public class TrickCollection
{

    // https://stackoverflow.com/questions/9033/hidden-features-of-c?page=2&tab=votes#tab-top

    public string Chain(string arg1, string arg2, string arg3) =>
        arg1 ?? arg2 ?? arg3 ?? String.Empty;


    public bool OptimizedStringComparison(string str1, string str2) =>
        String.Equals(str1, str2, StringComparison.CurrentCultureIgnoreCase);

    
    // avoid combining path strings yourself. Use the method
    public void CombinePath()
    {
        string assemblyPath = System.IO.Path.GetDirectoryName(Assembly.GetEntryAssembly().Location);
        string filename = "crap.txt";
        string path = System.IO.Path.Combine(assemblyPath, filename);
        Console.WriteLine(path);
    }

    // If you want to exit your program without calling
    // any finally blocks or finalizers use FailFast
    public void FailFast() =>
        Environment.FailFast("Bye...");


    // Use C# keywords as variable names (string int...)
    public void KeywordVariables()
    {
        int @int = 0;
        string @string = "Crap";
        Console.WriteLine(@int + " " + @string);
    }

    // [as, is] operators usage
    public void Aziz_Light()
    {
        // https://www.youtube.com/watch?v=IKmRtJcRX_I

        // IS some object equal to certain type?
        object obj = "Crap";
        if (obj is string) Console.WriteLine("Same type");

        // can we convert that object AS some other object?
        int? x = obj as int?; // x will be null if conversion fails
    }
    
    public SomeEnum GetEnumByNumber(int n) =>
      (SomeEnum)n;

    public bool CompareEnumAndNumber(int n, SomeEnum someEnum) =>
       n == (int)someEnum;
      
    // method that instantiates object from class
    // that implements another class or interface
    // (probably overkill)
    public T Construct<T, U>() where U : T, new()
      {
          return new U();
      }
      
      
    public DateTime FormatDateFromString(string dateString)
    {
      var date = DateTime.ParseExact(dateString, "d/M/yyyy", CultureInfo.InvariantCulture);
      return date;
    }
    
    public string FormatStringFromDate(DateTime date)
    {
      string dateString = String.Format($"{date:yyyyMdd}"); // any format is possible
      return dateString;
    }
    
    public string ConvertToBinary(int value, int numOfBits) =>
            (numOfBits > 1 ? ConvertToBinary(value >> 1, numOfBits - 1) : null) + "01"[value & 1];
            
    public int[] NullFilter(int?[] nullers) =>
            return nullers.OfType().ToArray();
            
    // most efficient way to calculate fibonacci series from 0 to n
    public void Fibonacci(int n)
    {
        double sq = Math.Sqrt(5);
        for (int i = 0; i < n; i++)
        {
            double number = 1 / sq * (Math.Pow((1 + sq) / 2, i) - Math.Pow((1 - sq) / 2, i));
            Console.WriteLine(number) ;
        }
    }
    
     // cipher (and decipher) a message
     public void Cipher(string message, string password)
     {
            int plen = password.Length;
            var pChars = new byte[plen];
            for (int i = 0; i < plen; i++)
            {
                pChars[i] = (byte)password[i];
            }

            int mlen = message.Length;
            var mChars = new byte[mlen];
            for (int i = 0; i < mlen; i++)
            {
                mChars[i] = (byte)message[i];
            }

            int counter = 0;
            var encoded = new int[mlen];
            for (int i = 0; i < mlen; i++)
            {
                if (counter == plen)
                    counter = 0;

                encoded[i] = mChars[i] ^ pChars[counter];
            }

            string encodedMessage = "";
            for (int i = 0; i < mlen; i++)
            {
                encodedMessage += (char)encoded[i];
            }

            var cryptoEventArgs = new CryptoEventArgs()
            {
                EncodedMessage = encodedMessage,
                Notification = "Message encrypted"
            };
        }
}