Reoraganized project

solution/pulse/api/countries/apps.py

@@ -0,0 +1,6 @@
+from django.apps import AppConfig
+
+
+class CountriesConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "api.countries"

solution/pulse/api/countries/models.py

@@ -0,0 +1,15 @@
+from django.db import models
+
+
+class Country(models.Model):
+    name = models.CharField(max_length=100)
+    alpha2 = models.CharField(max_length=2)
+    alpha3 = models.CharField(max_length=3)
+    region = models.CharField()
+
+    class Meta:
+        db_table = "countries"
+        managed = False
+
+    def __str__(self):
+        return self.name

solution/pulse/api/countries/serializers.py

@@ -0,0 +1,9 @@
+from rest_framework import serializers
+
+from api.countries.models import Country
+
+
+class CountrySerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Country
+        fields = ["name", "alpha2", "alpha3", "region"]

solution/pulse/api/countries/urls.py

@@ -0,0 +1,12 @@
+from django.urls import path
+
+import api.countries.views
+
+urlpatterns = [
+    path("", api.countries.views.CountryListView.as_view(), name="countries"),
+    path(
+        "/<str:alpha2>",
+        api.countries.views.CountryByAlpha2View.as_view(),
+        name="country_by_alpha2",
+    ),
+]

solution/pulse/api/countries/views.py

@@ -0,0 +1,34 @@
+from django.conf import settings
+from rest_framework.exceptions import ValidationError
+from rest_framework.generics import ListAPIView, RetrieveAPIView
+
+from api.countries.models import Country
+from api.countries.serializers import CountrySerializer
+
+
+class CountryListView(ListAPIView):
+    queryset = Country.objects.all().order_by("alpha2")
+    serializer_class = CountrySerializer
+
+    def filter_queryset(self, queryset):
+        regions = self.request.query_params.get("region")
+        if regions:
+            regions_list = regions.split(",")
+            invalid_regions = [
+                region
+                for region in regions_list
+                if region not in settings.REGIONS
+            ]
+            if invalid_regions:
+                invalid_regions_str = ", ".join(invalid_regions)
+                error_message = f"Invalid region(s): {invalid_regions_str}"
+                raise ValidationError(error_message)
+
+            queryset = queryset.filter(region__in=regions_list)
+        return queryset
+
+
+class CountryByAlpha2View(RetrieveAPIView):
+    queryset = Country.objects.all()
+    serializer_class = CountrySerializer
+    lookup_field = "alpha2"