Basically, if the undercover cop suggests X and you say no. Then come on nobody will know, and you say no. And then they spend the next six weeks convincing you it's a good idea, then that's entrapment.
The issue is he was on a sting for over a year and that's plenty of time to cross the line.
Of note, asking several times and catching someone at a moment of weakness is not entrapment. So, if you have been clean for 10 years then you’re out of luck.