Sith/subscription/models.py

# -*- coding:utf-8 -*
#
# Copyright 2016,2017
# - Skia <skia@libskia.so>
#
# Ce fichier fait partie du site de l'Association des Étudiants de l'UTBM,
# http://ae.utbm.fr.
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License a published by the Free Software
# Foundation; either version 3 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Sofware Foundation, Inc., 59 Temple
# Place - Suite 330, Boston, MA 02111-1307, USA.
#
#

from datetime import date, timedelta
from django.db import models
from django.utils import timezone
from django.utils.translation import gettext_lazy as _
from django.conf import settings
from django.core.exceptions import ValidationError
from django.urls import reverse
from django.contrib.auth.forms import PasswordResetForm

from dateutil.relativedelta import relativedelta

import math

from core.models import User
from core.utils import get_start_of_semester


def validate_type(value):
    if value not in settings.SITH_SUBSCRIPTIONS.keys():
        raise ValidationError(_("Bad subscription type"))


def validate_payment(value):
    if value not in settings.SITH_SUBSCRIPTION_PAYMENT_METHOD:
        raise ValidationError(_("Bad payment method"))


class Subscription(models.Model):
    member = models.ForeignKey(
        User, related_name="subscriptions", on_delete=models.CASCADE
    )
    subscription_type = models.CharField(
        _("subscription type"),
        max_length=255,
        choices=(
            (k, v["name"]) for k, v in sorted(settings.SITH_SUBSCRIPTIONS.items())
        ),
    )
    subscription_start = models.DateField(_("subscription start"))
    subscription_end = models.DateField(_("subscription end"))
    payment_method = models.CharField(
        _("payment method"),
        max_length=255,
        choices=settings.SITH_SUBSCRIPTION_PAYMENT_METHOD,
    )
    location = models.CharField(
        choices=settings.SITH_SUBSCRIPTION_LOCATIONS,
        max_length=20,
        verbose_name=_("location"),
    )

    class Meta:
        ordering = ["subscription_start"]

    def clean(self):
        try:
            for s in (
                Subscription.objects.filter(member=self.member)
                .exclude(pk=self.pk)
                .all()
            ):
                if (
                    s.is_valid_now()
                    and s.subscription_end
                    - timedelta(weeks=settings.SITH_SUBSCRIPTION_END)
                    > date.today()
                ):
                    raise ValidationError(
                        _("You can not subscribe many time for the same period")
                    )
        except:  # This should not happen, because the form should have handled the data before, but sadly, it still
            # calls the model validation :'(
            # TODO see SubscriptionForm's clean method
            raise ValidationError(_("Subscription error"))

    def save(self, *args, **kwargs):
        super(Subscription, self).save()
        from counter.models import Customer

        if not Customer.objects.filter(user=self.member).exists():
            Customer.new_for_user(self.member).save()
            form = PasswordResetForm({"email": self.member.email})
            if form.is_valid():
                form.save(
                    use_https=True,
                    email_template_name="core/new_user_email.jinja",
                    subject_template_name="core/new_user_email_subject.jinja",
                    from_email="ae@utbm.fr",
                )
        self.member.make_home()

    def get_absolute_url(self):
        return reverse("core:user_edit", kwargs={"user_id": self.member.pk})

    def __str__(self):
        if hasattr(self, "member") and self.member is not None:
            return self.member.username + " - " + str(self.pk)
        else:
            return "No user - " + str(self.pk)

    @staticmethod
    def compute_start(d=None, duration=1, user=None):
        """
        This function computes the start date of the subscription with respect to the given date (default is today),
        and the start date given in settings.SITH_START_DATE.
        It takes the nearest past start date.
        Exemples: with SITH_START_DATE = (8, 15)
            Today      -> Start date
            2015-03-17 -> 2015-02-15
            2015-01-11 -> 2014-08-15
        """
        if not d:
            d = date.today()
        if user is not None and user.subscriptions.exists():
            last = user.subscriptions.last()
            if last.is_valid_now():
                d = last.subscription_end
        if duration <= 2:  # Sliding subscriptions for 1 or 2 semesters
            return d
        return get_start_of_semester(d)

    @staticmethod
    def compute_end(duration, start=None, user=None):
        """
        This function compute the end date of the subscription given a start date and a duration in number of semestre
        Exemple:
            Start - Duration -> End date
            2015-09-18 - 1 -> 2016-03-18
            2015-09-18 - 2 -> 2016-09-18
            2015-09-18 - 3 -> 2017-03-18
            2015-09-18 - 4 -> 2017-09-18
        """
        if start is None:
            start = Subscription.compute_start(duration=duration, user=user)

        return start + relativedelta(
            months=round(6 * duration),
            days=math.ceil((6 * duration - round(6 * duration)) * 30),
        )

    def can_be_edited_by(self, user):
        return user.is_in_group(settings.SITH_MAIN_BOARD_GROUP) or user.is_root

    def is_valid_now(self):
        return (
            self.subscription_start <= date.today()
            and date.today() <= self.subscription_end
        )


def guy_test(date, duration=4):
    print(
        str(date)
        + " - "
        + str(duration)
        + " -> "
        + str(Subscription.compute_start(date, duration))
    )


def bibou_test(duration, date=date.today()):
    print(
        str(date)
        + " - "
        + str(duration)
        + " -> "
        + str(
            Subscription.compute_end(
                duration, Subscription.compute_start(date, duration)
            )
        )
    )


def guy():
    guy_test(date(2015, 7, 11))
    guy_test(date(2015, 8, 11))
    guy_test(date(2015, 2, 17))
    guy_test(date(2015, 3, 17))
    guy_test(date(2015, 1, 11))
    guy_test(date(2015, 2, 11))
    guy_test(date(2015, 8, 17))
    guy_test(date(2015, 9, 17))
    print("=" * 80)
    guy_test(date(2015, 7, 11), 1)
    guy_test(date(2015, 8, 11), 2)
    guy_test(date(2015, 2, 17), 3)
    guy_test(date(2015, 3, 17), 4)
    guy_test(date(2015, 1, 11), 1)
    guy_test(date(2015, 2, 11), 2)
    guy_test(date(2015, 8, 17), 3)
    guy_test(date(2015, 9, 17), 4)
    print("=" * 80)
    bibou_test(1, date(2015, 2, 18))
    bibou_test(2, date(2015, 2, 18))
    bibou_test(3, date(2015, 2, 18))
    bibou_test(4, date(2015, 2, 18))
    bibou_test(1, date(2015, 9, 18))
    bibou_test(2, date(2015, 9, 18))
    bibou_test(3, date(2015, 9, 18))
    bibou_test(4, date(2015, 9, 18))
    print("=" * 80)
    bibou_test(1, date(2000, 2, 29))
    bibou_test(2, date(2000, 2, 29))
    bibou_test(1, date(2000, 5, 31))
    bibou_test(1, date(2000, 7, 31))
    bibou_test(1)
    bibou_test(2)
    bibou_test(3)
    bibou_test(4)


if __name__ == "__main__":
    guy()