mikf/gallery-dl ? reverse-engineered prompt

I want to build a powerful command-line tool in Python for downloading entire image galleries and collections. I'm thinking of something that can handle a whole bunch of different websites, from popular ones like Twitter and Tumblr to more niche art communities like Pixiv, Danbooru, and DeviantArt.

The basic idea is that I can just give the script a URL—whether it's to a user's page, a search result, or a specific post—and have it grab all the associated images and even videos automatically. It definitely needs to handle logins for sites that require authentication to view content.

It should also have some more advanced capabilities, like being able to filter content, for example, downloading only a specific range of chapters from a manga on Mangadex. It should also have flexible options for naming and organizing the downloaded files, so they aren't just a mess.