use cgmath::{Deg, InnerSpace, Point3, Vector2};
use rapier2d::{
	dynamics::{RigidBody, RigidBodyBuilder, RigidBodyHandle},
	geometry::{ColliderBuilder, ColliderHandle},
};

use crate::util;
use galactica_content as content;
use galactica_render::ObjectSprite;

/// A helper struct that contains parameters for a projectile
/// TODO: decouple data from physics
pub struct ProjectileBuilder {
	/// TODO
	pub rigid_body: RigidBodyBuilder,

	/// TODO
	pub collider: ColliderBuilder,

	/// TODO
	pub sprite_texture: content::TextureHandle,

	/// TODO
	pub lifetime: f32,

	/// TODO
	pub size: f32,

	/// TODO
	pub damage: f32,

	/// TODO
	pub faction: content::FactionHandle,
}

/// A single projectile in the world
#[derive(Debug)]
pub struct Projectile {
	/// TODO
	pub rigid_body: RigidBodyHandle,

	/// TODO
	pub collider: ColliderHandle,

	/// TODO
	pub sprite_texture: content::TextureHandle,

	/// TODO
	pub lifetime: f32,

	/// TODOd
	pub size: f32,

	/// TODO
	pub damage: f32,

	/// TODO
	pub faction: content::FactionHandle,
}

impl Projectile {
	/// Make a new projectile
	pub fn new(b: ProjectileBuilder, r: RigidBodyHandle, c: ColliderHandle) -> Self {
		Projectile {
			rigid_body: r,
			collider: c,
			sprite_texture: b.sprite_texture,
			lifetime: b.lifetime,
			size: b.size,
			damage: b.damage,
			faction: b.faction,
		}
	}

	/// Update this projectile's state after `t` seconds
	pub fn tick(&mut self, t: f32) {
		self.lifetime -= t;
	}

	/// Is this projectile expired?
	pub fn is_expired(&self) -> bool {
		return self.lifetime < 0.0;
	}

	/// Get this projectiles' sprite
	pub fn get_sprite(&self, r: &RigidBody) -> ObjectSprite {
		let pos = util::rigidbody_position(r);
		let rot = util::rigidbody_rotation(r);

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

		ObjectSprite {
			texture: self.sprite_texture,
			pos: Point3 {
				x: pos.x,
				y: pos.y,
				z: 1.0,
			},
			size: self.size,
			angle: -ang,
			children: None,
		}
	}
}