Anyways you're right I do have a lot of constants.

Yes, and I've tried the whole "keep the constants in one file thing" before a long time ago and I was not a fan of the results.

I was planning to shrink my code using something call enum but this option seems efficient too

I'd encourage you to try any method that you come up with. Simply taking someone's word for something is not nearly as effective of a learning experience as trying something yourself and deciding that it isn't efficient.