Decompose the adapter into multiple cohesive modules housed in different files

[kpto]

Currently all code is put inside one long file which introduces the following issues:

1. Visually noisy and distracting
2. Hard to find the code one wants to work on
3. Error prone on editing

The long code should be decomposed into multiple cohesive modules housed in different files.

[laulopezreal]

Hi @kpto, I would like to separate the classes from the main adapter's script. Do you think that enters into the scope of this issue?