Adjust username change cost

[notbakaneko]

closes #11790

The new logic is the price goes up 1 tier for every paid change, and down 1 tier for every year since the last paid change, to a minimum of 1.

[nanaya]

the function signature is $expected, $actual so it should be $cost, $user->... here (and the rest of this file).

[Phippe]

Once someone has changed their name 5 times or more, the default cost will be $100.

Now assume they wait for 4 years and then pay $8 for another name change. Shortly afterwards, they want to change their name again, but - if I understand the code correctly - now the price is back up to $100, not $16.

When I first read the proposal, I interpreted the cooldown to be more "permanent". Like once you've waited long enough, you would start at tier 1 again and then "work your way back up" for each name change after that.

I just wanted to ask if this is the intended behaviour.

Edit: After thinking a bit about how I'd implement this, it's probably just unnecessarily difficult for the handful of people that are affected by that, so should be fine.

[nanaya]

yeah I think it's an oversight. A simpler logic would probably be to just set the tier to be the number of name changes over the last 4-5 years. @notbakaneko

[peppy]

I guess we should wait for the oversight to be addressed before deploying to stop people getting confused.

[notbakaneko]

After going through it again, it's a lot more complicated to handle if the cost tier gets 'reset' to a new level each time.
Consider the case where the username is changed once a year:
If you go to the highest tier then the cost is $100 (tier 5), after a year the price drops to $64 (tier 4) moving the next change to tier 5 but if you wait a year again, it drops to tier 4.
The same applies to the other tiers where it'll just stay the same price if you wait a year before every change.
The $8 tier also requires an exception for handling it since it can't go below $8.

It doesn't seem practical without going through every username change in the user's history and calculating the current tier the name change should put it at, or storing the current tier.

I think it might make more sense if it was based on username changes in the past X years and maybe a reduction based on when the last change was made.