99 lines
2.8 KiB
Go

package nip60
import (
"context"
"fmt"
"time"
"github.com/elnosh/gonuts/cashu"
"github.com/elnosh/gonuts/cashu/nuts/nut05"
"github.com/nbd-wtf/go-nostr/nip60/client"
)
func (w *Wallet) PayBolt11(ctx context.Context, invoice string, opts ...SendOption) (string, error) {
ss := &sendSettings{}
for _, opt := range opts {
opt(ss)
}
invoiceAmount, err := getSatoshisAmountFromBolt11(invoice)
if err != nil {
return "", err
}
w.tokensMu.Lock()
defer w.tokensMu.Unlock()
var chosen chosenTokens
var meltQuote string
var meltAmount uint64
feeReservePct := uint64(1)
feeReserveAbs := uint64(1)
for range 10 {
amount := invoiceAmount*(100+feeReservePct)/100 + feeReserveAbs
var fee uint64
chosen, fee, err = w.getProofsForSending(ctx, amount, ss.specificMint)
if err != nil {
return "", err
}
// request _melt_ quote (ask the mint how much will it cost to pay a bolt11 invoice)
meltResp, err := client.PostMeltQuoteBolt11(ctx, chosen.mint, nut05.PostMeltQuoteBolt11Request{
Request: invoice,
Unit: cashu.Sat.String(),
})
if err != nil {
return "", fmt.Errorf("error requesting melt quote from %s: %w", chosen.mint, err)
}
// if amount in proofs is not sufficient to pay for the melt request,
// increase the amount and get proofs again (because of lighting fees)
meltQuote = meltResp.Quote
meltAmount = meltResp.Amount + meltResp.FeeReserve + fee
if meltAmount > chosen.proofs.Amount() {
feeReserveAbs++
} else {
goto meltworked
}
}
return "", fmt.Errorf("stop trying to do the melt because the invoice is too expensive")
meltworked:
// swap our proofs so we get the exact amount for paying the invoice
principal, change, err := w.SwapProofs(ctx, chosen.mint, chosen.proofs, meltAmount)
if err != nil {
return "", fmt.Errorf("failed to swap at %s into the exact melt amount: %w", chosen.mint, err)
}
if err := w.saveChangeAndDeleteUsedTokens(ctx, chosen.mint, change, chosen.tokenIndexes); err != nil {
return "", err
}
// request from mint to _melt_ into paying the invoice
delay := 200 * time.Millisecond
// this request will block until the invoice is paid or it fails
// (but the API also says it can return "pending" so we handle both)
meltStatus, err := client.PostMeltBolt11(ctx, chosen.mint, nut05.PostMeltBolt11Request{
Quote: meltQuote,
Inputs: principal,
})
inspectmeltstatusresponse:
if err != nil || meltStatus.State == nut05.Unpaid {
return "", fmt.Errorf("error melting token: %w", err)
} else if meltStatus.State == nut05.Unknown {
return "", fmt.Errorf("we don't know what happened with the melt at %s: %v", chosen.mint, meltStatus)
} else if meltStatus.State == nut05.Pending {
for {
time.Sleep(delay)
delay *= 2
meltStatus, err = client.GetMeltQuoteState(ctx, chosen.mint, meltStatus.Quote)
goto inspectmeltstatusresponse
}
}
return meltStatus.Preimage, nil
}