use crate::solar_system::{GRAVITATIONAL_CONSTANT, Kilometers, SolarSystem, body::OrbitalBody, orbit::StaticOrbit};
use crate::timeman::Second;

pub type FleetId = usize;

pub struct Fleet
{
    id: FleetId,
    name: String,

    position: cgmath::Vector3<Kilometers>,
    velocity: cgmath::Vector3<f32>,
    acceleration: cgmath::Vector3<f32>,

    baked_orbit: Option<(f64, StaticOrbit)>,
}

impl Fleet
{
    pub fn new(
        id: FleetId,
        name: String)
    -> Self
    {
        Self {
            id,
            name,
            position: cgmath::vec3(0.0, 0.0, 0.0),
            velocity: cgmath::vec3(0.0, 0.0, 0.0),
            acceleration: cgmath::vec3(0.0, 0.0, 0.0),
            baked_orbit: None,
        }
    }

    pub fn id(&self) -> FleetId { self.id }
    pub fn name(&self) -> &String { &self.name }

    pub fn make_orbit(
        &mut self,
        body: &OrbitalBody,
        radius: Kilometers)
    {
        let sgp = body.mass() * GRAVITATIONAL_CONSTANT;
        self.baked_orbit = Some((sgp, StaticOrbit::new_circular(body, radius)));
    }

    pub fn tick(
        &mut self,
        time: Second)
    {
        match &self.baked_orbit {
            Some(orbit_info) => {
                let sgp = orbit_info.0;
                let orbit = &orbit_info.1;
                self.position = orbit.calculate_position_at(sgp, time);
            },
            None => {}
        }
    }
}