Washing machine done notifications

So I have a smart plug tasmotized that sends me the current power consumption along with other parameters (reactive, apparent, active power) to mqtt and then connected to a backend. How do I know when the washing machine is done?

My main concern is that the power rises and drops during different stages and will not be accurate. I thought I could eventually gather enough data to do an AI model, but I cannot find a dataset. And the system will improve eventually, but after some time.

Do you have any ideas how to do it right?