I didn't get round to castling yet but thank you. I did my AI by having a controller class and the AI inherits from that. The AI is given a list of moves and orders it by the value of the move and takes a random move from all moves that are equal to the top value. A value is assigned by if a piece can be taken then it adds on the value of that piece and if the piece that's moving can be taken in the next move it should take away the value of the piece. I also added a value if the piece doesn't move and can be taken it adds the value of the piece to the move. I'm still not sure if all that works because when playing the AI still does some moves I wouldn't expect it to.