/*************************************************************************/
/*  nav_agent.cpp                                                        */
/*************************************************************************/
/*                         This file is part of:                         */
/*                          PANDEMONIUM ENGINE                           */
/*             https://github.com/Relintai/pandemonium_engine            */
/*************************************************************************/
/* Copyright (c) 2022-present Péter Magyar.                              */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
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/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
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/*************************************************************************/

#include "nav_agent.h"

#include "nav_map.h"

NavAgent::NavAgent() {
	height = 1.0;
	radius = 1.0;
	max_speed = 1.0;
	time_horizon_agents = 1.0;
	time_horizon_obstacles = 0.0;
	max_neighbors = 5;
	neighbor_distance = 5.0;
	clamp_speed = true; // Experimental, clamps velocity to max_speed.

	map = nullptr;

	use_3d_avoidance = false;
	avoidance_enabled = false;

	avoidance_layers = 1;
	avoidance_mask = 1;
	avoidance_priority = 1.0;

	avoidance_callback.id = ObjectID(0);
	agent_dirty = true;

	map_update_id = 0;
	paused = false;
}

void NavAgent::set_avoidance_enabled(bool p_enabled) {
	avoidance_enabled = p_enabled;
	_update_rvo_agent_properties();
}

void NavAgent::set_use_3d_avoidance(bool p_enabled) {
	use_3d_avoidance = p_enabled;
	_update_rvo_agent_properties();
}

void NavAgent::_update_rvo_agent_properties() {
	if (use_3d_avoidance) {
		rvo_agent_3d.neighborDist_ = neighbor_distance;
		rvo_agent_3d.maxNeighbors_ = max_neighbors;
		rvo_agent_3d.timeHorizon_ = time_horizon_agents;
		rvo_agent_3d.timeHorizonObst_ = time_horizon_obstacles;
		rvo_agent_3d.radius_ = radius;
		rvo_agent_3d.maxSpeed_ = max_speed;
		rvo_agent_3d.position_ = RVO3D::Vector3(position.x, position.y, position.z);
		// Replacing the internal velocity directly causes major jitter / bugs due to unpredictable velocity jumps, left line here for testing.
		//rvo_agent_3d.velocity_ = RVO3D::Vector3(velocity.x, velocity.y ,velocity.z);
		rvo_agent_3d.prefVelocity_ = RVO3D::Vector3(velocity.x, velocity.y, velocity.z);
		rvo_agent_3d.height_ = height;
		rvo_agent_3d.avoidance_layers_ = avoidance_layers;
		rvo_agent_3d.avoidance_mask_ = avoidance_mask;
		rvo_agent_3d.avoidance_priority_ = avoidance_priority;
	} else {
		rvo_agent_2d.neighborDist_ = neighbor_distance;
		rvo_agent_2d.maxNeighbors_ = max_neighbors;
		rvo_agent_2d.timeHorizon_ = time_horizon_agents;
		rvo_agent_2d.timeHorizonObst_ = time_horizon_obstacles;
		rvo_agent_2d.radius_ = radius;
		rvo_agent_2d.maxSpeed_ = max_speed;
		rvo_agent_2d.position_ = RVO2D::Vector2(position.x, position.z);
		rvo_agent_2d.elevation_ = position.y;
		// Replacing the internal velocity directly causes major jitter / bugs due to unpredictable velocity jumps, left line here for testing.
		//rvo_agent_2d.velocity_ = RVO2D::Vector2(velocity.x, velocity.z);
		rvo_agent_2d.prefVelocity_ = RVO2D::Vector2(velocity.x, velocity.z);
		rvo_agent_2d.height_ = height;
		rvo_agent_2d.avoidance_layers_ = avoidance_layers;
		rvo_agent_2d.avoidance_mask_ = avoidance_mask;
		rvo_agent_2d.avoidance_priority_ = avoidance_priority;
	}

	if (map != nullptr) {
		if (avoidance_enabled) {
			map->set_agent_as_controlled(this);
		} else {
			map->remove_agent_as_controlled(this);
		}
	}
	agent_dirty = true;
}

