use bevy::prelude::*;
use bevy_rapier2d::prelude::*;
use serde::{Deserialize, Serialize};

use crate::{config::StkConfig, module::component::PartType, planet};

#[derive(Component, Clone, Copy, Serialize, Deserialize, Debug, PartialEq, Eq, Hash)]
pub enum PlanetType {
    Earth,
    Moon,
    Mars,
}

#[derive(Bundle)]
pub struct PlanetBundle {
    pub planet_type: PlanetType,
    pub transform: TransformBundle,
}

pub fn spawn_planets(mut commands: Commands) {
    info!("Spawning planets");
    let earth_pos = Transform::from_xyz(0.0, 0.0, 0.0);
    commands
        .spawn(PlanetBundle {
            planet_type: PlanetType::Earth,
            transform: TransformBundle::from(earth_pos),
        })
        .insert(Collider::ball(planet!(PlanetType::Earth).size))
        .insert(AdditionalMassProperties::Mass(
            planet!(PlanetType::Earth).mass,
        ))
        .insert(ReadMassProperties::default())
        .with_children(|children| {
            children
                .spawn(Collider::ball(planet!(PlanetType::Earth).size + 0.3))
                .insert(ActiveEvents::COLLISION_EVENTS)
                .insert(Sensor);
        })
        .insert(RigidBody::Fixed);
    let moon_pos = Transform::from_xyz(50.0, 20.0, 0.0);
    commands
        .spawn(PlanetBundle {
            planet_type: PlanetType::Moon,
            transform: TransformBundle::from(moon_pos),
        })
        .insert(Collider::ball(planet!(PlanetType::Moon).size))
        .insert(AdditionalMassProperties::Mass(
            planet!(PlanetType::Moon).mass,
        ))
        .insert(ReadMassProperties::default())
        .with_children(|children| {
            children
                .spawn(Collider::ball(planet!(PlanetType::Moon).size + 0.1))
                .insert(ActiveEvents::COLLISION_EVENTS)
                .insert(Sensor);
        })
        .insert(RigidBody::Fixed);
    let mars_pos = Transform::from_xyz(-50.0, 300.0, 0.0);
    commands
        .spawn(PlanetBundle {
            planet_type: PlanetType::Mars,
            transform: TransformBundle::from(mars_pos),
        })
        .insert(Collider::ball(planet!(PlanetType::Mars).size))
        .insert(AdditionalMassProperties::Mass(
            planet!(PlanetType::Mars).mass,
        ))
        .insert(ReadMassProperties::default())
        .with_children(|children| {
            children
                .spawn(Collider::ball(planet!(PlanetType::Mars).size + 0.1))
                .insert(ActiveEvents::COLLISION_EVENTS)
                .insert(Sensor);
        })
        .insert(RigidBody::Fixed);
}

pub fn gravity_update(
    mut part_query: Query<
        (
            &Transform,
            &ReadMassProperties,
            &mut ExternalForce,
            &mut ExternalImpulse,
        ),
        With<PartType>,
    >,
    planet_query: Query<(&Transform, &ReadMassProperties), With<PlanetType>>,
    server_config: Res<StkConfig>,
) {
    for (part_transform, part_mp, mut forces, mut impulses) in &mut part_query {
        impulses.impulse = Vec2::ZERO;
        forces.force = Vec2::ZERO;
        forces.torque = 0.;
        let part_mp = part_mp.get();
        let part_mass = part_mp.mass;
        let part_translate = part_transform.translation;
        for (planet_transform, planet_mp) in &planet_query {
            let planet_mp = planet_mp.get();
            let planet_mass = planet_mp.mass;
            let planet_translate = planet_transform.translation;
            let distance = planet_translate.distance(part_translate);
            // gravity equation
            let force =
                server_config.world.gravity * ((part_mass * planet_mass) / (distance * distance));
            // gravity vector
            let direction = (planet_translate - part_translate).normalize() * force;
            // apply gravity vector as impulse to body
            impulses.impulse += direction.xy();
        }
    }
}