// astronomy-engine at the study's moments.
//
// Horospire ephemeris accuracy study, version 1.0. MIT licence (LICENSE-CODE.txt).
// astronomy-engine is Don Cross's, MIT; this script calls it.
//
// Usage: node astronomy_engine.mjs PATH_TO_ASTRONOMY_ENGINE_PACKAGE MOMENTS_JSON OUT_JSON
//
// Pinned: astronomy-engine 2.1.19 (npm).
// Calls: the Sun from SunPosition(time).elon (apparent ecliptic longitude of
// date); the Moon and the planets from Ecliptic(GeoVector(body, time, true)).elon,
// geocentric with aberration, on the true ecliptic and equinox of date.
// Time: MakeTime(new Date(civil time)), read as UT; the library applies its own
// Delta T.
import { readFileSync, writeFileSync } from 'node:fs';
import { createRequire } from 'node:module';

const [pkg, momentsPath, outPath] = process.argv.slice(2);
const require = createRequire(import.meta.url);
const Astronomy = require(pkg);
const version = JSON.parse(readFileSync(`${pkg}/package.json`, 'utf8')).version;
const B = Astronomy.Body;
const bodies = [B.Sun, B.Moon, B.Mercury, B.Venus, B.Mars, B.Jupiter, B.Saturn, B.Uranus, B.Neptune, B.Pluto];

const lon = JSON.parse(readFileSync(momentsPath, 'utf8')).map((civil) => {
    const t = Astronomy.MakeTime(new Date(civil));
    return bodies.map((b) => (b === B.Sun ? Astronomy.SunPosition(t).elon : Astronomy.Ecliptic(Astronomy.GeoVector(b, t, true)).elon));
});
writeFileSync(outPath, JSON.stringify({ engine: `astronomy-engine ${version}`, lon }));
console.log(`${lon.length} moments, astronomy-engine ${version}`);