using GB5Shared.DTO.Framework.Login;
using GB5Shared.Resource.Response;
using GB5Shared.Telemetry;
using Microsoft.Extensions.Logging;
using TMSDAL.CustomCode.KpiPosting;

namespace TMSBLL.KpiPosting
{
    // Bypasses AnalyticsBLL.KPIEvaluationBLL entirely -- that engine only evaluates
    // MKPI.ACTUALVALUEEXPRESSION strings against the FFINANCE BI catalog (hardcoded
    // BICatalogId=2). TMS's 11 KPIs are computed directly against TMS's own tables here and
    // written straight into the shared TKPIVALUE/MKPISTATUS tables, using the exact same
    // delete-then-insert-per-(Period,OU) shape KPIEvaluationBLL.PostKPIValues established --
    // just with a TMS-scoped delete (see TmsKpiPostingQB.DELETE_EXISTING_VALUES) so this job can
    // never touch another module's posted KPI rows.
    public class TmsKpiPostingBLL : ITmsKpiPostingBLL
    {
        private readonly ITmsKpiPostingDAL _dal;
        private readonly ILogger<TmsKpiPostingBLL> _logger;

        public TmsKpiPostingBLL(ITmsKpiPostingDAL dal, ILogger<TmsKpiPostingBLL> logger)
        {
            _dal = dal;
            _logger = logger;
        }

        public async Task<string?> PostAllTmsKpis(LoginDTO login, CancellationToken ct)
        {
            try
            {
                GB5Trace.Step("validate-tms-kpi-posting", new { login.ClientId });

                var period = await _dal.ResolveCurrentMonthlyPeriod(login, ct).ConfigureAwait(false);
                if (period is null)
                {
                    _logger.LogWarning("TmsKpiPostingBLL: no MONTHLY MGBPERIODDETAIL row covers today for ClientId {ClientId} -- skipping.", login.ClientId);
                    return null;
                }

                var (periodDetailId, fromDate, toDate) = period.Value;
                const int ouId = TmsKpiIds.WholeOrgOuId;

                GB5Trace.Step("compute-tms-kpi-actuals", new { login.ClientId, periodDetailId });
                var actuals = new Dictionary<int, decimal?>
                {
                    [TmsKpiIds.ComplianceCoveragePct] = await _dal.GetComplianceCoveragePct(toDate, login, ct).ConfigureAwait(false),
                    [TmsKpiIds.NominationApprovalTatDays] = await _dal.GetNominationApprovalTatDays(fromDate, toDate, login, ct).ConfigureAwait(false),
                    [TmsKpiIds.CostPerTrainedEmployee] = await _dal.GetCostPerTrainedEmployee(fromDate, toDate, login, ct).ConfigureAwait(false),
                    [TmsKpiIds.VenueUtilizationPct] = await _dal.GetVenueUtilizationPct(fromDate, toDate, login, ct).ConfigureAwait(false),
                    [TmsKpiIds.PassRatePct] = await _dal.GetPassRatePct(fromDate, toDate, login, ct).ConfigureAwait(false),
                    [TmsKpiIds.FirstAttemptPassRatePct] = await _dal.GetFirstAttemptPassRatePct(fromDate, toDate, login, ct).ConfigureAwait(false),
                    [TmsKpiIds.SkillUpgradeApprovalRatePct] = await _dal.GetSkillUpgradeApprovalRatePct(fromDate, toDate, login, ct).ConfigureAwait(false),
                    [TmsKpiIds.CertRenewalCompliancePct] = await _dal.GetCertRenewalCompliancePct(toDate, login, ct).ConfigureAwait(false),
                    [TmsKpiIds.ExpiringCertificates30D] = await _dal.GetExpiringCertificates30D(login, ct).ConfigureAwait(false),
                    [TmsKpiIds.FeedbackResponseRatePct] = await _dal.GetFeedbackResponseRatePct(fromDate, toDate, login, ct).ConfigureAwait(false),
                    [TmsKpiIds.LearningGainPct] = await _dal.GetLearningGainPct(fromDate, toDate, login, ct).ConfigureAwait(false),
                };

                GB5Trace.Step("delete-existing-tms-kpi-values", new { login.ClientId, periodDetailId });
                await _dal.DeleteExistingValues(periodDetailId, ouId, TmsKpiIds.All.ToList(), login, ct).ConfigureAwait(false);

                var previousPeriodDetailId = await _dal.GetPreviousMonthlyPeriodDetailId(periodDetailId, login, ct).ConfigureAwait(false);

                GB5Trace.Step("post-tms-kpi-values", new { login.ClientId, periodDetailId, count = actuals.Count });
                var posted = 0;
                foreach (var (kpiId, actual) in actuals)
                {
                    var bands = await _dal.GetStatusBands(kpiId, login, ct).ConfigureAwait(false);
                    var statusId = actual is null
                        ? -1
                        : bands.FirstOrDefault(b => actual.Value >= b.VALUEFROM && actual.Value <= b.VALUETO)?.KPISTATUSID ?? -1;

                    byte? trend = null;
                    if (actual is not null && previousPeriodDetailId is not null)
                    {
                        var previousActual = await _dal.GetPreviousActual(kpiId, previousPeriodDetailId.Value, ouId, login, ct).ConfigureAwait(false);
                        if (previousActual is not null)
                            trend = actual.Value > previousActual.Value ? (byte)1 : actual.Value < previousActual.Value ? (byte)2 : (byte)0;
                    }

                    await _dal.InsertValue(kpiId, periodDetailId, ouId, actual, trend, statusId, login, ct).ConfigureAwait(false);
                    posted++;
                }

                return $"{SuccessResponse.SaveSuccessMessage} {posted} TMS KPI value(s) posted for ClientId {login.ClientId}, PeriodDetailId {periodDetailId}.";
            }
            catch (Exception ex)
            {
                GB5Trace.MarkFailed("post-tms-kpi-values-failed", ex);
                _logger.LogError(ex, "TmsKpiPostingBLL.PostAllTmsKpis failed for ClientId {ClientId}", login.ClientId);
                throw;
            }
        }
    }
}