feat: add price.price_per field (#127)

alembic/versions/20240111_0914_a8ad2f078f3f_add_product_price_per_field.py

@@ -0,0 +1,40 @@
+"""add product.price_per field
+
+Revision ID: a8ad2f078f3f
+Revises: 007443669adc
+Create Date: 2024-01-11 09:14:25.778905
+
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "a8ad2f078f3f"
+down_revision: Union[str, None] = "007443669adc"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column(
+        "prices",
+        sa.Column(
+            "price_per",
+            sa.String(length=255),
+            nullable=True,
+        ),
+    )
+    op.execute(
+        "UPDATE prices SET price_per = 'KILOGRAM' WHERE price_per IS NULL AND category_tag IS NOT NULL;"
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column("prices", "price_per")
+    # ### end Alembic commands ###

app/enums.py

@@ -1,4 +1,4 @@
-from enum import Enum
+from enum import Enum, unique
 
 from babel.numbers import list_currencies
 
@@ -17,3 +17,13 @@ class ProofTypeEnum(Enum):
     PRICE_TAG = "PRICE_TAG"
     RECEIPT = "RECEIPT"
     GDPR_REQUEST = "GDPR_REQUEST"
+
+
+@unique
+class PricePerEnum(Enum):
+    """For raw products (fruits, vegetables, etc.), the price is either
+    per unit or per kilogram. This enum is used to store this information.
+    """
+
+    UNIT = "UNIT"
+    KILOGRAM = "KILOGRAM"

app/models.py

@@ -18,7 +18,7 @@
 from sqlalchemy_utils.types.choice import ChoiceType
 
 from app.db import Base
-from app.enums import CurrencyEnum, LocationOSMEnum, ProofTypeEnum
+from app.enums import CurrencyEnum, LocationOSMEnum, PricePerEnum, ProofTypeEnum
 
 force_auto_coercion()
 JSONVariant = JSON().with_variant(JSONB(), "postgresql")
@@ -108,6 +108,7 @@ class Price(Base):
 
     price = Column(Numeric(precision=10, scale=2))
     currency = Column(ChoiceType(CurrencyEnum))
+    price_per = Column(ChoiceType(PricePerEnum))
 
     location_osm_id = Column(BigInteger, index=True)
     location_osm_type = Column(ChoiceType(LocationOSMEnum))

app/schemas.py

@@ -13,7 +13,7 @@
     model_validator,
 )
 
-from app.enums import CurrencyEnum, LocationOSMEnum, ProofTypeEnum
+from app.enums import CurrencyEnum, LocationOSMEnum, PricePerEnum, ProofTypeEnum
 from app.models import Price, Product
 
 
@@ -154,6 +154,14 @@ class PriceCreate(BaseModel):
         "kilogram or per liter.",
         examples=["1.99"],
     )
+    price_per: PricePerEnum | None = Field(
+        default=PricePerEnum.KILOGRAM,
+        description="""if the price is about a barcode-less product
+        (if `category_tag` is provided), this field must be set to `KILOGRAM`
+        or `UNIT` (KILOGRAM by default).
+        This field is set to null and ignored if `product_code` is provided.
+        """,
+    )
     currency: CurrencyEnum = Field(
         description="currency of the price, as a string. "
         "The currency must be a valid currency code. "
@@ -249,6 +257,13 @@ def product_code_and_category_tag_are_exclusive(self):
             raise ValueError("either `product_code` or `category_tag` must be set")
         return self
 
+    @model_validator(mode="after")
+    def set_price_per_to_null_if_barcode(self):
+        """Validator that sets `price_per` to null if `product_code` is set."""
+        if self.product_code is not None:
+            self.price_per = None
+        return self
+
 
 class PriceBase(PriceCreate):
     product_id: int | None

tests/test_api.py

@@ -142,6 +142,7 @@ def test_create_price_with_category_tag(db_session, user, clean_prices):
             "labels_tags": ["en:Organic"],
             "origins_tags": ["en:France"],
             "date": "2023-12-01",
+            "price_per": "UNIT",
         }
     )
     response = client.post(
@@ -155,6 +156,7 @@ def test_create_price_with_category_tag(db_session, user, clean_prices):
     assert json_response.get("labels_tags") == ["en:organic"]
     assert json_response.get("origins_tags") == ["en:france"]
     assert json_response.get("date") == "2023-12-01"
+    assert json_response.get("price_per") == "UNIT"
     assert "id" not in response.json()
     db_prices = crud.get_prices(db_session)
     assert len(db_prices) == 1