feat: Implement currency management with models, routes, and UI updates; add backfill script for existing records

routes/costs.py

@@ -16,7 +16,8 @@ class _CostBase(BaseModel):
     scenario_id: int
     amount: float
     description: Optional[str] = None
-    currency_code: str = "USD"
+    currency_code: Optional[str] = "USD"
+    currency_id: Optional[int] = None
 
     @field_validator("currency_code")
     @classmethod
@@ -31,8 +32,12 @@ class CapexCreate(_CostBase):
 
 class CapexRead(_CostBase):
     id: int
+    # use from_attributes so Pydantic reads attributes off SQLAlchemy model
     model_config = ConfigDict(from_attributes=True)
 
+    # optionally include nested currency info
+    currency: Optional["CurrencyRead"] = None
+
 
 class OpexCreate(_CostBase):
     pass
@@ -41,12 +46,41 @@ class OpexCreate(_CostBase):
 class OpexRead(_CostBase):
     id: int
     model_config = ConfigDict(from_attributes=True)
+    currency: Optional["CurrencyRead"] = None
+
+
+class CurrencyRead(BaseModel):
+    id: int
+    code: str
+    name: Optional[str] = None
+    symbol: Optional[str] = None
+    is_active: Optional[bool] = True
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+# forward refs
+CapexRead.model_rebuild()
+OpexRead.model_rebuild()
 
 
 # Capex endpoints
 @router.post("/capex", response_model=CapexRead)
 def create_capex(item: CapexCreate, db: Session = Depends(get_db)):
-    db_item = Capex(**item.model_dump())
+    payload = item.model_dump()
+    # Prefer explicit currency_id if supplied
+    cid = payload.get("currency_id")
+    if not cid:
+        code = (payload.pop("currency_code", "USD") or "USD").strip().upper()
+        currency_cls = __import__(
+            "models.currency", fromlist=["Currency"]).Currency
+        currency = db.query(currency_cls).filter_by(code=code).one_or_none()
+        if currency is None:
+            currency = currency_cls(code=code, name=code, symbol=None)
+            db.add(currency)
+            db.flush()
+        payload["currency_id"] = currency.id
+    db_item = Capex(**payload)
     db.add(db_item)
     db.commit()
     db.refresh(db_item)
@@ -61,7 +95,19 @@ def list_capex(db: Session = Depends(get_db)):
 # Opex endpoints
 @router.post("/opex", response_model=OpexRead)
 def create_opex(item: OpexCreate, db: Session = Depends(get_db)):
-    db_item = Opex(**item.model_dump())
+    payload = item.model_dump()
+    cid = payload.get("currency_id")
+    if not cid:
+        code = (payload.pop("currency_code", "USD") or "USD").strip().upper()
+        currency_cls = __import__(
+            "models.currency", fromlist=["Currency"]).Currency
+        currency = db.query(currency_cls).filter_by(code=code).one_or_none()
+        if currency is None:
+            currency = currency_cls(code=code, name=code, symbol=None)
+            db.add(currency)
+            db.flush()
+        payload["currency_id"] = currency.id
+    db_item = Opex(**payload)
     db.add(db_item)
     db.commit()
     db.refresh(db_item)