::get_singleton()->region_set_travel_cost(region, travel_cost);
}

real_t NavigationPolygonInstance::get_travel_cost() const {
	return travel_cost;
}

RID NavigationPolygonInstance::get_region_rid() const {
	return region;
}

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

bool NavigationPolygonInstance::_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 NavigationPolygonInstance::_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) {
						Navigation2DServer::get_singleton()->region_set_map(region, navigation->get_rid());
					}
					break;
				}

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

			if (enabled && navigation == nullptr) {
				// did not find a valid navigation node parent, fallback to default navigation map on world resource
				if (map_override.is_valid()) {
					Navigation2DServer::get_singleton()->region_set_map(region, map_override);
				} else {
					Navigation2DServer::get_singleton()->region_set_map(region, get_world_2d()->get_navigation_map());
				}
			}
		} break;
		case NOTIFICATION_TRANSFORM_CHANGED: {
			Navigation2DServer::get_singleton()->region_set_transform(region, get_global_transform());
		} break;
		case NOTIFICATION_EXIT_TREE: {
			if (navigation) {
				Navigation2DServer::get_singleton()->region_set_map(region, RID());
			}
			navigation = nullptr;
		} break;
		case NOTIFICATION_DRAW: {
#ifdef DEBUG_ENABLED
			if (is_inside_tree() && (Engine::get_singleton()->is_editor_hint() || Navigation2DServer::get_singleton()->get_debug_enabled()) && navpoly.is_valid()) {
				_update_debug_mesh();
				_update_debug_edge_connections_mesh();
			}
#endif // DEBUG_ENABLED
		} break;
	}
}

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

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

	navpoly = p_navpoly;
	Navigation2DServer::get_singleton()->region_set_navpoly(region, p_navpoly);

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

	_navpoly_changed();
}

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

void NavigationPolygonInstance::set_navigation_map(RID p_navigation_map) {
	if (map_override == p_navigation_map) {
		return;
	}

	map_override = p_navigation_map;

	Navigation2DServer::get_singleton()->region_set_map(region, map_override);
}

RID NavigationPolygonInstance::get_navigation_map() const {
	if (map_override.is_valid()) {
		return map_override;
	} else if (is_inside_tree()) {
		return get_world_2d()->get_navigation_map();
	}
	return RID();
}

void NavigationPolygonInstance::bake_navigation_polygon(bool p_on_thread) {
	ERR_FAIL_COND_MSG(!get_navigation_polygon().is_valid(), "Can't bake the navigation polygon if the `NavigationPolygon` resource doesn't exist");
	if (baking_started) {
		WARN_PRINT("NavigationPolygon baking already started. Wait for it to finish.");
		return;
	}
	baking_started = true;

	navpoly->clear();
	if (p_on_thread) { // && OS::get_singleton()->get_render_thread_mode() == OS::RenderThreadMode::RENDER_SEPARATE_THREAD
		Ref<FuncRef> f;
		f.instance();
		f->set_instance(this);
		f->set_function("_bake_finished");

		NavigationMeshGenerator::get_singleton()->parse_and_bake_2d(navpoly, this, f);
	} else {
		Ref<NavigationMeshSourceGeometryData2D> source_geometry_data = NavigationMeshGenerator::get_singleton()->parse_2d_source_geometry_data(navpoly, this);
		NavigationMeshGenerator::get_singleton()->bake_2d_from_source_geometry_data(navpoly, source_geometry_data);
		_bake_finished();
	}
}

void NavigationPolygonInstance::_bake_finished() {
	baking_started = false;
	set_navigation_polygon(navpoly);
	emit_signal("bake_finished");
}

void NavigationPolygonInstance::_navpoly_changed() {
	if (is_inside_tree() && (Engine::get_singleton()->is_editor_hint() || get_tree()->is_debugging_navigation_hint())) {
		update();
	}
	if (navpoly.is_valid()) {
		Navigation2DServer::get_singleton()->region_set_navpoly(region, navpoly);
	}

	emit_signal("navigation_polygon_changed");
	_change_notify("navpoly");

	update_configuration_warning();
}

#ifdef DEBUG_ENABLED
void NavigationPolygonInstance::_navigation_map_changed(RID p_map) {
	if (navigation != nullptr && enabled && (navigation->get_rid() == p_map)) {
		update();
	} else if (is_inside_tree() && enabled && (get_world_2d()->get_navigation_map() == p_map)) {
		update();
	}
}
void NavigationPolygonInstance::_navigation_debug_changed() {
	if (navigation != nullptr && enabled) {
		update();
	} else if (is_inside_tree() && enabled) {
		update();
	}
}
#endif // DEBUG_ENABLED

