init

weather_client.py

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+import datetime
+from math import inf
+import os
+from dataclasses import dataclass
+from urllib.parse import urlencode
+
+from cnet import HttpError, as_dict, as_float, as_int, as_list, as_str, fetch_json
+from db_models import DailyForecast
+from geo_locator import Geo
+
+
+messages = {
+    401: "[401] Wrong WEATHER_API_KEY",
+    404: "[404] City not found",
+    429: "[429] Limit exceeded",
+}
+
+
+class WeatherAPIError(Exception): ...
+
+
+@dataclass
+class _Item:
+    date: datetime.date
+    hour: int
+    temp_min: float
+    temp_max: float
+    humidity: float
+    wind_speed: float
+    description: str
+
+
+@dataclass
+class _DayMetrics:
+    t_mins: float = inf
+    t_maxs: float = -inf
+    h_sum: float = 0
+    n: int = 0
+    wind_max: float = -inf
+    noon_dst: int | None = None
+    description: str = ""
+
+
+def _timezone_offset(city: dict[str, object]) -> datetime.timedelta:
+    shift = as_float(city.get("timezone"), default=0.0) or 0.0
+    return datetime.timedelta(seconds=int(shift))
+
+
+def _parse_item(raw: object, offset: datetime.timedelta) -> _Item | None:
+    entry = as_dict(raw)
+    main = as_dict(entry.get("main"))
+    wind = as_dict(entry.get("wind"))
+    weather_list = as_list(entry.get("weather"))
+    weather = as_dict(weather_list[0]) if weather_list else {}
+
+    dt = as_float(entry.get("dt"), default=0.0)
+    if dt is None or dt <= 0:
+        return None
+    time = datetime.datetime.fromtimestamp(dt, tz=datetime.timezone.utc) + offset
+
+    return _Item(
+        date=time.date(),
+        hour=time.hour,
+        temp_min=as_float(main.get("temp_min"), default=0.0) or 0.0,
+        temp_max=as_float(main.get("temp_max"), default=0.0) or 0.0,
+        humidity=as_float(main.get("humidity"), default=0.0) or 0.0,
+        wind_speed=as_float(wind.get("speed"), default=0.0) or 0.0,
+        description=as_str(weather.get("description"), default=""),
+    )
+
+
+def _calc(intervals: list[_Item], city: str) -> list[DailyForecast]:
+    days_metrics: dict[datetime.date, _DayMetrics] = {}
+    for i in intervals:
+        m = days_metrics.setdefault(i.date, _DayMetrics())
+        m.t_mins = min(m.t_mins, i.temp_min)
+        m.t_maxs = max(m.t_maxs, i.temp_max)
+
+        m.h_sum += i.humidity
+        m.n += 1
+        m.wind_max = max(m.wind_max, i.wind_speed)
+        dst = abs(i.hour - 12)
+        if m.noon_dst is None or dst < m.noon_dst:
+            m.noon_dst = dst
+            m.description = i.description
+
+    result: list[DailyForecast] = []
+    for day, m in sorted(days_metrics.items()):
+        result.append(
+            DailyForecast(
+                city=city,
+                forecast_date=day,
+                temp_min=m.t_mins,
+                temp_max=m.t_maxs,
+                humidity=round(m.h_sum / m.n) if m.n else 0,
+                wind_speed=m.wind_max,
+                description=m.description,
+            )
+        )
+    return result[:4]
+
+
+def get_forecast(geo: Geo) -> list[DailyForecast]:
+    api_key = os.getenv("WEATHER_API_KEY", "").strip()
+    if not api_key:
+        raise WeatherAPIError("no WEATHER_API_KEY")
+    base_url = os.getenv(
+        "WEATHER_API_BASE_URL", "https://api.openweathermap.org/data/2.5/forecast"
+    )
+
+    params: dict[str, str] = {"appid": api_key, "units": "metric", "lang": "ru"}
+    if geo.lat is not None and geo.lon is not None:
+        params["lat"] = f"{geo.lat}"
+        params["lon"] = f"{geo.lon}"
+    else:
+        params["q"] = geo.city
+
+    url = f"{base_url}?{urlencode(params)}"
+
+    try:
+        raw = fetch_json(url)
+    except HttpError as e:
+        if e.status_code == HttpError.NO_CODE:
+            raise WeatherAPIError(f"weather request failed: {e.body}") from e
+        raise WeatherAPIError(
+            messages.get(e.status_code, f"[{e.status_code}] weather error")
+        ) from e
+
+    resp = as_dict(raw)
+
+    cod = as_int(resp.get("cod"), 200)
+    if cod != 200:
+        raise WeatherAPIError(messages.get(cod, f"[{cod}] weather error"))
+
+    resp_city = as_dict(resp.get("city"))
+    city = as_str(resp_city.get("name"), default=geo.city)
+    offset = _timezone_offset(resp_city)
+    items = [
+        i
+        for i in (_parse_item(entry, offset) for entry in as_list(resp.get("list")))
+        if i is not None
+    ]
+    if not items:
+        raise WeatherAPIError("weather is empty")
+
+    return _calc(items, city)