Because we ended up with such a big error, and it doesn't have an easy
fix, I'm wrapping up today by reverting the entire set of refactors
we've done lately, so modeling in production can continue while we
improve this code further over time.
I generated this commit by hand-picking the refactor-y commits
recently, running `git revert --no-commit <hash>` in reverse order,
then manually updating `pet_spec.rb` to reflect the state of the code:
passing the most important behavioral tests, but no longer passing one
of the kinds of annoyances I *did* fix in the new code.
```shell
git revert --no-commit 48c1a58df9
git revert --no-commit 42e7eabdd8
git revert --no-commit d82c7f817a
git revert --no-commit 5264947608
git revert --no-commit 90407403ba
git revert --no-commit 242b85470d
git revert --no-commit 9eaee4a2d4
git revert --no-commit 52ca41dbff
git revert --no-commit c03e7446e3
git revert --no-commit f81415d327
git revert --no-commit 13ceec8fcc
```
Ah right, the callbacks in `ParentSwfAssetRelationship` don't get
called when Rails does automatic join-model management stuff. We need
the `Item` to call its `update_cached_fields` callback itself, too!
When fixing this, I found a new bug that arose, in how we infer
`body_id` for assets that fit all pets. Fixing that next!
This is the first part of a change to improve search performance, by
caching occupied zone IDs and supported body IDs onto the Item record
itself, instead of always doing joins with `SwfAsset`.
It's unfortunate, because part of the power of SQL is joins! But doing
joins with big tables, in ways that can't take advantage of indexes in
the same ways as we often want to, is… slow.
It's possible there's something I'm misunderstanding about SQL
optimization, and this _could_ be done with query optimization or
indexes instead of duplicating data like this? This complexity carries
the risk of data getting out of sync in unforeseen ways. But this is
what I know how to do, and it seems to be working, so! Okay!
Some important little upgrades but mostly straightforward!
Note that there's still a known issue where item searches crash, I was hoping that this was a bug in Rails 4.2 that would be fixed on upgading to 5, but nope, oh well!
Also uhh I just got a bit silly and didn't actually mean to go all the way to 5.2 in one go, I had meant to start at 5.0… but tbh the 5.1 and 5.2 changes seem small, and this seems to be working, so. Yeah ok let's roll!
Lots of scary bugs were being caused by the fact that the possibly-duplicate Neopets ID
was being treated as an SWF's real primary key, meaning that a save meant for object swf
number 123 could be saved to biology swf number 123. Which is awful.
This update gives SWFs their own unique internal ID numbers. All external lookups still use
the remote ID and the type, meaning that the client side remains totally unchanged (phew).
However, all database relationships with SWFs use the new ID numbers, making everything
cleaner. Yay.
There are probably a few places where it would be appropriate to optimize certain lookups
that still depend on remote ID and type. Whatever. Today's goal was to remove crazy
glitches that have been floating around like mad. And I think that goal has been met.
