Reading disk drive SMART information - part 2

public Dictionary<int, HDD> GetAllDisks()
{
	// retrieve list of drives on computer (this will return both HDD's and CDROM's and Virtual CDROM's)                    
	var dicDrives = new Dictionary<int, HDD>();
	var wdSearcher = new ManagementObjectSearcher("SELECT * FROM Win32_DiskDrive");

	// extract model and interface information
	int iDriveIndex = 0;
	foreach (ManagementObject drive in wdSearcher.Get())
	{
		//LogWmiData(drive);

		var hdd = new HDD();
		hdd.Id = drive["DeviceId"].ToString().Trim();
		hdd.Index = Convert.ToInt32(drive["Index"].ToString().Trim());
		hdd.Model = drive["Model"].ToString().Trim();
		_logger.Write($"disk drive {hdd.Index} {hdd.Id} {hdd.Model}");
		hdd.Type = drive["InterfaceType"].ToString().Trim();
		hdd.PnpDeviceId = drive["PNPDeviceID"].ToString().Trim();
		if (drive["Availability"] != null)
		{
			hdd.Availability = (Availability)(drive["Availability"]);
		}
		if (drive["Capabilities"] != null)
		{
			hdd.Capabilities = (UInt16[])(drive["Capabilities"]);
		}
		dicDrives.Add(iDriveIndex, hdd);
		iDriveIndex++;
	}
	return dicDrives;
}

public string GetProperty(ManagementObject obj, string key)
{
	PropertyData data = obj.Properties[key];
	if (data == null || data.Value == null)
	{
		return "N/A";
	}
	return data.Value.ToString();
}

public bool isDevice(HDD drive, string instanceName)
{
	return instanceName.StartsWith(drive.PnpDeviceId, StringComparison.InvariantCultureIgnoreCase);
}

public void GetSMARTInformation(HDD drive)
{
	// this is the actual physical drive number
	_logger.Write($"Drive Number {drive.Index} Drive {drive.Id}, {drive.Model}, PNP {drive.PnpDeviceId}");

	// get wmi access to hdd 
	var searcher = new ManagementObjectSearcher("Select * from Win32_DiskDrive");
	searcher.Scope = new ManagementScope(@"\root\wmi");

	// check if SMART reports the drive is failing
	searcher.Query = new ObjectQuery("Select * from MSStorageDriver_FailurePredictStatus");
	foreach (ManagementObject thisDrive in searcher.Get())
	{
		_logger.Write($"Instance Name 1 {GetProperty(thisDrive,"InstanceName")}");
		if (isDevice(drive, GetProperty(thisDrive, "InstanceName")))
		{
			drive.IsOK = (bool)thisDrive.Properties["PredictFailure"].Value == false;
		}
	}

	// retrieve attribute flags, value worst and vendor data information
	searcher.Query = new ObjectQuery("Select * from MSStorageDriver_FailurePredictData");
	foreach (ManagementObject data in searcher.Get())
	{
		_logger.Write($"Instance Name 2 {GetProperty(data, "InstanceName")}");
		if (isDevice(drive, GetProperty(data, "InstanceName")))
		{
			Byte[] bytes = (Byte[])data.Properties["VendorSpecific"].Value;
			for (int i = 0; i < 30; ++i)
			{
				int id = 0;
				try
				{
					id = bytes[i * 12 + 2];

					int flags = bytes[i * 12 + 4]; // least significant status byte, +3 most significant byte, but not used so ignored.
													//bool advisory = (flags & 0x1) == 0x0;
					bool failureImminent = (flags & 0x1) == 0x1;
					//bool onlineDataCollection = (flags & 0x2) == 0x2;

					int value = bytes[i * 12 + 5];
					int worst = bytes[i * 12 + 6];
					int vendordata = BitConverter.ToInt32(bytes, i * 12 + 7);
					if (id == 0) continue;

					//_logger.Write($"SMART Data: {id} {vendordata}");

					Smart attr = drive.Attributes[id];
					attr.Current = value;
					attr.Worst = worst;
					attr.Data = vendordata;
					attr.IsOK = failureImminent == false;
					attr.IsPopulatedFromWmi = true;
				}
				catch
				{
					// given key does not exist in attribute collection (attribute not in the dictionary of attributes)
					_logger.Write($"SMART Key Not found {id}");
				}
			}
		}
	}

	// retrieve threshold values foreach attribute
	searcher.Query = new ObjectQuery("Select * from MSStorageDriver_FailurePredictThresholds");
	foreach (ManagementObject data in searcher.Get())
	{
		_logger.Write($"Instance Name 3 {GetProperty(data, "InstanceName")}");
		if (isDevice(drive, GetProperty(data, "InstanceName")))
		{
			Byte[] bytes = (Byte[])data.Properties["VendorSpecific"].Value;
			for (int i = 0; i < 30; ++i)
			{
				try
				{

					int id = bytes[i * 12 + 2];
					int thresh = bytes[i * 12 + 3];
					if (id == 0) continue;

					var attr = drive.Attributes[id];
					attr.Threshold = thresh;
				}
				catch
				{
					// given key does not exist in attribute collection (attribute not in the dictionary of attributes)
				}
			}
		}
	}
}