[Feature Request]: Fallback to channel playlists if something goes wrong on the channel page

[ChunkyProgrammer]

Guidelines

• [X] I have searched the issue tracker for open and closed issues that are similar to the feature request I want to file, without success.
• [X] I have searched the documentation for information that matches the description of the feature request I want to file, without success.
• [X] This issue contains only one feature request.

Problem Description

We fallback to RSS feeds if something goes wrong on the subscriptions page, it'd be nice if we were to do the same on the channel page (since we can't get continuations for RSS feeds, we should use the playlist api instead)

Proposed Solution

Invidious API/ no backend fallback + Local API/ no backend fallback

• if there's an error, then check if videos is empty. If videos is empty then fetch the videos from autogenerated channel playlist
• repeat for live and shorts (and also check to make sure hideLive/hideShorts isn't enabled)

Invidious API/ with backend fallback + Local API/ with backend fallback

• if there's another error then fallback to autogenerated channel playlist of preferred backend
• check if videos is empty. If videos is empty then fetch the videos from autogenerated channel playlist
• repeat for live and shorts (and also check to make sure hideLive/hideShorts isn't enabled)
• if there's an error fallback to the other api

Additional

• if we can't find any values in the channel tab array and there's an error then we should automatically add those tabs if the RSS request is successful

Alternatives Considered

Don't bother since channel page breakages don't happen often.

Issue Labels

improvement to existing feature

Additional Information

No response

[absidue]

I would suggest falling back to the API playlists first, we already do that for artist topic channels with the local API, additionally they contain more information (video durations, live status, etc) and support continuations compared to the playlists RSS which only contains 15 items. The reason that the API playlists aren't used on the subscriptions page is that most of the time when RSS is used on the subscriptions page it is because of ratelimits with the API and as channels and playlists use the same endpoint you would just get ratelimited the same as with channels.

My revised strategy would be:

1. Channel API
2. Playlists API
3. if backend fallback enabled -> switch to other backend
4. if all else fails try playlists RSS