There is no deal because there is no deal to be had. The parties are in different universes.
Krankenbruder
As of now, Trump and Iran are claiming that the 'deal' says different things.
A key test: will there be an agreed, public copy of the text of whatever Iran and the US are supposedly signing?
Even if there is, it'll be hard sailing. But if not, it's all bullshit on stilts.
Arieh Kovler
Prediction:
Trump signs the deal
Iran signs the deal
Trump claims the deal contains provisions that Iran denies and aren't in the leaked drafts
Iran claims that the US isn't honouring the deal.
Iran attacks ships in the Strait of Hormuz
US and Iran negotiate another deal...