changes

app/apps/currencies/admin.py

@@ -1,6 +1,6 @@
 from django.contrib import admin
 
-from apps.currencies.models import Currency
+from apps.currencies.models import Currency, ExchangeRate
 
 
 @admin.register(Currency)
@@ -9,3 +9,6 @@ class CurrencyAdmin(admin.ModelAdmin):
         if db_field.name == "suffix" or db_field.name == "prefix":
             kwargs["strip"] = False
         return super().formfield_for_dbfield(db_field, request, **kwargs)
+
+
+admin.site.register(ExchangeRate)

app/apps/currencies/forms.py

@@ -0,0 +1,45 @@
+from crispy_forms.bootstrap import FormActions
+from crispy_forms.helper import FormHelper
+from crispy_forms.layout import Layout
+from django import forms
+from django.forms import CharField
+from django.utils.translation import gettext_lazy as _
+
+from apps.common.widgets.crispy.submit import NoClassSubmit
+from apps.currencies.models import Currency
+
+
+class CurrencyForm(forms.ModelForm):
+    prefix = CharField(strip=False, required=False)
+    suffix = CharField(strip=False, required=False)
+
+    class Meta:
+        model = Currency
+        fields = ["name", "decimal_places", "prefix", "suffix", "code"]
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self.helper = FormHelper()
+        self.helper.form_tag = False
+        self.helper.form_method = "post"
+        self.helper.layout = Layout(
+            "code", "name", "decimal_places", "prefix", "suffix"
+        )
+
+        if self.instance and self.instance.pk:
+            self.helper.layout.append(
+                FormActions(
+                    NoClassSubmit(
+                        "submit", _("Update"), css_class="btn btn-outline-primary w-100"
+                    ),
+                ),
+            )
+        else:
+            self.helper.layout.append(
+                FormActions(
+                    NoClassSubmit(
+                        "submit", _("Add"), css_class="btn btn-outline-primary w-100"
+                    ),
+                ),
+            )

app/apps/currencies/migrations/0004_exchangerate.py

@@ -0,0 +1,58 @@
+# Generated by Django 5.1.1 on 2024-10-04 03:33
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("currencies", "0003_alter_currency_decimal_places"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="ExchangeRate",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                (
+                    "rate",
+                    models.DecimalField(
+                        decimal_places=30, max_digits=42, verbose_name="Exchange Rate"
+                    ),
+                ),
+                ("date", models.DateTimeField(verbose_name="Date and Time")),
+                (
+                    "from_currency",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="from_exchange_rates",
+                        to="currencies.currency",
+                        verbose_name="From Currency",
+                    ),
+                ),
+                (
+                    "to_currency",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="to_exchange_rates",
+                        to="currencies.currency",
+                        verbose_name="To Currency",
+                    ),
+                ),
+            ],
+            options={
+                "verbose_name": "Exchange Rate",
+                "verbose_name_plural": "Exchange Rates",
+                "unique_together": {("from_currency", "to_currency", "date")},
+            },
+        ),
+    ]

app/apps/currencies/models.py

@@ -20,3 +20,30 @@ class Currency(models.Model):
     class Meta:
         verbose_name = _("Currency")
         verbose_name_plural = _("Currencies")
+
+
+class ExchangeRate(models.Model):
+    from_currency = models.ForeignKey(
+        Currency,
+        on_delete=models.CASCADE,
+        related_name="from_exchange_rates",
+        verbose_name=_("From Currency"),
+    )
+    to_currency = models.ForeignKey(
+        Currency,
+        on_delete=models.CASCADE,
+        related_name="to_exchange_rates",
+        verbose_name=_("To Currency"),
+    )
+    rate = models.DecimalField(
+        max_digits=42, decimal_places=30, verbose_name=_("Exchange Rate")
+    )
+    date = models.DateTimeField(verbose_name=_("Date and Time"))
+
+    class Meta:
+        verbose_name = _("Exchange Rate")
+        verbose_name_plural = _("Exchange Rates")
+        unique_together = ("from_currency", "to_currency", "date")
+
+    def __str__(self):
+        return f"{self.from_currency.code} to {self.to_currency.code} on {self.date}"

