[Feature] Better stock management

[rafaelurben]

To do

• Add "infinite" flag for product stock.
  • Disable email warnings
  • Hide from App_Stock querysets
  • Exclude on stats page

Check how stock is handled in WooCommerce to keep compatibility and prepare for potential future 2-way-connection.

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Current general problems

• Slow calculations
• Too many emails or admin messages
• Products have no option to be stock-independent (e.g. services paid by hour/minute)
• Stock history not reproducible

App bulk save & WC bulk import

In the app, when multiple orders are saved / marked as shipped, the stock is calculated for every order separately, which results in a lot of calculations and multiple times the same message.

In a bulk WC import, the stock is calculated for every import separately, which can result in A LOT of emails.

=> Possible solution: static method accepts queryset => aggregate functions on entire queryset

(in case of WC bulk import: queryset via id_in=[...])

Idea: Better admin display

Maybe use aggregate functions and also show incoming/outgoing?

https://books.agiliq.com/projects/django-admin-cookbook/en/latest/optimize_queries.html

Idea: Stock list

Design with 'details' element, somewhat like payment import processing page.

Categories:

• Negative (< 0)
• Warning (>= 0, <soll)
• Positive (>= soll)

Alternative: Update print stylesheet for app_stock changelist.

Idea: Stock log

Separate model, which stores all changes in incoming/outgoing and current stock.