String NavigationPolygonInstance::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 != String()) {
			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.");
	}

	return warning;
}

void NavigationPolygonInstance::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_enabled", "enabled"), &NavigationPolygonInstance::set_enabled);
	ClassDB::bind_method(D_METHOD("is_enabled"), &NavigationPolygonInstance::is_enabled);

	ClassDB::bind_method(D_METHOD("set_navigation_layers", "navigation_layers"), &NavigationPolygonInstance::set_navigation_layers);
	ClassDB::bind_method(D_METHOD("get_navigation_layers"), &NavigationPolygonInstance::get_navigation_layers);

	ClassDB::bind_method(D_METHOD("set_navigation_layer_value", "layer_number", "value"), &NavigationPolygonInstance::set_navigation_layer_value);
	ClassDB::bind_method(D_METHOD("get_navigation_layer_value", "layer_number"), &NavigationPolygonInstance::get_navigation_layer_value);

	ClassDB::bind_method(D_METHOD("set_enter_cost", "enter_cost"), &NavigationPolygonInstance::set_enter_cost);
	ClassDB::bind_method(D_METHOD("get_enter_cost"), &NavigationPolygonInstance::get_enter_cost);

	ClassDB::bind_method(D_METHOD("set_travel_cost", "travel_cost"), &NavigationPolygonInstance::set_travel_cost);
	ClassDB::bind_method(D_METHOD("get_travel_cost"), &NavigationPolygonInstance::get_travel_cost);

	ClassDB::bind_method(D_METHOD("set_navigation_polygon", "navpoly"), &NavigationPolygonInstance::set_navigation_polygon);
	ClassDB::bind_method(D_METHOD("get_navigation_polygon"), &NavigationPolygonInstance::get_navigation_polygon);

	ClassDB::bind_method(D_METHOD("set_navigation_map", "navigation_map"), &NavigationPolygonInstance::set_navigation_map);
	ClassDB::bind_method(D_METHOD("get_navigation_map"), &NavigationPolygonInstance::get_navigation_map);

	ClassDB::bind_method(D_METHOD("bake_navigation_polygon", "on_thread"), &NavigationPolygonInstance::bake_navigation_polygon);
	ClassDB::bind_method(D_METHOD("_bake_finished"), &NavigationPolygonInstance::_bake_finished);

	ClassDB::bind_method(D_METHOD("get_region_rid"), &NavigationPolygonInstance::get_region_rid);

	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");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "navigation_layers", PROPERTY_HINT_LAYERS_2D_NAVIGATION), "set_navigation_layers", "get_navigation_layers");
	ADD_PROPERTY(PropertyInfo(Variant::REAL, "enter_cost"), "set_enter_cost", "get_enter_cost");
	ADD_PROPERTY(PropertyInfo(Variant::REAL, "travel_cost"), "set_travel_cost", "get_travel_cost");

#ifdef DEBUG_ENABLED
	ClassDB::bind_method(D_METHOD("_navigation_map_changed"), &NavigationPolygonInstance::_navigation_map_changed);
	ClassDB::bind_method(D_METHOD("_navigation_debug_changed"), &NavigationPolygonInstance::_navigation_debug_changed);
#endif
	ClassDB::bind_method(D_METHOD("_navpoly_changed"), &NavigationPolygonInstance::_navpoly_changed);

	ADD_SIGNAL(MethodInfo("navigation_polygon_changed"));
	ADD_SIGNAL(MethodInfo("bake_finished"));
}

NavigationPolygonInstance::NavigationPolygonInstance() {
	enabled = true;
	set_notify_transform(true);
	region = Navigation2DServer::get_singleton()->region_create();

	navigation = nullptr;

	enter_cost = 0.0;
	travel_cost = 1.0;

	navigation_layers = 1;

	baking_started = false;

	Navigation2DServer::get_singleton()->region_set_enter_cost(region, get_enter_cost());
	Navigation2DServer::get_singleton()->region_set_travel_cost(region, get_travel_cost());

