from __future__ import annotations

from django.conf import settings
from django.core.exceptions import ValidationError
from rest_framework import status, viewsets
from rest_framework.decorators import action
from rest_framework.permissions import AllowAny
from rest_framework.response import Response
from rest_framework.views import APIView

from apps.accounts.scoping import filter_cycles_queryset, filter_flocks_queryset
from apps.farms.models import Cycle, Flock
from apps.operations.models import (
    AIInsight,
    ChickenCounting,
    ChickenWeight,
    FeedSacks,
    IotPanel,
    KPI,
    ManualInput,
)
from apps.operations.serializers import (
    AIInsightSerializer,
    ChickenCountingSerializer,
    ChickenWeightSerializer,
    FeedSacksSerializer,
    IotPanelSerializer,
    KPISerializer,
    ManualInputSerializer,
)
from apps.operations.services.karung_web import KarungWebError, sync_karung_for_cycle
from apps.operations.services.chicken_counting_edge import (
    ChickenCountingEdgeError,
    sync_chicken_counting_for_cycle,
)
from apps.operations.services.visibility import dashboard_publish_time, visible_through_date

READ_ACTIONS = frozenset({"list", "retrieve", "latest_average", "latest", "dates"})


class VisibilityFilteredMixin:
    visibility_date_field = "date"

    def applies_visibility_filter(self) -> bool:
        return getattr(self, "action", None) in READ_ACTIONS

    def filter_visible_through(self, qs):
        if not self.applies_visibility_filter():
            return qs
        cutoff = visible_through_date()
        return qs.filter(**{f"{self.visibility_date_field}__lte": cutoff})


class CycleScopedViewSet(VisibilityFilteredMixin, viewsets.ModelViewSet):
    def get_queryset(self):
        qs = super().get_queryset()
        # Scope via cycle → kandang → site → owner
        visible_cycles = filter_cycles_queryset(Cycle.objects.all(), self.request.user)
        qs = qs.filter(cycle_id__in=visible_cycles.values_list("pk", flat=True))
        params = self.request.query_params
        if params.get("cycle_id"):
            qs = qs.filter(cycle_id=params["cycle_id"])
        if params.get("flock_id"):
            qs = qs.filter(cycle__kandang__flocks=params["flock_id"]).distinct()
        if params.get("date"):
            qs = qs.filter(date=params["date"])
        return self.filter_visible_through(qs)


class KPIViewSet(CycleScopedViewSet):
    queryset = KPI.objects.select_related("cycle").all()
    serializer_class = KPISerializer


class ManualInputViewSet(CycleScopedViewSet):
    queryset = ManualInput.objects.select_related("cycle").all()
    serializer_class = ManualInputSerializer


class ChickenCountingViewSet(CycleScopedViewSet):
    """Chicken counting + mortality IoT — not subject to dashboard publish cutoff."""

    queryset = ChickenCounting.objects.select_related("cycle").all()
    serializer_class = ChickenCountingSerializer

    def applies_visibility_filter(self) -> bool:
        return False

    @action(detail=False, methods=["post"], url_path="sync")
    def sync_from_edge(self, request):
        cycle_id = request.data.get("cycle_id")
        if not cycle_id:
            return Response(
                {"detail": "cycle_id is required."},
                status=status.HTTP_400_BAD_REQUEST,
            )
        try:
            cycle = filter_cycles_queryset(
                Cycle.objects.select_related("kandang"),
                request.user,
            ).get(pk=cycle_id)
        except Cycle.DoesNotExist:
            return Response({"detail": "Cycle not found."}, status=status.HTTP_404_NOT_FOUND)
        try:
            summary = sync_chicken_counting_for_cycle(cycle)
        except (ChickenCountingEdgeError, ValidationError) as exc:
            code = getattr(exc, "status_code", None)
            return Response(
                {"detail": str(exc)},
                status=code if code and code >= 400 else status.HTTP_502_BAD_GATEWAY,
            )
        return Response(
            {
                "upserted": summary["upserted"],
                "dates": [d.isoformat() for d in summary["dates"]],
            }
        )


class ChickenWeightViewSet(CycleScopedViewSet):
    """Chicken weight — not subject to dashboard publish cutoff."""

