Files
lndhub.go/lib/service/invoicesubscription.go
2022-07-15 01:08:34 +02:00

271 lines
10 KiB
Go

package service
import (
"context"
"crypto/sha256"
"database/sql"
"encoding/hex"
"fmt"
"strconv"
"strings"
"time"
"github.com/getAlby/lndhub.go/common"
"github.com/getAlby/lndhub.go/db/models"
"github.com/getAlby/lndhub.go/lnd"
"github.com/getsentry/sentry-go"
"github.com/lightningnetwork/lnd/lnrpc"
"github.com/uptrace/bun"
)
func (svc *LndhubService) HandleInternalKeysendPayment(ctx context.Context, invoice *models.Invoice) (result *models.Invoice, err error) {
//Find the payee user
user, err := svc.FindUserByLogin(ctx, string(invoice.DestinationCustomRecords[TLV_WALLET_ID]))
if err != nil {
return nil, err
}
preImage, err := makePreimageHex()
if err != nil {
return nil, err
}
pHash := sha256.New()
pHash.Write(preImage)
expiry := time.Hour * 24
incomingInvoice := models.Invoice{
Type: common.InvoiceTypeIncoming,
UserID: user.ID,
Amount: invoice.Amount,
Internal: true,
Memo: "",
State: common.InvoiceStateInitialized,
ExpiresAt: bun.NullTime{Time: time.Now().Add(expiry)},
Keysend: true,
RHash: hex.EncodeToString(pHash.Sum(nil)),
Preimage: hex.EncodeToString(preImage),
DestinationCustomRecords: invoice.DestinationCustomRecords,
DestinationPubkeyHex: svc.IdentityPubkey,
AddIndex: invoice.AddIndex,
}
//persist the incoming invoice
_, err = svc.DB.NewInsert().Model(&incomingInvoice).Exec(ctx)
return &incomingInvoice, err
}
func (svc *LndhubService) HandleKeysendPayment(ctx context.Context, rawInvoice *lnrpc.Invoice) error {
var invoice models.Invoice
rHashStr := hex.EncodeToString(rawInvoice.RHash)
//First check if this keysend payment was already processed
count, err := svc.DB.NewSelect().Model(&invoice).Where("type = ? AND r_hash = ? AND state = ?",
common.InvoiceTypeIncoming,
rHashStr,
common.InvoiceStateSettled).Count(ctx)
if err != nil {
return err
}
if count != 0 {
return fmt.Errorf("Already processed keysend payment %s", rHashStr)
}
//construct the invoice
invoice, err = svc.createKeysendInvoice(ctx, rawInvoice)
if err != nil {
return err
}
//persist the invoice
_, err = svc.DB.NewInsert().Model(&invoice).Exec(ctx)
if err != nil {
return err
}
return nil
}
func (svc *LndhubService) ProcessInvoiceUpdate(ctx context.Context, rawInvoice *lnrpc.Invoice) error {
var invoice models.Invoice
rHashStr := hex.EncodeToString(rawInvoice.RHash)
svc.Logger.Infof("Invoice update: r_hash:%s state:%v", rHashStr, rawInvoice.State.String())
//Check if it's a keysend payment
//If it is, an invoice will be created on-the-fly
if rawInvoice.IsKeysend {
err := svc.HandleKeysendPayment(ctx, rawInvoice)
if err != nil {
return err
}
}
// Search for an incoming invoice with the r_hash that is NOT settled in our DB
err := svc.DB.NewSelect().Model(&invoice).Where("type = ? AND r_hash = ? AND state <> ? AND expires_at > ?",
common.InvoiceTypeIncoming,
rHashStr,
common.InvoiceStateSettled,
time.Now()).Limit(1).Scan(ctx)
if err != nil {
svc.Logger.Infof("Invoice not found. Ignoring. r_hash:%s", rHashStr)
return nil
}
// Update the DB entry of the invoice
// If the invoice is settled we save the settle date and the status otherwise we just store the lnd status
