_DataTableHelpers.cshtml

@using Microsoft.AspNetCore.Http
@using Microsoft.AspNetCore.Routing
@using WebApp.UI.Areas.Dashboard.Models.DataTables

@inherits GlobalRazorHelpersPage
@implements IDataTableHelpers

@functions {
    // for progressive enhancement with AJAX see
    // * wwwroot/ts/data-table.ts

    // for styling see
    // * wwwroot/lib/bootstrap/scss/_tables.scss
    // * wwwroot/scss/dashboard/_data-table.scss

    // template delegates, tag helpers need the following pragmas to compile (https://github.com/dotnet/aspnetcore/issues/20055)
    //#pragma warning disable MVC1006
    //#pragma warning disable 1998

    public void Table(DataTableModel tableModel)
    {
        if (tableModel.TableTemplate != null)
        {
            @tableModel.TableTemplate(tableModel)
            return;
        }

        <div class="data-table-wrapper">
            @{ TableFilterForm(tableModel); }

            <table id="@tableModel.TableHtmlId" class="table table-bordered table-striped table-hover data-table">
                @{
                    TableHeader(tableModel);
                    TableBody(tableModel);
                    TableFooter(tableModel);
                }
            </table>
        </div>
    }

    public void TableFilterForm(DataTableModel tableModel)
    {
        var tableFieldNames = tableModel.Columns
            .OfType<DataTableColumnModel.DataColumn>()
            .SelectMany(column => column.Filter?.FormFieldNames ?? Enumerable.Empty<string>())
            .Append(tableModel.PageIndexFormFieldName)
            .Append(tableModel.PageSizeFormFieldName)
            .Append(tableModel.OrderByFormFieldName)
            .Where(fieldName => fieldName != null)
            .ToHashSet(StringComparer.OrdinalIgnoreCase)!;

        <!form id="@tableModel.FilterFormHtmlId" method="get" action="@tableModel.GenerateDisplayUrl(Url, null)">
            @foreach (var (key, value) in ViewContext.HttpContext.Request.Query)
                if (!tableFieldNames.Contains(key))
                    for (int i = 0, n = value.Count; i < n; i++)
                    {
                        <input type="hidden" name="@key" value="@value[i]" />
                    }
        </!form>
    }

    #region Header

    public void TableHeader(DataTableModel tableModel)
    {
        <thead>
            @if (tableModel.ShowTableHeaderRow)
            {
                TableHeaderRow(tableModel);
            }

            @if (tableModel.ShowColumnHeaderRow)
            {
                ColumnHeaderRow(tableModel);
            }

            @if (tableModel.AllowFiltering)
            {
                ColumnFilterRow(tableModel);
            }
        </thead>
    }

    public void TableHeaderRow(DataTableModel tableModel)
    {
        if (tableModel.TableHeaderRowTemplate != null)
        {
            @tableModel.TableHeaderRowTemplate(tableModel)
            return;
        }

        <tr class="table-header-row">
            <th class="font-weight-normal" colspan="@tableModel.Columns.Count">
                <div class="alert alert-danger server-error-alert" role="alert">
                    @T["A server error occurred. Try again or contact the system administrator if the problem persists."]
                </div>
                <div class="d-flex">
                    <div class="flex-grow-1">
                        @if (tableModel.AllowPaging && tableModel.Result.PageSize > 0)
                        {
                            var pageSizeSelector = HelperToHtmlContent((_, state) => PageSizeSelector(state), tableModel);

                            @T["Show {0} items", pageSizeSelector]
                        }
                    </div>
                    <div>
                        <button class="btn btn-info btn-sm refresh-table-btn" type="submit" form="@tableModel.FilterFormHtmlId"><i class="fa fa-refresh" aria-hidden="true"></i> @T["Refresh"]</button>
                        @if (tableModel.AllowEditing && tableModel.CanCreateRow)
                        {
                            var actionRouteValues = tableModel.GetReturnUrlRouteValues(Url);
                            <a class="btn btn-success btn-sm create-item-btn" href="@tableModel.GenerateCreateUrl(Url, actionRouteValues)" role="button"><i class="fa fa-plus" aria-hidden="true"></i> @T["Create New"]</a>
                        }
                    </div>
                </div>
            </th>
        </tr>
    }

    public void PageSizeSelector(DataTableModel tableModel)
    {
        var currentPageSize = tableModel.Result.PageSize;
        var maxPageSize = tableModel.Query.MaxPageSize;
        maxPageSize = maxPageSize > 0 ? maxPageSize : 500;

