using System;
using System.Collections.Generic;
using System.Text;

namespace SharedKernel.Extensions
{
    public static class QueryStringExtension
    {
        public static string ToQueryString(this object obj)
        {
            if (obj is null)
            {
                return string.Empty;
            }

            var properties = obj.GetType().GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance).Where(p => p.GetValue(obj) != null);
            var query = new StringBuilder('?');

            foreach (var prop in properties)
            {
                var value = prop.GetValue(obj);
                if (value is null)
                {
                    continue;
                }

                if (query.Length > 1)
                {
                    query.Append('&');
                }

                query.Append(Uri.EscapeDataString(prop.Name));
                query.Append('=');
                query.Append(Uri.EscapeDataString(value.ToString()!));
                query.Append("&");
            }

            return query.Length > 1 ? query.ToString().TrimEnd('&') : string.Empty;
        }
    }
}