using System;
using System.Threading;
using System.Threading.Tasks;
using FrameworkBLL.GOP;
using GB5Shared.DTO.GOP;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.Logging;

namespace FrameworkSL.Hubs.GOP
{
    // ============================================================
    // GopHubNotifier — SL implementation of IGopHubNotifier.
    //
    // Wraps IHubContext<GopExecutionHub, IGopExecutionClient> so
    // that FrameworkBLL (the pipeline) can push real-time status
    // updates to connected SignalR clients without referencing any
    // ASP.NET types directly.
    //
    // Registration:
    //   services.AddSingleton<IGopHubNotifier, GopHubNotifier>();
    //   (Singleton is safe: IHubContext is registered as Singleton
    //   and is thread-safe.)
    // ============================================================
    public class GopHubNotifier : IGopHubNotifier
    {
        private readonly IHubContext<GopExecutionHub, IGopExecutionClient> _HubContext;
        private readonly ILogger<GopHubNotifier>                           _Logger;

        public GopHubNotifier(
            IHubContext<GopExecutionHub, IGopExecutionClient> hubContext,
            ILogger<GopHubNotifier>                          logger)
        {
            _HubContext = hubContext;
            _Logger     = logger;
        }

        public async Task PushExecutionUpdate(
            int clientId, GopExecutionStatusDTO status, CancellationToken ct = default)
        {
            try
            {
                await _HubContext.Clients
                    .Group(GopExecutionHub.TenantGroup(clientId))
                    .ReceiveExecutionUpdate(status);
            }
            catch (Exception ex)
            {
                // Hub push failures are non-fatal — log and continue.
                _Logger.LogWarning(ex,
                    "GopHubNotifier: failed to push execution update for execution {ExecutionId}",
                    status.ExecutionId);
            }
        }

        public async Task PushDLQUpdate(
            int clientId, GopDLQSummaryDTO summary, CancellationToken ct = default)
        {
            try
            {
                await _HubContext.Clients
                    .Group(GopExecutionHub.TenantGroup(clientId))
                    .ReceiveDLQUpdate(summary);
            }
            catch (Exception ex)
            {
                _Logger.LogWarning(ex,
                    "GopHubNotifier: failed to push DLQ update for execution {ExecutionId}",
                    summary.ExecutionId);
            }
        }
    }
}