feat: Implement SQLAlchemy enum helper and normalize enum values in database initialization

models/enums.py

@@ -1,6 +1,21 @@
 from __future__ import annotations
 
 from enum import Enum
+from typing import Type
+
+from sqlalchemy import Enum as SQLEnum
+
+
+def sql_enum(enum_cls: Type[Enum], *, name: str) -> SQLEnum:
+    """Build a SQLAlchemy Enum that maps using the enum member values."""
+
+    return SQLEnum(
+        enum_cls,
+        name=name,
+        create_type=False,
+        validate_strings=True,
+        values_callable=lambda enum_cls: [member.value for member in enum_cls],
+    )
 
 
 class MiningOperationType(str, Enum):

models/financial_input.py

@@ -6,7 +6,6 @@ from typing import TYPE_CHECKING
 from sqlalchemy import (
     Date,
     DateTime,
-    Enum as SQLEnum,
     ForeignKey,
     Integer,
     Numeric,
@@ -18,7 +17,7 @@ from sqlalchemy.orm import Mapped, mapped_column, relationship, validates
 from sqlalchemy.sql import func
 
 from config.database import Base
-from .enums import CostBucket, FinancialCategory
+from .enums import CostBucket, FinancialCategory, sql_enum
 from services.currency import normalise_currency
 
 if TYPE_CHECKING:  # pragma: no cover
@@ -36,10 +35,10 @@ class FinancialInput(Base):
     )
     name: Mapped[str] = mapped_column(String(255), nullable=False)
     category: Mapped[FinancialCategory] = mapped_column(
-        SQLEnum(FinancialCategory, name="financialcategory", create_type=False), nullable=False
+        sql_enum(FinancialCategory, name="financialcategory"), nullable=False
     )
     cost_bucket: Mapped[CostBucket | None] = mapped_column(
-        SQLEnum(CostBucket, name="costbucket", create_type=False), nullable=True
+        sql_enum(CostBucket, name="costbucket"), nullable=True
     )
     amount: Mapped[float] = mapped_column(Numeric(18, 2), nullable=False)
     currency: Mapped[str | None] = mapped_column(String(3), nullable=True)

models/project.py

@@ -3,9 +3,9 @@ from __future__ import annotations
 from datetime import datetime
 from typing import TYPE_CHECKING, List
 
-from .enums import MiningOperationType
+from .enums import MiningOperationType, sql_enum
 
-from sqlalchemy import DateTime, Enum as SQLEnum, ForeignKey, Integer, String, Text
+from sqlalchemy import DateTime, ForeignKey, Integer, String, Text
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 from sqlalchemy.sql import func
 
@@ -16,8 +16,6 @@ if TYPE_CHECKING:  # pragma: no cover
     from .pricing_settings import PricingSettings
 
 
-
-
 class Project(Base):
     """Top-level mining project grouping multiple scenarios."""
 
@@ -27,7 +25,7 @@ class Project(Base):
     name: Mapped[str] = mapped_column(String(255), nullable=False, unique=True)
     location: Mapped[str | None] = mapped_column(String(255), nullable=True)
     operation_type: Mapped[MiningOperationType] = mapped_column(
-        SQLEnum(MiningOperationType, name="miningoperationtype", create_type=False),
+        sql_enum(MiningOperationType, name="miningoperationtype"),
         nullable=False,
         default=MiningOperationType.OTHER,
     )

models/scenario.py

@@ -6,7 +6,6 @@ from typing import TYPE_CHECKING, List
 from sqlalchemy import (
     Date,
     DateTime,
-    Enum as SQLEnum,
     ForeignKey,
     Integer,
     Numeric,
@@ -19,7 +18,7 @@ from sqlalchemy.sql import func
 
 from config.database import Base
 from services.currency import normalise_currency
-from .enums import ResourceType, ScenarioStatus
+from .enums import ResourceType, ScenarioStatus, sql_enum
 
 if TYPE_CHECKING:  # pragma: no cover
     from .financial_input import FinancialInput
@@ -43,7 +42,7 @@ class Scenario(Base):
     name: Mapped[str] = mapped_column(String(255), nullable=False)
     description: Mapped[str | None] = mapped_column(Text, nullable=True)
     status: Mapped[ScenarioStatus] = mapped_column(
-        SQLEnum(ScenarioStatus, name="scenariostatus", create_type=False),
+        sql_enum(ScenarioStatus, name="scenariostatus"),
         nullable=False,
         default=ScenarioStatus.DRAFT,
     )
@@ -53,7 +52,7 @@ class Scenario(Base):
         Numeric(5, 2), nullable=True)
     currency: Mapped[str | None] = mapped_column(String(3), nullable=True)
     primary_resource: Mapped[ResourceType | None] = mapped_column(
-        SQLEnum(ResourceType, name="resourcetype", create_type=False), nullable=True
+        sql_enum(ResourceType, name="resourcetype"), nullable=True
     )
     created_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), nullable=False, server_default=func.now()

models/simulation_parameter.py

@@ -3,12 +3,11 @@ from __future__ import annotations
 from datetime import datetime
 from typing import TYPE_CHECKING
 
-from .enums import DistributionType, ResourceType, StochasticVariable
+from .enums import DistributionType, ResourceType, StochasticVariable, sql_enum
 
 from sqlalchemy import (
     JSON,
     DateTime,
-    Enum as SQLEnum,
     ForeignKey,
     Integer,
     Numeric,
@@ -34,13 +33,13 @@ class SimulationParameter(Base):
     )
     name: Mapped[str] = mapped_column(String(255), nullable=False)
     distribution: Mapped[DistributionType] = mapped_column(
-        SQLEnum(DistributionType, name="distributiontype", create_type=False), nullable=False
+        sql_enum(DistributionType, name="distributiontype"), nullable=False
     )
     variable: Mapped[StochasticVariable | None] = mapped_column(
-        SQLEnum(StochasticVariable, name="stochasticvariable", create_type=False), nullable=True
+        sql_enum(StochasticVariable, name="stochasticvariable"), nullable=True
     )
     resource_type: Mapped[ResourceType | None] = mapped_column(
-        SQLEnum(ResourceType, name="resourcetype", create_type=False), nullable=True
+        sql_enum(ResourceType, name="resourcetype"), nullable=True
     )
     mean_value: Mapped[float | None] = mapped_column(
         Numeric(18, 4), nullable=True)