from __future__ import annotations

from drf_spectacular.utils import OpenApiExample, extend_schema
from rest_framework import status
from rest_framework.response import Response
from rest_framework.views import APIView

from config.openapi import (
    build_envelope_serializer,
    build_response,
    build_task_status_data_serializer,
)

from .growth_simulation import MAX_PAGE_SIZE, paginate_growth_stages
from .serializers import (
    GrowthSimulationQueuedSerializer,
    GrowthSimulationRequestSerializer,
    GrowthSimulationResultSerializer,
)
from .tasks import run_growth_simulation_task


GrowthSimulationQueuedResponseSerializer = build_envelope_serializer(
    "GrowthSimulationQueuedResponseSerializer",
    GrowthSimulationQueuedSerializer,
)
GrowthSimulationStatusResponseSerializer = build_envelope_serializer(
    "GrowthSimulationStatusResponseSerializer",
    build_task_status_data_serializer(
        "GrowthSimulationTaskStatusDataSerializer",
        GrowthSimulationResultSerializer,
    ),
)
GrowthSimulationErrorSerializer = build_envelope_serializer(
    "GrowthSimulationErrorSerializer",
    data_required=False,
    allow_null=True,
)


def _get_async_result(task_id: str):
    from celery.result import AsyncResult

    return AsyncResult(task_id)


def _coerce_positive_int(value, default: int) -> int:
    try:
        parsed = int(value)
    except (TypeError, ValueError):
        return default
    return max(parsed, 1)


class PlantGrowthSimulationView(APIView):
    @extend_schema(
        tags=["Crop Simulation"],
        summary="شروع شبیه سازی رشد گیاه",
        description=(
            "نوع گیاه و پارامترهای متغیر رشد را می گیرد، "
            "شبیه سازی را داخل Celery اجرا می کند و فقط task_id برمی گرداند."
        ),
        request=GrowthSimulationRequestSerializer,
        responses={
            202: build_response(
                GrowthSimulationQueuedResponseSerializer,
                "تسک شبیه سازی رشد گیاه در صف قرار گرفت.",
            ),
            400: build_response(
                GrowthSimulationErrorSerializer,
                "داده ورودی نامعتبر است.",
            ),
        },
        examples=[
            OpenApiExample(
                "نمونه درخواست با weather مستقیم",
                value={
                    "plant_name": "گوجه‌فرنگی",
                    "dynamic_parameters": ["DVS", "LAI", "TAGP", "TWSO", "SM"],
                    "weather": [
                        {
                            "DAY": "2026-04-01",
                            "LAT": 35.7,
                            "LON": 51.4,
                            "TMIN": 12,
                            "TMAX": 24,
                            "RAIN": 0.0,
                            "ET0": 0.32,
                        }
                    ],
                    "soil_parameters": {"SMFCF": 0.34, "SMW": 0.14, "RDMSOL": 120.0},
                    "site_parameters": {"WAV": 40.0},
                    "page_size": 2,
                },
                request_only=True,
            ),
            OpenApiExample(
                "نمونه درخواست با farm",
                value={
                    "plant_name": "گوجه‌فرنگی",
                    "dynamic_parameters": ["DVS", "LAI", "TAGP"],
                    "farm_uuid": "550e8400-e29b-41d4-a716-446655440000",
                },
                request_only=True,
            ),
        ],
    )
    def post(self, request):
        serializer = GrowthSimulationRequestSerializer(data=request.data)
        if not serializer.is_valid():
            return Response(
                {"code": 400, "msg": "داده نامعتبر.", "data": serializer.errors},
                status=status.HTTP_400_BAD_REQUEST,
            )

        task = run_growth_simulation_task.delay(serializer.validated_data)
        return Response(
            {
                "code": 202,
                "msg": "تسک شبیه سازی رشد در صف قرار گرفت.",
                "data": {
                    "task_id": task.id,
                    "status_url": f"/api/crop-simulation/growth/{task.id}/status/",
                    "plant_name": serializer.validated_data["plant_name"],
                },
            },
            status=status.HTTP_202_ACCEPTED,
        )


class PlantGrowthSimulationStatusView(APIView):
    @extend_schema(
        tags=["Crop Simulation"],
        summary="وضعیت شبیه سازی رشد گیاه",
        description="وضعیت تسک Celery را برمی گرداند و در صورت موفقیت مراحل رشد را به صورت صفحه بندی شده بازمی گرداند.",
        responses={
            200: build_response(
                GrowthSimulationStatusResponseSerializer,
                "وضعیت فعلی تسک شبیه سازی رشد گیاه.",
            )
        },
    )
    def get(self, request, task_id: str):
        result = _get_async_result(task_id)
        payload = {"task_id": task_id, "status": result.state}

        if result.state == "PENDING":
            payload["message"] = "تسک در صف یا یافت نشد."
        elif result.state == "PROGRESS":
            payload["progress"] = result.info
        elif result.state == "SUCCESS":
            task_result = dict(result.result or {})
            page = _coerce_positive_int(request.query_params.get("page", 1), 1)
            page_size = min(
                _coerce_positive_int(
                    request.query_params.get("page_size", task_result.get("default_page_size", 10)),
                    10,
                ),
                MAX_PAGE_SIZE,
            )
            paginated = paginate_growth_stages(
                task_result.get("stage_timeline", []),
                page=page,
                page_size=page_size,
            )
            task_result["stages_page"] = paginated["items"]
            task_result["pagination"] = paginated["pagination"]
            payload["result"] = task_result
        elif result.state == "FAILURE":
            payload["error"] = str(result.result)

        return Response(
            {"code": 200, "msg": "success", "data": payload},
            status=status.HTTP_200_OK,
        )