working with login and building inventory

trade-hub/backend/app/deps.py

@@ -0,0 +1,39 @@
+"""Shared FastAPI dependencies: origin check and current-user resolution."""
+from datetime import timezone
+
+from fastapi import Depends, HTTPException, Request
+from sqlalchemy.orm import Session as DbSession
+
+from app import config, security
+from app.db import get_db
+from app.models import User, UserSession, utcnow
+
+
+def require_same_origin(request: Request) -> None:
+    if not security.same_origin(request):
+        raise HTTPException(status_code=403, detail="Cross-origin request rejected")
+
+
+def _as_utc(value):
+    if value.tzinfo is None:
+        return value.replace(tzinfo=timezone.utc)
+    return value.astimezone(timezone.utc)
+
+
+def get_current_user(
+    request: Request, db: DbSession = Depends(get_db)
+) -> User:
+    token = request.cookies.get(config.COOKIE_NAME)
+    if not token:
+        raise HTTPException(status_code=401, detail="Not authenticated")
+
+    session = db.get(UserSession, security.hash_token(token))
+    if session is None:
+        raise HTTPException(status_code=401, detail="Not authenticated")
+
+    if _as_utc(session.expires_at) <= utcnow():
+        db.delete(session)
+        db.commit()
+        raise HTTPException(status_code=401, detail="Session expired")
+
+    return session.user