import random
import string

from functools import cached_property
from pathlib import Path

from django.db.models.functions import Lower
from django.contrib.gis.db import models
from django.contrib.gis.db.models.functions import Distance
from django.contrib.postgres.indexes import OpClass
from django.utils.text import slugify


class SoilOrder(models.Model):
    code = models.CharField(unique=True, max_length=1)
    name = models.CharField(unique=True, max_length=50)

    def __str__(self):
        return f"{self.name} ({self.code})"


class SoilVariant(models.Model):
    name = models.CharField(unique=True, max_length=10)

    def __str__(self):
        return self.name


class SoilLayer(models.Model):
    nzsc_class = models.CharField(max_length=4)
    nzsc_group = models.CharField(max_length=2)
    nzsc_order = models.ForeignKey(SoilOrder, on_delete=models.CASCADE)
    shape_leng = models.FloatField()
    geom = models.PolygonField(srid=2193)

    def __str__(self):
        return self.nzsc_class


class EcologicalRegion(models.Model):
    name = models.CharField(unique=True, max_length=50)

    def __str__(self):
        return self.name


class EcologicalDistrictLayer(models.Model):
    ecological = models.CharField(max_length=5)
    ecologic_1 = models.CharField(max_length=50)
    ecologic_2 = models.ForeignKey(EcologicalRegion, on_delete=models.CASCADE)
    shape_leng = models.FloatField()
    shape_area = models.FloatField()
    geom = models.PolygonField(srid=2193)

    def __str__(self):
        return f"{self.ecologic_1} ({self.ecologic_2})"


class ChristchurchRegion(models.Model):
    objectid = models.IntegerField()
    name = models.CharField(max_length=25)
    geom = models.MultiPolygonField(srid=2193)


class ToleranceLevel(models.Model):
    level = models.CharField(max_length=1)

    def __str__(self):
        return self.level


class Habitat(models.Model):
    name = models.CharField(max_length=50)

    def __str__(self):
        return self.name


class HabitatImage(models.Model):
    habitat = models.ForeignKey(
        Habitat, related_name='images', on_delete=models.CASCADE)
    name = models.CharField(max_length=50)
    image_filename = models.CharField(max_length=50, default='-')

    def __str__(self):
        return self.name


class Zone(models.Model):
    name = models.CharField(max_length=50)
    variant = models.CharField(null=True, blank=True, max_length=50)
    refined_variant = models.CharField(null=True, blank=True, max_length=100)
    habitat = models.ForeignKey(
        Habitat, blank=True, null=True, on_delete=models.CASCADE,  related_name='zones')
    redirect_habitat = models.ForeignKey(
        Habitat, blank=True, null=True, on_delete=models.CASCADE,  related_name='zone_redirects')
    related_svg_segment = models.CharField(null=True, blank=True, max_length=20)
    ignore_soil_order_filter = models.BooleanField(default=False)
    ignore_location_filter = models.BooleanField(default=False)
    tooltipText = models.CharField(null=True, blank=True, max_length=500)

    @property
    def tooltip_display_text(self):
        return self.tooltipText if self.tooltipText is not None else str(self)

    def __str__(self):
        refined_variant_str = f", {self.refined_variant}" if self.refined_variant is not None else ""
        variant_str = f"({self.variant}{refined_variant_str})" if self.variant is not None else ""
        return f"{self.name} {variant_str}"

    class Meta:
        ordering = ['name', 'variant', 'refined_variant', 'id']


class Plant(models.Model):
    name = models.CharField(unique=True, max_length=50)
    commonname = models.CharField(null=True, blank=True, max_length=200)
    maxheight = models.CharField(max_length=20)
    spacing = models.FloatField()
    synonym = models.CharField(null=True, blank=True, max_length=200)
    water_tolerance = models.ForeignKey(
        ToleranceLevel, related_name='water_tolerance', on_delete=models.CASCADE)
    drought_tolerance = models.ForeignKey(
        ToleranceLevel, related_name='drought_tolerance', on_delete=models.CASCADE)
    frost_tolerance = models.ForeignKey(
        ToleranceLevel, related_name='frost_tolerance', on_delete=models.CASCADE)
    salinity_tolerance = models.ForeignKey(
        ToleranceLevel, related_name='salinity_tolerance', on_delete=models.CASCADE)
    purpose = models.TextField(null=True, blank=True)
    stage = models.PositiveIntegerField()
    growth_form = models.CharField(null=True, blank=True, max_length=50)
    ecological_regions = models.ManyToManyField(EcologicalRegion)
    soil_order = models.ManyToManyField(SoilOrder)
    soil_variants = models.ManyToManyField(SoilVariant)
    zones = models.ManyToManyField(Zone)

    @property
    def forest_position(self):
        return self.zones.all().filter(name="BUSH PROFILE POSITION", variant__in={"Core", "Border", "Skin", "Epiphytes"}).values('variant')

    @property
    def display_name(self):
        common_name_str = f' / {str(self.commonname)}' if self.commonname is not None else ''
        synonym_str = f' / {str(self.synonym)}' if self.synonym is not None else ''
        return f"{self.name}{common_name_str}{synonym_str}"

    @property
    def display_growth_form(self):
        growth_form_str = f'{str(self.growth_form)} / ' if self.growth_form is not None else ''
        forest_position_values_str = ', '.join([position['variant'][0] for position in self.forest_position])
        forest_position_str = f' / {forest_position_values_str}' if len(self.forest_position) != 0 else ''
        return f"{growth_form_str}{self.maxheight} / {self.spacing}{forest_position_str}"

