from decimal import Decimal, getcontext
import logging
from typing import Dict

from django.contrib.auth import get_user_model
from django.conf import settings
from django.db import models
from django.urls import reverse
from scrobbles.mixins import ScrobblableConstants, ScrobblableMixin

logger = logging.getLogger(__name__)
BNULL = {"blank": True, "null": True}
User = get_user_model()

GEOLOC_ACCURACY = int(getattr(settings, "GEOLOC_ACCURACY", 4))
GEOLOC_PROXIMITY = Decimal(getattr(settings, "GEOLOC_PROXIMITY", "0.0001"))


class GeoLocation(ScrobblableMixin):
    COMPLETION_PERCENT = getattr(settings, "LOCATION_COMPLETION_PERCENT", 100)

    lat = models.FloatField()
    lon = models.FloatField()
    truncated_lat = models.FloatField(**BNULL)
    truncated_lon = models.FloatField(**BNULL)
    altitude = models.FloatField(**BNULL)

    class Meta:
        unique_together = [["lat", "lon", "altitude"]]

    def __str__(self):
        if self.title:
            return self.title

        return f"{self.lat} x {self.lon}"

    def get_absolute_url(self):
        return reverse(
            "locations:geo_location_detail", kwargs={"slug": self.uuid}
        )

    @classmethod
    def find_or_create(cls, data_dict: Dict) -> "GeoLocation":
        """Given a data dict from GPSLogger, does the heavy lifting of looking up
        the location, creating if if doesn't exist yet.

        """
        # TODO Add constants for all these data keys
        if "lat" not in data_dict.keys() or "lon" not in data_dict.keys():
            logger.error("No lat or lon keys in data dict")
            return

        int_lat, r_lat = str(data_dict.get("lat", "")).split(".")
        int_lon, r_lon = str(data_dict.get("lon", "")).split(".")

        try:
            trunc_lat = r_lat[0:GEOLOC_ACCURACY]
        except IndexError:
            trunc_lat = r_lat
        try:
            trunc_lon = r_lon[0:GEOLOC_ACCURACY]
        except IndexError:
            trunc_lon = r_lon

        data_dict["lat"] = float(f"{int_lat}.{trunc_lat}")
        data_dict["lon"] = float(f"{int_lon}.{trunc_lon}")

        int_alt, r_alt = str(data_dict.get("alt", "")).split(".")

        data_dict["altitude"] = float(int_alt)

        location = cls.objects.filter(
            lat=data_dict.get("lat"),
            lon=data_dict.get("lon"),
        ).first()

        if not location:
            location = cls.objects.create(
                lat=data_dict.get("lat"),
                lon=data_dict.get("lon"),
                altitude=data_dict.get("altitude"),
            )
        return location

    @property
    def subtitle(self) -> str:
        if self.title:
            return f"{self.lat} x {self.lon}"
        return ""

    @property
    def strings(self) -> ScrobblableConstants:
        return ScrobblableConstants(
            verb="Going", tags="world_map", priority="low"
        )

    def loc_diff(self, old_lat_lon: tuple) -> tuple:
        return (
            abs(Decimal(old_lat_lon[0]) - Decimal(self.lat)),
            abs(Decimal(old_lat_lon[1]) - Decimal(self.lon)),
        )

    def has_moved(self, previous_location: "GeoLocation") -> bool:
        has_moved = False

        loc_diff = self.loc_diff(
            (previous_location.lat, previous_location.lon)
        )
        if loc_diff[0] > GEOLOC_PROXIMITY or loc_diff[1] > GEOLOC_PROXIMITY:
            has_moved = True
        logger.debug(
            f"[locations] checked whether location has moved against proximity setting",
            extra={
                "location_id": self.id,
                "loc_diff": loc_diff,
                "has_moved": has_moved,
                "previous_location_id": previous_location.id,
                "geoloc_proximity": GEOLOC_PROXIMITY,
            },
        )
        return has_moved

    def in_proximity(self, named=False) -> models.QuerySet:
        lat_min = Decimal(self.lat) - GEOLOC_PROXIMITY
        lat_max = Decimal(self.lat) + GEOLOC_PROXIMITY
        lon_min = Decimal(self.lon) - GEOLOC_PROXIMITY
        lon_max = Decimal(self.lon) + GEOLOC_PROXIMITY
        is_title_null = not named
        close_locations = GeoLocation.objects.filter(
            title__isnull=is_title_null,
            lat__lte=lat_max,
            lat__gte=lat_min,
            lon__lte=lon_max,
            lon__gte=lon_min,
        ).exclude(id=self.id)
        return close_locations