Indexing software

Hi,

I need an indexing software that can create indexes of files contained within a given folder (Windows indexing is not suitable for this because the files will not be on the computer itself, rather a cloud storage provider)

It must meet several requirements:
1. it must be able to export the index database as a file for upload with the files that are indexed as all files will be hosted on a cloud storage provider (MEGA.nz), and then be able to reimport it at a later date (say if i wanted to find a specific file)
2. it should preferably be able to index the title of the file (if there is one) and hopefully the first few lines of the file text, as it will be indexing several tens of thousands of files with mostly meaningless filenames (downloaded from medical journals and the filenames of pdf documents from scientific journals rarely make any sense, an example would be: '1-s2.0-S0924977X14003265-main.pdf', which is actually titled (in the first few lines of the document) as 'A randomised,double-blind, placebo-controlled trial investigating the potential of peripheral biomarkers to predict treatment response and antidepressant mechanisms of change', I have several tens of thousands of files named like this so it is unfeasible for me to go through and rename each and every single one, also the windows-enforced 256 character filename limit poses a problem with my current filing system in the cloud to rename each one)
[edit: 3. It needs to be compatible with .pdf, .doc, .docx, .epub files as well as audio & video files]
4. it needs to run unsupervised and automatically, so that i do not need to manually put in details about each and every file, and be updatable so I can rescan and add indexes to new files
5. it MUST have a search function for the created index
6. it should be free (for compatibility, I won't be the only person using the index and it could get rather expensive if every user needed to buy a license) or a low-cost option, but preferably NOT a subscription service
I think that's all, I might think of more requirements at a later date and I'll add them in

Does anyone on here have any suggestions as to what might be usable for this purpose?
Thank you

T

No, I am looking for a client-based indexing software that can be run on my laptop, because I have so much in my cloud drives, I would like to have a database (the index) of all the files on there that I can download separately, open, locate the file I want in the index (and therefore the folder path) and then go to that specific file in the cloud and download it (the folder structure would be exactly the same locally as it is in the cloud).
Thank you

another solution would be an indexing software that could take screenshots of the first page, does anyone know of any software capable of doing so?
Thanks