How to know the current viewed page and line in writer

Hello

We would like to implement a new GUI element (for mobile), so to show the
current viewed location in writer.

For this, we need to know:

1. Which line the writer GUI is currently showing (which may be different
from the line the caret / cursor is on - such as when scrolling, for
example)
2. How many lines there are in total, in the writer document

What is the simplest way to get this information?
is it available through UNO, and if not, how can we attain it?

Additionally, as a fallback, we would like to simply to know which page
writer is showing, and how many pages there are in total.
What is the simplest way to get this data?

If there are no already existing accessors for this information, can you
please direct me to methods and files to hack into or modify to get this
data?

Thank you in advance

Ptyl