// Additionally to the invoice update we create a transaction entry from the user's incoming account to the user's current account
// This transaction entry makes the balance available for the user
svc.Logger.Infof("Invoice update: invoice_id:%v settled:%v value:%v state:%v", invoice.ID, rawInvoice.Settled, rawInvoice.AmtPaidSat, rawInvoice.State)
// Get the user's current account for the transaction entry
creditAccount, err := svc.AccountFor(ctx, common.AccountTypeCurrent, invoice.UserID)
if err != nil {
svc.Logger.Errorf("Could not find current account user_id:%v invoice_id:%v", invoice.UserID, invoice.ID)
return err
}
// Get the user's incoming account for the transaction entry
debitAccount, err := svc.AccountFor(ctx, common.AccountTypeIncoming, invoice.UserID)
if err != nil {
svc.Logger.Errorf("Could not find incoming account user_id:%v invoice_id:%v", invoice.UserID, invoice.ID)
return err
}
// Process any update in a DB transaction
tx, err := svc.DB.BeginTx(ctx, &sql.TxOptions{})
if err != nil {
svc.Logger.Errorf("Failed to update the invoice invoice_id:%v r_hash:%s %v", invoice.ID, rHashStr, err)
return err
}
// if the invoice is NOT settled we just update the invoice state
if !rawInvoice.Settled {
svc.Logger.Infof("Invoice not settled invoice_id:%v state: %s", invoice.ID, rawInvoice.State.String())
invoice.State = strings.ToLower(rawInvoice.State.String())
} else {
// if the invoice is settled we update the state and create an transaction entry to the current account
invoice.SettledAt = bun.NullTime{Time: time.Unix(rawInvoice.SettleDate, 0)}
invoice.State = common.InvoiceStateSettled
_, err = tx.NewUpdate().Model(&invoice).WherePK().Exec(ctx)
if err != nil {
tx.Rollback()
svc.Logger.Errorf("Could not update invoice invoice_id:%v", invoice.ID)
return err
}
// Transfer the amount from the user's incoming account to the user's current account
entry := models.TransactionEntry{
UserID: invoice.UserID,
InvoiceID: invoice.ID,
CreditAccountID: creditAccount.ID,
DebitAccountID: debitAccount.ID,
Amount: rawInvoice.AmtPaidSat,
}
if rawInvoice.AmtPaidSat != invoice.Amount {
svc.Logger.Infof("Incoming invoice amount mismatch. user_id:%v invoice_id:%v, amt:%d, amt_paid:%d.", invoice.UserID, invoice.ID, invoice.Amount, rawInvoice.AmtPaidSat)
}
// Save the transaction entry
_, err = tx.NewInsert().Model(&entry).Exec(ctx)
if err != nil {
tx.Rollback()
svc.Logger.Errorf("Could not create incoming->current transaction user_id:%v invoice_id:%v %v", invoice.UserID, invoice.ID, err)
return err
}
}
// Commit the DB transaction. Done, everything worked
err = tx.Commit()
if err != nil {
svc.Logger.Errorf("Failed to commit DB transaction user_id:%v invoice_id:%v %v", invoice.UserID, invoice.ID, err)
return err
}
svc.InvoicePubSub.Publish(strconv.FormatInt(invoice.UserID, 10), invoice)
svc.InvoicePubSub.Publish(common.InvoiceTypeIncoming, invoice)
return nil
}
func (svc *LndhubService) createKeysendInvoice(ctx context.Context, rawInvoice *lnrpc.Invoice) (result models.Invoice, err error) {
//Look for the user-identifying TLV record
//which are located in the HTLC's.