    @property
    def moisture_preferences(self):
        return ', '.join([variant.name for variant in self.soil_variants.all()])

    @property
    def plant_tolerances(self):
        return f"{self.water_tolerance.level} / {self.drought_tolerance.level} / {self.frost_tolerance.level} / {self.salinity_tolerance.level}"

    @property
    def ecosystem_services(self):
        return f"{str(self.purpose) or ''}"

    @property
    def carbon_sequestration(self):
        return ""

    def __str__(self):
        return self.name

    class Meta:
        ordering = ['stage', 'name', 'commonname', 'synonym']


class Address(models.Model):
    ogc_fid = models.AutoField(primary_key=True)

    # fields for queries
    address_number = models.IntegerField()  # ignore the 'A' in '32A' for now
    suburb_locality_ascii = models.CharField(max_length=255)
    town_city_ascii = models.CharField(max_length=255)
    full_road_name_ascii = models.CharField(max_length=255)
    wkb_geometry = models.PointField()

    # use only for displaying to user
    full_address = models.CharField(max_length=500)

    class Meta:
        db_table = 'linz\".\"nz_street_address'
        indexes = [
            models.Index(OpClass(Lower('full_road_name_ascii'), name='text_pattern_ops'), name='full_road_name_lower_idx'),
            models.Index(OpClass(Lower('suburb_locality_ascii'), name='text_pattern_ops'), name='suburb_locality_lower_idx'),
            models.Index(OpClass(Lower('town_city_ascii'), name='text_pattern_ops'), name='town_city_lower_idx'),
            models.Index(fields=['address_number'], name='address_number_idx'),
        ]

        # effectively read-only
        # https://docs.djangoproject.com/en/3.2/ref/models/options/#managed
        managed = False


class CustomerAddress(models.Model):
    city = models.CharField(max_length=100)
    line1 = models.CharField(max_length=255)
    line2 = models.CharField(max_length=255, blank=True, null=True)
    postal_code = models.SmallIntegerField()

    def __str__(self):
        return f"{self.line1}, {self.line2}, {self.city} {self.postal_code}" \
            if self.line2 else f"{self.line1}, {self.city} {self.postal_code}"


class Customer(models.Model):
    email = models.EmailField()
    name = models.CharField(max_length=100)
    address = models.ForeignKey(CustomerAddress, on_delete=models.PROTECT)

    def __str__(self):
        return self.name


class ActivationKeySet(models.Model):
    creation_date = models.DateTimeField(auto_now_add=True)
    name = models.CharField(max_length=255, unique=True)
    size = models.PositiveSmallIntegerField()
    initial_activations = models.SmallIntegerField(default=1)

    def __str__(self):
        return self.name


class ActivationKey(models.Model):

    def key_default():
        return "".join(
            random.choice(
                [string.ascii_uppercase, string.digits][random.randint(0, 1)]
            ) for _ in range(20)
        )

    key = models.CharField(max_length=20, unique=True, default=key_default)
    key_set = models.ForeignKey(ActivationKeySet, on_delete=models.PROTECT, null=True)
    activations = models.SmallIntegerField(default=0)
    remaining_activations = models.SmallIntegerField(default=1)
    creation_date = models.DateTimeField(auto_now_add=True)
    customer = models.ForeignKey(Customer, on_delete=models.PROTECT, null=True)

    def __str__(self):
        return self.key


class Questionnaire(models.Model):
    location = models.PointField()
    soil_variant = models.ForeignKey(SoilVariant, on_delete=models.CASCADE)
    zone = models.ForeignKey(Zone, on_delete=models.CASCADE)
    key = models.ForeignKey(ActivationKey, on_delete=models.PROTECT, null=True)
    creation_date = models.DateTimeField(auto_now_add=True)

    @property
    def habitat(self):
        return self.zone.habitat

    @cached_property
    def address(self):
        return \
            Address.objects.filter(
                wkb_geometry__dwithin=(self.location, 1e-3),  # order of ~100 metres in degrees for NZ
            ).annotate(
                distance=Distance('wkb_geometry', self.location),
            ).order_by(
                'distance',
            ).first()

    @property
    def plants(self):
        return self.zone.plant_set.all() & self.soil_variant.plant_set.all()

    @cached_property
    def slug(self):
        return "_".join(
            map(slugify, [
                self.address.full_address if self.address else str(self.location),
                self.zone.name,
                self.zone.variant,
                self.zone.refined_variant,
                self.soil_variant.name,
                str(self.zone.pk),  # need this for uniqueness
                str(self.soil_variant.pk),  # # need this for uniqueness
            ])
        )


class Export(models.Model):
    creation_date = models.DateTimeField()
    completion_date = models.DateTimeField(null=True)
    questionnaires = models.ManyToManyField(Questionnaire)

    @property
    def complete(self):
        return self.completion_date is not None

    @property
    def completion(self):
        if self.complete:
            return 1.0

        from .resource_generation_utils import storage

        _, files = storage.listdir(f"export_{self.pk}")

        # 0.25 multiplier as there are four files per questionnaire:
        # csv, filters PDF, plants PDF, merged PDF
        return 0.25 * len(files) / self.questionnaires.count()

    def export(self):
        from .tasks import generate_pdf
        from .resource_generation_utils import storage

        parent = Path(storage.path(f"export_{self.pk}"))

        if not parent.exists():
            parent.mkdir()

        for q in self.questionnaires.all():
            generate_pdf.delay(q.pk, self.pk)