weather.py

"""Keyless current-weather lookup via Open-Meteo (no API key required).

FR24's API does not expose airport weather, so we fetch real conditions from
Open-Meteo for the airport's coordinates. Cached briefly to stay polite.
"""
from __future__ import annotations

import time

import requests

_CACHE: dict[tuple, tuple[float, dict]] = {}
_TTL = 600  # seconds

_ARROWS = ["↑", "↗", "→", "↘", "↓", "↙", "←", "↖"]


def wind_arrow(deg) -> str:
    if deg is None:
        return "·"
    # Arrow points in the direction the wind blows TOWARD (deg is "from").
    idx = int(((float(deg) + 180) % 360) / 45 + 0.5) % 8
    return _ARROWS[idx]


def current(lat: float, lon: float) -> dict | None:
    """Return {temp_c, wind_kts, wind_dir, code} or None."""
    if lat is None or lon is None:
        return None
    key = (round(lat, 2), round(lon, 2))
    now = time.time()
    hit = _CACHE.get(key)
    if hit and now - hit[0] < _TTL:
        return hit[1]
    try:
        resp = requests.get(
            "https://api.open-meteo.com/v1/forecast",
            params={
                "latitude": lat,
                "longitude": lon,
                "current": "temperature_2m,wind_speed_10m,wind_direction_10m,weather_code",
                "wind_speed_unit": "kn",
            },
            timeout=10,
        )
        if resp.status_code >= 400:
            return None
        cur = resp.json().get("current", {})
        out = {
            "temp_c": cur.get("temperature_2m"),
            "wind_kts": cur.get("wind_speed_10m"),
            "wind_dir": cur.get("wind_direction_10m"),
            "code": cur.get("weather_code"),
        }
        _CACHE[key] = (now, out)
        return out
    except Exception:
        return None


# WMO weather codes -> compact glyph for the hacker readout.
def code_glyph(code) -> str:
    if code is None:
        return "·"
    code = int(code)
    if code == 0:
        return "☀"
    if code in (1, 2):
        return "⛅"
    if code == 3:
        return "☁"
    if code in (45, 48):
        return "≋"
    if 51 <= code <= 67:
        return "☂"
    if 71 <= code <= 77:
        return "❄"
    if 80 <= code <= 82:
        return "☔"
    if 95 <= code <= 99:
        return "⚡"
    return "·"