using Microsoft.AspNetCore.SignalR;

namespace ControlCenter.Api.Hubs;

/// <summary>
/// SignalR hub for broadcasting agent status updates to connected clients.
///
/// <para>
/// Clients connect to this hub at the <c>/hub</c> endpoint to receive
/// real-time agent state changes. A background service subscribes to
/// OpenClaw Gateway events and pushes them through this hub.
/// </para>
///
/// <para>
/// Architecture note: This hub bridges OpenClaw Gateway events to SignalR clients.
/// The full typed client interface and extension methods will be added in a
/// subsequent task (CUB-55).
/// </para>
/// </summary>
public class AgentStatusHub : Hub
{
    private readonly ILogger<AgentStatusHub> _logger;

    /// <summary>
    /// Initializes a new instance of the <see cref="AgentStatusHub"/> class.
    /// </summary>
    /// <param name="logger">Logger for diagnostic output.</param>
    public AgentStatusHub(ILogger<AgentStatusHub> logger)
    {
        _logger = logger;
    }

    /// <summary>
    /// Overrides <see cref="Hub.OnConnectedAsync"/> to log new connections.
    /// </summary>
    public override Task OnConnectedAsync()
    {
        _logger.LogDebug("Client connected: {ConnectionId}", Context.ConnectionId);
        return base.OnConnectedAsync();
    }

    /// <summary>
    /// Overrides <see cref="Hub.OnDisconnectedAsync"/> to log disconnections.
    /// SignalR automatically removes disconnected connections from all groups.
    /// </summary>
    /// <param name="exception">Exception that caused the disconnection, if any.</param>
    public override Task OnDisconnectedAsync(Exception? exception)
    {
        _logger.LogDebug("Client disconnected: {ConnectionId}", Context.ConnectionId);
        return base.OnDisconnectedAsync(exception);
    }
}