From c6fd849aa35117c5d623b58c75d15a5daf62f8a5 Mon Sep 17 00:00:00 2001
From: Christian Decker <decker.christian@gmail.com>
Date: Wed, 28 Apr 2021 18:36:56 +0200
Subject: [PATCH] pay: Add notification for pay_success

---
 plugins/keysend.c                     |  6 +++++-
 plugins/libplugin-pay.c               |  8 ++++++++
 plugins/pay.c                         |  7 ++++++-
 tests/plugins/custom_notifications.py | 10 ++++++++++
 tests/test_plugin.py                  |  7 ++++++-
 5 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/plugins/keysend.c b/plugins/keysend.c
index 69cf7e38b..54f5ecfa1 100644
--- a/plugins/keysend.c
+++ b/plugins/keysend.c
@@ -377,6 +377,10 @@ static const struct plugin_hook hooks[] = {
 	},
 };
 
+static const char *notification_topics[] = {
+	"pay_success",
+};
+
 int main(int argc, char *argv[])
 {
 	struct feature_set features;
@@ -388,5 +392,5 @@ int main(int argc, char *argv[])
 
 	plugin_main(argv, init, PLUGIN_STATIC, true, &features, commands,
 		    ARRAY_SIZE(commands), NULL, 0, hooks, ARRAY_SIZE(hooks),
-		    NULL, 0, NULL);
+		    notification_topics, ARRAY_SIZE(notification_topics), NULL);
 }
diff --git a/plugins/libplugin-pay.c b/plugins/libplugin-pay.c
index d8193fbad..7538022da 100644
--- a/plugins/libplugin-pay.c
+++ b/plugins/libplugin-pay.c
@@ -1844,6 +1844,8 @@ static void payment_finished(struct payment *p)
 	struct json_stream *ret;
 	struct command *cmd = p->cmd;
 	const char *msg;
+	struct json_stream *n;
+	struct payment *root = payment_root(p);
 
 	/* Either none of the leaf attempts succeeded yet, or we have a
 	 * preimage. */
@@ -1885,6 +1887,12 @@ static void payment_finished(struct payment *p)
 
 			json_add_string(ret, "status", "complete");
 
+			n = plugin_notification_start(p->plugin, "pay_success");
+			json_add_sha256(n, "payment_hash", p->payment_hash);
+			if (root->invstring != NULL)
+				json_add_string(n, "bolt11", root->invstring);
+			plugin_notification_end(p->plugin, n);
+
 			if (command_finished(cmd, ret)) {/* Ignore result. */}
 			return;
 		} else if (p->aborterror != NULL) {
diff --git a/plugins/pay.c b/plugins/pay.c
index f5ce5f4ee..c3007dc64 100644
--- a/plugins/pay.c
+++ b/plugins/pay.c
@@ -2193,12 +2193,17 @@ static const struct plugin_command commands[] = {
 	},
 };
 
+static const char *notification_topics[] = {
+	"pay_success",
+	"pay_failure",
+};
+
 int main(int argc, char *argv[])
 {
 	setup_locale();
 	plugin_main(argv, init, PLUGIN_RESTARTABLE, true, NULL, commands,
 		    ARRAY_SIZE(commands), NULL, 0, NULL, 0,
-		    NULL, 0,
+		    notification_topics, ARRAY_SIZE(notification_topics),
 		    plugin_option("disable-mpp", "flag",
 				  "Disable multi-part payments.",
 				  flag_option, &disablempp),
diff --git a/tests/plugins/custom_notifications.py b/tests/plugins/custom_notifications.py
index 092f2d2c2..a3fa9b9aa 100755
--- a/tests/plugins/custom_notifications.py
+++ b/tests/plugins/custom_notifications.py
@@ -24,6 +24,16 @@ def faulty_emit(plugin):
     plugin.notify("ididntannouncethis", "Hello world")
 
 
+@plugin.subscribe("pay_success")
+def on_pay_success(origin, payload, **kwargs):
+    plugin.log(
+        "Got a pay_success notification from plugin {} for payment_hash {}".format(
+            origin,
+            payload['payment_hash']
+        )
+    )
+
+
 @plugin.subscribe("ididntannouncethis")
 def on_faulty_emit(origin, payload, **kwargs):
     """We should never receive this as it gets dropped.
diff --git a/tests/test_plugin.py b/tests/test_plugin.py
index 4691873bb..a4584ef34 100644
--- a/tests/test_plugin.py
+++ b/tests/test_plugin.py
@@ -2408,10 +2408,15 @@ def test_custom_notification_topics(node_factory):
     plugin = os.path.join(
         os.path.dirname(__file__), "plugins", "custom_notifications.py"
     )
-    l1 = node_factory.get_node(options={'plugin': plugin})
+    l1, l2 = node_factory.line_graph(2, opts=[{'plugin': plugin}, {}])
     l1.rpc.emit()
     l1.daemon.wait_for_log(r'Got a custom notification Hello world')
 
+    inv = l2.rpc.invoice(42, "lbl", "desc")['bolt11']
+    l1.rpc.pay(inv)
+
+    l1.daemon.wait_for_log(r'Got a pay_success notification from plugin pay for payment_hash [0-9a-f]{64}')
+
     # And now make sure that we drop unannounced notifications
     l1.rpc.faulty_emit()
     l1.daemon.wait_for_log(