using System;
using ArchestrA.MxAccess;
using ZB.MOM.WW.OtOpcUa.Host.Domain;

namespace ZB.MOM.WW.OtOpcUa.Host.MxAccess
{
    public sealed partial class MxAccessClient
    {
        /// <summary>
        ///     COM event handler for MxAccess OnDataChange events.
        ///     Signature matches the ArchestrA.MxAccess ILMXProxyServerEvents interface.
        /// </summary>
        private void HandleOnDataChange(
            int hLMXServerHandle,
            int phItemHandle,
            object pvItemValue,
            int pwItemQuality,
            object pftItemTimeStamp,
            ref MXSTATUS_PROXY[] ItemStatus)
        {
            try
            {
                if (!_handleToAddress.TryGetValue(phItemHandle, out var address))
                {
                    Log.Debug("OnDataChange for unknown handle {Handle}", phItemHandle);
                    return;
                }

                var quality = QualityMapper.MapFromMxAccessQuality(pwItemQuality);

                // Check MXSTATUS_PROXY — if success is false, use more specific quality
                if (ItemStatus != null && ItemStatus.Length > 0 && ItemStatus[0].success == 0)
                    quality = MxErrorCodes.MapToQuality(ItemStatus[0].detail);

                var timestamp = ConvertTimestamp(pftItemTimeStamp);
                var vtq = new Vtq(pvItemValue, timestamp, quality);

                // Update probe timestamp
                if (string.Equals(address, _probeTag, StringComparison.OrdinalIgnoreCase))
                    _lastProbeValueTime = DateTime.UtcNow;

                // Invoke stored subscription callback
                if (_storedSubscriptions.TryGetValue(address, out var callback)) callback(address, vtq);

                if (_pendingReadsByAddress.TryGetValue(address, out var pendingReads))
                    foreach (var pendingRead in pendingReads.Values)
                        pendingRead.TrySetResult(vtq);

                // Global handler
                OnTagValueChanged?.Invoke(address, vtq);
            }
            catch (Exception ex)
            {
                Log.Error(ex, "Error processing OnDataChange for handle {Handle}", phItemHandle);
            }
        }

        /// <summary>
        ///     COM event handler for MxAccess OnWriteComplete events.
        /// </summary>
        private void HandleOnWriteComplete(
            int hLMXServerHandle,
            int phItemHandle,
            ref MXSTATUS_PROXY[] ItemStatus)
        {
            try
            {
                if (_pendingWrites.TryRemove(phItemHandle, out var tcs))
                {
                    var success = ItemStatus == null || ItemStatus.Length == 0 || ItemStatus[0].success != 0;
                    if (success)
                    {
                        tcs.TrySetResult(true);
                    }
                    else
                    {
                        var detail = ItemStatus![0].detail;
                        var message = MxErrorCodes.GetMessage(detail);
                        Log.Warning("Write failed for handle {Handle}: {Message}", phItemHandle, message);
                        tcs.TrySetResult(false);
                    }
                }
            }
            catch (Exception ex)
            {
                Log.Error(ex, "Error processing OnWriteComplete for handle {Handle}", phItemHandle);
            }
        }

        private static DateTime ConvertTimestamp(object pftItemTimeStamp)
        {
            if (pftItemTimeStamp is DateTime dt)
                return dt.Kind == DateTimeKind.Utc ? dt : dt.ToUniversalTime();
            return DateTime.UtcNow;
        }
    }
}