Add support for subscribe JSON RPC

- psot subscriptions
- get messages

nwaku.go

@@ -27,19 +27,29 @@ func main() {
 	// Assumes node started
 	client, _ := rpc.Dial("http://127.0.0.1:8545")
 
+	var defaultTopic = "/waku/2/default-waku/proto"
+	var contentTopic = "/toy-chat/2/huilong/proto"
+
 	// Get node info
 	var wakuInfo = nwaku.GetWakuDebugInfo(client)
 	fmt.Println("WakuInfo ListenStr", wakuInfo.ListenStr)
 
 	// Query messages
-	var contentTopic = "/toy-chat/2/huilong/proto"
 	var storeResponse, _ = nwaku.GetWakuStoreMessages(client, contentTopic)
 	fmt.Println("Fetched", len(storeResponse.Messages), "messages")
 
+	// Subscribe
+	var res, _ = nwaku.PostWakuRelaySubscriptions(client, []string{defaultTopic})
+	fmt.Println("Subscribe", res)
+
 	// Publish
 	var message = nwaku.WakuRelayMessage{Payload: "0x1a2b3c4d5e6f", ContentTopic: contentTopic}
-	var res, _ = nwaku.PostWakuRelayMessage(client, message)
-	fmt.Println("Publish", res)
+	var res2, _ = nwaku.PostWakuRelayMessage(client, message)
+	fmt.Println("Publish", res2)
+
+	// Get messages
+	var wakuMessages, _ = nwaku.GetWakuRelayMessages(client, defaultTopic)
+	fmt.Println("Get messages", wakuMessages)
 
     <-nodeStopped
     log.Printf("exiting main")

nwaku/jsonrpc.go

@@ -39,10 +39,25 @@ func PostWakuRelayMessage(client *rpc.Client, message WakuRelayMessage) (bool, e
 	return res, nil
 }
 
-// TODO Subscribe, then poll for getting messages
-// https://rfc.vac.dev/spec/16/#post_waku_v2_relay_v1_subscriptions
-// https://rfc.vac.dev/spec/16/#get_waku_v2_relay_v1_messages
-// For now, just use query and publish
+func PostWakuRelaySubscriptions(client *rpc.Client, topics []string) (bool, error) {
+	var res bool
+
+	if err := client.Call(&res, "post_waku_v2_relay_v1_subscriptions", topics); err != nil {
+		return res, err
+	}
+
+	return res, nil
+}
+
+func GetWakuRelayMessages(client *rpc.Client, topic string) ([]WakuMessage, error) {
+	var res []WakuMessage
+
+	if err := client.Call(&res, "get_waku_v2_relay_v1_messages", topic); err != nil {
+		return res, err
+	}
+
+	return res, nil
+}
 
 // General things that can be improved:
 // - Generalized with different transports (HTTP, IPC, WS etc), see