I watch a lot of TV and need a way to keep track of what I have already watched. Right now that way is using Kodi modified to use MPV was the media player.

There are a few problems I have with Kodi. Problems listed below.
1. It is organized for specific type of media. Meaning you can't go to an audio file or picture and open it to listen or view.
2. It is bloated with all the fancy UI stuff not needed.
3. It has it's own media player (mostly fixed with adding redirect to MPV).

I have tried Midnight Commander but it doesn't keep track of media played and the terminal interface doesn't work as I would expect it to as a terminal interface (tab key doesn't auto complete, even if you modify the key bindings).

So what I need is something like a combination of Midnight Commander and Kodi.

Keyboard focused, keep track of media played, choice of media player, and ability to see all files and open all files (jpg, flac, pdf, ect..)

Does such a program exist? Do I have to go out of my way and invent yet another file browser?

Until such a file browser exists, I'm stuck with the slow Kodi having to go out and into my systems' default file browser when wanting to view jpegs and pdfs and going out and into the music portion to play music.

From my research it seems like Kodi is the only solution, and I need to find a solution to fix Kodi to show all files.

a partial solution is to write yourself a wrapper around mpv.
first, make sure you have "$HOME/bin" in your $PATH.
then, create a file "$HOME/bin/mpv":
now everytime you play sth with mpv, it will be added to playedfiles.txt, which you can look at with any text editor.

ps: you have to make sure that kodi calls for "mpv" and not "/usr/bin/mpv".

Kodi already keeps track of what I watched, why it's the only solution right now. But Kodi only shows media files for what you're viewing.

oh, i see now what you want.
you want the file manager to automatically play files you haven't seen yet.
I'm sure many file managers have plugin capabilities, so you could write yourself a plugin that does just that.
there's another non-graphical file manager called "ranger", you might want to start there (just because it's under active development, and has media file previews).

I agree with ondoho,... What you probably want to do is create a plugin for a file manager that uses the touch command to adjust the timestamp for the files which you've watched already and then just sort by age...

Actually, I just want it to put a check box saying I saw it.

I'm probably going to have to ether modify Kodi to show everything or write my own file manager.

How are you recording the shows? MythTV??? I thought MythTV had a function to let you know what you had watched and what you didn't...

I'm ripping them from BD and DVDs mostly. I don't watch live because they are foreign and not on local tv.

In that case, one thing you might consider is simply writing a Python script that is set to be the default handler for that file type (the file managers in most DE's have a setting for the default file handler). The Python script would launch the file with your preferred media app and in the script, use touch to "age" the files, "shoving" them to the back, as I suggested above...