This is a sample User Simulator class for Azure Personalizer

UserSimulator.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Simulator
{
    public class UserSimulator
    {
        Random randomIndex;

        string[] possibleActionIds = new string[] { "chocolate_cake", "banoffee_pie", "the_original", "fruit_trifle", "mango_delight", "nutella_cupcake", "vanilla_cupcake" };
        private new Dictionary<string, string> responses = new Dictionary<string, string>();

        public UserSimulator(Random rand)
        {
            randomIndex = rand;

            InitializeResponses();
        }

        public void InitializeResponses()
        {
            AddSimulatedResponse("birthday", "cake", "chocolate_cake");
            AddSimulatedResponse("birthday", "dessert", "fruit_trifle");
            AddSimulatedResponse("birthday", "cupcake", "vanilla_cupcake");
            AddSimulatedResponse("birthday", "shake", "mango_delight");

            AddSimulatedResponse("meal", "cake", "chocolate_cake");
            AddSimulatedResponse("meal", "dessert", "banoffee_pie");
            AddSimulatedResponse("meal", "cupcake", "nutella_cupcake");
            AddSimulatedResponse("meal", "shake", "the_original");

            AddSimulatedResponse("catchup", "cake", "chocolate_cake");
            AddSimulatedResponse("catchup", "dessert", "fruit_trifle");
            AddSimulatedResponse("catchup", "cupcake", "nutella_cupcake");
            AddSimulatedResponse("catchup", "shake", "the_original");
        }

        public string ReturnSimulatedAction(IList<object> context)
        {
            return GetResponse((Dictionary<string,string>)context[0]);
        }

        public string GetResponse(Dictionary<string,string> ctx)
        {
            string key = GetKey(ctx);
            if (responses.ContainsKey(key))
            {
                return responses[key];
            }
            else
            {
                return GetRandomResponse();
            }
        }

        public string GetRandomResponse()
        {
            return possibleActionIds[randomIndex.Next(possibleActionIds.Length)];
        }

        public void AddSimulatedResponse(string occassion, string variety, string foodChoice)
        {
            responses.Add(GetKey(occassion, variety), foodChoice);
        }

        public string GetKey(string occassion, string variety)
        {
            return occassion + "_" + variety;
        }

        public string GetKey(Dictionary<string,string> ctx)
        {
            return GetKey(ctx["occassion"], ctx["variety"]);
        }
    }
}