using DigitalData.MessagingService.Application.Common.Interfaces;
using DigitalData.MessagingService.Infrastructure.Queue;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

namespace DigitalData.MessagingService.Infrastructure.Services.Background;

/// <summary>
/// A hosted background service responsible for initializing the outgoing email queue consumer.
/// Leverages a push-based, event-driven RabbitMQ consumer to eliminate polling overhead.
/// Email account configuration is resolved exclusively from application settings; no database access is performed.
/// </summary>
public class AsyncInitWorker(IOutgoingEmailQueue EmailQueue, ILogger<AsyncInitWorker> Logger) : BackgroundService
{
    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        Logger.LogInformation("Outgoing email queue worker is starting. Initializing event-driven RabbitMQ consumer.");

        try
        {
            // Initialize the RabbitMQ push-based consumer. This call is non-blocking;
            // message processing is handled asynchronously via registered event callbacks.
            if (EmailQueue is OutgoingEmailQueue outgoingEmailQueue)
                await outgoingEmailQueue.InitAsync(stoppingToken);
        }
        catch (Exception ex)
        {
            Logger.LogError(ex, "A critical error occurred while initializing the outgoing email queue consumer. The worker cannot proceed.");
            throw;
        }
    }
}