void NavAgent::set_map(NavMap *p_map) {
	map = p_map;
	agent_dirty = true;
}

bool NavAgent::is_map_changed() {
	if (map) {
		bool is_changed = map->get_map_update_id() != map_update_id;
		map_update_id = map->get_map_update_id();
		return is_changed;
	} else {
		return false;
	}
}

void NavAgent::set_neighbor_distance(real_t p_neighbor_distance) {
	neighbor_distance = p_neighbor_distance;
	if (use_3d_avoidance) {
		rvo_agent_3d.neighborDist_ = neighbor_distance;
	} else {
		rvo_agent_2d.neighborDist_ = neighbor_distance;
	}
	agent_dirty = true;
}

void NavAgent::set_max_neighbors(int p_max_neighbors) {
	max_neighbors = p_max_neighbors;
	if (use_3d_avoidance) {
		rvo_agent_3d.maxNeighbors_ = max_neighbors;
	} else {
		rvo_agent_2d.maxNeighbors_ = max_neighbors;
	}
	agent_dirty = true;
}

void NavAgent::set_time_horizon_agents(real_t p_time_horizon) {
	time_horizon_agents = p_time_horizon;
	if (use_3d_avoidance) {
		rvo_agent_3d.timeHorizon_ = time_horizon_agents;
	} else {
		rvo_agent_2d.timeHorizon_ = time_horizon_agents;
	}
	agent_dirty = true;
}

void NavAgent::set_time_horizon_obstacles(real_t p_time_horizon) {
	time_horizon_obstacles = p_time_horizon;
	if (use_3d_avoidance) {
		rvo_agent_3d.timeHorizonObst_ = time_horizon_obstacles;
	} else {
		rvo_agent_2d.timeHorizonObst_ = time_horizon_obstacles;
	}
	agent_dirty = true;
}

void NavAgent::set_radius(real_t p_radius) {
	radius = p_radius;
	if (use_3d_avoidance) {
		rvo_agent_3d.radius_ = radius;
	} else {
		rvo_agent_2d.radius_ = radius;
	}
	agent_dirty = true;
}

void NavAgent::set_height(real_t p_height) {
	height = p_height;
	if (use_3d_avoidance) {
		rvo_agent_3d.height_ = height;
	} else {
		rvo_agent_2d.height_ = height;
	}
	agent_dirty = true;
}

void NavAgent::set_max_speed(real_t p_max_speed) {
	max_speed = p_max_speed;
	if (avoidance_enabled) {
		if (use_3d_avoidance) {
			rvo_agent_3d.maxSpeed_ = max_speed;
		} else {
			rvo_agent_2d.maxSpeed_ = max_speed;
		}
	}
	agent_dirty = true;
}

void NavAgent::set_position(const Vector3 p_position) {
	position = p_position;
	if (avoidance_enabled) {
		if (use_3d_avoidance) {
			rvo_agent_3d.position_ = RVO3D::Vector3(p_position.x, p_position.y, p_position.z);
		} else {
			rvo_agent_2d.elevation_ = p_position.y;
			rvo_agent_2d.position_ = RVO2D::Vector2(p_position.x, p_position.z);
		}
	}
	agent_dirty = true;
}

void NavAgent::set_target_position(const Vector3 p_target_position) {
	target_position = p_target_position;
}

void NavAgent::set_velocity(const Vector3 p_velocity) {
	// Sets the "wanted" velocity for an agent as a suggestion
	// This velocity is not guaranteed, RVO simulation will only try to fulfill it
	velocity = p_velocity;
	if (avoidance_enabled) {
		if (use_3d_avoidance) {
			rvo_agent_3d.prefVelocity_ = RVO3D::Vector3(velocity.x, velocity.y, velocity.z);
		} else {
			rvo_agent_2d.prefVelocity_ = RVO2D::Vector2(velocity.x, velocity.z);
		}
	}
	agent_dirty = true;
}

