using System;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        // original ndef

        var ndef = "en11203931373354377F061E28000000000000002200FFE01E0DFEC800000000000000000E00050F0210021102123D13FE0E0E140001001015009C010101160000FFFF1700BA1800141907D01A00141B0028FFAA1ED81C051D012504B0266427012805330A340A350A6503E83202";

        Console.WriteLine("NDEF:              \t" + ndef);

        // cleaned ndef

        var cleaned = cleanNdefRecord(ndef);

        Console.WriteLine("CLEANED:           \t" + cleaned);

        // device address

        var deviceAddress = retrieveDeviceAddress(ndef);

        Console.WriteLine("ADDRESS:           \t" + deviceAddress);

        // firmware version

        int major;

        int minor;

        var version = retrieveVersion(ndef, out major, out minor);

        Console.WriteLine("VERSION:           \t" + version);

        Console.WriteLine("MAJOR:             \t" + major);

        Console.WriteLine("MINOR:             \t" + minor);

        // is NDEF record updated? (note: this should be false, because the first ndef in this example is from v1.8 (not 1.14+)

        bool isV14OrGreater;

        var isNdefUpdated = isNDEFUpdatedV14(ndef, out isV14OrGreater);

        Console.WriteLine("IS V1.14+:         \t" + isV14OrGreater); // should be false

        Console.WriteLine("RECORD UPDATED:    \t" + isNdefUpdated);  // should be false

        // for firmware less than 1.14, perform a second ndef read (note last digit is odd value...............................................................................................................................)          here (3)

        var ndef2 = "en11203931373354377F061E28000000000000002200FFE01E0DFEC800000000000000000E00050F0210021102123D13FE0E0E140001001015009C010101160000FFFF1700BA1800141907D01A00141B0028FFAA1ED81C051D012504B0266427012805330A340A350A6503E83203";

        isNdefUpdated = IsNdefRecordUpdated(ndef, ndef2);

        Console.WriteLine("RECORD UPDATED (2):\t" + isNdefUpdated);

        // v1.14 ndef example

        var ndefv114 = "en112039313733773777071E2E020000000000152202FFE01A0DFEC8000000000000000037000E01E00F0F100F110F123E13140E0E140000138815009C010101160000FFFF1700BA1800141907D01A00141BFFF2FF961F101C051D012500002600270128053300340A350A6503E83609383C6600803209";

        isNdefUpdated = isNDEFUpdatedV14(ndefv114, out isV14OrGreater);

        Console.WriteLine("IS V1.14+:         \t" + isV14OrGreater); // should be true

        Console.WriteLine("RECORD UPDATED:    \t" + isNdefUpdated);  // should be true

    }

​

    public static string retrieveVersion(string ndefRecord, out int Major, out int Minor)

    {

        ndefRecord = cleanNdefRecord(ndefRecord);

        String version = ndefRecord.Substring(22, 2);

        var versionByte = HexStringToByteArray(version);

        //Right Shift this byte 5 to receive the Major of this version

        Major = (versionByte[0] >> 5);

        //Binary AND the byte with 31 to receive the Minor of this version

        Minor = (versionByte[0] & 31);

        //combine the two for the string version

        return Major + "." + Minor;

    }

​

    public static string cleanNdefRecord(string ndefRecord)

    {

        if (ndefRecord.Contains("en"))

        {

            //clean the record type variables from the record                       

            ndefRecord = ndefRecord.Replace("\0", "").Split("en".ToCharArray(), StringSplitOptions.RemoveEmptyEntries)[0];

        }

​

        return ndefRecord;

    }

​

    public static string retrieveDeviceAddress(string ndefRecord)

    {

        ndefRecord = cleanNdefRecord(ndefRecord);

        return ndefRecord.Substring(4, 16);

    }

​

    public static byte[] HexStringToByteArray(string hex)

    {

        return Enumerable.Range(0, hex.Length).Where(x => x % 2 == 0).Select(x => Convert.ToByte(hex.Substring(x, 2), 16)).ToArray();

    }

​

    public static bool isNDEFUpdatedV14(string ndefRecord, out bool IsVersion114OrGreater)

    {

        IsVersion114OrGreater = false;

        try

        {

            var ndefRecordClean = cleanNdefRecord(ndefRecord);

            int versionMajor;

            int versionMinor;

            String version = retrieveVersion(ndefRecordClean, out versionMajor, out versionMinor);

            // starting with v1.14 and beyond, single scan is supported

            if (versionMinor >= 14 || versionMajor >= 2)

            {

                IsVersion114OrGreater = true;

                string firstTick = ndefRecordClean.Substring(ndefRecordClean.Length - 2, 2);

                int first = HexStringToByteArray(firstTick)[0];

                // If the ticker is odd, the Sensor was successfully tapped and updated

                return first % 2 == 1;

            }

        }

        catch (Exception e)

        {

            Console.WriteLine(e);

        }

​

        return false;

    }

​

    private static bool IsNdefRecordUpdated(string firstNdef, string secondNdef)

    {

        firstNdef = cleanNdefRecord(firstNdef);

        secondNdef = cleanNdefRecord(secondNdef);

        string firstTick = firstNdef.Substring(firstNdef.Length - 2, 2);

        string secondTick = secondNdef.Substring(secondNdef.Length - 2, 2);

        return firstTick != secondTick;

    }

}