Как C# переделать в php (для wordpress)?

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using Blog.Bll.Models;
using Blog.Models;
using PagedList;

namespace Blog.Controllers
{
    public class KalkulyatorController : Controller
    {
        private BlogDb db = new BlogDb();

        public ActionResult CalcNds(double sum, double stavkaNds, string typeNds)
        {
            double total = sum;
            double ndsSum = 0;
            string ndsTxt = string.Empty;
            if (typeNds == "nach")
            {
                ndsSum = okrugl(sum * stavkaNds / 100);
                total += ndsSum;
                ndsTxt = string.Format("Итого, сумма с НДС: {0}, в том числе НДС {1}% - {2}", RuDateAndMoneyConverter.CurrencyToTxtFull(total, false), stavkaNds,
                       RuDateAndMoneyConverter.CurrencyToTxtFull(ndsSum, false));
            }
            else
            {
                ndsSum = okrugl(sum / (100 + stavkaNds) * stavkaNds);
                ndsTxt = string.Format("Итого, сумма с НДС: {0}, в том числе НДС {1}% - {2}", RuDateAndMoneyConverter.CurrencyToTxtFull(total, false), stavkaNds,
                       RuDateAndMoneyConverter.CurrencyToTxtFull(ndsSum, false));
            }

            var result = new NdsResult()
                {
                    SumTxt = ndsTxt
                };
            return PartialView("_CalcNdsResult", result);
        }

        private double okrugl(double oraz)
        {
        return Math.Round(oraz, 2);
        }

        private double okrugl2(double oraz)
        {
            return Math.Round(oraz, 0);
        }

    }
}

var calc = {
    init: function () {
        $("body").on("click", "#ndsNach", this.ndsNach);
        $("body").on("click", "#ndsVydel", this.ndsVydel);
    },
    
    ndsNach: function () {
        var sum = $('#sum').val();
        var stavkaNds = $('#stavkaNds').val();

        $.ajax({
            type: 'post',
            url: '/Kalkulyator/CalcNds',
            data: {
                sum: sum,
                stavkaNds: stavkaNds,
                typeNds: 'nach'
            },
            success: function (data) {
                $('#resultForm').html(data);
            },
            error: function (data) {
                $('#resultForm').html(data);
            }
        });
    },
    
    ndsVydel: function () {
        var sum = $('#sum').val();
        var stavkaNds = $('#stavkaNds').val();

        $.ajax({
            type: 'post',
            url: '/Kalkulyator/CalcNds',
            data: {
                sum: sum,
                stavkaNds: stavkaNds,
                typeNds: 'vydel'
            },
            success: function (data) {
                $('#resultForm').html(data);
            },
            error: function (data) {
                $('#resultForm').html(data);
            }
        });
    },
}

<table class="table table-striped">
                        <tbody><tr>
                            <td style="color: black; font-size: 20px;"><b>Сумма</b> (<span style="color: red"></span>):</td>
                            <td>
                                <input type="text" id="sum" value="0"></td>
                        </tr>

                        <tr>
                            <td style="color: black; font-size: 20px;"><b>Ставка НДС</b>:</td>
                            <td>
                                <input type="text" id="stavkaNds" value="18"></td>
                        </tr>
                        <tr>
                            <td colspan="2">
                                <a class="button gray" id="ndsNach">Начислить</a> <a class="button blue" id="ndsVydel">Выделить</a>
                            </td>
                        </tr>
                    </tbody></table>
                    <div id="resultForm">
                    </div>