feat: add exchange_currency to currency

app/apps/currencies/forms.py

@@ -8,6 +8,7 @@ from django.utils.translation import gettext_lazy as _
 from apps.common.widgets.crispy.submit import NoClassSubmit
 from apps.common.widgets.decimal import ArbitraryDecimalDisplayNumberInput
 from apps.currencies.models import Currency, ExchangeRate
+from apps.common.widgets.tom_select import TomSelect
 
 
 class CurrencyForm(forms.ModelForm):
@@ -16,7 +17,17 @@ class CurrencyForm(forms.ModelForm):
 
     class Meta:
         model = Currency
-        fields = ["name", "decimal_places", "prefix", "suffix", "code"]
+        fields = [
+            "name",
+            "decimal_places",
+            "prefix",
+            "suffix",
+            "code",
+            "exchange_currency",
+        ]
+        widgets = {
+            "exchange_currency": TomSelect(),
+        }
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
@@ -25,7 +36,12 @@ class CurrencyForm(forms.ModelForm):
         self.helper.form_tag = False
         self.helper.form_method = "post"
         self.helper.layout = Layout(
-            "code", "name", "decimal_places", "prefix", "suffix"
+            "code",
+            "name",
+            "decimal_places",
+            "prefix",
+            "suffix",
+            "exchange_currency",
         )
 
         if self.instance and self.instance.pk:

app/apps/currencies/migrations/0006_currency_exchange_currency.py

@@ -0,0 +1,19 @@
+# Generated by Django 5.1.2 on 2024-11-09 05:03
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('currencies', '0005_alter_currency_name'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='currency',
+            name='exchange_currency',
+            field=models.ForeignKey(blank=True, help_text='Default currency for exchange calculations', null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='exchange_currencies', to='currencies.currency', verbose_name='Exchange Currency'),
+        ),
+    ]

app/apps/currencies/models.py

@@ -14,6 +14,16 @@ class Currency(models.Model):
     prefix = models.CharField(max_length=10, verbose_name=_("Prefix"), blank=True)
     suffix = models.CharField(max_length=10, verbose_name=_("Suffix"), blank=True)
 
+    exchange_currency = models.ForeignKey(
+        "self",
+        verbose_name=_("Exchange Currency"),
+        on_delete=models.SET_NULL,
+        related_name="exchange_currencies",
+        null=True,
+        blank=True,
+        help_text=_("Default currency for exchange calculations"),
+    )
+
     def __str__(self):
         return self.name