Fix Abnahme-Feedback: Timestamps, Offer-Image, Registrierung u. a.

auth_app/api/serializers.py

@@ -11,7 +11,17 @@ class RegistrationSerializer(serializers.Serializer):
     email = serializers.EmailField()
     password = serializers.CharField(write_only=True)
     repeated_password = serializers.CharField(write_only=True)
-    type = serializers.CharField(write_only=True)
+    type = serializers.ChoiceField(
+        choices=UserProfile.ProfileType.choices,
+        write_only=True,
+    )
+
+    def validate_username(self, value):
+        if get_user_model().objects.filter(username=value).exists():
+            raise serializers.ValidationError(
+                'A user with that username already exists.'
+            )
+        return value
 
     def validate(self, attrs):
         if attrs['password'] != attrs['repeated_password']:
@@ -21,6 +31,7 @@ def validate(self, attrs):
         return attrs
 
     def create(self, validated_data):
+        validated_data.pop('repeated_password', None)
         user = get_user_model().objects.create_user(
             username=validated_data['username'],
             email=validated_data['email'],

auth_app/api/test_auth_endpoints.py

@@ -29,6 +29,31 @@ def test_registration_creates_customer_user_and_returns_token():
     assert profile.type == UserProfile.ProfileType.CUSTOMER
 
 
+@pytest.mark.django_db
+def test_registration_creates_business_user_and_returns_token():
+    client = APIClient()
+    url = reverse('registration')
+    payload = {
+        'username': 'business_user',
+        'email': 'business@example.com',
+        'password': 'StrongPass123!',
+        'repeated_password': 'StrongPass123!',
+        'type': 'business',
+    }
+
+    response = client.post(url, data=payload, format='json')
+
+    assert response.status_code == 201
+    assert response.data == {
+        'username': 'business_user',
+        'email': payload['email'],
+        'user_id': response.data['user_id'],
+        'token': response.data['token'],
+    }
+    profile = UserProfile.objects.get(user_id=response.data['user_id'])
+    assert profile.type == UserProfile.ProfileType.BUSINESS
+
+
 @pytest.mark.django_db
 def test_registration_rejects_password_mismatch():
     client = APIClient()
@@ -47,6 +72,62 @@ def test_registration_rejects_password_mismatch():
     assert not get_user_model().objects.filter(username='customer_user').exists()
 
 
+@pytest.mark.django_db
+def test_registration_rejects_invalid_user_type():
+    client = APIClient()
+    url = reverse('registration')
+    payload = {
+        'username': 'invalid_type_user',
+        'email': 'invalid@example.com',
+        'password': 'StrongPass123!',
+        'repeated_password': 'StrongPass123!',
+        'type': 'admin',
+    }
+
+    response = client.post(url, data=payload, format='json')
+
+    assert response.status_code == 400
+    assert 'type' in response.data
+    assert not get_user_model().objects.filter(username='invalid_type_user').exists()
+
+
+@pytest.mark.django_db
+def test_registration_rejects_duplicate_username():
+    get_user_model().objects.create_user(
+        username='customer_user',
+        email='existing@example.com',
+        password='StrongPass123!',
+    )
+    client = APIClient()
+    url = reverse('registration')
+    payload = {
+        'username': 'customer_user',
+        'email': 'customer@example.com',
+        'password': 'StrongPass123!',
+        'repeated_password': 'StrongPass123!',
+        'type': 'customer',
+    }
+
+    response = client.post(url, data=payload, format='json')
+
+    assert response.status_code == 400
+    assert 'username' in response.data
+
+
+@pytest.mark.django_db
+def test_registration_rejects_missing_required_fields():
+    response = APIClient().post(reverse('registration'), data={}, format='json')
+
+    assert response.status_code == 400
+    assert set(response.data) == {
+        'username',
+        'email',
+        'password',
+        'repeated_password',
+        'type',
+    }
+
+
 @pytest.mark.django_db
 def test_login_returns_token_and_user_data():
     user = get_user_model().objects.create_user(
@@ -87,3 +168,27 @@ def test_login_rejects_invalid_password():
     response = client.post(url, data=payload, format='json')
 
     assert response.status_code == 400
+    assert 'detail' in response.data
+
+
+@pytest.mark.django_db
+def test_login_rejects_unknown_username():
+    client = APIClient()
+    url = reverse('login')
+    payload = {
+        'username': 'missing_user',
+        'password': 'StrongPass123!',
+    }
+
+    response = client.post(url, data=payload, format='json')
+
+    assert response.status_code == 400
+    assert 'detail' in response.data
+
+
+@pytest.mark.django_db
+def test_login_rejects_missing_required_fields():
+    response = APIClient().post(reverse('login'), data={}, format='json')
+
+    assert response.status_code == 400
+    assert set(response.data) == {'username', 'password'}

core/settings.py

@@ -97,6 +97,7 @@ def _env_list(name, default=''):
 # https://www.django-rest-framework.org/
 
 REST_FRAMEWORK = {
+    'DATETIME_FORMAT': '%Y-%m-%dT%H:%M:%SZ',
     'DEFAULT_AUTHENTICATION_CLASSES': [
         'rest_framework.authentication.TokenAuthentication',
         'rest_framework.authentication.SessionAuthentication',
@@ -158,7 +159,7 @@ def _env_list(name, default=''):
 
 LANGUAGE_CODE = 'en-us'
 
-TIME_ZONE = 'Europe/Berlin'
+TIME_ZONE = 'UTC'
 
 USE_I18N = True
 

offers_app/api/serializers.py

@@ -7,6 +7,8 @@
 class OfferDetailSerializer(serializers.ModelSerializer):
     """Serialize full offer detail data for writes and detail retrieval."""
 
