solarsystems 0.0.1

use sciforge::hub::domain::common::constants::{AU, EARTH_MASS, EARTH_RADIUS, G, SOLAR_MASS};

use crate::{BodyId, CelestialBody, Vec3};

pub const MU_SUN: f64 = G * SOLAR_MASS;
pub const DEFAULT_TIMESTEP_S: f64 = 3600.0;
pub const GRAVITATIONAL_SOFTENING: f64 = 1e3;
pub const J2_EARTH: f64 = 1.08263e-3;
pub const J2_JUPITER: f64 = 1.4736e-2;
pub const J2_SATURN: f64 = 1.6298e-2;
pub const J2_MARS: f64 = 1.96045e-3;
pub const J2_SUN: f64 = 2.0e-7;

pub fn default_bodies() -> Vec<CelestialBody> {
    vec![
        CelestialBody {
            id: BodyId::Sun,
            name: "Sun",
            mass: SOLAR_MASS,
            radius: suns::SOLAR_RADIUS,
            position: Vec3::ZERO,
            velocity: Vec3::ZERO,
            acceleration: Vec3::ZERO,
            j2: J2_SUN,
        },
        CelestialBody {
            id: BodyId::Mercury,
            name: "Mercury",
            mass: mercurys::physics::orbit::MERCURY_MASS,
            radius: mercurys::physics::orbit::MERCURY_RADIUS,
            position: Vec3::new(0.387 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 47_362.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Venus,
            name: "Venus",
            mass: venuss::VENUS_MASS,
            radius: venuss::VENUS_RADIUS,
            position: Vec3::new(0.723 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 35_020.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Earth,
            name: "Earth",
            mass: EARTH_MASS,
            radius: EARTH_RADIUS,
            position: Vec3::new(AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 29_784.8, 0.0),
            acceleration: Vec3::ZERO,
            j2: J2_EARTH,
        },
        CelestialBody {
            id: BodyId::Mars,
            name: "Mars",
            mass: marss::MARS_MASS,
            radius: marss::MARS_RADIUS,
            position: Vec3::new(1.524 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 24_077.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: J2_MARS,
        },
        CelestialBody {
            id: BodyId::Jupiter,
            name: "Jupiter",
            mass: jupiters::JUPITERMASS,
            radius: jupiters::JUPITERMEANRADIUS,
            position: Vec3::new(5.203 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 13_070.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: J2_JUPITER,
        },
        CelestialBody {
            id: BodyId::Saturn,
            name: "Saturn",
            mass: saturns::SATURNMASS,
            radius: saturns::SATURNMEANRADIUS,
            position: Vec3::new(9.537 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 9_680.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: J2_SATURN,
        },
        CelestialBody {
            id: BodyId::Uranus,
            name: "Uranus",
            mass: uranuss::URANUSMASS,
            radius: uranuss::URANUSMEANRADIUS,
            position: Vec3::new(19.191 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 6_810.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Neptune,
            name: "Neptune",
            mass: neptunes::NEPTUNEMASS,
            radius: neptunes::NEPTUNEMEANRADIUS,
            position: Vec3::new(30.069 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 5_430.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // ─── Satellites ─────────────────────────────────────────────────
        CelestialBody {
            id: BodyId::Moon,
            name: "Moon",
            mass: moons::MOON_MASS,
            radius: moons::MOON_RADIUS_M,
            position: Vec3::new(AU + 3.844e8, 0.0, 0.0),
            velocity: Vec3::new(0.0, 29_784.8 + 1_022.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Phobos,
            name: "Phobos",
            mass: phoboss::PHOBOS_MASS,
            radius: phoboss::PHOBOS_RADIUS_M,
            position: Vec3::new(1.524 * AU + 9.376e6, 0.0, 0.0),
            velocity: Vec3::new(0.0, 24_077.0 + 2_138.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Deimos,
            name: "Deimos",
            mass: deimoss::DEIMOS_MASS,
            radius: deimoss::DEIMOS_RADIUS_M,
            position: Vec3::new(1.524 * AU + 2.3464e7, 0.0, 0.0),
            velocity: Vec3::new(0.0, 24_077.0 + 1_351.3, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Io,
            name: "Io",
            mass: ioss::IO_MASS,
            radius: ioss::IO_RADIUS_M,
            position: Vec3::new(5.203 * AU + 4.217e8, 0.0, 0.0),
            velocity: Vec3::new(0.0, 13_070.0 + 17_334.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Europa,
            name: "Europa",
            mass: europas::EUROPA_MASS,
            radius: europas::EUROPA_RADIUS_M,
            position: Vec3::new(5.203 * AU + 6.711e8, 0.0, 0.0),
            velocity: Vec3::new(0.0, 13_070.0 + 13_740.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Ganymede,
            name: "Ganymede",
            mass: ganymedes::GANYMEDE_MASS,
            radius: ganymedes::GANYMEDE_RADIUS_M,
            position: Vec3::new(5.203 * AU + 1.0704e9, 0.0, 0.0),
            velocity: Vec3::new(0.0, 13_070.0 + 10_880.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Callisto,
            name: "Callisto",
            mass: callistos::CALLISTO_MASS,
            radius: callistos::CALLISTO_RADIUS_M,
            position: Vec3::new(5.203 * AU + 1.8827e9, 0.0, 0.0),
            velocity: Vec3::new(0.0, 13_070.0 + 8_204.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Titan,
            name: "Titan",
            mass: titanss::TITAN_MASS,
            radius: titanss::TITAN_RADIUS_M,
            position: Vec3::new(9.537 * AU + 1.2219e9, 0.0, 0.0),
            velocity: Vec3::new(0.0, 9_680.0 + 5_570.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Enceladus,
            name: "Enceladus",
            mass: enceladuss::ENCELADUS_MASS,
            radius: enceladuss::ENCELADUS_RADIUS_M,
            position: Vec3::new(9.537 * AU + 2.3802e8, 0.0, 0.0),
            velocity: Vec3::new(0.0, 9_680.0 + 12_635.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Titania,
            name: "Titania",
            mass: titanias::TITANIA_MASS,
            radius: titanias::TITANIA_RADIUS_M,
            position: Vec3::new(19.191 * AU + 4.363e8, 0.0, 0.0),
            velocity: Vec3::new(0.0, 6_810.0 + 3_640.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Oberon,
            name: "Oberon",
