Issue 88 smart irrigation forecast (#90)

* Treat empty location responses from FarmCalendar, handle open-meteo error when connection lost (#14)

* Handle error on no internet

* Handle empty json response from FC

* Add a safer check on empty graph list

* Add farm name and parcel to the obs title and desc

* Eagerly fetch parcels from FC

* Fix duplicate method declaration

* Add daily irrigation api call

* Fixed typo on comment

Author: fedjo

src/api/api_v1/endpoints/forecast.py

@@ -22,7 +22,7 @@
 
 from src.external_services.openmeteo import WeatherClientFactory
 from src.schemas.point import GeoJSONOut
-from src.schemas.history_data import HourlyObservationOut, HourlyResponse
+from src.schemas.history_data import DailyResponse, HourlyObservationOut, HourlyResponse
 from src.schemas.spray import SprayForecastResponse
 from src.models.spray import SprayStatus
 from src import utils
@@ -165,3 +165,50 @@ async def get_hourly_spray_forecast(
         )
 
     return results
+
+
+# ---------------------------------------------------------------------------
+# Daily irrigation forecast
+# ---------------------------------------------------------------------------
+
+@router.get(
+    "/daily/irrigation/",
+    response_model=DailyResponse,
+    summary="Daily weather forecast for smart irrigation (1–16 days)",
+)
+async def get_daily_irrigation_forecast(
+    lat: float = Query(..., description="Latitude", example=38.25),
+    lon: float = Query(..., description="Longitude", example=21.74),
+    days: int = Query(
+        16, ge=1, le=16,
+        description="Number of forecast days (including today)",
+    ),
+):
+    """
+    Returns **daily** weather data optimized for smart irrigation systems.
+
+    Variables returned per day:
+    - **precipitation_sum** – total precipitation (mm)
+    - **precipitation_probability_max** – maximum precipitation probability (%)
+    - **temperature_2m_min** – minimum temperature (°C)
+    - **temperature_2m_max** – maximum temperature (°C)
+    - **et0_fao_evapotranspiration** – reference evapotranspiration ET₀ (mm)
+
+    Data comes from the Open-Meteo Forecast API.
+    Supports up to 16 days of forecast.
+    """
+    client = WeatherClientFactory.get_provider()
+    try:
+        results = await client.get_daily_forecast(lat, lon, days=days)
+    except Exception as e:
+        logger.error(f"Error fetching daily forecast from Open-Meteo: {e}")
+        raise HTTPException(
+            status_code=502,
+            detail="Could not retrieve daily forecast from Open-Meteo",
+        ) from e
+
+    return DailyResponse(
+        location={"lat": lat, "lon": lon},
+        data=results,
+        source="open-meteo",
+    )

src/external_services/openmeteo.py

@@ -27,6 +27,11 @@ async def get_hourly_forecast(
     ) -> List[HourlyObservationOut]:
         ...
 
+    async def get_daily_forecast(
+            self, lat: float, lon: float, days: int = 16
+    ) -> List[DailyObservationOut]:
+        ...
+
 
 class OpenMeteoClient:
     BASE_URL = "https://archive-api.open-meteo.com/v1/archive"
@@ -165,6 +170,73 @@ async def get_hourly_forecast(
         return results
 
 
+# ---- Daily forecast (Open-Meteo Forecast API) ----
+    # Variables for smart irrigation: precipitation, probability, temp range, ET0
+    DAILY_FORECAST_VARIABLES = [
+        "precipitation_sum",
+        "precipitation_probability_max",
+        "temperature_2m_min",
+        "temperature_2m_max",
+        "et0_fao_evapotranspiration",
+    ]
+
+    async def get_daily_forecast(
+        self, lat: float, lon: float, days: int = 16
+    ) -> List[DailyObservationOut]:
+        """
+        Fetch daily weather forecast for irrigation planning from the
+        Open-Meteo **Forecast** API.
+
+        Returns one :class:`DailyObservationOut` per day with:
+        - precipitation_sum (mm)
+        - precipitation_probability_max (%)
+        - temperature_2m_min (°C)
+        - temperature_2m_max (°C)
+        - et0_fao_evapotranspiration (mm)
+
+        Parameters
+        ----------
+        lat, lon : float
+            Location coordinates.
+        days : int
+            Number of forecast days (1–16, default 16).
+        """
+        params = {
+            "latitude": lat,
+            "longitude": lon,
+            "daily": ",".join(self.DAILY_FORECAST_VARIABLES),
+            "timezone": "auto",
+            "forecast_days": days,
+        }
+
+        data = await self._fetch_data(params, url=self.FORECAST_URL)
+
+        if "daily" not in data:
+            logger.warning("Open-Meteo returned no daily forecast data")
+            return []
+
+        timestamps = data["daily"]["time"]
+        results: List[DailyObservationOut] = []
+
+        for i, t in enumerate(timestamps):
+            values: Dict[str, Union[float, None]] = {}
+            for var in self.DAILY_FORECAST_VARIABLES:
+                if var in data["daily"]:
+                    values[var] = data["daily"][var][i]
+            results.append(
+                DailyObservationOut(
+                    date=date.fromisoformat(t),
+                    values=values,
+                )
+            )
+
+        logger.info(
+            "Open-Meteo daily forecast: %d days for (%s, %s)",
+            len(results), lat, lon,
+        )
+        return results
+
+
 # Factory using environment variable
 class WeatherClientFactory:
     _provider: Optional[WeatherProvider] = None