feat: Enhance currency handling and validation across scenarios

- Updated form template to prefill currency input with default value and added help text for clarity.
- Modified integration tests to assert more descriptive error messages for invalid currency codes.
- Introduced new tests for currency normalization and validation in various scenarios, including imports and exports.
- Added comprehensive tests for pricing calculations, ensuring defaults are respected and overrides function correctly.
- Implemented unit tests for pricing settings repository, ensuring CRUD operations and default settings are handled properly.
- Enhanced scenario pricing evaluation tests to validate currency handling and metadata defaults.
- Added simulation tests to ensure Monte Carlo runs are accurate and handle various distribution scenarios.

services/unit_of_work.py

@@ -6,16 +6,21 @@ from typing import Callable, Sequence
 from sqlalchemy.orm import Session
 
 from config.database import SessionLocal
-from models import Role, Scenario
+from models import PricingSettings, Project, Role, Scenario
+from services.pricing import PricingMetadata
 from services.repositories import (
     FinancialInputRepository,
+    PricingSettingsRepository,
+    PricingSettingsSeedResult,
     ProjectRepository,
     RoleRepository,
     ScenarioRepository,
     SimulationParameterRepository,
     UserRepository,
     ensure_admin_user as ensure_admin_user_record,
+    ensure_default_pricing_settings,
     ensure_default_roles,
+    pricing_settings_to_metadata,
 )
 from services.scenario_validation import ScenarioComparisonValidator
 
@@ -33,6 +38,7 @@ class UnitOfWork(AbstractContextManager["UnitOfWork"]):
         self.simulation_parameters: SimulationParameterRepository | None = None
         self.users: UserRepository | None = None
         self.roles: RoleRepository | None = None
+        self.pricing_settings: PricingSettingsRepository | None = None
 
     def __enter__(self) -> "UnitOfWork":
         self.session = self._session_factory()
@@ -43,6 +49,7 @@ class UnitOfWork(AbstractContextManager["UnitOfWork"]):
             self.session)
         self.users = UserRepository(self.session)
         self.roles = RoleRepository(self.session)
+        self.pricing_settings = PricingSettingsRepository(self.session)
         self._scenario_validator = ScenarioComparisonValidator()
         return self
 
@@ -60,6 +67,7 @@ class UnitOfWork(AbstractContextManager["UnitOfWork"]):
         self.simulation_parameters = None
         self.users = None
         self.roles = None
+        self.pricing_settings = None
 
     def flush(self) -> None:
         if not self.session:
@@ -116,3 +124,45 @@ class UnitOfWork(AbstractContextManager["UnitOfWork"]):
             username=username,
             password=password,
         )
+
+    def ensure_default_pricing_settings(
+        self,
+        *,
+        metadata: PricingMetadata,
+        slug: str = "default",
+        name: str | None = None,
+        description: str | None = None,
+    ) -> PricingSettingsSeedResult:
+        if not self.pricing_settings:
+            raise RuntimeError("UnitOfWork session is not initialised")
+        return ensure_default_pricing_settings(
+            self.pricing_settings,
+            metadata=metadata,
+            slug=slug,
+            name=name,
+            description=description,
+        )
+
+    def get_pricing_metadata(
+        self,
+        *,
+        slug: str = "default",
+    ) -> PricingMetadata | None:
+        if not self.pricing_settings:
+            raise RuntimeError("UnitOfWork session is not initialised")
+        settings = self.pricing_settings.find_by_slug(
+            slug,
+            include_children=True,
+        )
+        if settings is None:
+            return None
+        return pricing_settings_to_metadata(settings)
+
+    def set_project_pricing_settings(
+        self,
+        project: Project,
+        pricing_settings: PricingSettings | None,
+    ) -> Project:
+        if not self.projects:
+            raise RuntimeError("UnitOfWork session is not initialised")
+        return self.projects.set_pricing_settings(project, pricing_settings)