//! Various implementations of [`crate::ShipBehavior`]

mod null;
mod point;

use null::*;
use point::PointShipController;

use std::fmt::Debug;

use super::ShipControls;
use crate::phys::{PhysImage, PhysSimShipHandle, PhysStepResources};

/// Represents a ship controller
#[derive(Debug, Clone)]
pub enum ShipController {
	/// Null controller
	Null(NullShipController),

	/// Point controller
	Point(PointShipController),
}

impl ShipController {
	/// Make a new null controller
	pub fn new_null() -> Self {
		Self::Null(NullShipController::new())
	}

	/// Make a new point controller
	pub fn new_point() -> Self {
		Self::Point(PointShipController::new())
	}

	/// Compute new ship controls from world state
	pub fn update_controls(
		&mut self,
		res: &PhysStepResources,
		img: &PhysImage,
		this_ship: PhysSimShipHandle,
	) -> Option<ShipControls> {
		match self {
			Self::Null(n) => n.update_controls(res, img, this_ship),
			Self::Point(p) => p.update_controls(res, img, this_ship),
		}
	}
}

trait ShipControllerStruct
where
	Self: Debug + Clone,
{
	/// Update a ship's controls based on system state.
	/// This method returns the ship's new control values,
	/// or None if no change is to be made.
	fn update_controls(
		&mut self,
		res: &PhysStepResources,
		img: &PhysImage,
		this_ship: PhysSimShipHandle,
	) -> Option<ShipControls>;
}