# Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later

from django.db import models
from django.db.models import Q
from django.utils.translation import gettext_lazy as _
from rest_framework.exceptions import ValidationError
from note.models import NoteUser, Transaction


class ActivityType(models.Model):
    """
    Type of Activity, (e.g "Pot", "Soirée Club") and associated properties.

    Activity Type are used as a search field for Activity, and determine how
    some rules about the activity:
     - Can people be invited
     - What is the entrance fee.
    """
    name = models.CharField(
        verbose_name=_('name'),
        max_length=255,
    )
    can_invite = models.BooleanField(
        verbose_name=_('can invite'),
    )
    guest_entry_fee = models.PositiveIntegerField(
        verbose_name=_('guest entry fee'),
    )

    class Meta:
        verbose_name = _("activity type")
        verbose_name_plural = _("activity types")

    def __str__(self):
        return self.name


class Activity(models.Model):
    """
    An IRL event organized by a club for other club.

    By default the invited clubs should be the Club containing all the active accounts.
    """
    name = models.CharField(
        verbose_name=_('name'),
        max_length=255,
    )

    description = models.TextField(
        verbose_name=_('description'),
    )

    activity_type = models.ForeignKey(
        ActivityType,
        on_delete=models.PROTECT,
        related_name='+',
        verbose_name=_('type'),
    )

    organizer = models.ForeignKey(
        'member.Club',
        on_delete=models.PROTECT,
        related_name='+',
        verbose_name=_('organizer'),
    )

    note = models.ForeignKey(
        'note.Note',
        on_delete=models.PROTECT,
        related_name='+',
        verbose_name=_('note'),
    )

    attendees_club = models.ForeignKey(
        'member.Club',
        on_delete=models.PROTECT,
        related_name='+',
        verbose_name=_('attendees club'),
    )

    date_start = models.DateTimeField(
        verbose_name=_('start date'),
    )

    date_end = models.DateTimeField(
        verbose_name=_('end date'),
    )

    valid = models.BooleanField(
        default=False,
        verbose_name=_('valid'),
    )

    open = models.BooleanField(
        default=False,
        verbose_name=_('open'),
    )

    class Meta:
        verbose_name = _("activity")
        verbose_name_plural = _("activities")


class Entry(models.Model):
    activity = models.ForeignKey(
        Activity,
        on_delete=models.PROTECT,
        verbose_name=_("activity"),
    )

    time = models.DateTimeField(
        auto_now_add=True,
        verbose_name=_("entry time"),
    )

    note = models.ForeignKey(
        NoteUser,
        on_delete=models.PROTECT,
        verbose_name=_("note"),
    )

    guest = models.OneToOneField(
        'activity.Guest',
        on_delete=models.PROTECT,
        null=True,
    )

    class Meta:
        unique_together = (('activity', 'note', 'guest', ), )

    def save(self, force_insert=False, force_update=False, using=None,
             update_fields=None):

        qs = Entry.objects.filter(~Q(pk=self.pk), activity=self.activity, note=self.note, guest=self.guest)
        if qs.exists():
            raise ValidationError(_("Already entered on ") + _("{:%Y-%m-%d %H:%M:%S}").format(qs.get().time, ))

        if self.guest:
            self.note = self.guest.inviter

        insert = not self.pk
        if insert:
            if self.note.balance < 0:
                raise ValidationError(_("The balance is negative."))

        ret = super().save(force_insert, force_update, using, update_fields)

        if insert and self.guest:
            GuestTransaction.objects.create(
                source=self.note,
                source_alias=self.note.user.username,
                destination=self.note,
                destination_alias=self.activity.organizer.name,
                quantity=1,
                amount=self.activity.activity_type.guest_entry_fee,
                reason="Invitation " + self.activity.name + " " + self.guest.first_name + " " + self.guest.last_name,
                valid=True,
                guest=self.guest,
            ).save()

        return ret


class Guest(models.Model):
    """
    People who are not current members of any clubs, and are invited by someone who is a current member.
    """
    activity = models.ForeignKey(
        Activity,
        on_delete=models.PROTECT,
        related_name='+',
    )

    last_name = models.CharField(
        max_length=255,
        verbose_name=_("last name"),
    )

    first_name = models.CharField(
        max_length=255,
        verbose_name=_("first name"),
    )

    inviter = models.ForeignKey(
        NoteUser,
        on_delete=models.PROTECT,
        related_name='+',
        verbose_name=_("inviter"),
    )

    @property
    def has_entry(self):
        try:
            if self.entry:
                return True
            return False
        except AttributeError:
            return False

    class Meta:
        verbose_name = _("guest")
        verbose_name_plural = _("guests")


class GuestTransaction(Transaction):
    guest = models.OneToOneField(
        Guest,
        on_delete=models.PROTECT,
    )

    @property
    def type(self):
        return _('Invitation')