use crate::game::Level;

use bevy::prelude::{shape::Quad, *};
use bevy_rapier2d::prelude::*;

#[derive(Component)]
pub enum PassThroughFilter {
	/// Absorbs this color (ignoring alpha)
	Absorbing(Color),
	/// Rotates hue by this angle (in degrees)
	Rotating(f32),
}

impl PassThroughFilter {
	pub fn apply(&self, color: Color) -> Color {
		match self {
			PassThroughFilter::Absorbing(filter_color) => Vec4::from(color)
				.mul_add(
					-Vec4::from(*filter_color) * Vec4::from([1., 1., 1., 0.]),
					Vec4::from(color),
				)
				.into(),
			PassThroughFilter::Rotating(filter_angle) => {
				let mut hsla = color.as_hsla_f32();
				hsla[0] = (hsla[0] + filter_angle) % 360.;
				// floating rem is not modulo!
				if hsla[0] < 0. {
					hsla[0] += 360.;
				}
				Color::hsla(hsla[0], hsla[1], hsla[2], hsla[3])
			}
		}
	}
}

#[derive(Bundle)]
pub struct AbsorbingFilter {
	#[bundle]
	pub mesh: ColorMesh2dBundle,
	pub collider: Collider,
	pub sensor: Sensor,
	pub filter: PassThroughFilter,
}

pub fn spawn_absorbing_filter(
	commands: &mut Commands,
	meshes: &mut ResMut<Assets<Mesh>>,
	materials: &mut ResMut<Assets<ColorMaterial>>,

	transform: Transform,
	size: Vec2,
	color: Color,
) {
	let mut material_color = color;
	material_color.set_a(0.5);
	commands
		.spawn_bundle(AbsorbingFilter {
			mesh: ColorMesh2dBundle {
				mesh: meshes.add(Mesh::from(Quad { size, flip: false })).into(),
				material: materials.add(material_color.into()),
				transform,
				..Default::default()
			},
			collider: Collider::cuboid(size.x / 2., size.y / 2.),
			sensor: Sensor,
			filter: PassThroughFilter::Absorbing(color),
		})
		.insert(Level);
}

#[derive(Bundle)]
pub struct RotatingFilter {
	#[bundle]
	pub sprite: SpriteBundle,
	pub collider: Collider,
	pub sensor: Sensor,
	pub filter: PassThroughFilter,
	pub velocity: Velocity,
	pub rigid_body: RigidBody,
}

pub fn spawn_rotating_filter(
	commands: &mut Commands,
	asset_server: &Res<AssetServer>,

	transform: Transform,
	angle: f32,
) {
	commands
		.spawn_bundle(RotatingFilter {
			sprite: SpriteBundle {
				texture: asset_server.get_handle("bevy.png"),
				transform,
				..Default::default()
			},
			collider: Collider::ball(32.),
			sensor: Sensor,
			filter: PassThroughFilter::Rotating(angle),
			velocity: Velocity::angular(1.),
			rigid_body: RigidBody::KinematicVelocityBased,
		})
		.insert(Level);
}