using GB5Shared.DTO.Framework.Login;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.Logging;
using System.Text.Json;

namespace JobEngineSL.Hubs
{
    public class JobEngineHub : Hub<IJobEngineClient>
    {
        private readonly ILogger<JobEngineHub> _logger;

        public JobEngineHub(ILogger<JobEngineHub> logger) => _logger = logger;

        public override async Task OnConnectedAsync()
        {
            var login = GetLoginDTO();
            await Groups.AddToGroupAsync(Context.ConnectionId, HubGroup(login));
            _logger.LogInformation("JobEngineHub connected: {ConnectionId} tenant {TenantId}",
                Context.ConnectionId, login.ClientId);
            await base.OnConnectedAsync();
        }

        public override async Task OnDisconnectedAsync(Exception? exception)
        {
            var login = GetLoginDTO();
            await Groups.RemoveFromGroupAsync(Context.ConnectionId, HubGroup(login));
            if (exception is not null)
                _logger.LogWarning(exception, "JobEngineHub disconnected with error: {ConnectionId}",
                    Context.ConnectionId);
            await base.OnDisconnectedAsync(exception);
        }

        private LoginDTO GetLoginDTO()
        {
            var http = Context.GetHttpContext()
                ?? throw new InvalidOperationException("Hub invoked outside HTTP context.");
            var raw = http.Request.Headers["Login"].FirstOrDefault()
                ?? throw new InvalidOperationException("Login header missing.");
            return JsonSerializer.Deserialize<LoginDTO>(raw)
                ?? throw new InvalidOperationException("Login header is invalid JSON.");
        }

        public static string HubGroup(LoginDTO login) => $"jobengine:client:{login.ClientId}";
    }
}