skeledance/tools/build_constellations.py

#!/usr/bin/env python3
"""Gera constellations.js com os signos zodiacais em coordenadas J2000.

Os traçados são da cultura ``modern`` do Stellarium. As coordenadas J2000
dos respectivos identificadores Hipparcos vêm do d3-celestial. Os dados são
compactados para uso offline pelo wallpaper.
"""

import json
import urllib.request
from pathlib import Path


STELLARIUM_URL = (
    "https://raw.githubusercontent.com/Stellarium/stellarium/master/"
    "skycultures/modern/index.json"
)
STELLARIUM_ST_URL = (
    "https://raw.githubusercontent.com/Stellarium/stellarium/master/"
    "skycultures/modern_st/index.json"
)
D3_BASE = "https://raw.githubusercontent.com/ofrohn/d3-celestial/master/data/"
OUT = Path(__file__).resolve().parent.parent / "plugin/contents/ui/constellations.js"

ZODIAC = {
    "Ari": "Áries",
    "Tau": "Touro",
    "Gem": "Gêmeos",
    "Cnc": "Câncer",
    "Leo": "Leão",
    "Vir": "Virgem",
    "Lib": "Libra",
    "Sco": "Escorpião",
    "Sgr": "Sagitário",
    "Cap": "Capricórnio",
    "Aqr": "Aquário",
    "Psc": "Peixes",
}

# Avaliados signo a signo. S&T costuma usar traçados mais ricos e próximos
# aos mapas populares, enquanto a arte continua vindo do conjunto Modern.
LINE_OVERRIDES = {"Lib": "modern_st"}

LICENSE = """Constellation lines: Stellarium Modern and Modern (S&T) sky cultures,
CC BY-SA 4.0.
https://github.com/Stellarium/stellarium/tree/master/skycultures/modern
https://github.com/Stellarium/stellarium/tree/master/skycultures/modern_st

Hipparcos J2000 coordinates: d3-celestial.
Copyright (c) 2015, Olaf Frohn
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.
3. Neither the name of the copyright holder nor contributors may be used to
   endorse or promote products derived from this software without permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DAMAGES ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE.
"""


def fetch(url: str) -> dict:
    req = urllib.request.Request(url, headers={"User-Agent": "skeledance-build/1.0"})
    return json.loads(urllib.request.urlopen(req, timeout=30).read())


def rounded_point(point: list[float]) -> list[float]:
    return [round(float(point[0]), 4), round(float(point[1]), 4)]


def main() -> None:
    sky_culture = fetch(STELLARIUM_URL)
    sky_culture_st = fetch(STELLARIUM_ST_URL)
    st_constellations = {
        item["id"].split()[-1]: item for item in sky_culture_st["constellations"]
    }
    star_data = fetch(D3_BASE + "stars.8.json")["features"]
    name_data = fetch(D3_BASE + "constellations.json")["features"]
    stars = {
        int(feature["id"]): rounded_point(feature["geometry"]["coordinates"])
        for feature in star_data
    }
    metadata = {
        feature["id"]: {
            "name": feature["properties"].get("name", feature["id"]),
            "label": rounded_point(feature["geometry"]["coordinates"]),
        }
        for feature in name_data
    }

    merged: dict[str, dict] = {}
    for constellation in sky_culture["constellations"]:
        ident = constellation["id"].split()[-1]
        if ident not in ZODIAC:
            continue
        line_source = (st_constellations[ident]
                       if LINE_OVERRIDES.get(ident) == "modern_st"
                       else constellation)
        lines = []
        for hip_line in line_source.get("lines", []):
            missing = [hip for hip in hip_line if hip not in stars]
            if missing:
                raise RuntimeError(f"{ident}: HIP ausente no catálogo: {missing}")
            lines.append([stars[hip] for hip in hip_line])
        image = constellation.get("image")
        art = None
        if image:
            anchors = []
            for anchor in image["anchors"]:
                hip = int(anchor["hip"])
                if hip not in stars:
                    raise RuntimeError(f"{ident}: âncora HIP ausente: {hip}")
                anchors.append({"pos": anchor["pos"], "sky": stars[hip]})
            art = {
                "file": "constellation-art/" + Path(image["file"]).name,
                "size": image["size"],
                "anchors": anchors,
            }
        merged[ident] = {
            "id": ident,
            "name": ZODIAC[ident],
            "rank": 1 if ident in {"Ari", "Tau", "Gem", "Leo", "Vir", "Sco", "Sgr"} else 2,
            "label": metadata.get(ident, {}).get("label"),
            "lines": lines,
            "art": art,
        }

    payload = json.dumps(
        [merged[ident] for ident in ZODIAC],
        ensure_ascii=False,
        separators=(",", ":"),
    )
    OUT.write_text(
        "/* Gerado por tools/build_constellations.py.\n"
        "   Stellarium Modern/S&T constellation lines, coordenadas Hipparcos J2000.\n\n"
        + "\n".join(("   " + line) if line else "" for line in LICENSE.rstrip().splitlines())
        + " */\nconst CONSTELLATIONS=" + payload + ";\n",
        encoding="utf-8",
    )
    print(f"{len(merged)} signos -> {OUT} ({OUT.stat().st_size / 1024:.0f} KB)")


if __name__ == "__main__":
    main()