That's interesting, I was also in Barcelona last week and I saw slightly more Spanish flags than Catalan.

I think the real problem is that Spain have consistently blocked a peaceful referendum. I don't believe Catalonia would vote to leave in a fair vote, but I do feel that the repressive actions of the Kingdom of Spain on this matter are the kind of thing that could justify declaring independence unilaterally.

Again, what is the repression of the Kingdom of Spain exactly? Not allowing the referendum? It was ruled illegal by the high courts. Catalonia should push for a change of that, but not blame the government for applying the Constitution.

Yes, not allowing the referendum. It was ruled illegal because the Spanish constitution does not allow secession, effectively preventing self-determination for Catalonia.

Denying people a right that's commonly understood to be fundamental to international law and then using violence to enforce it is repression in my book. Spain has consistently escalated tensions rather than offering a path to a real democratic decision. They're going to have to accept the repercussions of that decision.

You are probably reading biased media. Spain has not consistently escalated tensions, it's been done by both sides. I disagree that something like this is commonly understood as fundamental. Referendums need to meet some conditions and be agreed. Disagreement happened in both sides, it wasn't an authoritarian decision in spite of what some international media seem to enjoy saying. What is illegal in the referendum is: - it asks something that is not allowed to happen by the constitution (thus the need to change it first) - there is no clear definition of who is allowed to vote (who is Catalan by which definition) - the right to vote on the ownership of that land belongs to all Spanish just like any other region belongs to those voting there. - What's the level at which we do the referendum? Not all areas might want to leave in the case of a hypothetical "yes" (which is not a majority at the moment by any poll). What if certain areas want independence from Catalonia?

Most importantly: the referendum is illegal even by the autonomic law of Catalonia. They should have had 2/3 of the chamber to push it, and they did it with less than half (48% IRCC).