    queryset = ChickenWeight.objects.select_related("cycle").all()
    serializer_class = ChickenWeightSerializer

    def applies_visibility_filter(self) -> bool:
        return False

    @action(detail=False, methods=["get"], url_path="latest-avg")
    def latest_average(self, request):
        cycle_id = request.query_params.get("cycle_id")
        if not cycle_id:
            return Response(
                {"detail": "cycle_id is required."},
                status=status.HTTP_400_BAD_REQUEST,
            )
        row = self.get_queryset().filter(cycle_id=cycle_id).order_by("-date", "-pk").first()
        if row is None:
            return Response(
                {"detail": "No chicken weight exists for this cycle."},
                status=status.HTTP_404_NOT_FOUND,
            )
        return Response(self.get_serializer(row).data)


class FeedSacksViewSet(CycleScopedViewSet):
    queryset = FeedSacks.objects.select_related("cycle").all()
    serializer_class = FeedSacksSerializer

    @action(detail=False, methods=["get"], url_path="latest")
    def latest(self, request):
        cycle_id = request.query_params.get("cycle_id")
        if not cycle_id:
            return Response(
                {"detail": "cycle_id is required."},
                status=status.HTTP_400_BAD_REQUEST,
            )
        row = self.get_queryset().filter(cycle_id=cycle_id).order_by("-date", "-pk").first()
        if row is None:
            return Response(
                {"detail": "No feed sacks row exists for this cycle."},
                status=status.HTTP_404_NOT_FOUND,
            )
        return Response(self.get_serializer(row).data)

    @action(detail=False, methods=["post"], url_path="request")
    def request_sync(self, request):
        cycle_id = request.data.get("cycle_id")
        if not cycle_id:
            return Response(
                {"detail": "cycle_id is required."},
                status=status.HTTP_400_BAD_REQUEST,
            )
        try:
            cycle = filter_cycles_queryset(Cycle.objects.all(), request.user).get(pk=cycle_id)
        except Cycle.DoesNotExist:
            return Response({"detail": "Cycle not found."}, status=status.HTTP_404_NOT_FOUND)
        section = request.data.get("section") or "today"
        try:
            feed_sack, summary = sync_karung_for_cycle(cycle, section=section)
        except (KarungWebError, ValidationError) as exc:
            code = getattr(exc, "status_code", None)
            return Response(
                {"detail": str(exc)},
                status=code if code and code >= 400 else status.HTTP_502_BAD_GATEWAY,
            )
        return Response(
            {"karung": self.get_serializer(feed_sack).data, "upstream": summary}
        )


class IotPanelViewSet(viewsets.ModelViewSet):
    """IoT panel is real-time — not subject to the 17:00 dashboard publish cutoff."""
    queryset = IotPanel.objects.select_related("flock", "flock__kandang").all()
    serializer_class = IotPanelSerializer

    def get_queryset(self):
        qs = super().get_queryset()
        visible_flocks = filter_flocks_queryset(Flock.objects.all(), self.request.user)
        qs = qs.filter(flock_id__in=visible_flocks.values_list("pk", flat=True))
        params = self.request.query_params
        cycle_id = params.get("cycle_id")
        if cycle_id:
            visible_cycles = filter_cycles_queryset(Cycle.objects.all(), self.request.user)
            try:
                cycle = visible_cycles.get(pk=cycle_id)
            except Cycle.DoesNotExist:
                return qs.none()
            # Active cycles have end_date=None; date__lte=None raises ValueError (500).
            end = cycle.end_date or cycle.soft_end_date()
            qs = qs.filter(
                flock__kandang_id=cycle.kandang_id,
                date__gte=cycle.start_date,
                date__lte=end,
            )
        if params.get("flock_id"):
            qs = qs.filter(flock_id=params["flock_id"])
        if params.get("date"):
            qs = qs.filter(date=params["date"])
        return qs

    def paginate_queryset(self, queryset):
        if self.request.query_params.get("date"):
            return None
        return super().paginate_queryset(queryset)