            mass: oberons::OBERON_MASS,
            radius: oberons::OBERON_RADIUS_M,
            position: Vec3::new(19.191 * AU + 5.835e8, 0.0, 0.0),
            velocity: Vec3::new(0.0, 6_810.0 + 3_150.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        CelestialBody {
            id: BodyId::Triton,
            name: "Triton",
            mass: tritons::TRITON_MASS,
            radius: tritons::TRITON_RADIUS_M,
            position: Vec3::new(30.069 * AU + 3.5476e8, 0.0, 0.0),
            velocity: Vec3::new(0.0, 5_430.0 - 4_390.0, 0.0), // retrograde
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // ─── Dwarf Planets ──────────────────────────────────────────────
        // Pluto: a = 39.482 AU, e = 0.2488, i = 17.16°
        // Position at perihelion-like reference, velocity from vis-viva at a
        CelestialBody {
            id: BodyId::Pluto,
            name: "Pluto",
            mass: 1.303e22,
            radius: 1.1883e6,
            position: Vec3::new(39.482 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 4_743.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // Eris: a = 67.781 AU, e = 0.4407, i = 44.04°
        CelestialBody {
            id: BodyId::Eris,
            name: "Eris",
            mass: 1.6466e22,
            radius: 1.163e6,
            position: Vec3::new(67.781 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 3_626.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // Haumea: a = 43.218 AU, e = 0.1912, i = 28.19°
        CelestialBody {
            id: BodyId::Haumea,
            name: "Haumea",
            mass: 4.006e21,
            radius: 8.16e5, // mean volumetric radius
            position: Vec3::new(43.218 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 4_538.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // Makemake: a = 45.430 AU, e = 0.1613, i = 29.00°
        CelestialBody {
            id: BodyId::Makemake,
            name: "Makemake",
            mass: 3.1e21,
            radius: 7.15e5,
            position: Vec3::new(45.430 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 4_419.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // Sedna: a = 506.8 AU, e = 0.8496, i = 11.93°
        CelestialBody {
            id: BodyId::Sedna,
            name: "Sedna",
            mass: 1.0e21, // estimated
            radius: 4.95e5,
            position: Vec3::new(506.8 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 1_327.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // ─── Asteroids ──────────────────────────────────────────────────
        // (1) Ceres: a = 2.7675 AU, e = 0.0758
        CelestialBody {
            id: BodyId::Ceres,
            name: "Ceres",
            mass: 9.3835e20,
            radius: 4.73e5,
            position: Vec3::new(2.7675 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 17_905.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // (4) Vesta: a = 2.3615 AU, e = 0.0887
        CelestialBody {
            id: BodyId::Vesta,
            name: "Vesta",
            mass: 2.5908e20,
            radius: 2.6278e5,
            position: Vec3::new(2.3615 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 19_346.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // (2) Pallas: a = 2.7731 AU, e = 0.2313, i = 34.83°
        CelestialBody {
            id: BodyId::Pallas,
            name: "Pallas",
            mass: 2.04e20,
            radius: 2.56e5,
            position: Vec3::new(2.7731 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 17_887.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // (10) Hygiea: a = 3.1415 AU, e = 0.1146
        CelestialBody {
            id: BodyId::Hygiea,
            name: "Hygiea",
            mass: 8.32e19,
            radius: 2.17e5,
            position: Vec3::new(3.1394 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 16_803.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // (3) Juno: a = 2.6691 AU, e = 0.2562
        CelestialBody {
            id: BodyId::Juno,
            name: "Juno",
            mass: 2.67e19,
            radius: 1.2335e5,
            position: Vec3::new(2.6691 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 18_222.0, 0.0),
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // ─── Comets ─────────────────────────────────────────────────────
        // 1P/Halley: a = 17.834 AU, e = 0.96714, q = 0.586 AU (perihelion start)
        CelestialBody {
            id: BodyId::Halley,
            name: "Halley",
            mass: 2.2e14,
            radius: 5.5e3, // ~11 km × 8 km, mean ~5.5 km
            position: Vec3::new(0.586 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 54_569.0, 0.0), // v at perihelion
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // 2P/Encke: a = 2.2152 AU, e = 0.8483, q = 0.336 AU
        CelestialBody {
            id: BodyId::Encke,
            name: "Encke",
            mass: 2.0e13, // estimated
            radius: 2.4e3,
            position: Vec3::new(0.336 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 69_548.0, 0.0), // v at perihelion
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // C/1995 O1 Hale-Bopp: a = 186.0 AU, e = 0.9951, q = 0.914 AU
        CelestialBody {
            id: BodyId::HaleBopp,
            name: "Hale-Bopp",
            mass: 1.3e16,  // estimated from nucleus size
            radius: 3.0e4, // ~30 km radius
            position: Vec3::new(0.914 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 44_121.0, 0.0), // v at perihelion
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // 67P/Churyumov-Gerasimenko: a = 3.4630 AU, e = 0.6410, q = 1.243 AU
        CelestialBody {
            id: BodyId::ChuryumovGerasimenko,
            name: "67P/C-G",
            mass: 9.982e12,
            radius: 2.0e3, // ~4 km × 3 km, effective ~2 km
            position: Vec3::new(1.243 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 34_271.0, 0.0), // v at perihelion
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
        // 9P/Tempel 1: a = 3.1256 AU, e = 0.5121, q = 1.542 AU
        CelestialBody {
            id: BodyId::Tempel1,
            name: "Tempel-1",
            mass: 4.5e13,   // estimated
            radius: 2.83e3, // ~6 km × 4.9 km, effective ~2.83 km
            position: Vec3::new(1.542 * AU, 0.0, 0.0),
            velocity: Vec3::new(0.0, 30_554.0, 0.0), // v at perihelion
            acceleration: Vec3::ZERO,
            j2: 0.0,
        },
    ]
}

