feat(auth): Implement /refresh endpoint and update login/register

backend/src/ea_chatbot/api/routers/auth.py

@@ -59,7 +59,8 @@ async def register(user_in: UserCreate, response: Response):
     )
     
     access_token = create_access_token(data={"sub": str(user.id)})
-    set_auth_cookie(response, access_token)
+    refresh_token = create_refresh_token(data={"sub": str(user.id)})
+    set_auth_cookie(response, access_token, refresh_token)
 
     return {
         "id": str(user.id),
@@ -80,15 +81,64 @@ async def login(response: Response, form_data: OAuth2PasswordRequestForm = Depen
         )
     
     access_token = create_access_token(data={"sub": str(user.id)})
-    set_auth_cookie(response, access_token)
+    refresh_token = create_refresh_token(data={"sub": str(user.id)})
+    set_auth_cookie(response, access_token, refresh_token)
     return {"access_token": access_token, "token_type": "bearer"}
 
 @router.post("/logout")
 async def logout(response: Response):
-    """Logout by clearing the auth cookie."""
-    response.delete_cookie(key="access_token")
+    """Logout by clearing the auth cookies."""
+    clear_auth_cookies(response)
     return {"detail": "Successfully logged out"}
 
+@router.post("/refresh", response_model=Token)
+async def refresh(request: Request, response: Response):
+    """Refresh the access token using a valid refresh token."""
+    refresh_token = request.cookies.get("refresh_token")
+    if not refresh_token:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Refresh token missing"
+        )
+    
+    from ea_chatbot.api.utils import decode_access_token # Using decode_access_token for both
+    payload = decode_access_token(refresh_token)
+    
+    if not payload:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid refresh token"
+        )
+    
+    if payload.get("type") != "refresh":
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid token type"
+        )
+    
+    user_id = payload.get("sub")
+    if not user_id:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid token payload"
+        )
+    
+    # Check if user still exists
+    user = history_manager.get_user_by_id(user_id)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="User not found"
+        )
+    
+    # Issue new tokens (Rotation)
+    new_access_token = create_access_token(data={"sub": str(user.id)})
+    new_refresh_token = create_refresh_token(data={"sub": str(user.id)})
+    
+    set_auth_cookie(response, new_access_token, new_refresh_token)
+    
+    return {"access_token": new_access_token, "token_type": "bearer"}
+
 @router.get("/oidc/login")
 async def oidc_login(response: Response):
     """Get the OIDC authorization URL and set temporary session cookie."""
@@ -158,9 +208,10 @@ async def oidc_callback(request: Request, response: Response, code: str, state:
         # 4. Sync user and establish session
         user = history_manager.sync_user_from_oidc(email=email, display_name=name)
         access_token = create_access_token(data={"sub": str(user.id)})
+        refresh_token = create_refresh_token(data={"sub": str(user.id)})
         
         redirect_response = RedirectResponse(url=settings.frontend_url, status_code=status.HTTP_302_FOUND)
-        set_auth_cookie(redirect_response, access_token)
+        set_auth_cookie(redirect_response, access_token, refresh_token)
         redirect_response.delete_cookie("oidc_session") # Cleanup
         
         return redirect_response