I am changing many of these to notes or resolving them as is,
most of these I have not actively worked on in years so someone
else can work on them when we get to these areas again.
When uploading a video, the composer will now show a thumbnail image in
the composer preview instead of just the video placeholder image.
If `enable_diffhtml_preview` is enabled the video will be rendered in
the composer preview and is playable.
Using min_trust_to_create_topic and create_topic_allowed_groups together was part of #24740
Now, when plugins specs are fixed, we can safely remove that part of logic.
Tries to fix the composer upload spec by making the upload
slow enough to allow clicking the Cancel button, and improves
generally the API for CDP network changes.
Short answer -- the problem is the video thumbnail generator & uploader
code added a couple of months back in f144c64e13.
It was implemented as another Mixin which overrides `this._uppyInstance`
when uploading the video thumbnail after the initial upload is complete,
which means the composer's `this._uppyInstance` value is overridden,
and it loses all of its preprocessors & upload code.
This is generally a problem with the Mixin based architecture that I
used for the Uppy code, which we need to remove at some point and
refacotr.
The most ideal thing to do here would be to convert this video thumbnail
code into an Uppy
[postprocessor](https://uppy.io/docs/uppy/#addpostprocessorfn) plugin,
which runs on each upload after they are complete. I started looking
into this, and the main hurdle here is adding support to tracking the
progress of postprocessors to
[ExtendableUploader](cf42466dea/app/assets/javascripts/discourse/app/mixins/extendable-uploader.js)
so that is out of scope at this time.
The fix here makes it so the ComposerVideoThumbnailUppy code is no
longer a Mixin, but acts more like a normal class, a pattern which
we have used in chat. I also clean up a lot of the thumbnail uploader
code and remove some unnecessary things.
Attempted to add a system spec, but video streaming does not work
in Chrome for Testing at this time, and it is needed for the
onloadedmetadata event.