/// Returns the full solar system including procedurally generated belt particles.
///
/// - `n_belt_asteroids`: number of main-belt asteroids (2.1–3.3 AU)
/// - `n_kuiper_objects`: number of Kuiper belt objects (30–100 AU)
pub fn default_bodies_with_belts(
    n_belt_asteroids: u16,
    n_kuiper_objects: u16,
) -> Vec<CelestialBody> {
    let mut bodies = default_bodies();
    bodies.extend(crate::belts::generate_main_belt(n_belt_asteroids));
    bodies.extend(crate::belts::generate_kuiper_belt(n_kuiper_objects));
    bodies
}

pub fn find_body(bodies: &[CelestialBody], id: BodyId) -> Option<&CelestialBody> {
    bodies.iter().find(|b| b.id == id)
}

pub fn find_body_mut(bodies: &mut [CelestialBody], id: BodyId) -> Option<&mut CelestialBody> {
    bodies.iter_mut().find(|b| b.id == id)
}

pub fn system_barycenter(bodies: &[CelestialBody]) -> (Vec3, Vec3) {
    let total_mass: f64 = bodies.iter().map(|b| b.mass).sum();
    let pos = bodies
        .iter()
        .fold(Vec3::ZERO, |acc, b| acc + b.position * b.mass)
        / total_mass;
    let vel = bodies
        .iter()
        .fold(Vec3::ZERO, |acc, b| acc + b.velocity * b.mass)
        / total_mass;
    (pos, vel)
}

pub fn total_energy(bodies: &[CelestialBody]) -> f64 {
    let kinetic: f64 = bodies.iter().map(|b| b.kinetic_energy()).sum();
    let mut potential = 0.0;
    for i in 0..bodies.len() {
        for j in (i + 1)..bodies.len() {
            potential += bodies[i].potential_energy(&bodies[j]);
        }
    }
    kinetic + potential
}

pub fn total_angular_momentum(bodies: &[CelestialBody]) -> Vec3 {
    bodies
        .iter()
        .fold(Vec3::ZERO, |acc, b| acc + b.angular_momentum())
}