The idea you refer to is generally known as the "Icebreaker Theory" after the infamous book by Viktor Suvorov that published advancing it in the late 1980s. Suvorov, actually Vladimir Bogdanovich Rezun, was a Soviet intelligence worker who defected to the west in 1978. To say the least, his claim that the Soviet Union was poised to launch a strike on Nazi Germany and that Barbarossa simply caught them with an attack-in-prep, and it would have been launched later that summer had Hitler not done so, was a controversial one. As such, the argument goes, part of the reason Barbarossa enjoyed its initial success was precisely because the Soviets were preparing for offensive operations at the time, not defensive. He wasn't the first to advance this theory, but it had been pretty much dead in academia for a long time, since it was straight up Nazi apologists who supported it back during and immediately after the war. Just about anyone who is anyone in Eastern Front studies has had their say on it by this point I would venture, but probably the most notable is David Glantz, who wrote "Stumbling Colossus" essentially as a rebuttal to Suvorov.

I would encourage you to check out Glantz in its entirely, but to quote briefly from the most pointed part of the preface:

As well constructed as Rezun's arguments are and as credible as the individual facts may be, the whole of his case regarding Soviet intentions in 1941 is incredible for a number of reasons. First, it is not consistent to reject in advance the validity of Soviet classified archival materials while basing one's arguments,in part or in total, on extensive unclassified memoirs and studies. Second, Rezun exploits memoir material, which in the main is accurate at least regarding time, place, and event but often contains subjective interpretation, by considering it wholly out of context and using it adroitly to support his arguments. Finally, and most important, the validity of Rezun's arguments is challenged by three fundamental types of sources: newly released and extensive Soviet declassified documents and studies on the war (all secret or top secret); German archival materials; and other materials that document the parlous state of the Red Army in 1941 and indicate that any offensive operations contemplated by the Soviets in 1941 would have bordered on the lunatic. Stalin may well have been an unscrupulous tyrant, but he was not a lunatic.

If you want something a bit quicker to digest, "The Icebreaker Controversy: Did Stalin Plan to Attack Hitler?" by Teddy J. Uldricks is a paper on the subject, published in "Slavic Review", Vol. 58, No. 3 (Autumn, 1999), and you can find that on JSTOR if you have access. He looks at the critiques more broadly, touching on Glantz, but also other historians who find Icebreaker to 'lack evidentiary base, make dubious assertions of fact, and put forward illogical arguments'. As he eventually concludes, about as charitably as one can be:

Whatever the attraction of the icebreaker theory, at this stage in the debate some issues are now clear and others still need to be resolved. First, we know for certain that Hitler did not fear a Soviet attack and that Operation Barbarossa was in no way a preemptive strike. The German assault on the USSR was central to Hitler's conception of race war as the theme of modern history. Second, the weight of available evidence does not support the charge that Stalin engineered World War II and had been plotting to do so for a long time, in order to spread communist revolution or Soviet imperialism. Suvorov's contention to the contrary is, to put it most generously, not proven. The currently available evidence suggests that Stalin was not preparing to launch a war of conquest in the summer of 1941, though some of his generals entertained the idea of a limited preemptive strike against the menacing buildup of German troops across the border. It is also true that Soviet military doctrine never envisioned fighting on the defensive for very long against an aggressor, but instead anticipated quickly blunting the enemy attack and then rapidly moving to offensive warfare in order to carry the battle onto enemy territory. Finally, it seems entirely possible, even likely, that at some point in the future, when military preparations had been completed, Stalin would have entered the war against the Third Reich. Ideological considerations aside, he would have done so for the same national security and balance of power concerns that impelled Franklin Roosevelt to oppose Nazi expansionism. German hegemony in Europe was an even worse prospect for Soviet Russia than for the United States. This latter topic—Stalin's perceptions and plans in the face of a consolidated Nazi empire from the Atlantic to the Soviet border—remains an important field for new research.

That is probably the most conciliatory assessment you'll get, at least from Western historians. Stalin perhaps would have launched a war eventually, but aside from a few minor voicings in the military, there is really nothing to indicate he was planning to soon, let alone that summer, and everything indicates that Hitler launched an intentional war of conquest, not a defensive attack of preemption.