void NavAgent::set_velocity_forced(const Vector3 p_velocity) {
	// This function replaces the internal rvo simulation velocity
	// should only be used after the agent was teleported
	// as it destroys consistency in movement in cramped situations
	// use velocity instead to update with a safer "suggestion"
	velocity_forced = p_velocity;
	if (avoidance_enabled) {
		if (use_3d_avoidance) {
			rvo_agent_3d.velocity_ = RVO3D::Vector3(p_velocity.x, p_velocity.y, p_velocity.z);
		} else {
			rvo_agent_2d.velocity_ = RVO2D::Vector2(p_velocity.x, p_velocity.z);
		}
	}
	agent_dirty = true;
}

void NavAgent::update() {
	// Updates this agent with the calculated results from the rvo simulation
	if (avoidance_enabled) {
		if (use_3d_avoidance) {
			velocity = Vector3(rvo_agent_3d.velocity_.x(), rvo_agent_3d.velocity_.y(), rvo_agent_3d.velocity_.z());
		} else {
			velocity = Vector3(rvo_agent_2d.velocity_.x(), 0.0, rvo_agent_2d.velocity_.y());
		}
	}
}

void NavAgent::set_avoidance_mask(uint32_t p_mask) {
	avoidance_mask = p_mask;
	if (use_3d_avoidance) {
		rvo_agent_3d.avoidance_mask_ = avoidance_mask;
	} else {
		rvo_agent_2d.avoidance_mask_ = avoidance_mask;
	}
	agent_dirty = true;
}

void NavAgent::set_avoidance_layers(uint32_t p_layers) {
	avoidance_layers = p_layers;
	if (use_3d_avoidance) {
		rvo_agent_3d.avoidance_layers_ = avoidance_layers;
	} else {
		rvo_agent_2d.avoidance_layers_ = avoidance_layers;
	}
	agent_dirty = true;
}

void NavAgent::set_avoidance_priority(real_t p_priority) {
	ERR_FAIL_COND_MSG(p_priority < 0.0, "Avoidance priority must be between 0.0 and 1.0 inclusive.");
	ERR_FAIL_COND_MSG(p_priority > 1.0, "Avoidance priority must be between 0.0 and 1.0 inclusive.");
	avoidance_priority = p_priority;
	if (use_3d_avoidance) {
		rvo_agent_3d.avoidance_priority_ = avoidance_priority;
	} else {
		rvo_agent_2d.avoidance_priority_ = avoidance_priority;
	}
	agent_dirty = true;
};

bool NavAgent::check_dirty() {
	const bool was_dirty = agent_dirty;
	agent_dirty = false;
	return was_dirty;
}

