using System;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.Logging;
using RecruitmentBLL.Common;

namespace RecruitmentSL.Hubs
{
    // Concrete implementation of the BLL-defined IRecruitmentHubNotifier, wrapping
    // IHubContext<RecruitmentHub, IRecruitmentClient> — this is the one place in this module
    // allowed to know about SignalR, per CLAUDE.md's "BLL must never reference ASP.NET types"
    // rule. Registered as a Scoped/Singleton service in RecruitmentSL/Program.cs (IHubContext
    // itself is a thread-safe singleton). Mirrors WiSL.EndPoints.Hubs.WiHubNotifier /
    // DXPSL.Hubs.DXPHubNotifier exactly.
    public class RecruitmentHubNotifier : IRecruitmentHubNotifier
    {
        private readonly IHubContext<RecruitmentHub, IRecruitmentClient> _hubContext;
        private readonly ILogger<RecruitmentHubNotifier> _logger;

        public RecruitmentHubNotifier(
            IHubContext<RecruitmentHub, IRecruitmentClient> hubContext,
            ILogger<RecruitmentHubNotifier> logger)
        {
            _hubContext = hubContext;
            _logger = logger;
        }

        public async Task NotifyApplicationStageChangedAsync(
            int applicationId,
            int jobRequisitionId,
            int oldSelectionProcessStageId,
            int newSelectionProcessStageId,
            int clientId,
            CancellationToken ct = default)
        {
            try
            {
                var update = new ApplicationStageChangedDTO
                {
                    ApplicationId = applicationId,
                    JobRequisitionId = jobRequisitionId,
                    OldSelectionProcessStageId = oldSelectionProcessStageId,
                    NewSelectionProcessStageId = newSelectionProcessStageId,
                    ChangedOn = DateTime.UtcNow
                };

                await _hubContext.Clients.Group(RecruitmentHub.ClientGroup(clientId))
                    .ReceiveApplicationStageChanged(update);
            }
            catch (Exception ex)
            {
                _logger.LogWarning(ex,
                    "RecruitmentHubNotifier: failed to push stage change for ApplicationId {ApplicationId}",
                    applicationId);
            }
        }

        public async Task NotifyInterviewScheduledAsync(
            int interviewId,
            int applicationId,
            int interviewerId,
            DateTime interviewDate,
            short interviewTime,
            short durationMinutes,
            bool isReschedule,
            CancellationToken ct = default)
        {
            try
            {
                var update = new InterviewScheduledDTO
                {
                    InterviewId = interviewId,
                    ApplicationId = applicationId,
                    InterviewerId = interviewerId,
                    InterviewDate = interviewDate,
                    InterviewTime = interviewTime,
                    DurationMinutes = durationMinutes,
                    IsReschedule = isReschedule
                };

                await _hubContext.Clients.Group(RecruitmentHub.UserGroup(interviewerId))
                    .ReceiveInterviewScheduled(update);
            }
            catch (Exception ex)
            {
                _logger.LogWarning(ex,
                    "RecruitmentHubNotifier: failed to push interview scheduled for InterviewId {InterviewId}",
                    interviewId);
            }
        }
    }
}