Credits support

[MartinKolarik]

Credits support

[alexey-yarmosh]

Insert to credits_additions may happen even when associated users are not registered. Since they don't have userId it is not possible create a row in credits for them. That means users can't get credits for their donations/adoptions before they are registered on dashboard.

I can add a e.g. consumed: false column to credits_additions and set it to true only if value was added to credits. Then, on user sign up it is possible to go through all additions and give them all their prev credits.

[MartinKolarik]

That seems nice, sure. So when you start sponsoring and register only sometime later, you'll get all the credits.

[alexey-yarmosh]

Should X-RateLimit-Limit return values as previously? Or include available credits data?

[MartinKolarik]

Existing headers as before and this:

When credits are involved in handling the request, it would be good to also add two new headers: X-Credits-Remaining and X-Credits-Cost

[alexey-yarmosh]

Oh, missed that description part.

• X-Credits-Cost is how much credits where deducted during that request?
• seems like a second sql request is required to support X-Credits-Remaining, as update only returns number of affected rows:

await this.sql(CREDITS_TABLE).where({ user_id: userId }).update({ amount: this.sql.raw('amount - ?', [ credits ]) });
const remaining = await this.sql(CREDITS_TABLE).where({ user_id: userId }).select('amount');

there is an option to add add .returning('amount');, but that requires Postgresql.

const remaining = await this.sql(CREDITS_TABLE).where({ user_id: userId }).update({ amount: this.sql.raw('amount - ?', [ credits ]) }).returning('amount');

[MartinKolarik]

Should be possible with our DB too now: https://mariadb.com/kb/en/insertreturning/

Maybe will need a raw query if knex doesn't know it yet.

[alexey-yarmosh]

We need to update gp_credits instead of inserting. Since there is no UPDATE...RETURNING it still looks doable with INSERT INTO ... ON DUPLICATE KEY UPDATE ... RETURNING, where insert does nothing (amount: 0) and subtraction logic is inside ON DUPLICATE KEY UPDATE.