"""The Swiss Ephemeris in Moshier mode at the study's moments.

Horospire ephemeris accuracy study, version 1.0. MIT licence (LICENSE-CODE.txt).
The Swiss Ephemeris itself is Astrodienst's, under its own licence (AGPL or
its professional licence); this script calls it and distributes none of it.

Usage:
    python swiss_ephemeris.py MOMENTS_JSON OUT_JSON

Pinned: pyswisseph 2.10.3.2, which wraps Swiss Ephemeris 2.10.03.
Call: swe.calc_ut(julian day of the civil time, body, FLG_MOSEPH | FLG_SPEED).
No ephemeris files are read, so this is Moshier mode, the library's built-in
analytical ephemeris, not its compressed JPL files. No other flag is set, so
the position is the library's default: apparent, geocentric, on the true
ecliptic and equinox of date (light time, aberration, deflection and nutation
applied), with Delta T by the library's own model.
"""
import json
import sys
from datetime import datetime

import swisseph as swe

BODIES = [swe.SUN, swe.MOON, swe.MERCURY, swe.VENUS, swe.MARS, swe.JUPITER, swe.SATURN,
          swe.URANUS, swe.NEPTUNE, swe.PLUTO]
FLAGS = swe.FLG_MOSEPH | swe.FLG_SPEED


def main():
    moments_path, out_path = sys.argv[1:3]
    rows = []
    for civil in json.load(open(moments_path)):
        d = datetime.strptime(civil, "%Y-%m-%dT%H:%M:%SZ")
        jd = swe.julday(d.year, d.month, d.day, d.hour + d.minute / 60.0 + d.second / 3600.0, swe.GREG_CAL)
        rows.append([swe.calc_ut(jd, body, FLAGS)[0][0] for body in BODIES])
    json.dump({"engine": f"Swiss Ephemeris {swe.version}, Moshier mode", "flags": "FLG_MOSEPH|FLG_SPEED", "lon": rows},
              open(out_path, "w"))
    print(f"{len(rows)} moments, Swiss Ephemeris {swe.version}")


if __name__ == "__main__":
    main()