app/apps/currencies/urls.py

@@ -0,0 +1,18 @@
+from django.urls import path
+
+from . import views
+
+urlpatterns = [
+    path("currencies/", views.currency_list, name="currencies_list"),
+    path("currencies/add/", views.currency_add, name="currency_add"),
+    path(
+        "currencies/<int:pk>/edit/",
+        views.currency_edit,
+        name="currency_edit",
+    ),
+    path(
+        "currencies/<int:pk>/delete/",
+        views.currency_delete,
+        name="currency_delete",
+    ),
+]

app/apps/currencies/utils/convert.py

@@ -0,0 +1,42 @@
+from django.db.models import Func, F, Value, DurationField, Case, When, DecimalField, Q
+from django.db.models.functions import Abs, Extract
+from django.utils import timezone
+from django.core.exceptions import ValidationError
+from django.utils.translation import gettext_lazy as _
+
+from apps.currencies.models import ExchangeRate
+
+
+def convert(amount, from_currency, to_currency, date=None):
+    if from_currency == to_currency:
+        return amount
+
+    if date is None:
+        date = timezone.localtime(timezone.now())
+
+    try:
+        exchange_rate = (
+            ExchangeRate.objects.filter(
+                Q(from_currency=from_currency, to_currency=to_currency)
+                | Q(from_currency=to_currency, to_currency=from_currency)
+            )
+            .annotate(
+                date_diff=Func(
+                    Extract(F("date") - Value(date), "epoch"), function="ABS"
+                ),
+                effective_rate=Case(
+                    When(from_currency=from_currency, then=F("rate")),
+                    default=1 / F("rate"),
+                    output_field=DecimalField(),
+                ),
+            )
+            .order_by("date_diff")
+            .first()
+        )
+
+        if exchange_rate is None:
+            return None
+
+        return amount * exchange_rate.effective_rate
+    except ExchangeRate.DoesNotExist:
+        return None

app/apps/currencies/views.py

@@ -1,3 +1,92 @@
-from django.shortcuts import render
+from django.contrib import messages
+from django.contrib.auth.decorators import login_required
+from django.http import HttpResponse
+from django.shortcuts import render, get_object_or_404
+from django.urls import reverse
+from django.utils.translation import gettext_lazy as _
+from django.views.decorators.csrf import csrf_exempt
+from django.views.decorators.http import require_http_methods
 
-# Create your views here.
+from apps.common.decorators.htmx import only_htmx
+from apps.currencies.forms import CurrencyForm
+from apps.currencies.models import Currency
+
+
+@login_required
+@require_http_methods(["GET"])
+def currency_list(request):
+    currencies = Currency.objects.all().order_by("id")
+    return render(request, "currencies/pages/list.html", {"currencies": currencies})
+
+
+@only_htmx
+@login_required
+@require_http_methods(["GET", "POST"])
+def currency_add(request, **kwargs):
+    if request.method == "POST":
+        form = CurrencyForm(request.POST)
+        if form.is_valid():
+            form.save()
+            messages.success(request, _("Currency added successfully"))
+
+            return HttpResponse(
+                status=204,
+                headers={
+                    "HX-Location": reverse("currencies_list"),
+                    "HX-Trigger": "hide_offcanvas, toasts",
+                },
+            )
+    else:
+        form = CurrencyForm()
+
+    return render(
+        request,
+        "currencies/fragments/add.html",
+        {"form": form},
+    )
+
+
+@only_htmx
+@login_required
+@require_http_methods(["GET", "POST"])
+def currency_edit(request, pk):
+    currency = get_object_or_404(Currency, id=pk)
+
+    if request.method == "POST":
+        form = CurrencyForm(request.POST, instance=currency)
+        if form.is_valid():
+            form.save()
+            messages.success(request, _("Currency updated successfully"))
+
+            return HttpResponse(
+                status=204,
+                headers={
+                    "HX-Location": reverse("currencies_list"),
+                    "HX-Trigger": "hide_offcanvas, toasts",
+                },
+            )
+    else:
+        form = CurrencyForm(instance=currency)
+
+    return render(
+        request,
+        "currencies/fragments/edit.html",
+        {"form": form, "currency": currency},
+    )
+
+
+@only_htmx
+@login_required
+@csrf_exempt
+@require_http_methods(["DELETE"])
+def currency_delete(request, pk):
+    currency = get_object_or_404(Currency, id=pk)
+
+    currency.delete()
+
+    messages.success(request, _("Currency deleted successfully"))
+
+    return HttpResponse(
+        status=204,
+        headers={"HX-Location": reverse("currencies_list")},
+    )