Auto roll-up or roll-down of intraday straddle Nifty50 & backtest

Algos, strategies, code
1

I wish to create and backtest the following strategy

  1. Enter short straddle in Nifty at 09.30
  2. If Nifty falls by 100 pts then close the existing straddle at market price & enter a new short straddle at -100 of original straddle
  3. If Nifty falls again by 100pts then close all positions and exit.

On what platform can this condition be tested our automated?

2

Algotest ,

Atm straddle (stop loss = underlying 100)
Close all position on stop loss
Re asap =5 on both legs