Good day, good forums friends,
Greetings to everyone from Turkey. 
Let me talk a little bit about what I do. I download suitable English PDF books from the internet and translate them into Turkish. Of course, I often have to split and merge them due to the file size and number of characters. Then, although there are books that are not locked, they lock themselves after the merging process and I break them. If there are unnecessary links and watermarks to be cleaned, I clean them.
Finally, I try to fix the bookmarks and hyperlinks, but no matter what I did, I couldn't automate it. How can I automatically determine the titles of the book and create bookmarks from all the titles? How do I create a table of content automatically from the titles of the book. Which software should I use? Because they are very long books, I don't like to edit my bookmarks and hyperlinks one by one, it's not practical. I wonder how I can automatically fix my broken bookmarks and hyperlinks after these operations. I would be very grateful if there is a good document or booklet on this subject or if there is a friend who can help.