//TODO: can the records differe from HTLC to HTLC? Probably not
if len(rawInvoice.Htlcs) == 0 {
return result, fmt.Errorf("Invoice's HTLC array has length 0")
}
userLoginCustomRecord := rawInvoice.Htlcs[0].CustomRecords[TLV_WALLET_ID]
//Find user. Our convention here is that the TLV
//record should contain the user's login string
//(LND already returns the decoded string so there is no need to hex-decode it)
user, err := svc.FindUserByLogin(ctx, string(userLoginCustomRecord))
if err != nil {
return result, err
}
expiry := time.Hour * 24 // not really relevant here, the invoice will be updated immediately
result = models.Invoice{
Type: common.InvoiceTypeIncoming,
UserID: user.ID,
Amount: rawInvoice.AmtPaidSat,
Memo: "",
State: common.InvoiceStateInitialized,
ExpiresAt: bun.NullTime{Time: time.Now().Add(expiry)},
Keysend: true,
RHash: hex.EncodeToString(rawInvoice.RHash),
Preimage: hex.EncodeToString(rawInvoice.RPreimage),
DestinationCustomRecords: rawInvoice.Htlcs[0].CustomRecords,
DestinationPubkeyHex: svc.IdentityPubkey,
AddIndex: rawInvoice.AddIndex,
}
return result, nil
}
func (svc *LndhubService) ConnectInvoiceSubscription(ctx context.Context) (lnd.SubscribeInvoicesWrapper, error) {
var invoice models.Invoice
invoiceSubscriptionOptions := lnrpc.InvoiceSubscription{}
// Find the oldest NOT settled AND NOT expired invoice with an add_index
// Note: expired invoices will not be settled anymore, so we don't care about those
err := svc.DB.NewSelect().Model(&invoice).Where("invoice.settled_at IS NULL AND invoice.add_index IS NOT NULL AND invoice.expires_at >= now()").OrderExpr("invoice.id ASC").Limit(1).Scan(ctx)
// IF we found an invoice we use that index to start the subscription
if err == nil {
invoiceSubscriptionOptions = lnrpc.InvoiceSubscription{AddIndex: invoice.AddIndex - 1} // -1 because we want updates for that invoice already
}
svc.Logger.Infof("Starting invoice subscription from index: %v", invoiceSubscriptionOptions.AddIndex)
return svc.LndClient.SubscribeInvoices(ctx, &invoiceSubscriptionOptions)
}
func (svc *LndhubService) InvoiceUpdateSubscription(ctx context.Context) error {
invoiceSubscriptionStream, err := svc.ConnectInvoiceSubscription(ctx)
if err != nil {
sentry.CaptureException(err)
return err
}
for {
select {
case <-ctx.Done():
return fmt.Errorf("Context was canceled")
default:
// receive the next invoice update
rawInvoice, err := invoiceSubscriptionStream.Recv()
if err != nil {
svc.Logger.Errorf("Error processing invoice update subscription: %v", err)
sentry.CaptureException(err)
// TODO: close the stream somehoe before retrying?
// Wait 30 seconds and try to reconnect
// TODO: implement some backoff
time.Sleep(30 * time.Second)
invoiceSubscriptionStream, _ = svc.ConnectInvoiceSubscription(ctx)
continue
}
// Ignore updates for open invoices
// We store the invoice details in the AddInvoice call
// Processing open invoices here could cause a race condition:
// We could get this notification faster than we finish the AddInvoice call
if rawInvoice.State == lnrpc.Invoice_OPEN {
svc.Logger.Infof("Invoice state is open. Ignoring update. r_hash:%v", hex.EncodeToString(rawInvoice.RHash))
continue
}
processingError := svc.ProcessInvoiceUpdate(ctx, rawInvoice)
if processingError != nil {
svc.Logger.Error(fmt.Errorf("Error %s, invoice hash %s", processingError.Error(), hex.EncodeToString(rawInvoice.RHash)))
sentry.CaptureException(fmt.Errorf("Error %s, invoice hash %s", processingError.Error(), hex.EncodeToString(rawInvoice.RHash)))
}
}
}
}