A tad bit unkempt

I found this butterfly in my bathroom today. It must have come in through the window I had left open for some hours yesterday due to the great weather. Anyway, it looked a bit messed up and seemed to be missing a part of one wing, but was quite ok when I had taken it outside.
Only thing I have no idea of is what kind of butterfly this is, maybe one of you can help me out on that.