FIFO Logic - days in inventory excel

Hello,

I am trying to create a system of arrays formulas to implement  a Fifo logic in excel to calculate the days in inventory of each product batch.

However after a couple of days working on this I have not found a solution using dynamic arrays ( I am not very familiar with scan/lambda functions yet).

The main issue I am running into is the fact that same sale transactions might require selling quantities from more than a buy transaction. See below for more detail?

Would someone be able to provide a dynamic array formula solution?

Thank you very much in advance,

Simone