    @action(detail=False, methods=["get"], url_path="dates")
    def dates(self, request):
        dates = list(
            self.get_queryset()
            .order_by("date")
            .values_list("date", flat=True)
            .distinct()
        )
        return Response(dates)


class AIInsightViewSet(CycleScopedViewSet):
    queryset = AIInsight.objects.select_related("cycle", "kandang").all()
    serializer_class = AIInsightSerializer

    def get_queryset(self):
        qs = super().get_queryset()
        params = self.request.query_params
        if params.get("kandang_id"):
            qs = qs.filter(kandang_id=params["kandang_id"])
        if params.get("topic"):
            qs = qs.filter(topic=params["topic"])
        if params.get("report_type"):
            qs = qs.filter(report_type=params["report_type"])
        if params.get("report_period"):
            qs = qs.filter(report_period=params["report_period"])
        return qs

    @action(detail=False, methods=["get"], url_path="cached")
    def cached(self, request):
        import json
        params = request.query_params
        cycle_id = params.get("cycle_id")
        kandang_id = params.get("kandang_id")
        topic = params.get("topic")
        if not cycle_id or not kandang_id or not topic:
            return Response(
                {"detail": "cycle_id, kandang_id, and topic are required."},
                status=status.HTTP_400_BAD_REQUEST,
            )
        report_type = params.get("report_type") or "page"
        report_period = params.get("report_period") or "current"
        row = (
            AIInsight.objects.filter(
                cycle_id=cycle_id,
                kandang_id=kandang_id,
                topic=topic,
                report_type=report_type,
                report_period=report_period,
            )
            .order_by("-updated_at")
            .first()
        )
        if row is None:
            return Response({"detail": "No cached insight."}, status=status.HTTP_404_NOT_FOUND)

        raw_cites = row.citations
        if isinstance(raw_cites, list):
            cites = raw_cites
        elif isinstance(raw_cites, str) and raw_cites.strip():
            try:
                cites = json.loads(raw_cites)
            except Exception:
                cites = []
        else:
            cites = []

        return Response({
            "success": True,
            "insight_text": row.insight_text,
            "summary": row.summary,
            "alert": row.alert,
            "citations": cites,
            "topic": row.topic,
            "report_type": row.report_type,
            "report_period": row.report_period,
        })

    @action(detail=False, methods=["post"], url_path="generate")
    def generate(self, request):
        params = request.data or {}
        cycle_id = params.get("cycle_id")
        kandang_id = params.get("kandang_id")
        topic = params.get("topic")
        if not cycle_id or not kandang_id or not topic:
            return Response(
                {"detail": "cycle_id, kandang_id, and topic are required."},
                status=status.HTTP_400_BAD_REQUEST,
            )
        report_type = params.get("report_type") or "page"
        report_period = params.get("report_period") or "current"
        row = (
            AIInsight.objects.filter(
                cycle_id=cycle_id,
                kandang_id=kandang_id,
                topic=topic,
                report_type=report_type,
                report_period=report_period,
            )
            .order_by("-updated_at")
            .first()
        )
        if row is not None:
            import json
            raw_cites = row.citations
            try:
                cites = json.loads(raw_cites) if isinstance(raw_cites, str) else (raw_cites or [])
            except Exception:
                cites = []
            return Response({
                "success": True,
                "insight_text": row.insight_text,
                "summary": row.summary,
                "alert": row.alert,
                "citations": cites,
                "topic": row.topic,
                "report_type": row.report_type,
                "report_period": row.report_period,
            })
        return Response(
            {"detail": "Insight belum tersedia pada mirror HQ. Pastikan insight telah di-generate pada site dashboard dan disinkronkan."},
            status=status.HTTP_404_NOT_FOUND,
        )


class HealthView(APIView):
    permission_classes = [AllowAny]
    authentication_classes = []

    def get(self, request):
        cutoff = visible_through_date()
        publish = dashboard_publish_time()
        payload = {
            "status": "ok",
            "service": "newdashboard-api",
            "karung_web_admin_base_configured": bool(settings.KARUNG_WEB_ADMIN_BASE_URL),
            "visible_through_date": cutoff.isoformat(),
            "dashboard_publish_time": publish.strftime("%H:%M"),
            "dashboard_timezone": settings.TIME_ZONE,
        }
        return Response(payload)