send all on results on amqp

cmd/cart/amqp-order-handler.go

@@ -9,42 +9,48 @@ import (
 )
 
 type AmqpOrderHandler struct {
-	Url        string
-	Connection *amqp.Connection
-	Channel    *amqp.Channel
+	conn *amqp.Connection
 }
 
-func (h *AmqpOrderHandler) Connect() error {
-	conn, err := amqp.Dial(h.Url)
-	if err != nil {
-		return fmt.Errorf("failed to connect to RabbitMQ: %w", err)
+func NewAmqpOrderHandler(conn *amqp.Connection) *AmqpOrderHandler {
+	return &AmqpOrderHandler{
+		conn: conn,
 	}
-	h.Connection = conn
+}
 
-	ch, err := conn.Channel()
+func (h *AmqpOrderHandler) DefineTopics() error {
+	ch, err := h.conn.Channel()
 	if err != nil {
 		return fmt.Errorf("failed to open a channel: %w", err)
 	}
-	h.Channel = ch
+	defer ch.Close()
 
-	return nil
-}
+	err = ch.ExchangeDeclare(
+		"orders", // name
+		"direct", // type
+		true,     // durable
+		false,    // auto-deleted
+		false,    // internal
+		false,    // no-wait
+		nil,      // arguments
+	)
+	if err != nil {
+		return fmt.Errorf("failed to declare an exchange: %w", err)
+	}
 
-func (h *AmqpOrderHandler) Close() error {
-	if h.Channel != nil {
-		h.Channel.Close()
-	}
-	if h.Connection != nil {
-		return h.Connection.Close()
-	}
 	return nil
 }
 
 func (h *AmqpOrderHandler) OrderCompleted(body []byte) error {
+	ch, err := h.conn.Channel()
+	if err != nil {
+		return fmt.Errorf("failed to open a channel: %w", err)
+	}
+	defer ch.Close()
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
 
-	err := h.Channel.PublishWithContext(ctx,
+	return ch.PublishWithContext(ctx,
 		"orders", // exchange
 		"new",    // routing key
 		false,    // mandatory
@@ -53,9 +59,5 @@ func (h *AmqpOrderHandler) OrderCompleted(body []byte) error {
 			ContentType: "application/json",
 			Body:        body,
 		})
-	if err != nil {
-		return fmt.Errorf("failed to publish a message: %w", err)
-	}
 
-	return nil
 }