#ifdef DEBUG_ENABLED
	Navigation2DServer::get_singleton_mut()->connect("map_changed", this, "_navigation_map_changed");
	NavigationServer::get_singleton_mut()->connect("navigation_debug_changed", this, "_navigation_debug_changed");
#endif // DEBUG_ENABLED
}

NavigationPolygonInstance::~NavigationPolygonInstance() {
	ERR_FAIL_NULL(Navigation2DServer::get_singleton());

	Navigation2DServer::get_singleton()->free(region);

#ifdef DEBUG_ENABLED
	Navigation2DServer::get_singleton_mut()->disconnect("map_changed", this, "_navigation_map_changed");
	NavigationServer::get_singleton_mut()->disconnect("navigation_debug_changed", this, "_navigation_debug_changed");
#endif // DEBUG_ENABLED
}

#ifdef DEBUG_ENABLED
void NavigationPolygonInstance::_update_debug_mesh() {
	/*
	Vector<Vector2> navigation_polygon_vertices = navigation_polygon->get_vertices();
	if (navigation_polygon_vertices.size() < 3) {
		return;
	}

	const Navigation2DServer2D *ns2d = Navigation2DServer2D::get_singleton();

	bool enabled_geometry_face_random_color = ns2d->get_debug_navigation_enable_geometry_face_random_color();
	bool enabled_edge_lines = ns2d->get_debug_navigation_enable_edge_lines();

	Color debug_face_color = ns2d->get_debug_navigation_geometry_face_color();
	Color debug_edge_color = ns2d->get_debug_navigation_geometry_edge_color();

	if (!enabled) {
		debug_face_color = ns2d->get_debug_navigation_geometry_face_disabled_color();
		debug_edge_color = ns2d->get_debug_navigation_geometry_edge_disabled_color();
	}

	RandomPCG rand;

	for (int i = 0; i < navigation_polygon->get_polygon_count(); i++) {
		// An array of vertices for this polygon.
		Vector<int> polygon = navigation_polygon->get_polygon(i);
		Vector<Vector2> debug_polygon_vertices;
		debug_polygon_vertices.resize(polygon.size());
		for (int j = 0; j < polygon.size(); j++) {
			ERR_FAIL_INDEX(polygon[j], navigation_polygon_vertices.size());
			debug_polygon_vertices.write[j] = navigation_polygon_vertices[polygon[j]];
		}

		// Generate the polygon color, slightly randomly modified from the settings one.
		Color random_variation_color = debug_face_color;
		if (enabled_geometry_face_random_color) {
			random_variation_color.set_hsv(
					debug_face_color.get_h() + rand.random(-1.0, 1.0) * 0.1,
					debug_face_color.get_s(),
					debug_face_color.get_v() + rand.random(-1.0, 1.0) * 0.2);
		}
		random_variation_color.a = debug_face_color.a;

		Vector<Color> debug_face_colors;
		debug_face_colors.push_back(random_variation_color);
		RS::get_singleton()->canvas_item_add_polygon(get_canvas_item(), debug_polygon_vertices, debug_face_colors);

		if (enabled_edge_lines) {
			Vector<Color> debug_edge_colors;
			debug_edge_colors.push_back(debug_edge_color);
			debug_polygon_vertices.push_back(debug_polygon_vertices[0]); // Add first again for closing polyline.
			RS::get_singleton()->canvas_item_add_polyline(get_canvas_item(), debug_polygon_vertices, debug_edge_colors);
		}
	}
	*/

	PoolVector<Vector2> navigation_polygon_vertices = navpoly->get_vertices();
	if (navigation_polygon_vertices.size() < 3) {
		return;
	}

	const Navigation2DServer *ns2d = Navigation2DServer::get_singleton();

	bool enabled_geometry_face_random_color = ns2d->get_debug_navigation_enable_geometry_face_random_color();
	bool enabled_edge_lines = ns2d->get_debug_navigation_enable_edge_lines();
	bool enable_edge_connections = ns2d->get_debug_navigation_enable_edge_connections();

	Color debug_face_color = ns2d->get_debug_navigation_geometry_face_color();
	Color debug_edge_color = ns2d->get_debug_navigation_geometry_edge_color();
	Color debug_edge_connection_color = ns2d->get_debug_navigation_edge_connection_color();

	if (!enabled) {
		debug_face_color = ns2d->get_debug_navigation_geometry_face_disabled_color();
		debug_edge_color = ns2d->get_debug_navigation_geometry_edge_disabled_color();
	}

