So, I have a lot of the technical stuff in my game finished, such as graphics and pathfinding and it's all completely separated from the game itself. I am now starting to develop the game logic. Up until now, all of my game logic has been in a single class dealing mainly with game map generation. Now that I'm ready to experiment with actual game rules, AI and units moving around, I'm afraid my 'GameLogic' class is just going to become huge and unmanageable.
Is there any conventional wisdom regarding the division of labor at this stage that I should be aware of? I know I don't want a giant, confusing lump of code, but my predictions for what would make things cleaner often don't pan out.