using System;

using System.Linq;

using System.Collections.Generic;

​

public class SafeProtectDeviceReportUsage

{

    public long Vehicleid { get; set; }

​

    public DateTime TimestampLastConnection { get; set; }

​

    // Minutes

    public double AvgConnectionDuration { get; set; }

}

​

public class Program

{

    public static void Main()

    {

        List<SafeProtectDeviceReportUsage> toInsertDatesRecords = new List<SafeProtectDeviceReportUsage>(){

            new SafeProtectDeviceReportUsage(){TimestampLastConnection = new DateTime(2022,05,02),AvgConnectionDuration = 302,Vehicleid =1},

            new SafeProtectDeviceReportUsage(){TimestampLastConnection = new DateTime(2022,05,02),AvgConnectionDuration = 1129,Vehicleid =1},

            new SafeProtectDeviceReportUsage(){TimestampLastConnection = new DateTime(2022,05,02),AvgConnectionDuration = 500,Vehicleid =5},

            new SafeProtectDeviceReportUsage(){TimestampLastConnection = new DateTime(2022,05,03),AvgConnectionDuration = 1440,Vehicleid =1}

        }; 

        var result = toInsertDatesRecords.GroupBy(row =>row.TimestampLastConnection.ToLocalTime().Date).Select(g => {

            int vCount = g.Select(c => c.Vehicleid).Distinct().Count();

            return new {

             date = g.Key.Date,

             count = vCount,

             AvgConnectedDuration = g.Sum(x=> x.AvgConnectionDuration) / vCount

            };

        });

        foreach(var item in result){

           Console.WriteLine(item.date+ "  "+ item.count+"  "+item.AvgConnectedDuration);

        }

        Console.WriteLine("Hello World");

    }

}