From 574017626624315640f4b19cb2d6eb8eed1afc61 Mon Sep 17 00:00:00 2001
From: Edouard Paris <m@edouard.paris>
Date: Tue, 26 Mar 2019 13:30:39 +0100
Subject: [PATCH] pubsub: watch invoices

---
 pubsub/pubsub.go | 73 +++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 69 insertions(+), 4 deletions(-)

diff --git a/pubsub/pubsub.go b/pubsub/pubsub.go
index c039279..1609fb2 100644
--- a/pubsub/pubsub.go
+++ b/pubsub/pubsub.go
@@ -2,18 +2,83 @@ package pubsub
 
 import (
 	"context"
+	"os"
+	"os/signal"
 	"sync"
 
 	"github.com/edouardparis/lntop/app"
 	"github.com/edouardparis/lntop/events"
 	"github.com/edouardparis/lntop/logging"
+	"github.com/edouardparis/lntop/network"
+	"github.com/edouardparis/lntop/network/models"
 )
 
+type pubSub struct {
+	stop    chan bool
+	logger  logging.Logger
+	network *network.Network
+	wg      *sync.WaitGroup
+}
+
+func newPubSub(logger logging.Logger, network *network.Network) *pubSub {
+	return &pubSub{
+		logger:  logger.With(logging.String("logger", "pubsub")),
+		network: network,
+		wg:      &sync.WaitGroup{},
+		stop:    make(chan bool),
+	}
+}
+
+func (p *pubSub) invoices(ctx context.Context, sub chan *events.Event) {
+	p.wg.Add(2)
+	invoices := make(chan *models.Invoice)
+
+	go func() {
+		for {
+			select {
+			case <-p.stop:
+				p.wg.Done()
+				return
+			default:
+				invoice := <-invoices
+				p.logger.Debug("receive invoice", logging.Object("invoice", invoice))
+			}
+		}
+	}()
+
+	go func() {
+		select {
+		case <-p.stop:
+			p.wg.Done()
+			return
+		default:
+			err := p.network.SubscribeInvoice(ctx, invoices)
+			if err != nil {
+				p.logger.Error("SubscribeInvoice returned an error", logging.Error(err))
+			}
+		}
+	}()
+}
+
+func (p *pubSub) wait() {
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, os.Interrupt)
+	p.wg.Add(1)
+	go func() {
+		for sig := range c {
+			p.logger.Debug("Received signal, gracefully stopping", logging.String("sig", sig.String()))
+			p.wg.Done()
+			close(p.stop)
+		}
+	}()
+	p.wg.Wait()
+}
+
 func Run(ctx context.Context, app *app.App, sub chan *events.Event) error {
-	logger := app.Logger.With(logging.String("logger", "pubsub"))
-	wg := &sync.WaitGroup{}
+	pubSub := newPubSub(app.Logger, app.Network)
+	pubSub.logger.Debug("Starting...")
 
-	logger.Debug("Starting...")
-	wg.Wait()
+	pubSub.invoices(ctx, sub)
+	pubSub.wait()
 	return nil
 }