How can I code my own cryptocurrency mining software

I've been researching for months. But I still haven't learned it. I want to write my own cryptocurrency mining algorithm. There are many ready-made libraries on Github. However, they all perform this mining process by referencing a website or a pool.
I want to write from scratch myself. However, I couldn't find any lesson, pdf, book etc. for this.
Is there any paid or free resource that explains how to code a cryptocurrency mining algorithm from scratch?
(I want to learn this cryptocurrency mining specifically for monero. But it can be litecoin, dogecoin, tron or any other.)