Ai/dashboard_data/cards/soil_moisture_heatmap.py

from __future__ import annotations

from math import sqrt
from typing import Any

from farm_data.models import SensorData


QUALITY_REAL = "REAL"
QUALITY_INTERPOLATED = "INTERPOLATED"
QUALITY_MISSING = "MISSING"
INTERPOLATION_LIMIT = 3
IDW_POWER = 2
MAX_GRID_STEPS = 10


def _interpolate_series(points: list[dict[str, Any]], limit: int = INTERPOLATION_LIMIT) -> list[dict[str, Any]]:
    output = [dict(point) for point in points]
    known_indexes = [index for index, point in enumerate(output) if point["value"] is not None]

    for start_index, end_index in zip(known_indexes, known_indexes[1:]):
        gap = end_index - start_index - 1
        if gap <= 0 or gap > limit:
            continue

        start_value = output[start_index]["value"]
        end_value = output[end_index]["value"]
        if start_value is None or end_value is None:
            continue

        step = (end_value - start_value) / (gap + 1)
        for offset in range(1, gap + 1):
            target_index = start_index + offset
            output[target_index]["value"] = round(start_value + (step * offset), 2)
            output[target_index]["quality_flag"] = QUALITY_INTERPOLATED

    return output


def _sensor_time_series(sensor: Any, histories: list[Any]) -> list[dict[str, Any]]:
    points = []
    for item in reversed(histories):
        points.append(
            {
                "timestamp": item.recorded_at.isoformat(),
                "value": float(item.soil_moisture) if item.soil_moisture is not None else None,
                "quality_flag": QUALITY_REAL if item.soil_moisture is not None else QUALITY_MISSING,
            }
        )
    points.append(
        {
            "timestamp": sensor.updated_at.isoformat() if getattr(sensor, "updated_at", None) else None,
            "value": float(sensor.soil_moisture) if getattr(sensor, "soil_moisture", None) is not None else None,
            "quality_flag": QUALITY_REAL if getattr(sensor, "soil_moisture", None) is not None else QUALITY_MISSING,
        }
    )
    return _interpolate_series(points)


def _latest_sensor_measurement(sensor: Any, histories: list[Any]) -> dict[str, Any]:
    series = _sensor_time_series(sensor, histories)
    latest = series[-1] if series else {"timestamp": None, "value": None, "quality_flag": QUALITY_MISSING}
    return {
        "sensor_id": str(sensor.farm_uuid),
        "latitude": float(sensor.center_location.latitude),
        "longitude": float(sensor.center_location.longitude),
        "depth": None,
        "timestamp": latest["timestamp"],
        "soil_moisture_value": latest["value"],
        "quality_flag": latest["quality_flag"],
    }


def _idw_value(lat: float, lon: float, sensor_points: list[dict[str, Any]]) -> float | None:
    weighted_sum = 0.0
    weight_total = 0.0
    for point in sensor_points:
        value = point["soil_moisture_value"]
        if value is None:
            continue
        distance = sqrt(((lat - point["latitude"]) ** 2) + ((lon - point["longitude"]) ** 2))
        if distance == 0:
            return round(float(value), 2)
        weight = 1 / (distance**IDW_POWER)
        weighted_sum += weight * float(value)
        weight_total += weight
    if weight_total == 0:
        return None
    return round(weighted_sum / weight_total, 2)


def _grid_axis(min_value: float, max_value: float) -> list[float]:
    if min_value == max_value:
        return [round(min_value, 6)]
    step_count = min(MAX_GRID_STEPS, max(int((max_value - min_value) / 0.0001) + 1, 2))
    step = (max_value - min_value) / (step_count - 1)
    return [round(min_value + (step * index), 6) for index in range(step_count)]


def _load_sensor_network(current_sensor: Any) -> list[Any]:
    plant_ids = list(current_sensor.plants.values_list("id", flat=True))
    queryset = SensorData.objects.select_related("center_location").prefetch_related("plants")
    if plant_ids:
        queryset = queryset.filter(plants__id__in=plant_ids).distinct()
    return list(queryset)


def build_soil_moisture_heatmap(sensor_id: str, context: dict | None = None, ai_bundle: dict | None = None) -> dict:
    context = context or {}
    current_sensor = context.get("sensor")
    if current_sensor is None:
        return {
            "timestamp": None,
            "grid_resolution": None,
            "grid_cells": [],
            "sensor_points": [],
            "quality_legend": {},
        }

    sensors = _load_sensor_network(current_sensor)
    sensor_points = [
        _latest_sensor_measurement(sensor, [])
        for sensor in sensors
    ]
    valid_sensor_points = [point for point in sensor_points if point["soil_moisture_value"] is not None]

    if not valid_sensor_points:
        return {
            "timestamp": current_sensor.updated_at.isoformat() if getattr(current_sensor, "updated_at", None) else None,
            "grid_resolution": None,
            "grid_cells": [],
            "sensor_points": sensor_points,
            "quality_legend": {
                QUALITY_REAL: "اندازه‌گیری واقعی سنسور",
                QUALITY_INTERPOLATED: "مقدار سنسور با درون‌یابی زمانی کوتاه‌مدت",
                QUALITY_MISSING: "داده معتبر برای سنسور موجود نیست",
            },
        }

    min_lat = min(point["latitude"] for point in valid_sensor_points)
    max_lat = max(point["latitude"] for point in valid_sensor_points)
    min_lon = min(point["longitude"] for point in valid_sensor_points)
    max_lon = max(point["longitude"] for point in valid_sensor_points)

    lat_axis = _grid_axis(min_lat, max_lat)
    lon_axis = _grid_axis(min_lon, max_lon)

    grid_cells = []
    for lat in lat_axis:
        for lon in lon_axis:
            direct_sensor = next(
                (
                    point for point in valid_sensor_points
                    if point["latitude"] == lat and point["longitude"] == lon
                ),
                None,
            )
            if direct_sensor is not None:
                moisture_value = direct_sensor["soil_moisture_value"]
                quality_flag = direct_sensor["quality_flag"]
            elif len(valid_sensor_points) >= 2:
                moisture_value = _idw_value(lat, lon, valid_sensor_points)
                quality_flag = QUALITY_INTERPOLATED if moisture_value is not None else QUALITY_MISSING
            else:
                moisture_value = None
                quality_flag = QUALITY_MISSING

            grid_cells.append(
                {
                    "lat": lat,
                    "lon": lon,
                    "moisture_value": moisture_value,
                    "quality_flag": quality_flag,
                }
            )

    lat_step = round(abs(lat_axis[1] - lat_axis[0]), 6) if len(lat_axis) > 1 else 0.0
    lon_step = round(abs(lon_axis[1] - lon_axis[0]), 6) if len(lon_axis) > 1 else 0.0

    return {
        "timestamp": max(point["timestamp"] for point in sensor_points if point["timestamp"]),
        "grid_resolution": {
            "lat_step": lat_step,
            "lon_step": lon_step,
            "rows": len(lat_axis),
            "cols": len(lon_axis),
        },
        "grid_cells": grid_cells,
        "sensor_points": sensor_points,
        "quality_legend": {
            QUALITY_REAL: "اندازه‌گیری واقعی سنسور",
            QUALITY_INTERPOLATED: "مقدار برآوردشده با درون‌یابی زمانی/فضایی",
            QUALITY_MISSING: "داده معتبر در دسترس نیست",
        },
    }