rentals: Change numbering scheme to match reality

rentals/admin.py

@@ -1,6 +1,17 @@
 from django.contrib import admin
 
-from .models import LockerBank, LockerRental
+from .models import LockerBank, LockerRental, LockerUnit
+
+
+class LockerUnitInline(admin.TabularInline):
+    model = LockerUnit
+    extra = 0
+
+
+@admin.register(LockerBank)
+class LockerBankAdmin(admin.ModelAdmin):
+    inlines = [LockerUnitInline]
+    prepopulated_fields = {"slug": ("name",)}
 
 
 class LockerRentalInline(admin.TabularInline):
@@ -8,10 +19,9 @@ class LockerRentalInline(admin.TabularInline):
     extra = 0
 
 
-@admin.register(LockerBank)
+@admin.register(LockerUnit)
-class LockerBankAdmin(admin.ModelAdmin):
+class LockerUnitAdmin(admin.ModelAdmin):
     inlines = [LockerRentalInline]
-    prepopulated_fields = {"slug": ("name",)}
 
 
 admin.site.register(LockerRental)

rentals/migrations/0001_initial.py

@@ -1,6 +1,7 @@
-# Generated by Django 3.2.11 on 2022-01-24 04:08
+# Generated by Django 3.2.11 on 2022-01-27 22:14
 
 from django.conf import settings
+import django.core.validators
 from django.db import migrations, models
 import django.db.models.deletion
 
@@ -21,18 +22,35 @@ class Migration(migrations.Migration):
                 ('name', models.CharField(max_length=200)),
                 ('location', models.CharField(max_length=200)),
                 ('slug', models.SlugField(unique=True)),
-                ('rows', models.PositiveIntegerField()),
-                ('columns', models.PositiveIntegerField()),
             ],
         ),
+        migrations.CreateModel(
+            name='LockerUnit',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('index', models.PositiveIntegerField()),
+                ('first_letter', models.CharField(max_length=1, unique=True, validators=[django.core.validators.RegexValidator('[A-Z]')])),
+                ('first_number', models.PositiveIntegerField()),
+                ('rows', models.PositiveIntegerField(default=5)),
+                ('columns', models.PositiveIntegerField(default=2)),
+                ('bank', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='units', to='rentals.lockerbank')),
+            ],
+            options={
+                'ordering': ['index'],
+            },
+        ),
         migrations.CreateModel(
             name='LockerRental',
             fields=[
                 ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
-                ('row', models.PositiveIntegerField()),
                 ('column', models.PositiveIntegerField()),
-                ('locker_bank', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='rentals.lockerbank')),
+                ('row', models.PositiveIntegerField()),
+                ('locker_unit', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='rentals', to='rentals.lockerunit')),
                 ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
             ],
         ),
+        migrations.AddConstraint(
+            model_name='lockerunit',
+            constraint=models.UniqueConstraint(fields=('bank', 'index'), name='unique_bank_index'),
+        ),
     ]

rentals/models.py

@@ -1,45 +1,75 @@
 from django.contrib.auth import get_user_model
+from django.core import validators
 from django.db import models
 
 
 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)
-    rows = models.PositiveIntegerField()
-    columns = models.PositiveIntegerField()
-    # TODO: add constraint for unique first letter?
 
     def __str__(self):
-        return f"{self.name} ({self.columns}x{self.rows})"
+        return f"{self.name} ({self.units.count()} units)"
 
-    @property
+
-    def initial(self):
+class LockerUnit(models.Model):
-        return self.name[0].upper()
+    """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 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 + column * self.rows
 
     @property
     def iter_doors(self):
         for row in range(self.rows):
             for column in range(self.columns):
                 # TODO: filter could be optimized
-                yield chr(row + ord("A")), column + 1, self.rentals.filter(
+                yield (
-                    row=row, column=column
+                    self.letter_for_column(column),
+                    self.number_for_locker(column, row),
+                    self.rentals.filter(row=row, column=column),
                 )
 
 
+# TODO: add check constraint to ensure that column and number are within locker_unit bounds
+# TODO: add unique constraint on (unit, row, column)?
 class LockerRental(models.Model):
-    locker_bank = models.ForeignKey(
+    """A rental of a single locker"""
-        LockerBank, on_delete=models.CASCADE, related_name="rentals"
+
+    locker_unit = models.ForeignKey(
+        LockerUnit, on_delete=models.CASCADE, related_name="rentals"
     )
-    user = models.ForeignKey(get_user_model(), on_delete=models.CASCADE)
-    row = models.PositiveIntegerField()
     column = models.PositiveIntegerField()
-    # TODO: add check constraint to ensure that row and column are within locker_bank bounds
+    row = models.PositiveIntegerField()
-    # TODO: add unique constraint on (bank, row, column)?
+    user = models.ForeignKey(get_user_model(), on_delete=models.CASCADE)
 
     @property
     def address(self) -> str:
-        return f"{self.locker_bank.name}-{self.locker_bank.initial}{chr(self.row + ord('A'))}{self.column}"
+        letter = self.locker_unit.letter_for_column(self.column)
+        number = self.locker_unit.number_for_locker(self.column, self.row)
+        return f"{self.locker_unit}-{letter}{number}"
 
     def __str__(self):
         return f"{self.user}: {self.address}"

rentals/templates/rentals/lockers.dj.html

@@ -1,7 +1,9 @@
 {% extends "base.dj.html" %}
 
 {% block title %}Lockers Index{% endblock %}
-{% block admin_link %}{% url 'admin:app_list' 'rentals' %}{% endblock %}
+{% block admin_link %}
+  {% url 'admin:app_list' 'rentals' %}
+{% endblock %}
 {% block content %}
   <style>
   .locker-bank {
@@ -9,12 +11,17 @@
     text-align: center;
   }
 
-  .locker {
+  .lockers {
-    display: grid;
-    gap: 0.5rem;
     padding: 1rem;
     background-color: #333333;
     border-radius: 0.4rem;
+    display: flex;
+    gap: 0.5rem;
+  }
+
+  .locker {
+    display: grid;
+    gap: 0.5rem;
   }
 
   .locker[data-columns="2"] {
@@ -50,13 +57,13 @@
 }
   </style>
   {% for bank in locker_banks %}
-    <div class="locker-bank">
+    <div class="locker-bank" data-bank="{{ bank.slug }}">
       <h2>{{ bank.name }}</h2>
       <div>{{ bank.location }}</div>
-      <div class="locker"
+      <div class="lockers">
-           data-columns="{{ bank.columns }}"
+        {% for unit in bank.units.all %}
-           data-bank="{{ bank.slug }}">
+          <div class="locker" data-columns="{{ unit.columns }}">
-        {% for row, column, rentals in bank.iter_doors %}
+            {% for row, column, rentals in unit.iter_doors %}
               <div class="door"
                    data-rentals="{{ rentals|length }}"
                    data-row="{{ row }}"
@@ -77,6 +84,8 @@
               </div>
             {% endfor %}
           </div>
+        {% endfor %}
+      </div>
     </div>
   {% endfor %}
 {% endblock %}