+    price = serializers.FloatField()
+
     class Meta:
         model = OfferDetail
         fields = [
@@ -21,7 +23,25 @@ class Meta:
 
 
 class OfferDetailLinkSerializer(serializers.ModelSerializer):
-    """Serialize offer detail references for offer list and detail responses."""
+    """Serialize offer detail references for offer detail responses."""
+
+    url = serializers.SerializerMethodField()
+
+    class Meta:
+        model = OfferDetail
+        fields = [
+            'id',
+            'url',
+        ]
+
+    def get_url(self, obj):
+        url = reverse('offerdetail-detail', kwargs={'pk': obj.id})
+        request = self.context.get('request')
+        return request.build_absolute_uri(url) if request else url
+
+
+class OfferListDetailLinkSerializer(serializers.ModelSerializer):
+    """Serialize offer detail references for offer list responses."""
 
     url = serializers.SerializerMethodField()
 
@@ -33,7 +53,7 @@ class Meta:
         ]
 
     def get_url(self, obj):
-        return reverse('offerdetail-detail', kwargs={'pk': obj.id})
+        return f'/offerdetails/{obj.id}/'
 
 
 class UserDetailsSerializer(serializers.Serializer):
@@ -45,43 +65,24 @@ class UserDetailsSerializer(serializers.Serializer):
 
 
 class OfferSerializer(serializers.ModelSerializer):
-    """Serialize offer writes with nested details and computed summary fields."""
+    """Serialize offer writes with nested details."""
 
     details = OfferDetailSerializer(many=True, required=False)
-    min_price = serializers.SerializerMethodField()
-    min_delivery_time = serializers.SerializerMethodField()
+    image = serializers.ImageField(required=False, allow_null=True)
 
     class Meta:
         model = Offer
         fields = [
             'id',
-            'user',
             'title',
-            'description',
             'image',
+            'description',
             'details',
-            'min_price',
-            'min_delivery_time',
-            'created_at',
-            'updated_at',
         ]
         read_only_fields = [
             'id',
-            'user',
-            'min_price',
-            'min_delivery_time',
-            'created_at',
-            'updated_at',
         ]
 
-    def get_min_price(self, obj):
-        prices = [detail.price for detail in obj.details.all()]
-        return float(min(prices)) if prices else None
-
-    def get_min_delivery_time(self, obj):
-        times = [detail.delivery_time_in_days for detail in obj.details.all()]
-        return min(times) if times else None
-
     def validate(self, attrs):
         if self.instance is None and 'details' not in attrs:
             raise serializers.ValidationError(
@@ -104,15 +105,23 @@ def validate_details(self, value):
         return value
 
     def _validate_update_details(self, value):
+        existing_types = set(self.instance.details.values_list('offer_type', flat=True))
         for detail in value:
-            if 'offer_type' not in detail:
+            offer_type = detail.get('offer_type')
+            if offer_type is None:
                 raise serializers.ValidationError(
                     'Offer type is required to update a detail.',
                 )
+            if offer_type not in existing_types:
+                raise serializers.ValidationError(
+                    f'No detail with offer type "{offer_type}" exists for this offer.',
+                )
         return value
 
     def create(self, validated_data):
         details_data = validated_data.pop('details', None)
+        if 'image' in validated_data and validated_data['image'] is None:
+            validated_data['image'] = ''
         offer = Offer.objects.create(
             user=self.context['request'].user,
             **validated_data,
@@ -122,6 +131,8 @@ def create(self, validated_data):
 
     def update(self, instance, validated_data):
         details_data = validated_data.pop('details', [])
+        if 'image' in validated_data and validated_data['image'] is None:
+            validated_data['image'] = ''
         offer = super().update(instance, validated_data)
         self._update_details(offer, details_data)
         return offer
@@ -143,11 +154,37 @@ class OfferReadSerializer(OfferSerializer):
     """Serialize offers for read endpoints with linked details."""
 
     details = OfferDetailLinkSerializer(many=True)
+    min_price = serializers.SerializerMethodField()
+    min_delivery_time = serializers.SerializerMethodField()
+
+    class Meta(OfferSerializer.Meta):
+        fields = [
+            'id',
+            'user',
+            'title',
+            'image',
+            'description',
+            'created_at',
+            'updated_at',
+            'details',
+            'min_price',
+            'min_delivery_time',
+        ]
+        read_only_fields = fields
+
+    def get_min_price(self, obj):
+        prices = [detail.price for detail in obj.details.all()]
+        return float(min(prices)) if prices else None
+
+    def get_min_delivery_time(self, obj):
+        times = [detail.delivery_time_in_days for detail in obj.details.all()]
+        return min(times) if times else None
 
 
 class OfferListSerializer(OfferReadSerializer):
     """Serialize paginated offer list entries with compact creator details."""
 
+    details = OfferListDetailLinkSerializer(many=True)
     user_details = UserDetailsSerializer(source='user')
 
     class Meta(OfferReadSerializer.Meta):