Extracting ref and source tables from a dbt model

Question

I have a model in dbt which uses different sources and ref tables. So my question is... Is it possible to create a macro that will extract all the ref and source tables from the model? Let me give you and example

I have this model:

    select
*

from        {{ ref('x') }}   a
left join   {{ source('landing', 'y') }} ma on a.... = ma....
left join   {{ source('landing', 'z') }} b on a.... = b....

So, once the macro is run for that model, I would like to get the names or the ref and source tables. Is that possible? I would like to do this in dbt, but let me know if it would be better to use python instead.

Thanks!