create reservation models

reservation/models.py

@@ -0,0 +1,102 @@
+from __future__ import annotations
+
+from typing import Self
+
+from django.core.exceptions import ValidationError
+from django.db import models
+from django.db.models import F, Q
+from django.urls import reverse
+from django.utils.translation import gettext_lazy as _
+
+from club.models import Club
+from core.models import User
+
+
+class Room(models.Model):
+    name = models.CharField(_("room name"), max_length=100)
+    description = models.TextField(_("description"), blank=True, default="")
+    club = models.ForeignKey(
+        Club,
+        on_delete=models.CASCADE,
+        related_name="reservable_rooms",
+        verbose_name=_("room owner"),
+        help_text=_("The club which manages this room"),
+    )
+    location = models.CharField(
+        _("site"),
+        blank=True,
+        choices=[
+            ("BELFORT", "Belfort"),
+            ("SEVENANS", "Sévenans"),
+            ("MONTBELIARD", "Montbéliard"),
+        ],
+    )
+
+    class Meta:
+        verbose_name = _("reservable room")
+        verbose_name_plural = _("reservable rooms")
+
+    def __str__(self):
+        return self.name
+
+    def get_absolute_url(self):
+        return reverse("reservation:room_detail", kwargs={"room_id": self.id})
+
+    def can_be_edited_by(self, user: User) -> bool:
+        # a user may edit a room if it has the global perm
+        # or is in the owner club board
+        return user.has_perm("reservation.change_room") or self.club.board_group_id in [
+            g.id for g in user.cached_groups
+        ]
+
+
+class ReservationSlotQuerySet(models.QuerySet):
+    def overlapping_with(self, other: ReservationSlot) -> Self:
+        return self.filter(
+            Q(start_at__lt=other.start_at, start_at__gt=other.start_at)
+            | Q(end_at__gt=other.start_at, end_at__lt=other.end_at)
+        )
+
+
+class ReservationSlot(models.Model):
+    room = models.ForeignKey(
+        Room,
+        on_delete=models.CASCADE,
+        related_name="slots",
+        verbose_name=_("reserved room"),
+    )
+    author = models.ForeignKey(User, on_delete=models.CASCADE, verbose_name=_("author"))
+    comment = models.TextField(_("comment"), blank=True, default="")
+    start_at = models.DateTimeField(_("slot start"), db_index=True)
+    end_at = models.DateTimeField(verbose_name=_("slot end"))
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    objects = ReservationSlotQuerySet.as_manager()
+
+    class Meta:
+        verbose_name = _("reservation slot")
+        verbose_name_plural = _("reservation slots")
+        constraints = [
+            models.CheckConstraint(
+                check=Q(end_at__gt=F("start_at")),
+                name="reservation_slot_end_after_start",
+            )
+        ]
+
+    def __str__(self):
+        return f"{self.room.name} : {self.start_at} - {self.end_at}"
+
+    def clean(self):
+        super().clean()
+        if self.end_at is None or self.start_at is None:
+            # if there is no start or no end, then there is no
+            # point to check if this perm overlap with another,
+            # so in this case, don't do the overlap check and let
+            # Django manage the non-null constraint error.
+            return
+        if (
+            ReservationSlot.objects.overlapping_with(self)
+            .filter(room_id=self.room_id)
+            .exists()
+        ):
+            raise ValidationError(_("There is already a reservation on this slot."))