Refactor classes to be more object oriented

[teekay]

At this point, the code is procedural.

The goal is as follows:

1. Separate Commands and Queries - the method either calculates, transforms, or otherwise provides a value, or does something that changes the state of the system.
2. Break down monolothical classes that are doing too much into smaller, specialized ones.
3. Favor readonly properties over read-write ones: wherever there's a read-write property, the class is just a "dumb" holder of data; instead, it should own its data and only provide them via methods.