I'm not who you are replying to, but here's a fun fact: years ago I did some research on the International Brigades that required pulling out documents from the SOVDOC.

One of these was the record of a political discussion in 1936-37 between members of a communist unit that included Catalonian independentists, about the question of self-determination for Spain's various nationalities. The meeting ended with a recommendation of Stalin's Marxism and the National Question as a read for the unit's members and the decision that the text's conclusions was the way of thought to follow.

To this day, I still recommend that one text to anyone who wishes to know how to proceed ideologically in regards to any movement for national independence, including Catalonia's.