using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using Murmur;

public class Program

{

    public static void Main()

    {

        var experimentName = "test1";

        List<(string, decimal)> groups = [

            ("group1", 0.5M),

            ("group2", 0.5M),

        ];

        var email = "test@test.com";

        var purchaseBucket = 2;

        var lifeTimeFlag = "test";

        var agent = "webapp";

        // дальше не трогаем

        var experiment = new Experiment{

            Name = experimentName,

            Groups = groups.Select(x=>new ExperimentGroup{Name = x.Item1,Share = x.Item2}).ToList()

        };

        var userDTO = new UserDTO {

            Email = email,

            Agent = agent

        };

        var winner = GroupCalculator.Get(userDTO, experiment,purchaseBucket,lifeTimeFlag);

        Console.WriteLine($"Winner {winner?.Name}.");

    }

}

​

public static class HashUtils

{

     public static uint GetMurMurHash(string input)

     {

         using var murmurhash = MurmurHash.Create32();

         var strinAsBytes = Encoding.UTF8.GetBytes(input);

         var hash = murmurhash.ComputeHash(strinAsBytes);

​

         return BitConverter.ToUInt32(hash, 0);

     }

​

     public static uint GetHash(string input)

     {

         return GetMurMurHash(input);

     }

}

​

public static class GroupCalculator

{

    public static ExperimentGroup? Get(UserDTO user, Experiment experiment, int purchaseBucket, string? lifeTimeFlag)

    {

        var strToHash =

            $"{user.Email}_{experiment.Name}_{purchaseBucket}_{user.Agent}_{lifeTimeFlag}";

​

        var hash = HashUtils.GetHash(strToHash);

​

        var point = (hash % 100) / (decimal)100;

​

        var groups = experiment.Groups

            .Where(x => x.Share != decimal.Zero)

            .OrderBy(x => x.Name)

            .ToList();

​

        decimal currentShare = 0;

​

        for (var i = 0; i < groups.Count; i++)

        {

            currentShare += groups[i].Share;

​

            if (point < currentShare)

            {

                return groups[i];

            }

        }

​

        return null;

    }

}

​

public class ExperimentGroup

{

    public string Name { get; set;}

    public decimal Share { get; set; }

}

​

public class Experiment

{

    public string Name { get; set;}

    public List<ExperimentGroup> Groups { get; set;}

}

​

public class UserDTO

{

    public string Email {get;set;}

    public string Agent {get;set;}

}

​