@page "/"


@using Syncfusion.Blazor
@using Syncfusion.Blazor.Data
@using Syncfusion.Blazor.Grids
@using System.Collections

<button class="btn btn-primary" @onclick="ExportarGrid">Export Excel</button>


<SfGrid TValue="Order" ID="Grid" @ref="Grid" AllowGrouping AllowSorting="true" AllowExcelExport="true" AllowFiltering="true" AllowPaging="true">
    <SfDataManager AdaptorInstance="@typeof(CustomAdaptor)" Adaptor="Adaptors.CustomAdaptor"></SfDataManager>
    <GridPageSettings PageSize="8"></GridPageSettings>

   <GridGroupSettings Columns=@GroupOption></GridGroupSettings>
    <GridColumns>
        <GridColumn Field=@nameof(Order.OrderID) HeaderText="Order ID" IsPrimaryKey="true" TextAlign="@TextAlign.Center" Width="140"></GridColumn>
        <GridColumn Field=@nameof(Order.CustomerID) HeaderText="Customer Name" Width="150">
            <Template>
                @{
                    var data = context as Order;
                    <span>@data.CustomerID</span>
                }
            </Template>
        </GridColumn>
        <GridColumn Field=@nameof(Order.Freight) HeaderText="Freight" Format="C2" Width="150"></GridColumn>
    </GridColumns>
    <GridAggregates>
        <GridAggregate>
            <GridAggregateColumns>
                <GridAggregateColumn Field=@nameof(Order.Freight) Type="AggregateType.Sum" Format="C2">
                    <GroupFooterTemplate>
                        @{
                            var aggregate = (context as AggregateTemplateContext);
                            <div>
                                <p>Sum: @aggregate.Sum</p>
                            </div>
                        }
                    </GroupFooterTemplate>
                </GridAggregateColumn>
            </GridAggregateColumns>
        </GridAggregate>
    </GridAggregates>
</SfGrid>

@code {
    public static List<Order> Orders { get; set; }
    private SfGrid<Order> Grid { get; set; }

    private string[] GroupOption = (new string[] { "CustomerID" });
    protected override void OnInitialized()
    {
        Orders = Enumerable.Range(1, 75).Select(x => new Order()
            {
                OrderID = 1000 + x,
                CustomerID = (new string[] { "ALFKI", "ANANTR", "ANTON", "BLONP", "BOLID" })[new Random().Next(5)],
                Freight = 2.1 * x,
            }).ToList();
    }
    private async Task ExportarGrid(MouseEventArgs args)
    {
       

        await Grid.ExportToExcelAsync();
    }

    public void ExcelAggregateTemplateInfoHandler(ExcelAggregateEventArgs args)
    {
        if (args.Column.Field == "Freight")
        {
            args.Cell.Value = args.Value.ToString();

        }
    }

    public class Order
    {
        public int OrderID { get; set; }
        public string CustomerID { get; set; }
        public double Freight { get; set; }
    }

    // Implementing custom adaptor by extending the DataAdaptor class
    public class CustomAdaptor : DataAdaptor
    {
        // Performs data Read operation
        public override async Task<object> ReadAsync(DataManagerRequest dm, string key = null)
        {
            IEnumerable<Order> DataSource = Orders;
            if (dm.Search != null && dm.Search.Count > 0)
            {
                // Searching
                DataSource = DataOperations.PerformSearching(DataSource, dm.Search);
            }
            if (dm.Sorted != null && dm.Sorted.Count > 0)
            {
                // Sorting
                DataSource = DataOperations.PerformSorting(DataSource, dm.Sorted);
            }
            if (dm.Where != null && dm.Where.Count > 0)
            {
                // Filtering
                DataSource = DataOperations.PerformFiltering(DataSource, dm.Where, dm.Where[0].Operator);
            }
            int count = DataSource.Cast<Order>().Count();
            if (dm.Skip != 0)
            {
                //Paging
                DataSource = DataOperations.PerformSkip(DataSource, dm.Skip);
            }
            if (dm.Take != 0)
            {
                DataSource = DataOperations.PerformTake(DataSource, dm.Take);
            }

            DataResult DataObject = new DataResult();
            if (dm.Group != null)
            {
                IEnumerable ResultData = DataSource.ToList();
                // Grouping
                foreach (var group in dm.Group)
                {
                    ResultData = DataUtil.Group<Order>(ResultData, group, dm.Aggregates, 0, dm.GroupByFormatter);
                }
                DataObject.Result = ResultData;
                DataObject.Count = count;
                return dm.RequiresCounts ? DataObject : (object)ResultData;
            }

            DataResult DataObject1 = new DataResult();
            if (dm.Aggregates != null) // Aggregation
            {
                DataObject1.Result = DataSource;
                DataObject1.Count = count;
                DataObject1.Aggregates = DataUtil.PerformAggregation(DataSource, dm.Aggregates);

                return dm.RequiresCounts ? DataObject1 : (object)DataSource;
            }
            return dm.RequiresCounts ? new DataResult() { Result = DataSource, Count = count } : (object)DataSource;
        }
    }
}