At first Iam not Iranian, and Iam not great fan of your governement, nevertheless, I appreciate very well its anti imperialism stance. Especially under President Ahmadinejad.
Russian decision was taken under presidency of Dmitry Medvedev, who was more western leaning leader. Putin is completely different leader and has different strategic vision for Russia.
If you consider Putin is different than Medvedev U are wrong. The Russia's leaders are a group, an entity, and those who that lead the foreign, and defense policiy is the FSB. Most of the FSB members chosen among the elites, that did two coups, one in 1991, and the other 1993. There is no differences between Medvedev, PUtin, Ivanov, Lavrov, Choigu etc..
That being said, Iran can negotiate some sort of assembly/manufacturing/joint production capacity...
Indeed with another country than Russia.
Russians are divided in forigen affairs ... some of them want to be in westerns camp and some of them in eastern camp and some of them want to revive soviet glory ( from international power perspective ) ...
The leaders are near all pro-westerners, in the expense of the population.
we made a deal about S300 and pay the price in 2007 . but russians didn't honor their promise and froze the deal with some fancy excuse ...
It is a lesson, actual russian leaders are not reliable.
...we bought 24 Mig 29A from them in 1990 but till today , they refused to sell us spare parts and our 27 year old Mig 29A were grounded till 3 years ago ( from 2013 we are overhaul these fighters with by our own ) ...
If it wasn't for western Sanction on them , they wouldn't give us S300s ...
In spite of many difficulties China is becoming a real super power. It is worth to give up cooperation with Russia until true honnest leaders will be in power at the Kremlin, and choose China instead.
Its success regarding J-11 are real, and could be an interesting option for Iran. The Bavar 373 was developped thanks to the help of China, and North Korea.
The J-11 D with its vector thrust is equal as SU-35, but regarding avionic, the chinese fighter is more sophisticated than the SU-35. The J-31 once it is ready would be an oppurtinity for Iran.
Once Iran will get 200 if not 300 J-11 no one will dare to attack it.