feat: add targets and holdings API endpoints

backend/app/api/portfolio.py

@@ -8,9 +8,11 @@ from sqlalchemy.orm import Session
 
 from app.core.database import get_db
 from app.api.deps import CurrentUser
-from app.models.portfolio import Portfolio, PortfolioType
+from app.models.portfolio import Portfolio, PortfolioType, Target, Holding
 from app.schemas.portfolio import (
     PortfolioCreate, PortfolioUpdate, PortfolioResponse, PortfolioDetail,
+    TargetCreate, TargetResponse,
+    HoldingCreate, HoldingResponse,
 )
 
 router = APIRouter(prefix="/api/portfolios", tags=["portfolios"])
@@ -108,3 +110,101 @@ async def delete_portfolio(
     db.delete(portfolio)
     db.commit()
     return None
+
+
+def _get_portfolio(db: Session, portfolio_id: int, user_id: int) -> Portfolio:
+    """Helper to get portfolio with ownership check."""
+    portfolio = db.query(Portfolio).filter(
+        Portfolio.id == portfolio_id,
+        Portfolio.user_id == user_id,
+    ).first()
+    if not portfolio:
+        raise HTTPException(status_code=404, detail="Portfolio not found")
+    return portfolio
+
+
+@router.get("/{portfolio_id}/targets", response_model=List[TargetResponse])
+async def get_targets(
+    portfolio_id: int,
+    current_user: CurrentUser,
+    db: Session = Depends(get_db),
+):
+    """Get target allocations for a portfolio."""
+    portfolio = _get_portfolio(db, portfolio_id, current_user.id)
+    return portfolio.targets
+
+
+@router.put("/{portfolio_id}/targets", response_model=List[TargetResponse])
+async def set_targets(
+    portfolio_id: int,
+    targets: List[TargetCreate],
+    current_user: CurrentUser,
+    db: Session = Depends(get_db),
+):
+    """Set target allocations for a portfolio (replaces all existing)."""
+    portfolio = _get_portfolio(db, portfolio_id, current_user.id)
+
+    # Validate total ratio
+    total_ratio = sum(t.target_ratio for t in targets)
+    if total_ratio != 100:
+        raise HTTPException(
+            status_code=400,
+            detail=f"Target ratios must sum to 100%, got {total_ratio}%"
+        )
+
+    # Delete existing targets
+    db.query(Target).filter(Target.portfolio_id == portfolio_id).delete()
+
+    # Create new targets
+    new_targets = []
+    for t in targets:
+        target = Target(
+            portfolio_id=portfolio_id,
+            ticker=t.ticker,
+            target_ratio=t.target_ratio,
+        )
+        db.add(target)
+        new_targets.append(target)
+
+    db.commit()
+    return new_targets
+
+
+@router.get("/{portfolio_id}/holdings", response_model=List[HoldingResponse])
+async def get_holdings(
+    portfolio_id: int,
+    current_user: CurrentUser,
+    db: Session = Depends(get_db),
+):
+    """Get holdings for a portfolio."""
+    portfolio = _get_portfolio(db, portfolio_id, current_user.id)
+    return portfolio.holdings
+
+
+@router.put("/{portfolio_id}/holdings", response_model=List[HoldingResponse])
+async def set_holdings(
+    portfolio_id: int,
+    holdings: List[HoldingCreate],
+    current_user: CurrentUser,
+    db: Session = Depends(get_db),
+):
+    """Set holdings for a portfolio (replaces all existing)."""
+    portfolio = _get_portfolio(db, portfolio_id, current_user.id)
+
+    # Delete existing holdings
+    db.query(Holding).filter(Holding.portfolio_id == portfolio_id).delete()
+
+    # Create new holdings
+    new_holdings = []
+    for h in holdings:
+        holding = Holding(
+            portfolio_id=portfolio_id,
+            ticker=h.ticker,
+            quantity=h.quantity,
+            avg_price=h.avg_price,
+        )
+        db.add(holding)
+        new_holdings.append(holding)
+
+    db.commit()
+    return new_holdings