using System;

using System.Collections.Generic;

using System.Linq;

using Microsoft.AspNetCore.WebUtilities;

using Microsoft.AspNetCore.Http.Extensions;

public class Program

{

    public static void Main()

    {

        var id = Guid.NewGuid();

        var urlWithExistingQuery = "http://joesauve.com?param1=something&param2=somethingelse";

        var urlWithoutExistingQuery = "http://joesauve.com";

        var dirtyUrlWithExistingQuery = QueryHelpers.AddQueryString(urlWithExistingQuery, "zbidref", id.ToString());

        var dirtyUrlWithoutExistingQuery = QueryHelpers.AddQueryString(urlWithoutExistingQuery, "zbidref", id.ToString());

        System.Console.WriteLine(dirtyUrlWithExistingQuery);

        System.Console.WriteLine(GetSanitizedUrlForUserNotififcation(dirtyUrlWithExistingQuery));

        System.Console.WriteLine();

        System.Console.WriteLine(dirtyUrlWithoutExistingQuery);

        System.Console.WriteLine(GetSanitizedUrlForUserNotififcation(dirtyUrlWithoutExistingQuery));

    }

    static string GetSanitizedUrlForUserNotififcation(string url)

    {

        var uri = new Uri(url);

​

        var baseUri = uri.GetComponents(UriComponents.Scheme | UriComponents.Host | UriComponents.Port | UriComponents.Path, UriFormat.UriEscaped).TrimEnd(new char[] { '/' });

​

        var query = QueryHelpers.ParseNullableQuery(uri.Query);

​

        if (query == null)

            return url;

​

        var queryItems = query.SelectMany(x => x.Value, (col, value) => new KeyValuePair<string, string>(col.Key, value)).ToList();

​

        queryItems.RemoveAll(x => x.Key.ToLowerInvariant() == "zbidref".ToLowerInvariant());

​

        var sanitizedUrl = baseUri + (new QueryBuilder(queryItems)).ToQueryString();

​

        return sanitizedUrl;

    }

}