use mass_driver_core::station;
use orbital_mechanics::bodies;
use orbital_mechanics::orbits;
use wasm_bindgen::prelude::*;

/// Initialize the WASM module. Called once on page load.
#[wasm_bindgen]
pub fn init() -> Result<(), JsValue> {
    web_sys::console::log_1(&"mass-driver WASM initialized".into());
    Ok(())
}

/// Get the number of celestial bodies in the simulation.
#[wasm_bindgen]
pub fn get_body_count() -> usize {
    bodies::all_bodies().len()
}

/// Get positions of all celestial bodies at a given Julian Date.
///
/// Returns a Float64Array of [x0, y0, z0, x1, y1, z1, ...] in AU.
#[wasm_bindgen]
pub fn get_body_positions_at_epoch(jd: f64) -> Vec<f64> {
    let all = bodies::all_bodies();
    orbits::all_positions_at_epoch(&all, jd)
}

/// Get body names as a JSON array of strings.
#[wasm_bindgen]
pub fn get_body_names() -> String {
    let all = bodies::all_bodies();
    let names: Vec<&str> = all.iter().map(|b| b.name).collect();
    serde_json::to_string(&names).unwrap()
}

/// Get body colors as a flat array [r0, g0, b0, r1, g1, b1, ...].
#[wasm_bindgen]
pub fn get_body_colors() -> Vec<u8> {
    let all = bodies::all_bodies();
    all.iter().flat_map(|b| b.color.iter().copied()).collect()
}

/// Get body radii in km as a Float64Array.
#[wasm_bindgen]
pub fn get_body_radii() -> Vec<f64> {
    let all = bodies::all_bodies();
    all.iter().map(|b| b.radius_km).collect()
}

/// Get velocities of all celestial bodies at a given Julian Date.
///
/// Returns a Float64Array of [vx0, vy0, vz0, vx1, vy1, vz1, ...] in AU/day.
#[wasm_bindgen]
pub fn get_body_velocities_at_epoch(jd: f64) -> Vec<f64> {
    let all = bodies::all_bodies();
    orbits::all_velocities_at_epoch(&all, jd)
}

/// Get orbit points for a given body, sampled around its full orbit.
/// Returns a Float64Array of [x0, y0, z0, x1, y1, z1, ...] in AU.
/// `samples` is the number of points around the orbit.
#[wasm_bindgen]
pub fn get_orbit_points(body_id: usize, jd: f64, samples: usize) -> Vec<f64> {
    let all = bodies::all_bodies();
    if body_id >= all.len() || body_id == bodies::id::SUN {
        return vec![];
    }
    orbits::orbit_points(&all, body_id, jd, samples)
}

/// Generate default stations and return their configuration as JSON.
#[wasm_bindgen]
pub fn generate_stations(count: usize) -> String {
    let stations = station::generate_default_stations(count);
    serde_json::to_string(&stations).unwrap()
}

/// Get station positions at a given Julian Date.
/// Takes a JSON config string (from generate_stations) and returns
/// Float64Array of [x0, y0, z0, x1, y1, z1, ...] in AU.
#[wasm_bindgen]
pub fn get_station_positions(stations_json: &str, jd: f64) -> Vec<f64> {
    let stations: Vec<station::Station> = match serde_json::from_str(stations_json) {
        Ok(s) => s,
        Err(_) => return vec![],
    };
    let all_bodies = bodies::all_bodies();
    station::all_station_positions(&stations, &all_bodies, jd)
}

/// Get station names from a config JSON string.
#[wasm_bindgen]
pub fn get_station_names(stations_json: &str) -> String {
    let stations: Vec<station::Station> = match serde_json::from_str(stations_json) {
        Ok(s) => s,
        Err(_) => return "[]".to_string(),
    };
    let names: Vec<&str> = stations.iter().map(|s| s.name.as_str()).collect();
    serde_json::to_string(&names).unwrap()
}