        <select class="page-size-selector" form="@tableModel.FilterFormHtmlId" name="@tableModel.PageSizeFormFieldName">
            @using (var enumerator = GeneratePageSizes())
            {
                enumerator.MoveNext();
                var pageSize = enumerator.Current;
                do
                {
                    <!option value="@pageSize" selected="@(pageSize == currentPageSize)">@pageSize</!option>

                    enumerator.MoveNext();
                    pageSize = enumerator.Current;
                }
                while (pageSize <= maxPageSize);
            }
        </select>

        static IEnumerator<int> GeneratePageSizes()
        {
            @for (var pageSize = 10; ; pageSize = checked(pageSize * 10))
            {
                yield return pageSize;
                yield return checked(pageSize * 2);
                yield return checked(pageSize * 5);
            }
        }
    }

    public void ColumnHeaderRow(DataTableModel tableModel)
    {
        if (tableModel.ColumnHeaderRowTemplate != null)
        {
            @tableModel.ColumnHeaderRowTemplate(tableModel)
            return;
        }

        var columns = tableModel.Columns;

        <tr class="column-header-row">
            @for (int i = 0, n = columns.Count; i < n; i++)
            {
                ColumnHeaderCell(columns[i]);
            }
        </tr>
    }

    public void ColumnHeaderCell(DataTableColumnModel columnModel)
    {
        if (columnModel.HeaderCellTemplate != null)
        {
            @columnModel.HeaderCellTemplate(columnModel)
            return;
        }

        var dataColumn = columnModel as DataTableColumnModel.DataColumn;
        var title = columnModel.Title ?? dataColumn?.Binding.GetDisplayName(Html.MetadataProvider);
        string? currentOrderKeyPropertyPath;

        <th class="@columnModel.HeaderCellCssClasses">
            @if (columnModel.Table.AllowSorting && columnModel.CanSort && (currentOrderKeyPropertyPath = columnModel.OrderKeyPropertyPath ?? dataColumn?.Binding.PropertyPathString) != null)
            {
                var (isActiveOrderColumn, currentOrderDescending, newOrderKeyPropertyPath, newOrderDescending) =
                    GetOrderByState(currentOrderKeyPropertyPath, columnModel.Table.QueryOrderByElements);

                var formFieldName = columnModel.Table.OrderByFormFieldName;
                var routeValues = CreateOrderByRouteValues(ViewContext.HttpContext, formFieldName, newOrderKeyPropertyPath, newOrderDescending);

                <div>
                    <a class="title" href="@columnModel.Table.GenerateDisplayUrl(Url, routeValues)">@title</a>
                    @if (isActiveOrderColumn)
                    {
                        <input type="hidden" form="@columnModel.Table.FilterFormHtmlId" name="@formFieldName" value="@QueryableHelper.ComposeOrderByElement(currentOrderKeyPropertyPath, currentOrderDescending)" />
                        var orderIconCssClass = currentOrderDescending ? columnModel.DescendingOrderIconCssClass : columnModel.AscendingOrderIconCssClass;
                        if (orderIconCssClass != null)
                        {
                            <i class="sort-order fa @(orderIconCssClass) ml-1" aria-hidden="true"></i>
                        }
                    }
                </div>
            }
            else
            {
                <div>
                    <span class="title">@title</span>
                </div>
            }
        </th>

        static (bool, bool, string?, bool) GetOrderByState(string currentOrderKeyPropertyPath, (string, bool)[] orderByElements)
        {
            if (orderByElements.Length > 0)
            {
                var (keyPropertyPath, descending) = orderByElements[0];

                if (currentOrderKeyPropertyPath.Equals(keyPropertyPath, StringComparison.OrdinalIgnoreCase))
                {
                    if (descending)
                        return (true, descending, null, default);

                    return (true, descending, currentOrderKeyPropertyPath, true);
                }
            }

            return (false, default, currentOrderKeyPropertyPath, false);
        }

        static RouteValueDictionary CreateOrderByRouteValues(HttpContext httpContext, string? formFieldName, string? orderKeyPropertyPath, bool orderDescending)
        {
            var routeValues = new RouteValueDictionary();
            routeValues.Merge(httpContext.Request.Query);

            if (formFieldName != null)
            {
                @if (orderKeyPropertyPath != null)
                {
                    routeValues[formFieldName] = QueryableHelper.ComposeOrderByElement(orderKeyPropertyPath, orderDescending);
                }
                else
                {
                    routeValues.Remove(formFieldName);
                }
            }

            return routeValues;
        }
    }

    public void ColumnFilterRow(DataTableModel tableModel)
    {
        if (tableModel.ColumnFilterRowTemplate != null)
        {
            @tableModel.ColumnFilterRowTemplate(tableModel)
            return;
        }

        var columns = tableModel.Columns;

        <tr class="column-filter-row">
            @for (int i = 0, n = columns.Count; i < n; i++)
            {
                ColumnFilterCell(columns[i]);
            }
        </tr>
    }

    public void ColumnFilterCell(DataTableColumnModel columnModel)
    {
        columnModel.RenderFilterCell(this);
    }

    public void ColumnFilterCell(DataTableColumnModel columnModel, Action<IDataTableHelpers> renderFilter)
    {
        <th class="@columnModel.FilterCellCssClasses">
            @{ renderFilter(this); }
        </th>
    }

    public void TextColumnFilter(DataTableColumnFilterModel.TextFilter filterModel)
    {
        <div>
            <input class="form-control form-control-sm" type="text" form="@filterModel.Column.Table.FilterFormHtmlId" name="@filterModel.FormFieldName" value="@filterModel.FormFieldValue" placeholder="@(filterModel.PlaceholderText ?? T["Filter text"])" />
        </div>
    }

