using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System;

public class Test
{
	public static void Main()
	{
		var originalString = "My name @is ,Wan.;'; Wan";
		Console.WriteLine("Original string:");
		Console.WriteLine(originalString);
		Console.WriteLine();
		
		var sanitizedString = RemoveExcept(originalString, alphas: true, spaces: true);
		Console.WriteLine("Sanitized string:");
		Console.WriteLine(sanitizedString);
		Console.WriteLine();
	}
	
	/// <summary>
	/// Returns a copy of the original string containing only the set of whitelisted characters.
	/// </summary>
	/// <param name="value">The string that will be copied and scrubbed.</param>
	/// <param name="alphas">If true, all alphabetical characters (a-zA-Z) will be preserved; otherwise, they will be removed.</param>
	/// <param name="numerics">If true, all alphabetical characters (a-zA-Z) will be preserved; otherwise, they will be removed.</param>
	/// <param name="dashes">If true, all alphabetical characters (a-zA-Z) will be preserved; otherwise, they will be removed.</param>
	/// <param name="underlines">If true, all alphabetical characters (a-zA-Z) will be preserved; otherwise, they will be removed.</param>
	/// <param name="spaces">If true, all alphabetical characters (a-zA-Z) will be preserved; otherwise, they will be removed.</param>
	/// <param name="periods">If true, all decimal characters (".") will be preserved; otherwise, they will be removed.</param>
	public static string RemoveExcept(string value, bool alphas = false, bool numerics = false, bool dashes = false, bool underlines = false, bool spaces = false, bool periods = false) {
		if (string.IsNullOrWhiteSpace(value)) return value;
		if (new[] { alphas, numerics, dashes, underlines, spaces, periods }.All(x => x == false)) return value;

		var whitelistChars = new HashSet<char>(string.Concat(
			alphas ? "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" : "",
			numerics ? "01234567890" : "",
			dashes ? "-" : "",
			underlines ? "_" : "",
			periods ? "." : "",
			spaces ? " " : ""
		).ToCharArray());

		var scrubbedValue = value.Aggregate(new StringBuilder(), (sb, @char) => {
			if (whitelistChars.Contains(@char)) sb.Append(@char);
			return sb;
		}).ToString();

		return scrubbedValue;
	}
}