This information is a mixture of information I have by personal relatives living in Iran and the official travel advice of the German MFA, which is usually up to date:
Getting a visa: Visa issuance is not officially suspended. This does not mean that you will certainly get a visa, they might simply deny all tourist visa applications at the moment, but you can try. I would not risk trying VoA at IKA airport as there have been several reports of people being denied a visa and deported even in "normal" times.
Getting in: the airports are technically open and have never been closed during the entire pandemic, but travellers arriving from most western countries will be quarantined in an airport hotel until they have been tested for Covid-19. This does usually take 48 hours but may take longer. However, the airports being open does not mean that flights operate as scheduled. There are very limited flights to Tehran IKA (IranAir is still flying to a few foreign destinations, maybe also Mahan Air and Qatar) and (close to?) zero international services to other airports in Iran.
All land border crossings are closed (by the neighboring countries, the Iranians have not closed any AFAIK).
Once you're in the country: The restrictions recently lifted used to apply to shops that had been closed (now, most may open again). Many restrictions still apply: Restaurants, museums, mosques, schools and universities are still closed, taxis may not transport more than two persons at a time.
Note that the official infection rates of Covid-19 in Iran are made up by the government and likely to be several times higher. I leave it up to you to decide if you fear the virus or not, but note that due to this, many governments warn against travel to Iran at the moment, which means that your travel health insurance might be void (even if you have a road accident).
In the case that the shit hits the fan and you need to get out of the country immediately (this can both be medical reasons and "larger" reasons such as escalating protests), your embassy will probably be of a lot less help (if any) than under normal conditions.
tl;dr: If you're willing to take a few risks, it might be technically possible to travel to Iran this summer, but your travel experience will be very limited. My recommendation is postponing it, but of course you can wait and see how the situation develops. I do not expect most of the above restrictions being lifted until July.