@using Telerik.DataSource;

<TelerikGrid Data=@GridData Groupable="true" Pageable="true" Height="650px"
             @ref="@GridRef">
    <GridAggregates>
        <GridAggregate Field=@nameof(Employee.Period1) Aggregate="@GridAggregateType.Sum" />
        <GridAggregate Field=@nameof(Employee.Period2) Aggregate="@GridAggregateType.Sum" />
        <GridAggregate Field=@nameof(Employee.Period3) Aggregate="@GridAggregateType.Sum" />
    </GridAggregates>
    <GridColumns>
        <GridColumn Field=@nameof(Employee.Name) Groupable="false" />
        <GridColumn Field=@nameof(Employee.Team) Title="Team">
        </GridColumn>
        <GridColumn Field=@nameof(Employee.Salary) Title="Salary" Groupable="false">
        </GridColumn>
        <GridColumn Field=@nameof(Employee.ActiveProjects) Title="Active Projects">
        </GridColumn>
        <GridColumn Field=@nameof(Employee.Period1) Title="Period 1">
            <GroupFooterTemplate>
                @context.Sum
            </GroupFooterTemplate>
        </GridColumn>
        <GridColumn Field=@nameof(Employee.Period2) Title="Period 2">
            <GroupFooterTemplate>
                @context.Sum
            </GroupFooterTemplate>
        </GridColumn>
        <GridColumn Field=@nameof(Employee.Period3) Title="Period 3">
            <GroupFooterTemplate>
                @context.Sum
            </GroupFooterTemplate>
        </GridColumn>
    </GridColumns>
</TelerikGrid>

@code {
        TelerikGrid<Employee> GridRef { get; set; }
    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
        {
            GridState<Employee> desiredState = new GridState<Employee>()
            {
                GroupDescriptors = new List<GroupDescriptor>()
            {
                new GroupDescriptor()
                {
                    Member = "Team",
                    MemberType = typeof(string)
                }
            }
            };
            await GridRef.SetState(desiredState);
        }
    }


    public List<Employee> GridData { get; set; }

    protected override void OnInitialized()
    {
        GridData = new List<Employee>();
        var rand = new Random();
        for (int i = 0; i < 15; i++)
        {
            Random rnd = new Random();
            GridData.Add(new Employee()
            {
                EmployeeId = i,
                Name = "Employee " + i.ToString(),
                Team = "Team " + i % 3,
                Salary = rnd.Next(1000, 5000),
                ActiveProjects = i % 4 == 0 ? 2 : 5,
                Period1 = i,
                Period2 = i * i,
                Period3 = i ^ 2
            });
        }
    }

    public class Employee
    {
        public int EmployeeId { get; set; }
        public string Name { get; set; }
        public string Team { get; set; }
        public decimal Salary { get; set; }
        public int ActiveProjects { get; set; }
        public decimal Period1 { get; set; }
        public decimal Period2 { get; set; }
        public decimal Period3 { get; set; }
    }
}