using System;

using System.Linq;

using System.Collections.Generic;

using System.Text.Json;

​

class tracking

{

    public string SellerProductId;

    public string TrackingNumber;

    public int Qte;

    public int QteExp;

}

​

​

public class Program

{

    public static void Main()

    {

        List<tracking> tracking = new List<tracking>()

        {

            /*new tracking { SellerProductId = "1", TrackingNumber = "TrackingNumber1", Qte = 1,QteExp = 1 },

            new tracking { SellerProductId = "1", TrackingNumber = "TrackingNumber1", Qte = 1,QteExp = 1 },

            new tracking { SellerProductId = "1", TrackingNumber = "TrackingNumber2" , Qte = 1,QteExp = 1 },

            new tracking { SellerProductId = "1", TrackingNumber = "TrackingNumber2", Qte = 1,QteExp = 1 },

            new tracking { SellerProductId = "1", TrackingNumber = null, Qte = 1,QteExp = 0*/

            new tracking { SellerProductId = "1", TrackingNumber = "TrackingNumber1", Qte = 1,QteExp = 1 },

            new tracking { SellerProductId = "1", TrackingNumber = "", Qte = 1,QteExp = 0 },

            new tracking { SellerProductId = "2", TrackingNumber = "TrackingNumber1", Qte = 1,QteExp = 1 }

        };

​

        var Grp1 = tracking.GroupBy(si => new {si.SellerProductId,si.TrackingNumber}).Select(s => new {s.Key.SellerProductId,s.Key.TrackingNumber,Qte = s.Sum(v => v.Qte),QteExp = s.Sum(v => v.QteExp),  Count = s.Count()}).ToList();

        Console.WriteLine(JsonSerializer.Serialize(Grp1));

        Console.WriteLine("-----");

        foreach(var item in Grp1)

        {

            Console.WriteLine(item.SellerProductId + " " + string.Join(";",item.TrackingNumber) + " " + item.Count.ToString() + " " );  

        }

        Console.WriteLine("-----");

        var Grp2 =  Grp1.GroupBy(g => g.SellerProductId).Where(w => w.Count()>1).Select(s => new { SellerProductId= s.Key, Nb = s.Count()});

        if(Grp2.Any())

        {

            foreach(var item in Grp2)

            {

                Console.WriteLine(item.SellerProductId + " Ligne diff : " + item.Nb.ToString() + " " ); 

            }

        }

        else

        {

            Console.WriteLine("Pas de SPLIT");

        }

    }

}