feat(gateway): add HeartbeatAck event (#253)

* feat(gateway): add HeartbeatAck event

* feat: HEARTBEAT_ACK -> __HEARTBEAT_ACK__

* feat(events): handle heartbeat ack events
* Added event payload: LastHeartbeat & NewHeartbeat

events/heartbeat_ack.go

@@ -0,0 +1,8 @@
+package events
+
+import "github.com/disgoorg/disgo/gateway"
+
+type HeartbeatAck struct {
+	*GenericEvent
+	gateway.EventHeartbeatAck
+}

gateway/gateway_event_type.go

@@ -7,6 +7,7 @@ type EventType string
 const (
 	// EventTypeRaw is not a real event type, but is used to pass raw payloads to the bot.EventManager
 	EventTypeRaw                                 EventType = "__RAW__"
+	EventTypeHeartbeatAck                        EventType = "__HEARTBEAT_ACK__"
 	EventTypeReady                               EventType = "READY"
 	EventTypeResumed                             EventType = "RESUMED"
 	EventTypeApplicationCommandPermissionsUpdate EventType = "APPLICATION_COMMAND_PERMISSIONS_UPDATE"

gateway/gateway_events.go

@@ -692,3 +692,11 @@ type EventRaw struct {
 
 func (EventRaw) messageData() {}
 func (EventRaw) eventData()   {}
+
+type EventHeartbeatAck struct {
+	LastHeartbeat time.Time
+	NewHeartbeat  time.Time
+}
+
+func (EventHeartbeatAck) messageData() {}
+func (EventHeartbeatAck) eventData()   {}

gateway/gateway_impl.go

@@ -448,7 +448,12 @@ loop:
 			break loop
 
 		case OpcodeHeartbeatACK:
-			g.lastHeartbeatReceived = time.Now().UTC()
+			newHeartbeat := time.Now().UTC()
+			g.eventHandlerFunc(EventTypeHeartbeatAck, message.S, g.config.ShardID, EventHeartbeatAck{
+				LastHeartbeat: g.lastHeartbeatReceived,
+				NewHeartbeat:  newHeartbeat,
+			})
+			g.lastHeartbeatReceived = newHeartbeat
 
 		default:
 			g.config.Logger.Debug(g.formatLogsf("unknown opcode received: %d, data: %s", message.Op, message.D))

handlers/all_handlers.go

@@ -32,6 +32,7 @@ func GetGatewayHandlers() map[gateway.EventType]bot.GatewayEventHandler {
 
 var allEventHandlers = []bot.GatewayEventHandler{
 	bot.NewGatewayEventHandler(gateway.EventTypeRaw, gatewayHandlerRaw),
+	bot.NewGatewayEventHandler(gateway.EventTypeHeartbeatAck, gatewayHandlerHeartbeatAck),
 	bot.NewGatewayEventHandler(gateway.EventTypeReady, gatewayHandlerReady),
 	bot.NewGatewayEventHandler(gateway.EventTypeResumed, gatewayHandlerResumed),
 

handlers/status_handler.go

@@ -13,6 +13,13 @@ func gatewayHandlerRaw(client bot.Client, sequenceNumber int, shardID int, event
 	})
 }
 
+func gatewayHandlerHeartbeatAck(client bot.Client, sequenceNumber int, shardID int, event gateway.EventHeartbeatAck) {
+	client.EventManager().DispatchEvent(&events.HeartbeatAck{
+		GenericEvent:      events.NewGenericEvent(client, sequenceNumber, shardID),
+		EventHeartbeatAck: event,
+	})
+}
+
 func gatewayHandlerReady(client bot.Client, sequenceNumber int, shardID int, event gateway.EventReady) {
 	client.Caches().SetSelfUser(event.User)