	RandomPCG rand;

	for (int i = 0; i < navpoly->get_polygon_count(); i++) {
		// An array of vertices for this polygon.
		Vector<int> polygon = navpoly->get_polygon(i);

		Vector<Vector2> debug_polygon_vertices;
		debug_polygon_vertices.resize(polygon.size());
		for (int j = 0; j < polygon.size(); j++) {
			ERR_FAIL_INDEX(polygon[j], navigation_polygon_vertices.size());
			debug_polygon_vertices.write[j] = navigation_polygon_vertices[polygon[j]];
		}
		// Generate the polygon color, slightly randomly modified from the settings one.
		Color random_variation_color = debug_face_color;
		if (enabled_geometry_face_random_color) {
			random_variation_color.set_hsv(debug_face_color.get_h() + rand.random(-1.0, 1.0) * 0.1, debug_face_color.get_s(), debug_face_color.get_v() + rand.random(-1.0, 1.0) * 0.2);
		}
		random_variation_color.a = debug_face_color.a;

		Vector<Color> debug_face_colors;
		debug_face_colors.push_back(random_variation_color);
		RS::get_singleton()->canvas_item_add_polygon(get_canvas_item(), debug_polygon_vertices, debug_face_colors);

		if (enabled_edge_lines) {
			Vector<Color> debug_edge_colors;
			debug_edge_colors.push_back(debug_edge_color);
			debug_polygon_vertices.push_back(debug_polygon_vertices[0]); // Add first again for closing polyline.
			RS::get_singleton()->canvas_item_add_polyline(get_canvas_item(), debug_polygon_vertices, debug_edge_colors);
		}
	}

	if (enable_edge_connections) {
		// Draw the region edge connections.
		Transform2D xform = get_global_transform();

		real_t radius = 1.0;
		if (navigation != nullptr) {
			radius = ns2d->map_get_edge_connection_margin(navigation->get_rid()) / 2.0;
		} else {
			radius = ns2d->map_get_edge_connection_margin(get_world_2d()->get_navigation_map()) / 2.0;
		}

		for (int i = 0; i < ns2d->region_get_connections_count(region); i++) {
			// Two main points
			Vector2 a = ns2d->region_get_connection_pathway_start(region, i);
			a = xform.affine_inverse().xform(a);
			Vector2 b = ns2d->region_get_connection_pathway_end(region, i);
			b = xform.affine_inverse().xform(b);
			draw_line(a, b, debug_edge_connection_color);

			// Draw a circle to illustrate the margins.
			real_t angle = a.angle_to_point(b);
			draw_arc(a, radius, angle + Math_PI / 2.0, angle - Math_PI / 2.0 + Math_TAU, 10, debug_edge_connection_color);
			draw_arc(b, radius, angle - Math_PI / 2.0, angle + Math_PI / 2.0, 10, debug_edge_connection_color);
		}
	}
}
#endif // DEBUG_ENABLED

#ifdef DEBUG_ENABLED
void NavigationPolygonInstance::_update_debug_edge_connections_mesh() {
	const Navigation2DServer *ns2d = Navigation2DServer::get_singleton();
	const Navigation2DServer *ns = Navigation2DServer::get_singleton();
	bool enable_edge_connections = ns->get_debug_navigation_enable_edge_connections();
	Color debug_edge_connection_color = ns->get_debug_navigation_edge_connection_color();

	if (enable_edge_connections) {
		// Draw the region edge connections.
		Transform2D xform = get_global_transform();
		real_t radius = ns2d->map_get_edge_connection_margin(get_world_2d()->get_navigation_map()) / 2.0;
		for (int i = 0; i < ns2d->region_get_connections_count(region); i++) {
			// Two main points
			Vector2 a = ns2d->region_get_connection_pathway_start(region, i);
			a = xform.affine_inverse().xform(a);
			Vector2 b = ns2d->region_get_connection_pathway_end(region, i);
			b = xform.affine_inverse().xform(b);
			draw_line(a, b, debug_edge_connection_color);

			// Draw a circle to illustrate the margins.
			real_t angle = a.angle_to_point(b);
			draw_arc(a, radius, angle + Math_PI / 2.0, angle - Math_PI / 2.0 + Math_TAU, 10, debug_edge_connection_color);
			draw_arc(b, radius, angle - Math_PI / 2.0, angle + Math_PI / 2.0, 10, debug_edge_connection_color);
		}
	}
}
#endif // DEBUG_ENABLED