From 7343edf756b17d819496feb1f2128d269b89c6cb Mon Sep 17 00:00:00 2001
From: michael1011 <michael101101@me.com>
Date: Thu, 29 Mar 2018 13:06:28 +0200
Subject: [PATCH] added ticker to remove expired invoices periodically

---
 config.go                 |  2 +-
 frontend/lightningTip.css |  2 +-
 frontend/lightningTip.js  | 18 ++++++++++++++----
 lightningtip.go           | 30 +++++++++++++++++++++++++++++-
 4 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/config.go b/config.go
index 8b49ec0..9638a60 100644
--- a/config.go
+++ b/config.go
@@ -33,7 +33,7 @@ type config struct {
 
 	RESTHost string `long:"resthost" Description:"Host for the rest interface of LightningTip"`
 
-	TipExpiry int64 `long:"tipexpiry" Description:"Expiry time in seconds"`
+	TipExpiry int64 `long:"tipexpiry" Description:"Invoice expiry time in seconds"`
 
 	LND *backends.LND `group:"LND" namespace:"lnd"`
 }
diff --git a/frontend/lightningTip.css b/frontend/lightningTip.css
index b12cef2..f6a0ee5 100644
--- a/frontend/lightningTip.css
+++ b/frontend/lightningTip.css
@@ -115,7 +115,7 @@
     float: right;
 }
 
-#lightningTipThankYou {
+#lightningTipFinished {
     margin-bottom: 0.2em;
 
     display: block;
diff --git a/frontend/lightningTip.js b/frontend/lightningTip.js
index 06c0a7c..8da814d 100644
--- a/frontend/lightningTip.js
+++ b/frontend/lightningTip.js
@@ -1,4 +1,5 @@
-var requestUrl = window.location.protocol + "//" + window.location.hostname + ":8081/";
+//var requestUrl = window.location.protocol + "//" + window.location.hostname + ":8081/";
+var requestUrl = "http://localhost:8081/";
 
 // To prohibit multiple requests at the same time
 var running = false;
@@ -109,7 +110,7 @@ function getInvoice() {
 }
 
 function listenInvoiceSettled(hash) {
-    if (EventSource === undefined) {
+    if (EventSource !== undefined) {
         var eventSrc = new EventSource(requestUrl + "eventsource");
 
         eventSrc.onmessage = function (event) {
@@ -154,19 +155,21 @@ function showThankYouScreen() {
     var wrapper = document.getElementById("lightningTip");
 
     wrapper.innerHTML = "<p id=\"lightningTipLogo\">⚡</p>";
-    wrapper.innerHTML += "<a id='lightningTipThankYou'>Thank you for your tip!</a>";
+    wrapper.innerHTML += "<a id='lightningTipFinished'>Thank you for your tip!</a>";
 }
 
 function starTimer(duration, element) {
     showTimer(duration, element);
 
     var interval = setInterval(function () {
-        if (duration > 0) {
+        if (duration > 1) {
             duration--;
 
             showTimer(duration, element);
 
         } else {
+            showExpired();
+
             clearInterval(interval);
         }
 
@@ -191,6 +194,13 @@ function showTimer(duration, element) {
 
 }
 
+function showExpired() {
+    var wrapper = document.getElementById("lightningTip");
+
+    wrapper.innerHTML = "<p id=\"lightningTipLogo\">⚡</p>";
+    wrapper.innerHTML += "<a id='lightningTipFinished'>Your invoice expired!</a>";
+}
+
 function addLeadingZeros(value) {
     return ("0" + value).slice(-2);
 }
diff --git a/lightningtip.go b/lightningtip.go
index 3eaba4b..3bbc3f7 100644
--- a/lightningtip.go
+++ b/lightningtip.go
@@ -75,6 +75,35 @@ func main() {
 		// Alternative for browsers which don't support EventSource (Internet Explorer and Edge)
 		http.HandleFunc("/invoicesettled", invoiceSettledHandler)
 
+		log.Debug("Starting ticker to clear expired invoices")
+
+		// A bit longer than the expiry time to make sure the invoice doesn't show as settled if it isn't (affects just invoiceSettledHandler)
+		duration := time.Duration(cfg.TipExpiry + 10)
+		ticker := time.Tick(duration * time.Second)
+
+		go func() {
+			for {
+				select {
+				case <-ticker:
+					now := time.Now()
+
+					for index := len(pendingInvoices) - 1; index >= 0; index-- {
+						invoice := pendingInvoices[index]
+
+						if now.Sub(invoice.Expiry) > 0 {
+							log.Debug("Invoice expired: " + invoice.Invoice)
+
+							pendingInvoices = append(pendingInvoices[:index], pendingInvoices[index+1:]...)
+						}
+
+					}
+
+				}
+
+			}
+
+		}()
+
 		log.Info("Subscribing to invoices")
 
 		go func() {
@@ -194,7 +223,6 @@ func getInvoiceHandler(writer http.ResponseWriter, request *http.Request) {
 
 					log.Info(logMessage)
 
-					// TODO: check every minute or so if expired
 					pendingInvoices = append(pendingInvoices, PendingInvoice{
 						Invoice: invoice,
 						Hash:    hash,