finished LND implementation

backends/lnd.go

@@ -3,10 +3,13 @@ package backends
 import (
 	"context"
 	"encoding/hex"
+	"errors"
+	"fmt"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/metadata"
+	"io"
 	"io/ioutil"
 )
 
@@ -76,3 +79,41 @@ func (lnd *LND) GetInvoice(description string, value int64, expiry int64) (invoi
 
 	return response.PaymentRequest, err
 }
+
+func (lnd *LND) SubscribeInvoices() error {
+	stream, err := lnd.client.SubscribeInvoices(lnd.ctx, &lnrpc.InvoiceSubscription{})
+
+	if err != nil {
+		return err
+	}
+
+	wait := make(chan struct{})
+
+	go func() {
+		for {
+			in, streamErr := stream.Recv()
+
+			if streamErr == io.EOF {
+				err = errors.New("lost connection to LND gRPC")
+
+				close(wait)
+
+				return
+			}
+
+			if streamErr != nil {
+				err = streamErr
+
+				close(wait)
+
+				return
+			}
+
+			fmt.Println(in)
+		}
+	}()
+
+	<-wait
+
+	return err
+}

config.go

@@ -10,12 +10,20 @@ import (
 	"strings"
 )
 
+// TODO: add option to show URI of Lightning node
+
 const (
 	defaultConfigFile = "lightningTip.conf"
 
 	defaultLogFile  = "lightningTip.log"
 	defaultLogLevel = "debug"
 
+	defaultRESTHost = "localhost:8081"
+
+	defaultTipMessage = "A generous tip"
+	defaultTipExpiry  = 3600
+	defaultTipValue   = 100
+
 	defaultLndRPCHost   = "localhost:10009"
 	defaultLndCertFile  = "tls.cert"
 	defaultMacaroonFile = "admin.macaroon"
@@ -27,13 +35,18 @@ type config struct {
 	LogFile  string `long:"logfile" Description:"Log file location"`
 	LogLevel string `long:"loglevel" Description:"Log level: debug, info, warning, error"`
 
+	RESTHost string `long:"resthost" Description:"Host for the rest interface of LightningTip"`
+
+	TipMessage      string `long:"tipmessage" Description:"Message embedded in the payment request"`
+	TipExpiry       int64  `long:"tipexpiry" Description:"Expiry time in seconds"`
+	DefaultTipValue int64  `long:"defaulttipvalue" Description:"The default value of a tip in satoshis"`
+
 	LND *backends.LND `group:"LND" namespace:"lnd"`
 }
 
 var cfg config
 
 var backend backends.Backend
-var backendName string
 
 func initConfig() {
 	lndDir := getDefaultLndDir()
@@ -44,6 +57,12 @@ func initConfig() {
 		LogFile:  defaultLogFile,
 		LogLevel: defaultLogLevel,
 
+		RESTHost: defaultRESTHost,
+
+		TipMessage:      defaultTipMessage,
+		TipExpiry:       defaultTipExpiry,
+		DefaultTipValue: defaultTipValue,
+
 		LND: &backends.LND{
 			RPCHost:      defaultLndRPCHost,
 			CertFile:     path.Join(lndDir, defaultLndCertFile),
@@ -82,9 +101,8 @@ func initConfig() {
 		log.Infof("Failed to parse config file: %v", errFile)
 	}
 
-	// TODO: add more backend options like for example c-lighting
+	// TODO: add more backend options like for example c-lighting and eclair
 	backend = cfg.LND
-	backendName = "LND"
 }
 
 func getDefaultLndDir() (dir string) {

lightningtip.go

@@ -1,6 +1,31 @@
 package main
 
-import "fmt"
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"strconv"
+)
+
+type getInvoiceRequest struct {
+	Value   int64
+	Message string
+}
+
+type invoiceResponse struct {
+	Invoice string
+	Error   string
+}
+
+type tipValueResponse struct {
+	TipValue int64
+}
+
+type errorResponse struct {
+	Error string
+}
 
 func main() {
 	initLog()
@@ -10,12 +35,108 @@ func main() {
 	err := backend.Connect()
 
 	if err == nil {
-		log.Info("Successfully connected to " + backendName)
+		http.HandleFunc("/", notFoundHandler)
+		http.HandleFunc("/getinvoice", getInvoiceHandler)
+		http.HandleFunc("/defaulttipvalue", defaultTipValueHandler)
 
-		invoice, err := backend.GetInvoice("Just a test", 1, 3600)
+		log.Info("Subscribing to invoices")
+
+		go func() {
+			err = cfg.LND.SubscribeInvoices()
+
+			if err != nil {
+				log.Error("Failed to subscribe to invoices: " + fmt.Sprint(err))
+
+				os.Exit(1)
+			}
+
+		}()
+
+		log.Info("Starting HTTP server")
+
+		go func() {
+			err = http.ListenAndServe(cfg.RESTHost, nil)
+
+			if err != nil {
+				log.Error("Failed to start HTTP server: " + fmt.Sprint(err))
+
+				os.Exit(1)
+			}
+
+		}()
+
+		select {}
 
-		log.Info("Got invoice " + invoice)
-		log.Info(fmt.Sprint(err))
 	}
 
 }
+
+func getInvoiceHandler(writer http.ResponseWriter, request *http.Request) {
+	var errorMessage string
+
+	tipValue := cfg.DefaultTipValue
+	tipMessage := cfg.TipMessage
+
+	if request.Method == http.MethodPost {
+		var body getInvoiceRequest
+
+		data, _ := ioutil.ReadAll(request.Body)
+
+		err := json.Unmarshal(data, &body)
+
+		if err == nil {
+			if body.Value != 0 {
+				tipValue = body.Value
+			}
+
+			if body.Message != "" {
+				tipMessage = body.Message
+			}
+
+		} else {
+			errorMessage = "Could not parse values from request"
+
+			log.Warning(errorMessage)
+		}
+
+	}
+
+	invoice, err := backend.GetInvoice(tipMessage, tipValue, cfg.TipExpiry)
+
+	if err == nil {
+		log.Info("Created invoice with value of " + strconv.FormatInt(tipValue, 10) + " satoshis")
+
+		writer.Write(marshalJson(invoiceResponse{
+			Invoice: invoice,
+			Error:   errorMessage,
+		}))
+
+	} else {
+		errorMessage := "Failed to create invoice"
+
+		log.Error(errorMessage + ": " + fmt.Sprint(err))
+
+		writer.Write(marshalJson(errorResponse{
+			Error: errorMessage,
+		}))
+	}
+
+}
+
+func defaultTipValueHandler(writer http.ResponseWriter, request *http.Request) {
+	writer.Write(marshalJson(tipValueResponse{
+		TipValue: cfg.DefaultTipValue,
+	}))
+}
+
+func notFoundHandler(writer http.ResponseWriter, request *http.Request) {
+	writer.Write(marshalJson(errorResponse{
+		Error: "Not found",
+	}))
+}
+
+func marshalJson(data interface{}) []byte {
+	response, _ := json.MarshalIndent(data, "", "    ")
+
+	return response
+}