using AnalyticsDAL.CustomCode.OEE;
using AnalyticsDAL.DTO.OEE;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.Telemetry;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;

namespace AnalyticsBLL.OEE
{
    public class OEECalculationEngine : IOEECalculationEngine
    {
        private readonly IOEEEngineDAL          _dal;
        private readonly ILogger<OEECalculationEngine> _logger;

        public OEECalculationEngine(IOEEEngineDAL dal, ILogger<OEECalculationEngine> logger)
        {
            _dal    = dal;
            _logger = logger;
        }

        public async Task<int> CalculateAndPersistOEE(DateTime fromDate, DateTime toDate, LoginDTO login, CancellationToken ct)
        {
            GB5Trace.Step("oee-calculate", new { fromDate, toDate, TenantId = login.ClientId });

            int factsWritten = 0;
            long factId = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();

            await foreach (var row in _dal.StreamOEEInputData(fromDate, toDate, login, ct).ConfigureAwait(false))
            {
                var fact = BuildOEEFact(row, factId++, login.ClientId);
                await _dal.UpsertOEEFact(fact, login, ct).ConfigureAwait(false);
                factsWritten++;
            }

            GB5Trace.Step("oee-calculate-done", new { factsWritten });
            _logger.LogInformation("OEE calculation complete: {FactsWritten} facts written for TenantId {TenantId}",
                factsWritten, login.ClientId);

            return factsWritten;
        }

        public async Task<string> GetOEEReport(DateTime fromDate, DateTime toDate, int workCenterId, LoginDTO login, CancellationToken ct)
        {
            var items = await _dal.GetOEEReport(fromDate, toDate, workCenterId, login, ct).ConfigureAwait(false);
            return JsonConvert.SerializeObject(items);
        }

        public async Task<string> GetOEELiveStatus(LoginDTO login, CancellationToken ct)
        {
            var items = await _dal.GetOEELiveStatus(login, ct).ConfigureAwait(false);
            return JsonConvert.SerializeObject(items);
        }

        // ── OEE Formula ───────────────────────────────────────────────────────
        // Availability = RunTime / PlannedProductionTime
        // Performance  = (TotalProduced × IdealCycleTime) / RunTime
        // Quality      = GoodQuantity / TotalProduced
        // OEE          = Availability × Performance × Quality

        private static OEEFactDTO BuildOEEFact(OEEInputRowDTO row, long factId, int tenantId)
        {
            var totalProduced = row.GoodQuantity + row.RejectedQuantity + row.ReworkQuantity;
            var runTime       = row.RunTimeMinutes > 0 ? row.RunTimeMinutes : 0.001m; // avoid /0
            var planned       = row.PlannedMinutes > 0 ? row.PlannedMinutes : 480m;

            var availability = Math.Min(runTime / planned, 1m);
            var performance  = row.IdealCycleTimeMin > 0 && runTime > 0
                ? Math.Min((totalProduced * row.IdealCycleTimeMin) / runTime, 1m)
                : 0m;
            var quality      = totalProduced > 0
                ? Math.Min(row.GoodQuantity / totalProduced, 1m)
                : 0m;
            var oee          = availability * performance * quality;

            return new OEEFactDTO
            {
                FactId           = factId,
                MachineId        = row.MachineId,
                WorkCenterId     = row.WorkCenterId,
                FactDate         = row.ProductionDate,
                ShiftId          = row.ShiftId,
                PlannedMinutes   = row.PlannedMinutes,
                RunTimeMinutes   = row.RunTimeMinutes,
                DowntimeMinutes  = row.DowntimeMinutes,
                TotalProduced    = totalProduced,
                GoodQuantity     = row.GoodQuantity,
                RejectedQuantity = row.RejectedQuantity,
                ReworkQuantity   = row.ReworkQuantity,
                Availability     = Math.Round(availability, 4),
                Performance      = Math.Round(performance, 4),
                Quality          = Math.Round(quality, 4),
                OEE              = Math.Round(oee, 4),
                TenantId         = tenantId
            };
        }
    }
}