"""
Weather.py
──────────
Fetches hourly weather from Open-Meteo (free, no API key).
Runs in a background thread and caches the last result.
"""

import threading
import time
import urllib.request
import json
from datetime import datetime

_lock   = threading.Lock()
_cache  = {}
_cfg    = {}

WMO_CODES = {
    0:  ("Klar",                "☀️"),
    1:  ("Überwiegend klar",    "🌤️"),
    2:  ("Teilweise bewölkt",   "⛅"),
    3:  ("Bedeckt",             "☁️"),
    45: ("Nebel",               "🌫️"),
    48: ("Reifnebel",           "🌫️"),
    51: ("Leichter Nieselregen","🌦️"),
    53: ("Nieselregen",         "🌦️"),
    55: ("Dichter Nieselregen", "🌦️"),
    61: ("Leichter Regen",      "🌧️"),
    63: ("Regen",               "🌧️"),
    65: ("Starker Regen",       "🌧️"),
    71: ("Leichter Schnee",     "🌨️"),
    73: ("Schnee",              "🌨️"),
    75: ("Starker Schnee",      "❄️"),
    80: ("Regenschauer",        "🌦️"),
    81: ("Regenschauer",        "🌦️"),
    82: ("Starke Schauer",      "⛈️"),
    95: ("Gewitter",            "⛈️"),
    96: ("Gewitter mit Hagel",  "⛈️"),
    99: ("Heftiges Gewitter",   "⛈️"),
}


def init(location_cfg: dict) -> None:
    global _cfg
    _cfg = location_cfg


def get_weather() -> dict:
    with _lock:
        return dict(_cache)


def start_fetcher() -> threading.Thread:
    t = threading.Thread(target=_fetch_loop, daemon=True, name="weather-fetch")
    t.start()
    return t


def _fetch_loop() -> None:
    interval = _cfg.get("weather_refresh_s", 600)
    while True:
        try:
            _do_fetch()
        except Exception as exc:
            print(f"[Weather] fetch error: {exc}")
        time.sleep(interval)


def _do_fetch() -> None:
    lat = _cfg["latitude"]
    lon = _cfg["longitude"]
    url = (
        f"https://api.open-meteo.com/v1/forecast"
        f"?latitude={lat}&longitude={lon}"
        f"&hourly=precipitation_probability"
        f"&current=temperature_2m,relative_humidity_2m,"
        f"apparent_temperature,weather_code,wind_speed_10m"
        f"&wind_speed_unit=kmh"
        f"&timezone=Europe%2FBerlin"
        f"&forecast_days=1"
    )
    with urllib.request.urlopen(url, timeout=10) as resp:
        raw = json.loads(resp.read())

    cur  = raw.get("current", {})
    hrly = raw.get("hourly", {})

    # Pick precipitation probability for current hour
    now_h = datetime.now().hour
    prec_prob = 0
    times = hrly.get("time", [])
    precs = hrly.get("precipitation_probability", [])
    for i, t in enumerate(times):
        if f"T{now_h:02d}:" in t and i < len(precs):
            prec_prob = precs[i]
            break

    code        = cur.get("weather_code", 0)
    desc, icon  = WMO_CODES.get(code, ("Unbekannt", "❓"))

    result = {
        "location":    _cfg.get("name", ""),
        "temp":        cur.get("temperature_2m"),
        "feels_like":  cur.get("apparent_temperature"),
        "humidity":    cur.get("relative_humidity_2m"),
        "wind_kmh":    cur.get("wind_speed_10m"),
        "weather_code": code,
        "description": desc,
        "icon":        icon,
        "rain_prob":   prec_prob,
        "fetched_at":  datetime.now().isoformat(timespec="seconds"),
    }

    with _lock:
        _cache.update(result)

    print(f"[Weather] {desc} {cur.get('temperature_2m')}°C, Regen {prec_prob}%")