/*************************************************************************/
/*  navigation_obstacle.cpp                                              */
/*************************************************************************/
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/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
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#include "navigation_obstacle.h"

#include "scene/3d/collision_shape.h"
#include "scene/3d/navigation.h"
#include "scene/3d/physics_body.h"
#include "servers/navigation_server.h"

void NavigationObstacle::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_navigation", "navigation"), &NavigationObstacle::set_navigation_node);
	ClassDB::bind_method(D_METHOD("get_navigation"), &NavigationObstacle::get_navigation_node);
	ClassDB::bind_method(D_METHOD("is_radius_estimated"), &NavigationObstacle::is_radius_estimated);
	ClassDB::bind_method(D_METHOD("set_estimate_radius", "estimate_radius"), &NavigationObstacle::set_estimate_radius);
	ClassDB::bind_method(D_METHOD("set_radius", "radius"), &NavigationObstacle::set_radius);
	ClassDB::bind_method(D_METHOD("get_radius"), &NavigationObstacle::get_radius);

	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "estimate_radius"), "set_estimate_radius", "is_radius_estimated");
	ADD_PROPERTY(PropertyInfo(Variant::REAL, "radius", PROPERTY_HINT_RANGE, "0.01,100,0.01"), "set_radius", "get_radius");
}

void NavigationObstacle::_validate_property(PropertyInfo &p_property) const {
	if (p_property.name == "radius") {
		if (estimate_radius) {
			p_property.usage = PROPERTY_USAGE_NOEDITOR;
		}
	}
}

void NavigationObstacle::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_ENTER_TREE: {
			parent_spatial = Object::cast_to<Spatial>(get_parent());
			reevaluate_agent_radius();

			// Search the navigation node and set it
			{
				Navigation *nav = nullptr;
				Node *p = get_parent();
				while (p != nullptr) {
					nav = Object::cast_to<Navigation>(p);
					if (nav != nullptr) {
						p = nullptr;
					} else {
						p = p->get_parent();
					}
				}

				set_navigation(nav);
			}

			set_physics_process_internal(true);
		} break;
		case NOTIFICATION_EXIT_TREE: {
			set_navigation(nullptr);
			set_physics_process_internal(false);
			request_ready(); // required to solve an issue with losing the navigation
		} break;
		case NOTIFICATION_PARENTED: {
			parent_spatial = Object::cast_to<Spatial>(get_parent());
			reevaluate_agent_radius();
		} break;
		case NOTIFICATION_UNPARENTED: {
			parent_spatial = nullptr;
		} break;
		case NOTIFICATION_INTERNAL_PHYSICS_PROCESS: {
			if (parent_spatial) {
				NavigationServer::get_singleton()->agent_set_position(agent, parent_spatial->get_global_transform().origin);
			}

			PhysicsBody *rigid = Object::cast_to<PhysicsBody>(get_parent());
			if (rigid) {
				Vector3 v = rigid->get_linear_velocity();
				NavigationServer::get_singleton()->agent_set_velocity(agent, v);
				NavigationServer::get_singleton()->agent_set_target_velocity(agent, v);
			}

		} break;
	}
}

NavigationObstacle::NavigationObstacle() :
		navigation(nullptr),
		agent(RID()) {
	agent = NavigationServer::get_singleton()->agent_create();
	initialize_agent();
}

NavigationObstacle::~NavigationObstacle() {
	NavigationServer::get_singleton()->free(agent);
	agent = RID(); // Pointless
}

void NavigationObstacle::set_navigation(Navigation *p_nav) {
	if (navigation == p_nav) {
		return; // Pointless
	}

	navigation = p_nav;
	NavigationServer::get_singleton()->agent_set_map(agent, navigation == nullptr ? RID() : navigation->get_rid());
}

void NavigationObstacle::set_navigation_node(Node *p_nav) {
	Navigation *nav = Object::cast_to<Navigation>(p_nav);
	ERR_FAIL_NULL(nav);
	set_navigation(nav);
}

Node *NavigationObstacle::get_navigation_node() const {
	return Object::cast_to<Node>(navigation);
}

String NavigationObstacle::get_configuration_warning() const {
	if (!Object::cast_to<Spatial>(get_parent())) {
		return TTR("The NavigationObstacle only serves to provide collision avoidance to a spatial object.");
	}

	return String();
}

void NavigationObstacle::initialize_agent() {
	NavigationServer::get_singleton()->agent_set_neighbor_dist(agent, 0.0);
	NavigationServer::get_singleton()->agent_set_max_neighbors(agent, 0);
	NavigationServer::get_singleton()->agent_set_time_horizon(agent, 0.0);
	NavigationServer::get_singleton()->agent_set_max_speed(agent, 0.0);
}

void NavigationObstacle::reevaluate_agent_radius() {
	if (!estimate_radius) {
		NavigationServer::get_singleton()->agent_set_radius(agent, radius);
	} else if (parent_spatial && parent_spatial->is_inside_tree()) {
		NavigationServer::get_singleton()->agent_set_radius(agent, estimate_agent_radius());
	}
}

real_t NavigationObstacle::estimate_agent_radius() const {
	if (parent_spatial) {
		// Estimate the radius of this physics body
		real_t radius = 0.0;
		for (int i(0); i < parent_spatial->get_child_count(); i++) {
			// For each collision shape
			CollisionShape *cs = Object::cast_to<CollisionShape>(parent_spatial->get_child(i));
			if (cs) {
				// Take the distance between the Body center to the shape center
				real_t r = cs->get_transform().origin.length();
				if (cs->get_shape().is_valid()) {
					// and add the enclosing shape radius
					r += cs->get_shape()->get_enclosing_radius();
				}
				Vector3 s = cs->get_global_transform().basis.get_scale();
				r *= MAX(s.x, MAX(s.y, s.z));
				// Takes the biggest radius
				radius = MAX(radius, r);
			}
		}
		Vector3 s = parent_spatial->get_global_transform().basis.get_scale();
		radius *= MAX(s.x, MAX(s.y, s.z));
	}

	if (radius > 0.0) {
		return radius;
	}

	return 1.0; // Never a 0 radius
}

void NavigationObstacle::set_estimate_radius(bool p_estimate_radius) {
	estimate_radius = p_estimate_radius;
	_change_notify();
	reevaluate_agent_radius();
}

void NavigationObstacle::set_radius(real_t p_radius) {
	ERR_FAIL_COND_MSG(p_radius <= 0.0, "Radius must be greater than 0.");
	radius = p_radius;
	reevaluate_agent_radius();
}
