from io import BytesIO

import pandas as pd
from django.contrib.gis.measure import Distance
from django.db.models import F

from postamates.settings import DEFAULT_PLACEMENT_POINT_UPDATE_RADIUS
from service import models
from service.enums import PointStatus
from service.tasks import raschet


class PointService:
    def update_fact(self, postamat_id: str, fact: int):
        qs = self.get_point_by_postamat_id(postamat_id)
        qs.update(**{'fact': fact})

    def update_postamat_id(self, point_id: int, postamat_id: str):
        qs = self.get_point_by_id(point_id)
        qs.update(**{'postamat_id': postamat_id})

    @staticmethod
    def update_points_in_radius(qs: models.PlacementPoint, new_status: str):
        for point in qs:
            if new_status == PointStatus.Installation.name:
                if point.status == PointStatus.Pending.name:
                    pnts = models.PlacementPoint.objects.filter(
                        geometry__distance_lt=(point.geometry, Distance(m=DEFAULT_PLACEMENT_POINT_UPDATE_RADIUS)),
                    )
                    pnts.update(target_post_cnt=F('target_post_cnt') + 1)
                    raschet.delay()
            elif new_status == PointStatus.Cancelled.name or new_status == PointStatus.Pending.name:
                if point.status == PointStatus.Installation.name:
                    pnts = models.PlacementPoint.objects.filter(
                        geometry__distance_lt=(point.geometry, Distance(m=DEFAULT_PLACEMENT_POINT_UPDATE_RADIUS)),
                    )
                    pnts.update(target_post_cnt=F('target_post_cnt') - 1 if F('target_post_cnt') != 0 else 0)
                    raschet.delay()

    @staticmethod
    def update_status(qs: models.PlacementPoint, new_status: str) -> models.PlacementPoint:
        qs.update(**{'status': new_status})

    @staticmethod
    def get_point_by_id(point_id: int):
        return models.PlacementPoint.objects.filter(pk=point_id)

    @staticmethod
    def get_point_by_postamat_id(postamat_id: str):
        return models.PlacementPoint.objects.filter(postamat_id=postamat_id)

    @staticmethod
    def to_excel(qs: models.PlacementPoint):
        data = pd.DataFrame(list(qs.values()))
        data['start_date'] = data['start_date'].dt.tz_localize(None)
        data['sample_trn'] = data['sample_trn'].astype(int)
        with BytesIO() as b:
            with pd.ExcelWriter(b) as writer:
                data.to_excel(
                    writer, sheet_name='Placement Points',
                    index=False,
                )
            return b.getvalue()

    @staticmethod
    def get_first_10_k():
        if models.PlacementPoint.objects.count() > 10000:
            qs = models.PlacementPoint.objects.order_by('-prediction_current').all()[10000]
            return qs.prediction_current
        else:
            return models.PlacementPoint.objects.order_by('prediction_current').first().prediction_current