use cgmath::{Deg, InnerSpace, Vector2};
use nalgebra::vector;

use rapier2d::dynamics::RigidBody;

use crate::{util, ShipPhysicsHandle};
use galactica_content as content;
use galactica_gameobject as object;
use galactica_render::ObjectSprite;

pub struct ShipControls {
	pub left: bool,
	pub right: bool,
	pub thrust: bool,
	pub guns: bool,
}

impl ShipControls {
	pub fn new() -> Self {
		ShipControls {
			left: false,
			right: false,
			thrust: false,
			guns: false,
		}
	}
}

/// A ship instance in the physics system
pub struct ShipWorldObject {
	/// TODO
	pub physics_handle: ShipPhysicsHandle,

	/// TODO
	pub ship: object::Ship,

	/// TODO
	pub controls: ShipControls,
}

impl ShipWorldObject {
	/// Make a new ship
	pub fn new(ship: object::Ship, physics_handle: ShipPhysicsHandle) -> Self {
		ShipWorldObject {
			physics_handle,
			ship,
			controls: ShipControls::new(),
		}
	}

	/// Step this ship's state by t seconds
	pub fn step(&mut self, r: &mut RigidBody, t: f32) {
		let ship_rot = util::rigidbody_rotation(r);
		let engine_force = ship_rot * t;

		if self.controls.thrust {
			r.apply_impulse(
				vector![engine_force.x, engine_force.y]
					* self.ship.outfits.stat_sum().engine_thrust,
				true,
			);
		}

		if self.controls.right {
			r.apply_torque_impulse(self.ship.outfits.stat_sum().steer_power * -100.0 * t, true);
		}

		if self.controls.left {
			r.apply_torque_impulse(self.ship.outfits.stat_sum().steer_power * 100.0 * t, true);
		}

		for i in self.ship.outfits.iter_guns() {
			i.cooldown -= t;
		}
	}

	/// Get this ship's sprite
	pub fn get_sprite(&self, ct: &content::Content, r: &RigidBody) -> ObjectSprite {
		let ship_pos = util::rigidbody_position(r);
		let ship_rot = util::rigidbody_rotation(r);

		// Sprites point north at 0 degrees
		let ship_ang: Deg<f32> = ship_rot.angle(Vector2 { x: 0.0, y: 1.0 }).into();

		let s = ct.get_ship(self.ship.handle);

		ObjectSprite {
			pos: (ship_pos.x, ship_pos.y, 1.0).into(),
			texture: s.sprite_texture,
			angle: -ship_ang,
			size: s.size,

			children: if self.controls.thrust {
				Some(self.ship.outfits.get_engine_flares())
			} else {
				None
			},
		}
	}
}