storj/satellite/payments/stripecoinpayments/tokens.go
paul cannon a16aecfa96 satellite/payments: specialized type for monetary amounts
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
2021-09-28 23:27:44 +00:00

245 lines
6.6 KiB
Go

// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.
package stripecoinpayments
import (
"context"
"encoding/json"
"strconv"
"strings"
"time"
"github.com/stripe/stripe-go/v72"
"go.uber.org/zap"
"storj.io/common/uuid"
"storj.io/storj/satellite/payments"
"storj.io/storj/satellite/payments/coinpayments"
"storj.io/storj/satellite/payments/monetary"
)
const (
// StripeDepositTransactionDescription is the description for Stripe
// balance transactions representing STORJ deposits.
StripeDepositTransactionDescription = "STORJ deposit"
// StripeDepositBonusTransactionDescription is the description for Stripe
// balance transactions representing bonuses received for STORJ deposits.
StripeDepositBonusTransactionDescription = "STORJ deposit bonus"
// StripeMigratedDepositBonusTransactionDescription is the description for
// Stripe balance transactions representing bonuses migrated from the
// 'credits' table of the satellite DB.
StripeMigratedDepositBonusTransactionDescription = "Migrated STORJ deposit bonus"
)
// ensure that storjTokens implements payments.StorjTokens.
var _ payments.StorjTokens = (*storjTokens)(nil)
// storjTokens implements payments.StorjTokens.
//
// architecture: Service
type storjTokens struct {
service *Service
}
// Deposit creates new deposit transaction with the given amount returning
// ETH wallet address where funds should be sent. There is one
// hour limit to complete the transaction. Transaction is saved to DB with
// reference to the user who made the deposit.
func (tokens *storjTokens) Deposit(ctx context.Context, userID uuid.UUID, amount int64) (_ *payments.Transaction, err error) {
defer mon.Task()(&ctx, userID, amount)(&err)
customerID, err := tokens.service.db.Customers().GetCustomerID(ctx, userID)
if err != nil {
return nil, Error.Wrap(err)
}
c, err := tokens.service.stripeClient.Customers().Get(customerID, nil)
if err != nil {
return nil, Error.Wrap(err)
}
rate, err := tokens.service.GetRate(ctx, monetary.StorjToken, monetary.USDollars)
if err != nil {
return nil, Error.Wrap(err)
}
tokenAmount := convertFromCents(rate, amount)
tx, err := tokens.service.coinPayments.Transactions().Create(ctx,
&coinpayments.CreateTX{
Amount: tokenAmount.AsDecimal(),
CurrencyIn: monetary.StorjToken,
CurrencyOut: monetary.StorjToken,
BuyerEmail: c.Email,
},
)
if err != nil {
return nil, Error.Wrap(err)
}
key, err := coinpayments.GetTransactionKeyFromURL(tx.CheckoutURL)
if err != nil {
return nil, Error.Wrap(err)
}
if err = tokens.service.db.Transactions().LockRate(ctx, tx.ID, rate); err != nil {
return nil, Error.Wrap(err)
}
cpTX, err := tokens.service.db.Transactions().Insert(ctx,
Transaction{
ID: tx.ID,
AccountID: userID,
Address: tx.Address,
Amount: tx.Amount,
Status: coinpayments.StatusPending,
Key: key,
Timeout: tx.Timeout,
},
)
if err != nil {
return nil, Error.Wrap(err)
}
return &payments.Transaction{
ID: payments.TransactionID(tx.ID),
Amount: tx.Amount,
Rate: rate,
Address: tx.Address,
Status: payments.TransactionStatusPending,
Timeout: tx.Timeout,
Link: tx.CheckoutURL,
CreatedAt: cpTX.CreatedAt,
}, nil
}
// ListTransactionInfos fetches all transactions from the database for specified user, reconstructing checkout link.
func (tokens *storjTokens) ListTransactionInfos(ctx context.Context, userID uuid.UUID) (_ []payments.TransactionInfo, err error) {
defer mon.Task()(&ctx, userID)(&err)
txs, err := tokens.service.db.Transactions().ListAccount(ctx, userID)
if err != nil {
return nil, Error.Wrap(err)
}
var infos []payments.TransactionInfo
for _, tx := range txs {
link := coinpayments.GetCheckoutURL(tx.Key, tx.ID)
var status payments.TransactionStatus
switch tx.Status {
case coinpayments.StatusPending:
status = payments.TransactionStatusPending
case coinpayments.StatusReceived:
status = payments.TransactionStatusPaid
case coinpayments.StatusCancelled:
status = payments.TransactionStatusCancelled
default:
// unknown
status = payments.TransactionStatus(tx.Status.String())
}
rate, err := tokens.service.db.Transactions().GetLockedRate(ctx, tx.ID)
if err != nil {
return nil, err
}
infos = append(infos,
payments.TransactionInfo{
ID: []byte(tx.ID),
Amount: tx.Amount,
Received: tx.Received,
AmountCents: convertToCents(rate, tx.Amount),
ReceivedCents: convertToCents(rate, tx.Received),
Address: tx.Address,
Status: status,
Link: link,
ExpiresAt: tx.CreatedAt.Add(tx.Timeout),
CreatedAt: tx.CreatedAt,
},
)
}
return infos, nil
}
// ListDepositBonuses returns all deposit bonuses from Stripe associated with user.
func (tokens *storjTokens) ListDepositBonuses(ctx context.Context, userID uuid.UUID) (_ []payments.DepositBonus, err error) {
defer mon.Task()(&ctx, userID)(&err)
cusID, err := tokens.service.db.Customers().GetCustomerID(ctx, userID)
if err != nil {
return nil, err
}
var bonuses []payments.DepositBonus
customer, err := tokens.service.stripeClient.Customers().Get(cusID, nil)
if err != nil {
return nil, err
}
for key, value := range customer.Metadata {
if !strings.HasPrefix(key, "credit_") {
continue
}
var credit payments.Credit
err = json.Unmarshal([]byte(value), &credit)
if err != nil {
tokens.service.log.Error("Error unmarshaling credit history from Stripe metadata",
zap.String("Customer ID", cusID),
zap.String("Metadata Key", key),
zap.String("Metadata Value", value),
zap.Error(err),
)
continue
}
bonuses = append(bonuses,
payments.DepositBonus{
TransactionID: payments.TransactionID(credit.TransactionID),
AmountCents: credit.Amount,
Percentage: 10,
CreatedAt: credit.Created,
},
)
}
it := tokens.service.stripeClient.CustomerBalanceTransactions().List(&stripe.CustomerBalanceTransactionListParams{Customer: stripe.String(cusID)})
for it.Next() {
tx := it.CustomerBalanceTransaction()
if tx.Type != stripe.CustomerBalanceTransactionTypeAdjustment {
continue
}
if tx.Description != StripeDepositBonusTransactionDescription {
continue
}
percentage := int64(10)
percentageStr, ok := tx.Metadata["percentage"]
if ok {
percentage, err = strconv.ParseInt(percentageStr, 10, 64)
if err != nil {
return nil, err
}
}
bonuses = append(bonuses,
payments.DepositBonus{
TransactionID: []byte(tx.Metadata["txID"]),
AmountCents: -tx.Amount,
Percentage: percentage,
CreatedAt: time.Unix(tx.Created, 0),
},
)
}
return bonuses, nil
}