Isn't this a good time to buy for the medium to long term?

The 5,000-point index level holds symbolic significance, and even if the government claims not to intervene, falling below that level could become a political issue. Therefore, wouldn't they manage it in some way to prevent it from dropping further?
As for the exchange rate, if it drops any further, it will cause issues with macroeconomic indicators, so both the private and public sectors will likely manage it to prevent further decline.
In any case, while we cannot know what might happen in the short term,
if you have funds that can be held for a long time, I think this might be a good time to invest in the index.
If you believe there won't be a massive surge, it might also be good to park your money in high-dividend index funds.