    #endregion

    #region Content

    public void TableBody(DataTableModel tableModel)
    {
        var items = tableModel.Result.Items;

        <tbody>
            @if (items?.Count > 0)
            {
                for (int i = 0, n = items.Count; i < n; i++)
                {
                    ContentRow(items[i]!, tableModel);
                }
            }
            else
            {
                NoContentRow(tableModel);
            }
        </tbody>
    }

    public void ContentRow(object item, DataTableModel tableModel)
    {
        if (tableModel.ContentRowTemplate != null)
        {
            @tableModel.ContentRowTemplate((item, tableModel))
            return;
        }

        var columns = tableModel.Columns;

        <tr class="content-row">
            @for (int i = 0, n = columns.Count; i < n; i++)
            {
                ContentCell(item, columns[i]);
            }
        </tr>
    }

    public void ContentCell(object item, DataTableColumnModel columnModel)
    {
        columnModel.RenderContentCell(this, item);
    }

    public void DataContentCell(object item, DataTableColumnModel.DataColumn columnModel)
    {
        <td class="@columnModel.ContentCellCssClasses">@columnModel.Binding.GetValue(item)</td>
    }

    public void ControlContentCell(object item, DataTableColumnModel.ControlColumn columnModel)
    {
        object? rowId;

        <td class="@columnModel.ContentCellCssClasses">
            @if (columnModel.Table.AllowEditing && (rowId = columnModel.Table.GetRowId(item)) != null)
            {
                var canEdit = columnModel.CanEditRow(item);
                var canDelete = columnModel.CanDeleteRow(item);

                if (canEdit || canDelete)
                {
                    var actionRouteValues = new RouteValueDictionary(columnModel.Table.GetReturnUrlRouteValues(Url)) { ["id"] = rowId };

                    @if (canEdit)
                    {
                        <a class="btn btn-info btn-sm edit-item-btn" href="@columnModel.Table.GenerateEditUrl(Url, actionRouteValues)" title="@T["Edit"]" role="button">
                            <i class="fa fa-pencil" aria-hidden="true"></i>
                        </a>
                    }

                    @if (canDelete)
                    {
                        <a class="btn btn-danger btn-sm delete-item-btn" href="@columnModel.Table.GenerateDeleteUrl(Url, actionRouteValues)" title="@T["Delete"]" role="button">
                            <i class="fa fa-trash" aria-hidden="true"></i>
                        </a>
                    }
                }
            }
        </td>
    }

    public void NoContentRow(DataTableModel tableModel)
    {
        if (tableModel.NoContentRowTemplate != null)
        {
            @tableModel.NoContentRowTemplate(tableModel)
            return;
        }

        <tr class="no-content-row">
            <td class="text-center" colspan="@tableModel.Columns.Count">
                @T["No data to display."]
            </td>
        </tr>
    }

    #endregion

    #region Footer

    public void TableFooter(DataTableModel tableModel)
    {
        <tfoot>
            @if (tableModel.ShowTableFooterRow)
            {
                TableFooterRow(tableModel);
            }
        </tfoot>
    }

    public void TableFooterRow(DataTableModel tableModel)
    {
        if (tableModel.TableFooterRowTemplate != null)
        {
            @tableModel.TableFooterRowTemplate(tableModel)
            return;
        }

        var result = tableModel.Result;

        @if (result.TotalItemCount > 0)
        {
            var pagerInfo = new PagerInfo(result.PageIndex, result.PageSize, result.TotalItemCount);

            <tr class="table-footer-row">
                <td colspan="@tableModel.Columns.Count">
                    <div class="d-flex">
                        <div class="flex-grow-1">
                            @T["Showing {0} to {1} of {2} item", pagerInfo.ItemStartIndex + 1, pagerInfo.ItemEndIndex, Plural.From("Showing {0} to {1} of {2} items", pagerInfo.TotalItemCount)]
                        </div>
                        <div>
                            @if (tableModel.AllowPaging && result.PageSize > 0)
                            {
                                @Html.Pager(in pagerInfo,
                                    page => tableModel.GenerateDisplayUrl(Url, CreatePagingRouteValues(ViewContext.HttpContext, tableModel.PageIndexFormFieldName, page - 1)),
                                    tableModel.PagerRenderOptions ?? PagerRenderOptions.Default)
                            }
                        </div>
                    </div>
                </td>
            </tr>
        }

        static RouteValueDictionary CreatePagingRouteValues(HttpContext httpContext, string? formFieldName, int pageIndex)
        {
            var routeValues = new RouteValueDictionary();
            routeValues.Merge(httpContext.Request.Query);

            if (formFieldName != null)
            {
                routeValues[formFieldName] = pageIndex;
            }

            return routeValues;
        }
    }

    #endregion
}