from django.db import models
from django.urls import reverse
from django.contrib.auth.models import User
from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation
from django.contrib.contenttypes.models import ContentType

from djadhere.utils import get_active_filter
from banking.models import Payment


# Terminologie : une « adhésion » désgine une instance de ce modèle
# tandis qu’un « adhérent » désigne un user ou une corporation.
class Adhesion(models.Model):
    limit = models.Q(app_label='auth', model='user') \
          | models.Q(app_label='adhesions', model='corporation')
    id = models.AutoField(verbose_name='Numéro d’adhérent', primary_key=True, editable=True)
    adherent_type = models.ForeignKey(ContentType, on_delete=models.CASCADE,
                                      limit_choices_to=limit, verbose_name='Type d’adhérent')
    adherent_id = models.PositiveIntegerField(verbose_name='ID')
    adherent = GenericForeignKey('adherent_type', 'adherent_id')
    contributions = GenericRelation(Payment,
                                   content_type_field='reason_type',
                                   object_id_field='reason_id',
                                   related_query_name='adhesion')
    created = models.DateTimeField(null=True, blank=True, auto_now_add=True)

    class Meta:
        verbose_name = 'adhérent'
        unique_together = ("adherent_type", "adherent_id")

    @property
    def contribution(self):
        try:
            return self.contributions.exclude(period=0).filter(get_active_filter()).get()
        except Payment.DoesNotExist:
            return None
        # MultipleObjectsReturned non catché volontairement, le filtrage par la méthode clean est censé
        # empêcher cette possibilité, si cette exception est levé on veut recevoir un mail avec l’erreur !

    def is_physical(self):
        return self.adherent_type.app_label == 'auth' and self.adherent_type.model == 'user'

    def is_moral(self):
        return self.adherent_type.app_label == 'adhesions' and self.adherent_type.model == 'corporation'

    @property
    def type(self):
        if self.is_physical():
            return 'Personne physique'
        else:
            return 'Personne morale'

    def get_adherent_name(self):
        if self.is_physical():
            return str(self.adherent.profile)
        else:
            return str(self.adherent)
    get_adherent_name.short_description = 'Nom ou raison sociale'

    def get_adherent_detail_url(self):
        if self.is_physical():
            return reverse('user-detail', kwargs={'pk': self.adherent.pk})
        else:
            return reverse('corporation-detail', kwargs={'pk': self.adherent.pk})

    def get_adherent_edit_url(self):
        if self.is_physical():
            return reverse('user-edit', kwargs={'pk': self.adherent.pk})
        else:
            return reverse('corporation-edit', kwargs={'pk': self.adherent.pk})

    def get_absolute_url(self):
        return reverse('adhesion-detail', kwargs={'pk': self.pk})

    def __str__(self):
        if self.id:
            return 'ADT%d (%s)' % (self.id, self.get_adherent_name())
        else:
            return '?'


class Corporation(models.Model):
    social_reason = models.CharField(max_length=256, verbose_name='Raison sociale', unique=True)
    description = models.TextField(blank=True, default='')
    address = models.TextField(blank=True, default='', verbose_name='Adresse')
    members = models.ManyToManyField(User, blank=True, verbose_name='Membres',
                                     related_name='corporations', related_query_name='corporation')

    @property
    def adhesion(self):
        ctype = ContentType.objects.get_for_model(self)
        try:
            return Adhesion.objects.get(adherent_type=ctype, adherent_id=self.pk)
        except Adhesion.DoesNotExist:
            return None

    def get_absolute_url(self):
        return reverse('corporation-detail', kwargs={'pk': self.pk})

    class Meta:
        verbose_name = 'personne morale'
        verbose_name_plural = 'personnes morales'

    def __str__(self):
        return self.social_reason