Fix currency validation & serialization

app/schemas.py

@@ -3,7 +3,9 @@
 
 from pydantic import BaseModel
 from pydantic import ConfigDict
+from pydantic import field_serializer
 from pydantic import field_validator
+from sqlalchemy_utils import Currency
 
 from app.enums import PriceLocationOSMType
 
@@ -16,21 +18,35 @@ class UserBase(BaseModel):
 
 
 class PriceCreate(BaseModel):
-    model_config = ConfigDict(from_attributes=True)
+    model_config = ConfigDict(from_attributes=True, arbitrary_types_allowed=True)
 
     product_code: str
     price: float
-    currency: str = "EUR"
+    currency: str | Currency = "EUR"
     location_osm_id: int
     location_osm_type: PriceLocationOSMType
     date: date
 
+    @field_validator("currency")
+    def currency_is_valid(cls, v):
+        try:
+            return Currency(v).code
+        except ValueError:
+            raise ValueError("not a valid currency code")
+
     @field_validator("location_osm_id")
     def location_osm_id_must_be_positive(cls, v):
         if v <= 0:
             raise ValueError("must be positive")
         return v
 
+    @field_serializer("currency")
+    def serialize_currency(self, currency: Currency, _info):
+        if type(currency) is Currency:
+            return currency.code
+        return currency
+
 
 class PriceBase(PriceCreate):
+    # owner: str
     created: datetime