Media Uploads for scheduled statuses

[andrlik]

Models for handling media uploads that will be attached to scheduled status updates.

• Needs to be able to handle images and video.
• Needs to generate thumbnails
• Needs to be able to validate in advance if an upload is accepted by the target service.
• Needs to handle the fact that media will be uploaded to multiple destinations, sometimes before the status itself is posted.
• Needs cleanup scripts to discard original media on a schedule.
• Needs to cleanly support remote storage through something like Django-storages, etc.

[andrlik]

I originally wanted to have a single upload model, but the challenges involved in doing that seem like that's me trying to be too clever.

Two options:

• Have separate models based on the type of media upload so that we don't lose existing conveniences for things like ImageField.
• Create a new Django model field type that can determine whether the content is image or video and extract properties without having to fully retrieve it from storage again.
• Create a single model and then use proxy models with distinct functions/properties for the media type.

Currently leaning towards option one, but that feels ugly to me.

[andrlik]

Also have to decide how we want to track where the files are already published. For example, to schedule a post in Mastodon, you need to upload the media and submit the post with the scheduled time in advance.

For Twitter, due to API limitations, you need to wait to upload the media and post the status until publish time.

For Instagram, if we do that, you need to store it locally until publish time, and (if not video content) needs to be a curl-able square jpeg exposed publicly.