well-goknown/lnd/lnd.go

package lnd

import (
	"context"
	b64 "encoding/base64"
	"encoding/hex"
	"errors"
	"fmt"
	"strconv"
	"time"

	"git.minhas.io/asara/well-goknown/config"
	"git.minhas.io/asara/well-goknown/logger"
	"git.minhas.io/asara/well-goknown/redis"
	"github.com/lightninglabs/lndclient"
	"github.com/lightningnetwork/lnd/lnrpc"
)

func Request(rKey string) (string, error) {
	l := logger.Get()
	ctx := context.TODO()
	// connect to lnd
	// TODO: move to its own function and don't connect on every request
	macaroon := config.GetConfig().LndMacaroonHex
	addr := config.GetConfig().LndAddr
	dec, _ := b64.StdEncoding.DecodeString(config.GetConfig().LndCertB64)
	lndCert := string(dec)
	lndCli, err := lndclient.NewBasicClient(addr, "", "", "bitcoind", lndclient.MacaroonData(macaroon), lndclient.TLSData(lndCert))
	if err != nil {
		l.Fatal().Msg("unable to connect to lnd")
	}

	// add invoice
	addrFee, err := strconv.ParseInt(config.GetConfig().NostrAddrFee, 10, 64)
	if err != nil {
		l.Fatal().Msg("nostr address fee not set properlly")
		return "", errors.New("internal server error")
	}

	expiryInMin := int64(5)
	invoice, err := lndCli.AddInvoice(ctx, &lnrpc.Invoice{
		Memo:   fmt.Sprintf("nostr addr %s", rKey),
		Expiry: expiryInMin * 60,
		Value:  addrFee,
	})
	if err != nil {
		l.Fatal().Msg("unable to create lnd invoice")
		return "", errors.New("internal server error")
	}

	// add a minute to the expiry time to ensure entries aren't removed from redis before they are expired
	expiryTime := time.Now().Local().Add(time.Minute * time.Duration(expiryInMin+1)).Unix()

	paymentReq := invoice.PaymentRequest
	rHash := hex.EncodeToString(invoice.RHash)

	// write lnd request to redis
	redisCli := redis.LndRedisConn.Client
	err = redisCli.Set(ctx, rKey, fmt.Sprintf("%d:%s:%s", expiryTime, rHash, paymentReq), 0).Err()
	if err != nil {
		l.Error().Msg("unable to connect to redis when writing lnd request")
		return "", errors.New("unable to make the request, please try again")
	}

	return paymentReq, nil
}