1. Event organizer publishes an activity

2. Customer receives booking information

3. System sends email/SMS notification

Producer Implementation

public void PublishEvent()
{
    ConnectionFactory connectionFactory = new ConnectionFactory()
    {
        HostName = "localhost",
        Port = 5672,
        Credentials = new NetworkCredential("guest", "guest"),
        VirtualHost = "/"
    };

    using (IConnection connection = connectionFactory.CreateConnection())
    {
        using (IModel channel = connection.CreateModel())
        {
            string exchangeName = "event_notification_fanout";
            
            channel.ExchangeDeclare(
                exchange: exchangeName,
                type: ExchangeType.Fanout,
                durable: true
            );

            EventDetails eventData = new EventDetails();
            string jsonPayload = JsonSerializer.Serialize(eventData);
            byte[] messageBody = Encoding.UTF8.GetBytes(jsonPayload);

            IBasicProperties messageProperties = channel.CreateBasicProperties();
            messageProperties.Persistent = true;

            channel.BasicPublish(
                exchange: exchangeName,
                routingKey: "",
                basicProperties: messageProperties,
                body: messageBody
            );
            
            Console.WriteLine($"Event published: {eventData.EventId}");
        }
    }
}

Consumer Implementation

public void SubscribeToNotifications()
{
    var factory = new ConnectionFactory() { HostName = "localhost" };
    var connection = factory.CreateConnection();
    var channel = connection.CreateModel();

    channel.ExchangeDeclare(
        exchange: "event_notification_fanout",
        type: ExchangeType.Fanout,
        durable: true
    );

    string queueName = channel.QueueDeclare().QueueName;
    
    channel.QueueBind(
        queue: queueName,
        exchange: "event_notification_fanout",
        routingKey: ""
    );

    var consumer = new EventingBasicConsumer(channel);
    consumer.Received += (model, ea) => 
    {
        string message = Encoding.UTF8.GetString(ea.Body.ToArray());
        Console.WriteLine($"Notification received: {message}");
        
        // Process notification
        channel.BasicAck(ea.DeliveryTag, false);
    };

    channel.BasicQos(0, 1, false);
    channel.BasicConsume(
        queue: queueName,
        autoAck: false,
        consumer: consumer
    );
}

Email Service Implementation

public void EmailNotificationService()
{
    var connection = new ConnectionFactory().CreateConnection();
    var channel = connection.CreateModel();

    channel.ExchangeDeclare(
        exchange: "event_notification_fanout",
        type: ExchangeType.Fanout,
        durable: true
    );

    string notificationQueue = channel.QueueDeclare().QueueName;
    
    channel.QueueBind(
        queue: notificationQueue,
        exchange: "event_notification_fanout",
        routingKey: ""
    );

    var emailConsumer = new EventingBasicConsumer(channel);
    emailConsumer.Received += (model, ea) => 
    {
        var eventData = JsonSerializer.Deserialize<EventDetails>(ea.Body.ToArray());
        Console.WriteLine($"Sending email for event: {eventData.EventName}");
        
        channel.BasicAck(ea.DeliveryTag, false);
    };

    channel.BasicConsume(
        queue: notificationQueue,
        autoAck: false,
        consumer: emailConsumer
    );
}