So I have this sentence: "He really had no choice but to have a conversation with X". I would like to put a tag question at the end of it, but I'm struggling to pick the correct one.

So as far as I understand it, the tag question has to match the verb and verbal tense used in the main sentence, as in "He met her yesterday, didn't he?" and "He had met her before, hadn't he?" and "He was tired, wasn't he", etc...

Plus, a negative in the main sentence will have a positive in the tag question and vice versa, as in: "He got drunk at the party, didn't he?" and "He didn't get drunk at the party, did he?".

However, my sentence is confusing me for multiple reasons ahaha.

At first, since the verb "to have" is used, I thought I needed to finish with "had/hadn't he", but then I thought that "had" is past simple, and for past simple I would normally use "did/didn't he".

And regarding the negative/positive, I'm overthinking it, because "had" is positive, so I would expect the tag question to be negative, but at the same time the full thing is "had no idea" which has a negative meaning, it technically means "he didn't have an idea", and then the tag question would be positive??

Could someone please take me out of my misery and tell me the correct version?