cmsmanage/rentals/models.py

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from django.contrib import admin
from django.core import validators
from django.core.exceptions import ValidationError
from django.db import models, transaction
from django.db.models import F, Q
from django.db.models.functions import Chr, Concat, Ord
from membershipworks.models import Member
class LockerBank(models.Model):
"""A set of locker units, placed together"""
name = models.CharField(max_length=200)
location = models.CharField(max_length=200)
slug = models.SlugField(unique=True)
def __str__(self):
return f"{self.name} ({self.units.count()} units)"
class LockerUnit(models.Model):
"""A standalone set of lockers"""
bank = models.ForeignKey(
LockerBank, on_delete=models.SET_NULL, related_name="units", null=True
)
index = models.PositiveIntegerField()
first_letter = models.CharField(
max_length=1, validators=[validators.RegexValidator("[A-Z]")], unique=True
)
first_number = models.PositiveIntegerField()
rows = models.PositiveIntegerField(default=5)
columns = models.PositiveIntegerField(default=2)
class Meta:
# TODO: add constraint to check for letter overlaps
constraints = [
models.UniqueConstraint(fields=["bank", "index"], name="unique_bank_index")
]
ordering = ["index"]
def __str__(self):
last_letter = chr(ord(self.first_letter) + self.columns - 1)
last_number = self.first_number + self.columns * self.rows
return f"{self.bank.name} (Unit {last_letter}{self.first_number}-{self.first_letter}{last_number})"
def save(self, *args, **kwargs):
if self._state.adding:
# Create LockerInfo for each locker
with transaction.atomic():
super().save(self, *args, **kwargs)
for column in range(self.columns):
for row in range(self.rows):
self.lockers.create(column=column + 1, row=row + 1)
else:
super().save(self, *args, **kwargs)
def letter_for_column(self, column: int) -> str:
return chr(column + ord(self.first_letter))
def number_for_locker(self, column: int, row: int) -> int:
return row + self.first_number + (self.columns - column - 1) * self.rows
# TODO: add check constraint to ensure that column and number are within locker_unit bounds
class LockerInfo(models.Model):
"""Information about a single locker"""
locker_unit = models.ForeignKey(
LockerUnit, on_delete=models.CASCADE, related_name="lockers"
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)
column = models.PositiveIntegerField()
row = models.PositiveIntegerField()
blind_code = models.CharField(
max_length=5,
help_text="Stamped on some keys. Usually D###A.",
blank=True,
)
bitting_code = models.CharField(
max_length=5,
help_text="National Disc Tumbler, depths 1-4. Read bow-to-tip.",
blank=True,
)
renter = models.ForeignKey(
Member, on_delete=models.CASCADE, null=True, blank=True, db_constraint=False
)
reserved = models.BooleanField(
default=False,
help_text="Locker is reserved for MakerSpace use, and cannot be rented.",
)
notes = models.TextField(blank=True)
class Meta:
constraints = [
models.UniqueConstraint(
fields=["locker_unit", "column", "row"], name="unique_locker_info"
),
models.CheckConstraint(
check=Q(reserved=False) | Q(renter__isnull=True),
name="locker_not_reserved_and_rented",
),
]
def __str__(self):
return f"{self.locker_unit}-{self.address} [{self.renter}]"
def clean(self):
if self.reserved and self.renter is not None:
raise ValidationError("Locker cannot both be reserved and rented!")
@property
def available(self) -> bool:
return self.renter is None and not self.reserved
@property
def letter(self) -> str:
return self.locker_unit.letter_for_column(self.column)
@property
def number(self) -> int:
return self.locker_unit.number_for_locker(self.column, self.row)
@property
@admin.display(
description="Address",
ordering=Concat(
Chr(F("column") + Ord("locker_unit__first_letter")),
(
F("row")
+ F("locker_unit__first_number")
+ (F("locker_unit__columns") - F("column") - 1) * F("locker_unit__rows")
),
),
)
def address(self) -> str:
return f"{self.letter}{self.number}"