KArtSell.Aegis/src/KArtSell.Host/Consumers/IdentityCreatedConsumer.cs

using KArtSell.Modules.IdentityAccess.ManageIdentityAndRoles.Events;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.Logging;

namespace KArtSell.Host.Consumers;

/// <summary>
/// Pushes identity creation notifications via SignalR.
/// Targets group: identity-notifications so all admins tracking new identities are notified.
/// Idempotent: SignalR deduplication via idempotency key.
/// </summary>
public sealed class IdentityCreatedConsumer : IInboxConsumer<IdentityCreated>
{
    private readonly IHubContext<IdentityNotificationHub>? _hubContext;
    private readonly ILogger<IdentityCreatedConsumer> _logger;

    private static readonly Action<ILogger, Guid, string, Exception?> LogNotification =
        LoggerMessage.Define<Guid, string>(
            LogLevel.Information,
            new EventId(1, nameof(LogNotification)),
            "Identity {IdentityId} ({Email}) created notification sent");

    private static readonly Action<ILogger, Exception?> LogHubNotConfigured =
        LoggerMessage.Define(
            LogLevel.Warning,
            new EventId(2, nameof(LogHubNotConfigured)),
            "SignalR hub not configured, skipping notification");

    public IdentityCreatedConsumer(
        IHubContext<IdentityNotificationHub>? hubContext,
        ILogger<IdentityCreatedConsumer> logger)
    {
        _hubContext = hubContext;
        _logger = logger;
    }

    public async Task HandleAsync(IdentityCreated message, CancellationToken cancellationToken = default)
    {
        try
        {
            LogNotification(_logger, message.IdentityId, message.Email, null);

            if (_hubContext == null)
            {
                LogHubNotConfigured(_logger, null);
                return;
            }

            var notification = new
            {
                message.IdentityId,
                message.Email,
                message.DisplayName,
                message.OccurredAt
            };

            await _hubContext.Clients
                .Group("identity-notifications")
                .SendAsync("IdentityCreated", notification, cancellationToken);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to send identity creation notification for {IdentityId}", message.IdentityId);
            throw;
        }
    }
}

/// <summary>
/// SignalR hub for identity notifications.
/// Clients subscribe to group: identity-notifications
/// </summary>
public sealed class IdentityNotificationHub : Hub
{
    private readonly ILogger<IdentityNotificationHub> _logger;

    public IdentityNotificationHub(ILogger<IdentityNotificationHub> logger)
    {
        _logger = logger;
    }

    public override async Task OnConnectedAsync()
    {
        _logger.LogInformation("Client {ConnectionId} connected to IdentityNotificationHub", Context.ConnectionId);
        await base.OnConnectedAsync();
    }

    public async Task SubscribeToIdentityNotifications()
    {
        await Groups.AddToGroupAsync(Context.ConnectionId, "identity-notifications");
        _logger.LogInformation(
            "Client {ConnectionId} subscribed to identity-notifications",
            Context.ConnectionId);
    }

    public async Task UnsubscribeFromIdentityNotifications()
    {
        await Groups.RemoveFromGroupAsync(Context.ConnectionId, "identity-notifications");
        _logger.LogInformation(
            "Client {ConnectionId} unsubscribed from identity-notifications",
            Context.ConnectionId);
    }
}