[WIP] Offline first product edition

[philippeauriach]

This PR is a work in progress. It aims to provide an offline first product creation / edition workflow.

Main goal is to always use the actual "offline" persisting solution (instead of checking if network is there, or waiting for the network to fail to fall down to offline), and create a periodic background job that will perform the upload.

Most of the methods used to upload data / pictures in OfflineProductService comes from the old OfflineEditFragment.

[teolemon]

Things working well:

• On the offline product addition, it does update well.
• upload is really fast, and save is instant.
• The background upload works

Issues

• There's no feedback of success, and as upload is really fast, and save is instant, it almost feels like something got wrong.
• When editing a product added offline, I have this weird behavior that was there before: it allows you to slide-up the card (with the tooltip “You can slide up the card for more details”), and displays an empty card. I would block the slide-up in this case, and say "You can click on the product to edit it" (related issues and PRs Disable dragging up in offline mode #2679 Disable dragging up on unknown product  #2680 disable dragging of bottom sheet in offline mode #2685 Disabled dragging up in offline mode #2682)
• Offline added product does not appear in the history
• The offline section having disappeared, there are 2 bars one on the other in the side menu
• The background upload is making the calls twice: https://world.openfoodfacts.org/product/8002270436635/san-pellegrino
• When adding a photo from the picture manager, the app redirects to an empty Scan window. I'd expect to be back to the product, as it was the case before.

(For the editors check when fixed)

Needs testing

• Background upload would need to be tested on older versions of Android, and on background activity stop agressive smartphone brands
• Now that all queries go offline first, we need to check what happens to Authentification with a degraded network. Previously, you could only add a new product anonymously. I suspect you might be either: (1) be able to edit anonymously or (2) not be able to add a new product anonymously >> What's the current status ?

[raphael0202]

Two behaviors to fix:
1.

• scan a new product
• add the missing front image by clicking on the image logo in the product header
• once the photo is validated, we go back to the continuous scan activity, instead of staying on the product page

• Scan a new product
• Edit it, save the edit
• the keyboard is still displayed when we go back to the product page

[raphael0202]

There is also an issue with the product history, it seems I switch between 2 product history lists.

[stephanegigandet]

Not sure if this is related to the new version: when I add a new product, the focus is on the "Expiration date" field, I don't see the top of the form.

Also, I think this field should be removed from the mobile app.

[stephanegigandet]

It's not the expiration date field in fact, it's the period after of opening. Which we don't have on OFF (we do on OBF).

[teolemon]

Thanks @stephanegigandet I could reproduce it, only on initial addition.

[teolemon]

I have filed a separate issue for the Best Before issue: #3124

[teolemon]

@philippeauriach reports the back to scan screen is in master. So I see no objection for merging, although I'd like this behaviour fixed before release (this is a regression vs production)