const Dictionary NavAgent::get_avoidance_data() const {
	// Returns debug data from RVO simulation internals of this agent.
	Dictionary _avoidance_data;
	if (use_3d_avoidance) {
		_avoidance_data["max_neighbors"] = int(rvo_agent_3d.maxNeighbors_);
		_avoidance_data["max_speed"] = float(rvo_agent_3d.maxSpeed_);
		_avoidance_data["neighbor_distance"] = float(rvo_agent_3d.neighborDist_);
		_avoidance_data["new_velocity"] = Vector3(rvo_agent_3d.newVelocity_.x(), rvo_agent_3d.newVelocity_.y(), rvo_agent_3d.newVelocity_.z());
		_avoidance_data["velocity"] = Vector3(rvo_agent_3d.velocity_.x(), rvo_agent_3d.velocity_.y(), rvo_agent_3d.velocity_.z());
		_avoidance_data["position"] = Vector3(rvo_agent_3d.position_.x(), rvo_agent_3d.position_.y(), rvo_agent_3d.position_.z());
		_avoidance_data["prefered_velocity"] = Vector3(rvo_agent_3d.prefVelocity_.x(), rvo_agent_3d.prefVelocity_.y(), rvo_agent_3d.prefVelocity_.z());
		_avoidance_data["radius"] = float(rvo_agent_3d.radius_);
		_avoidance_data["time_horizon_agents"] = float(rvo_agent_3d.timeHorizon_);
		_avoidance_data["time_horizon_obstacles"] = 0.0;
		_avoidance_data["height"] = float(rvo_agent_3d.height_);
		_avoidance_data["avoidance_layers"] = int(rvo_agent_3d.avoidance_layers_);
		_avoidance_data["avoidance_mask"] = int(rvo_agent_3d.avoidance_mask_);
		_avoidance_data["avoidance_priority"] = float(rvo_agent_3d.avoidance_priority_);
	} else {
		_avoidance_data["max_neighbors"] = int(rvo_agent_2d.maxNeighbors_);
		_avoidance_data["max_speed"] = float(rvo_agent_2d.maxSpeed_);
		_avoidance_data["neighbor_distance"] = float(rvo_agent_2d.neighborDist_);
		_avoidance_data["new_velocity"] = Vector3(rvo_agent_2d.newVelocity_.x(), 0.0, rvo_agent_2d.newVelocity_.y());
		_avoidance_data["velocity"] = Vector3(rvo_agent_2d.velocity_.x(), 0.0, rvo_agent_2d.velocity_.y());
		_avoidance_data["position"] = Vector3(rvo_agent_2d.position_.x(), 0.0, rvo_agent_2d.position_.y());
		_avoidance_data["prefered_velocity"] = Vector3(rvo_agent_2d.prefVelocity_.x(), 0.0, rvo_agent_2d.prefVelocity_.y());
		_avoidance_data["radius"] = float(rvo_agent_2d.radius_);
		_avoidance_data["time_horizon_agents"] = float(rvo_agent_2d.timeHorizon_);
		_avoidance_data["time_horizon_obstacles"] = float(rvo_agent_2d.timeHorizonObst_);
		_avoidance_data["height"] = float(rvo_agent_2d.height_);
		_avoidance_data["avoidance_layers"] = int(rvo_agent_2d.avoidance_layers_);
		_avoidance_data["avoidance_mask"] = int(rvo_agent_2d.avoidance_mask_);
		_avoidance_data["avoidance_priority"] = float(rvo_agent_2d.avoidance_priority_);
	}
	return _avoidance_data;
}

void NavAgent::set_paused(bool p_paused) {
	if (paused == p_paused) {
		return;
	}

	paused = p_paused;

	if (map) {
		if (paused) {
			map->remove_agent_as_controlled(this);
		} else {
			map->set_agent_as_controlled(this);
		}
	}
}

bool NavAgent::get_paused() const {
	return paused;
}

void NavAgent::set_avoidance_callback(ObjectID p_id, const StringName p_method, const Variant p_udata) {
	avoidance_callback.id = p_id;
	avoidance_callback.method = p_method;
	avoidance_callback.udata = p_udata;
}

bool NavAgent::has_avoidance_callback() const {
	return avoidance_callback.id != 0;
}

void NavAgent::dispatch_avoidance_callback() {
	if (avoidance_callback.id == 0) {
		return;
	}
	Object *obj = ObjectDB::get_instance(avoidance_callback.id);
	if (!obj) {
		avoidance_callback.id = ObjectID(0);
		return;
	}

	Variant::CallError responseCallError;

	Vector3 new_velocity;

	if (use_3d_avoidance) {
		new_velocity = Vector3(rvo_agent_3d.velocity_.x(), rvo_agent_3d.velocity_.y(), rvo_agent_3d.velocity_.z());
	} else {
		new_velocity = Vector3(rvo_agent_2d.velocity_.x(), 0.0, rvo_agent_2d.velocity_.y());
	}

	if (clamp_speed) {
		new_velocity = new_velocity.limit_length(max_speed);
	}

	avoidance_callback.new_velocity = new_velocity;

	const Variant *vp[2] = { &avoidance_callback.new_velocity, &avoidance_callback.udata };
	int argc = (avoidance_callback.udata.get_type() == Variant::NIL) ? 1 : 2;
	obj->call(avoidance_callback.method, vp, argc, responseCallError);
}