Initial MVP skeleton with auth, chat persistence, UI and text LLM integration

backend/app/api/deps.py

@@ -0,0 +1,30 @@
+import os
+from datetime import datetime, timezone
+
+from fastapi import Depends, HTTPException, Request, status
+from sqlalchemy.orm import Session as DBSession
+
+from app.db.session import get_db
+from app.db.models import Session, User
+
+COOKIE_NAME = os.getenv("SESSION_COOKIE_NAME", "ai_chat_session")
+
+def get_current_user(request: Request, db: DBSession = Depends(get_db)) -> User:
+    session_id = request.cookies.get(COOKIE_NAME)
+    if not session_id:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Not authenticated")
+    
+    db_session = db.get(Session, session_id)
+    if not db_session:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid session")
+    
+    if db_session.expires_at < datetime.now(timezone.utc).replace(tzinfo=None):
+        db.delete(db_session)
+        db.commit()
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Session expired")
+    
+    user = db_session.user
+    if not user or not user.is_active:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="User inactive")
+    
+    return user