feat: adds movement templates to ease the pain of writing records

Author: corp-0

src/transactions/admin.py

@@ -1,6 +1,48 @@
 from django.contrib import admin
 
-# Register your models here.
-from .models import Movement
+from django.contrib import admin
+from .models import Movement, MovementTemplate
+from django.urls import path, reverse
+from django.http import HttpResponseRedirect
+from django.utils.html import format_html
+
+@admin.register(Movement)
+class MovementAdmin(admin.ModelAdmin):
+    readonly_fields = ('balance_after',)
+    list_display = ('type', 'description', 'amount_usd', 'balance_after', 'created_at')  # optional, shows these columns in the list view
+
+    def get_changeform_initial_data(self, request):
+        return {
+            key: request.GET.get(key) for key in ['type', 'description', 'notes', 'amount_usd']
+            if key in request.GET
+        }
+
+@admin.register(MovementTemplate)
+class MovementTemplateAdmin(admin.ModelAdmin):
+    list_display = ('name', 'use_button',  'type', 'description', 'amount_usd')
+
+    def get_urls(self):
+        urls = super().get_urls()
+        custom_urls = [
+            path(
+                'use/<int:pk>/',
+                self.admin_site.admin_view(self.use_recurrent_movement),
+                name='use-recurrent-movement',
+            ),
+        ]
+        return custom_urls + urls
+
+    def use_button(self, obj):
+        url = reverse('admin:use-recurrent-movement', args=[obj.pk])
+        return format_html('<a class="button" href="{}">Use</a>', url)
+    use_button.short_description = "Use"
+    use_button.allow_tags = True
 
-admin.site.register(Movement)
+    def use_recurrent_movement(self, _, pk):
+        recurrent = MovementTemplate.objects.get(pk=pk)
+        add_url = (
+                reverse("admin:transactions_movement_add") +
+                f"?type={recurrent.type}&description={recurrent.description}"
+                f"&notes={recurrent.notes or ''}&amount_usd={recurrent.amount_usd}"
+        )
+        return HttpResponseRedirect(add_url)

src/transactions/api/serializers.py

@@ -1,6 +1,5 @@
 from rest_framework import serializers
 
-from .calc import recalculate_balances
 from ..models import Movement
 
 
@@ -12,5 +11,4 @@ class Meta:
 
     def create(self, validated_data):
         instance = Movement.objects.create(**validated_data)
-        recalculate_balances()
         return instance

src/transactions/migrations/0002_movement_description_movement_notes.py

@@ -0,0 +1,24 @@
+# Generated by Django 5.1.7 on 2025-03-31 00:38
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('transactions', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='movement',
+            name='description',
+            field=models.CharField(max_length=560),
+            preserve_default=False,
+        ),
+        migrations.AddField(
+            model_name='movement',
+            name='notes',
+            field=models.TextField(blank=True, null=True),
+        ),
+    ]

src/transactions/migrations/0003_movementtemplate.py

@@ -0,0 +1,24 @@
+# Generated by Django 5.1.7 on 2025-04-06 00:02
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('transactions', '0002_movement_description_movement_notes'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='MovementTemplate',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=100)),
+                ('type', models.CharField(choices=[('income', 'Income'), ('expense', 'Expense')], max_length=10)),
+                ('description', models.CharField(max_length=560)),
+                ('notes', models.TextField(blank=True, null=True)),
+                ('amount_usd', models.DecimalField(decimal_places=2, max_digits=10)),
+            ],
+        ),
+    ]

src/transactions/models.py

@@ -6,6 +6,8 @@
 
 
 def recalculate_balances():
+    """Recalculate the balance after each movement. This way the balance is updated even if you add a movement that happened in the past."""
+
     movements = Movement.objects.all().order_by("created_at")
     balance = Decimal('0.00')
 
@@ -19,14 +21,17 @@ def recalculate_balances():
             movement.balance_after = balance
             movement.save(update_fields=['balance_after'])
 
+MOVEMENT_TYPES = [
+    ("income", "Income"),
+    ("expense", "Expense"),
+]
 
-class Movement(models.Model):
-    MOVEMENT_TYPES = [
-        ("income", "Income"),
-        ("expense", "Expense"),
-    ]
 
+class Movement(models.Model):
+    """Represents a money movement (income or expense)."""
     type = models.CharField(max_length=10, choices=MOVEMENT_TYPES)
+    description = models.CharField(max_length=560)
+    notes = models.TextField(blank=True, null=True)
     amount_usd = models.DecimalField(max_digits=10, decimal_places=2)
     created_at = models.DateTimeField(default=timezone.now)
     balance_after = models.DecimalField(max_digits=10, decimal_places=2, editable=False)
@@ -42,7 +47,19 @@ def save(self, *args, **kwargs):
             self.balance_after = Decimal("0.00")
 
         super().save(*args, **kwargs)  # Save once so the row exists (with a temporary value)
-
-        # Recalculate all balances in chronological order
         recalculate_balances()
 
+    def __str__(self):
+        return f"{self.created_at.date()} - {self.type.capitalize()}: ${self.amount_usd} - {self.description}"
+
+
+class MovementTemplate(models.Model):
+    """Represents a template of sort, to automatically create movements that are recurrent in time."""
+    name = models.CharField(max_length=100)
+    type = models.CharField(max_length=10, choices=MOVEMENT_TYPES)
+    description = models.CharField(max_length=560)
+    notes = models.TextField(blank=True, null=True)
+    amount_usd = models.DecimalField(max_digits=10, decimal_places=2)
+
+    def __str__(self):
+        return self.name