Auto arrange shapes to a restriction

Hi, im having a little trouble coding an auto arrange, im just not sure where to start. i want to create a script that will auto arrange 2d rectangles within a bounding box (the restriction). i imagine that when i change the dimensions of the bounding box the shapes will rearrange themselves to the next best arrangement. they would also have to not overlap or if they do, that ill be able to control to what extent i allow it. 

Sorry if this sounds like a lot to ask for. Im just unsure where to start when scripting something like this.