Check-in dialog shows incorrect number

[nbearman]

Describe the bug
When opening the app for the first time each day, a dialog pops up showing the number of check-ins required before the next login incentive prize. This number is not calculated correctly; instead, it shows the number of total check-ins required for the next incentive.

e.g.: when checking in on the 15th day, the dialog says:

Next prize in 18 Check-ins

but it should say

Next prize in 3 Check-ins

To Reproduce
Steps to reproduce the behavior:

1. Open the app for the first time in a day
2. Note the daily check-in dialog
3. The number displayed ("Next prize in X Check-ins") shows the total number of check-ins required for the next incentive (not the number remaining).

(Android Version 4.0.5 (4760))

Expected behavior

The number shown in the check-in dialog should be the number of check-ins remaining until the next incentive.

Screenshots

Screenshot shows "18 Check-ins" remaining, when the next reward is unlocked at 18 total check-ins. It should show "3 Check-ins".

Smartphone (please complete the following information):

• OS: Android 13
• App Version: Version 4.0.5 (4760)

Additional context

The offending line appears to be here (ShowNotificationInteractor.kt)

val nextUnlockText = activity.getString(R.string.nextPrizeUnlocks, notificationData?.nextRewardAt)

I think the nextRewardAt contained in the notification comes from the server, and is calculated in loginIncentives.js. This field, stored on each incentive, represents the number of total check-ins required to reach the next incentive (e.g. the incentive earned at 450 check-ins holds 475 as it's nextRewardAt, since the next incentive in order requires 475 total check-ins).

This number is not relative to the player's current number of check-ins; it does not change. In order to show the number of additional check-ins the player needs before reaching the next incentive, the player's current total check-ins needs to be subtracted from the nextRewardAt (e.g. 475 - 468 = 7 == check-ins to next prize).

This calculation is done correctly in both the web app and the iOS app before showing the message:

Web app: (https://github.com/HabitRPG/habitica/blob/develop/website/client/src/components/achievements/login-incentives.vue#L85)

<h3>
    {{ $t('nextRewardUnlocksIn', {
        numberOfCheckinsLeft: data.nextRewardAt - user.loginIncentives}) }}
</h3>

iOS: (https://github.com/HabitRPG/habitica-ios/blob/develop/HabitRPG/Utilities/NotificationManager.swift#L178)

let nextRewardIn = nextRewardAt - loginIncentives
    mutableString.append(NSAttributedString(string: L10n.nextPrizeInXCheckins(nextRewardIn), attributes: [

It looks like the Android app needs to make this calculation as well, something like:

val nextUnlockText = activity.getString(R.string.nextPrizeUnlocks, notificationData.nextRewardAt - user.loginIncentives)

This should be straightforward, but I can't tell if the user is readily available in this context; it looks like it might not be.

An alternative might be to make the calculation on the server side and include it in the notification.