lncli: keysend acceptance [poc]

cmd/lncli/cmd_tlvshop.go

@@ -0,0 +1,126 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/lightningnetwork/lnd/lntypes"
+
+	"github.com/lightningnetwork/lnd/lnrpc"
+
+	"github.com/lightningnetwork/lnd/lnrpc/invoicesrpc"
+	"github.com/urfave/cli"
+)
+
+var ctxb = context.Background()
+
+var tlvshopCommand = cli.Command{
+	Name:   "tlvshop",
+	Action: actionDecorator(tlvshop),
+}
+
+func tlvshop(ctx *cli.Context) error {
+	conn := getClientConn(ctx, false)
+	defer conn.Close()
+
+	client := lnrpc.NewLightningClient(conn)
+	invoicesClient := invoicesrpc.NewInvoicesClient(conn)
+
+	allCtx, cancel := context.WithCancel(ctxb)
+	defer cancel()
+
+	stream, err := client.SubscribeInvoices(allCtx, &lnrpc.InvoiceSubscription{})
+	if err != nil {
+		return err
+	}
+
+	invoices := make(map[lntypes.Hash]struct{})
+	for {
+		invoice, err := stream.Recv()
+		if err != nil {
+			return err
+		}
+
+		// Don't need to track invoices without preimage.
+		if invoice.RPreimage == nil {
+			continue
+		}
+
+		hash, err := lntypes.MakeHash(invoice.RHash)
+		if err != nil {
+			return err
+		}
+
+		if _, ok := invoices[hash]; ok {
+			continue
+		}
+
+		invoices[hash] = struct{}{}
+
+		go func() {
+			err := trackSingle(allCtx, invoicesClient, hash)
+			if err != nil {
+				fmt.Printf("error: %v\n", err)
+				cancel()
+			}
+		}()
+	}
+}
+
+func trackSingle(ctx context.Context, invoicesClient invoicesrpc.InvoicesClient,
+	hash lntypes.Hash) error {
+
+	singleStream, err := invoicesClient.SubscribeSingleInvoice(
+		ctx,
+		&invoicesrpc.SubscribeSingleInvoiceRequest{
+			RHash: hash[:],
+		},
+	)
+	if err != nil {
+		return err
+	}
+
+	for {
+		invoice, err := singleStream.Recv()
+		if err != nil {
+			return err
+		}
+
+		fmt.Printf("%x: state=%v, preimage=%x\n", invoice.RHash,
+			invoice.State, invoice.RPreimage)
+
+		if invoice.State == lnrpc.Invoice_ACCEPTED {
+			// Check amount paid
+			amtOk := invoice.Value > 500
+
+			// Check webshop inventory here.
+			time.Sleep(2 * time.Second)
+			stockOk := true
+
+			settlePayment := amtOk && stockOk
+
+			if settlePayment {
+				_, err := invoicesClient.SettleInvoice(
+					ctxb,
+					&invoicesrpc.SettleInvoiceMsg{
+						Preimage: invoice.RPreimage,
+					},
+				)
+				if err != nil {
+					return err
+				}
+			} else {
+				_, err := invoicesClient.CancelInvoice(
+					ctxb,
+					&invoicesrpc.CancelInvoiceMsg{
+						PaymentHash: hash[:],
+					},
+				)
+				if err != nil {
+					return err
+				}
+			}
+		}
+	}
+}

cmd/lncli/main.go

@@ -302,6 +302,7 @@ func main() {
 		bakeMacaroonCommand,
 		trackPaymentCommand,
 		versionCommand,
+		tlvshopCommand,
 	}
 
 	// Add any extra commands determined by build flags.