Ai/weather/services.py

"""
سرویس‌های هواشناسی — واکشی پیش‌بینی ۷ روزه و ذخیره در دیتابیس.
"""

import logging
from datetime import date, timedelta

import requests
from django.conf import settings
from django.db import transaction

from location_data.models import SoilLocation

from .models import WeatherForecast

logger = logging.getLogger(__name__)


def fetch_weather_from_api(latitude: float, longitude: float) -> dict | None:
    """
    اتصال به API هواشناسی و دریافت پیش‌بینی ۷ روزه.

    TODO: پیاده‌سازی اتصال واقعی به API (مثلاً Open-Meteo).
    در حال حاضر این تابع خالی است و None برمی‌گرداند.

    پارامترها:
        latitude: عرض جغرافیایی
        longitude: طول جغرافیایی

    خروجی مورد انتظار (وقتی پیاده‌سازی شود):
        {
            "daily": {
                "time": ["2025-07-01", "2025-07-02", ...],
                "temperature_2m_max": [35.2, 36.1, ...],
                "temperature_2m_min": [22.1, 23.0, ...],
                "temperature_2m_mean": [28.6, 29.5, ...],
                "precipitation_sum": [0.0, 2.5, ...],
                "precipitation_probability_max": [0, 60, ...],
                "relative_humidity_2m_mean": [30.0, 45.0, ...],
                "wind_speed_10m_max": [15.0, 20.0, ...],
                "et0_fao_evapotranspiration": [6.5, 5.8, ...],
                "weather_code": [0, 61, ...],
            }
        }
    """
    params = {
        "latitude": latitude,
        "longitude": longitude,
        "forecast_days": 7,
        "timezone": "auto",
        "daily": [
            "temperature_2m_max",
            "temperature_2m_min",
            "temperature_2m_mean",
            "precipitation_sum",
            "precipitation_probability_max",
            "relative_humidity_2m_mean",
            "wind_speed_10m_max",
            "et0_fao_evapotranspiration",
            "weather_code",
        ],
    }
    headers = {"accept": "application/json"}
    if settings.WEATHER_API_KEY:
        headers["Authorization"] = f"Bearer {settings.WEATHER_API_KEY}"

    response = requests.get(
        settings.WEATHER_API_BASE_URL,
        params=params,
        headers=headers,
        timeout=60,
    )
    response.raise_for_status()
    return response.json()


def parse_weather_response(data: dict) -> list[dict]:
    """
    تبدیل پاسخ API به لیست dict برای ذخیره در WeatherForecast.
    فرمت ورودی: Open-Meteo daily format.
    """
    daily = data.get("daily", {})
    times = daily.get("time", [])
    forecasts = []

    for i, date_str in enumerate(times):
        forecasts.append(
            {
                "forecast_date": date_str,
                "temperature_max": _safe_index(
                    daily.get("temperature_2m_max"), i
                ),
                "temperature_min": _safe_index(
                    daily.get("temperature_2m_min"), i
                ),
                "temperature_mean": _safe_index(
                    daily.get("temperature_2m_mean"), i
                ),
                "precipitation": _safe_index(
                    daily.get("precipitation_sum"), i
                ),
                "precipitation_probability": _safe_index(
                    daily.get("precipitation_probability_max"), i
                ),
                "humidity_mean": _safe_index(
                    daily.get("relative_humidity_2m_mean"), i
                ),
                "wind_speed_max": _safe_index(
                    daily.get("wind_speed_10m_max"), i
                ),
                "et0": _safe_index(
                    daily.get("et0_fao_evapotranspiration"), i
                ),
                "weather_code": _safe_index(
                    daily.get("weather_code"), i
                ),
            }
        )
    return forecasts


def _safe_index(lst: list | None, index: int):
    """مقدار index را از لیست برمی‌گرداند یا None."""
    if lst is None or index >= len(lst):
        return None
    return lst[index]


def update_weather_for_location(location: SoilLocation) -> dict:
    """
    واکشی و ذخیره پیش‌بینی هواشناسی ۷ روزه برای یک SoilLocation.

    خروجی:
        {"status": "success"|"no_data"|"error", "location_id": int, ...}
    """
    lat = float(location.latitude)
    lon = float(location.longitude)

    try:
        data = fetch_weather_from_api(lat, lon)
    except Exception as exc:
        logger.error("Weather API error for location %s: %s", location.id, exc)
        return {
            "status": "error",
            "location_id": location.id,
            "error": str(exc),
        }

    if data is None:
        logger.info(
            "Weather API returned no data for location %s (stub mode).",
            location.id,
        )
        return {
            "status": "no_data",
            "location_id": location.id,
            "message": "API connection not implemented yet.",
        }

    forecasts = parse_weather_response(data)

    with transaction.atomic():
        for fc in forecasts:
            WeatherForecast.objects.update_or_create(
                location=location,
                forecast_date=fc.pop("forecast_date"),
                defaults=fc,
            )

    return {
        "status": "success",
        "location_id": location.id,
        "days_updated": len(forecasts),
    }


def update_weather_for_all_locations() -> list[dict]:
    """
    واکشی پیش‌بینی هواشناسی برای تمام SoilLocation‌های موجود.
    """
    results = []
    for location in SoilLocation.objects.all():
        result = update_weather_for_location(location)
        results.append(result)
    return results


def get_forecast_for_location(
    location: SoilLocation,
    days: int = 7,
) -> list[WeatherForecast]:
    """
    دریافت پیش‌بینی‌های ذخیره‌شده برای یک location (تا N روز آینده).
    """
    today = date.today()
    end_date = today + timedelta(days=days)
    return list(
        WeatherForecast.objects.filter(
            location=location,
            forecast_date__gte=today,
            forecast_date__lte=end_date,
        ).order_by("forecast_date")
    )


def should_irrigate_today(location: SoilLocation) -> dict:
    """
    بررسی ساده: آیا فردا باران می‌بارد؟
    اگر بارش فردا بیشتر از آستانه باشد → آبیاری لازم نیست.

    خروجی:
        {
            "needs_irrigation": bool | None,
            "tomorrow_precipitation": float | None,
            "tomorrow_date": str,
            "reason": str,
        }
    """
    tomorrow = date.today() + timedelta(days=1)
    forecast = WeatherForecast.objects.filter(
        location=location,
        forecast_date=tomorrow,
    ).first()

    if forecast is None:
        return {
            "needs_irrigation": None,
            "tomorrow_precipitation": None,
            "tomorrow_date": str(tomorrow),
            "reason": "داده پیش‌بینی فردا موجود نیست.",
        }

    rain_threshold_mm = 2.0
    if forecast.precipitation is not None and forecast.precipitation >= rain_threshold_mm:
        return {
            "needs_irrigation": False,
            "tomorrow_precipitation": forecast.precipitation,
            "tomorrow_date": str(tomorrow),
            "reason": (
                f"فردا {forecast.precipitation} mm بارش پیش‌بینی شده — "
                "نیاز به آبیاری نیست."
            ),
        }

    return {
        "needs_irrigation": True,
        "tomorrow_precipitation": forecast.precipitation,
        "tomorrow_date": str(tomorrow),
        "reason": "بارش فردا ناچیز یا صفر — آبیاری توصیه می‌شود.",
    }