Why: big.Float is not an ideal type for dealing with monetary amounts,
because no matter how high the precision, some non-integer decimal
values can not be represented exactly in base-2 floating point. Also,
storing gob-encoded big.Float values in the database makes it very hard
to use those values in meaningful queries, making it difficult to do
any sort of analysis on billing.
For better accuracy, then, we can just represent monetary values as
integers (in whatever base units are appropriate for the currency). For
example, STORJ tokens or Bitcoins can not be split into pieces smaller
than 10^-8, so we can store amounts of STORJ or BTC with precision
simply by moving the decimal point 8 digits to the right. For USD values
(assuming we don't want to deal with fractional cents), we can move the
decimal point 2 digits to the right.
To make it easier and less error-prone to deal with the math involved, I
introduce here a new type, monetary.Amount, instances of which have an
associated value _and_ a currency.
Change-Id: I03395d52f0e2473cf301361f6033722b54640265
Full path: satellite/{payments,console},web/satellite
* Adds the ability to apply coupon codes from the billing page in the
satellite UI.
* Flag for coupon code UI is split into two flags - one for the billing
page and one for the signup page. This commit implements the first, but
not the second.
* Update the Stripe dependency to v72, which is necessary to
use Stripe's promo code functionality.
Change-Id: I19d9815c48205932bef68d87d5cb0b000498fa70
Jira: https://storjlabs.atlassian.net/browse/USR-968
We want to keep track of the STORJ amount and exchange rate in the
metadata of Stripe Customer Balance Transaction to be able to generate
reports without the need of requesting CoinPayments for this info.
Change-Id: Ia93af95706cd2312cf688f044874495279fe8fa2