[Script] How to make a trainer rematch?

I would want to make every trainer have at lest one different team for their rematches, but i don't know ho to make a rematch. Also, how do I add more trainers in advance trainer to get enough trainers for this?

The every trainer have a flag that says that player have challenged him or not. For rematch I think you can just not use that flag.

This are my suspicion, I haven't delved into such things and I'm not sure what I said.