from django.db import models
from django.contrib.auth import get_user_model
from django.contrib.postgres.fields import ArrayField, JSONField
from django.core.validators import RegexValidator

from constance import config
from paymentwall import Pingback
from polymorphic.models import PolymorphicModel

from apps.course.models import Course
from apps.school.models import SchoolSchedule
from apps.notification.utils import send_email

User = get_user_model()

CREDIT_CARD_RE = r'^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6(?:011|5[0-9][0-9])[0-9]{12}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|(?:2131|1800|35\\d{3})\d{11})$'


class AuthorBalance(models.Model):
    IN = 0
    OUT = 1
    TYPE_CHOICES = (
        (IN, 'In'),
        (OUT, 'Out'),
    )
    PENDING = 0
    ACCEPTED = 1
    DECLINED = 2
    STATUS_CHOICES = (
        (PENDING, 'Pending'),
        (ACCEPTED, 'Accepted'),
        (DECLINED, 'Declined'),
    )
    author = models.ForeignKey(User, on_delete=models.CASCADE, verbose_name='Автор',
                               null=True, blank=True, related_name='balances')
    type = models.PositiveSmallIntegerField('Тип', choices=TYPE_CHOICES, default=0)
    amount = models.DecimalField('Итого', max_digits=8, decimal_places=2, default=0)
    commission = models.DecimalField('Комиссия', max_digits=8, decimal_places=2, default=0)
    status = models.PositiveSmallIntegerField('Статус', choices=STATUS_CHOICES, default=0)
    payment = models.OneToOneField('Payment', on_delete=models.CASCADE, null=True, blank=True, verbose_name='Платёж')
    cause = models.TextField('Причина отказа', null=True, blank=True)
    card = models.CharField(max_length=20, validators=[RegexValidator(regex=CREDIT_CARD_RE)], null=True, blank=True)

    declined_send_at = models.DateTimeField(null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    update_at = models.DateTimeField(auto_now=True)

    class Meta:
        verbose_name = 'Баланс'
        verbose_name_plural = 'Балансы'

    def save(self, *args, **kwargs):
        self.commission = self.calc_commission()
        if self.type == self.OUT:
            if self.status == self.DECLINED and not self.declined_send_at:
                send_email(
                    'Отказ вывода средств',
                    self.author.email,
                    'notification/email/decline_withdrawal.html',
                    author_balance=self,
                )
                self.declined_send_at = now()
        super().save(*args, **kwargs)

    def calc_commission(self):
        return self.amount * config.SERVICE_COMMISSION / 100


class Payment(PolymorphicModel):
    PW_STATUS_CHOICES = (
        (Pingback.PINGBACK_TYPE_REGULAR, 'regular',),
        (Pingback.PINGBACK_TYPE_GOODWILL, 'goodwill',),
        (Pingback.PINGBACK_TYPE_NEGATIVE, 'negative',),
        (Pingback.PINGBACK_TYPE_RISK_UNDER_REVIEW, 'risk under review',),
        (Pingback.PINGBACK_TYPE_RISK_REVIEWED_ACCEPTED, 'risk reviewed accepted',),
        (Pingback.PINGBACK_TYPE_RISK_REVIEWED_DECLINED, 'risk reviewed declined',),
        (Pingback.PINGBACK_TYPE_RISK_AUTHORIZATION_VOIDED, 'risk authorization voided',),
        (Pingback.PINGBACK_TYPE_SUBSCRIPTION_CANCELLATION, 'subscription cancelation',),
        (Pingback.PINGBACK_TYPE_SUBSCRIPTION_EXPIRED, 'subscription expired',),
        (Pingback.PINGBACK_TYPE_SUBSCRIPTION_PAYMENT_FAILED, 'subscription payment failed',),
    )
    user = models.ForeignKey(User, on_delete=models.CASCADE, verbose_name='Пользователь', related_name='payments')
    amount = models.DecimalField('Итого', max_digits=8, decimal_places=2, default=0, editable=False)
    status = models.PositiveSmallIntegerField('Статус платежа', choices=PW_STATUS_CHOICES, null=True, editable=False)
    data = JSONField('Данные платежа от провайдера', default={}, editable=False)

    class Meta:
        verbose_name = 'Платеж'
        verbose_name_plural = 'Платежи'

    def calc_commission(self):
        return self.amount * config.SERVICE_COMMISSION / 100

    def is_deliverable(self):
        return self.status in [
            Pingback.PINGBACK_TYPE_REGULAR,
            Pingback.PINGBACK_TYPE_GOODWILL,
            Pingback.PINGBACK_TYPE_RISK_REVIEWED_ACCEPTED,
        ]

    def is_under_review(self):
        return self.status == Pingback.PINGBACK_TYPE_RISK_UNDER_REVIEW

    def is_cancelable(self):
        return self.status in [
            Pingback.PINGBACK_TYPE_NEGATIVE,
            Pingback.PINGBACK_TYPE_RISK_REVIEWED_DECLINED,
        ]


class CoursePayment(Payment):
    course = models.ForeignKey(Course, on_delete=models.CASCADE, verbose_name='Курс', related_name='payments')

    class Meta:
        verbose_name = 'Платеж за курс'
        verbose_name_plural = 'Платежи за курсы'

    def save(self, *args, **kwargs):
        self.amount = self.course.price
        super().save(*args, **kwargs)
        author_balance = getattr(self, 'authorbalance', None)
        if not author_balance:
            AuthorBalance.objects.create(
                author=self.course.author,
                amount=self.amount,
                payment=self,
            )
        else:
            author_balance.amount = self.amount
            author_balance.save()


class SchoolPayment(Payment):
    weekdays = ArrayField(models.IntegerField(), size=7, verbose_name='Дни недели')
    date_start = models.DateField('Дата начала подписки', null=True, blank=True)
    date_end = models.DateField('Дата окончания подписки', null=True, blank=True)

    class Meta:
        verbose_name = 'Платеж за школу'
        verbose_name_plural = 'Платежи за школу'

    def __str__(self):
        days = ', '.join([dict(SchoolSchedule.WEEKDAY_CHOICES).get(weekday, '') for weekday in sorted(self.weekdays)])
        return days

    def save(self, *args, **kwargs):
        aggregate = SchoolSchedule.objects.filter(
            weekday__in=self.weekdays,
        ).aggregate(
            models.Sum('month_price'),
            models.Sum('day_discount'),
        )
        month_price_sum = aggregate.get('month_price__sum', 0)
        day_discount_sum = aggregate.get('day_discount__sum', 0) if len(self.weekdays) == 7 else 0
        self.amount = month_price_sum - day_discount_sum
        super().save(*args, **kwargs)