program MemoryGridExport;

// Atlas Virtual Grid quick start: an in-memory data source, a grid bound to it,
// sorting, filtering, totals, programmatic edits and CSV/HTML/SVG/PNG output.
// No window is shown; the grid works without a parent. Every result is checked.

{$APPTYPE CONSOLE}

uses
  Winapi.Windows, System.SysUtils, System.Classes, System.IOUtils, Atlas.VGridData, Atlas.VGrid;

procedure Verify(Condition: Boolean; const What: string);
begin
  if not Condition then raise Exception.Create('Check failed: ' + What);
  Writeln('  ok: ', What);
end;

function Rejected(const Action: TProc): Boolean;
begin
  Result := False;
  try
    Action();
  except
    on EAtlasGridError do Result := True;
  end;
end;

procedure Run;
var
  Orders: TAtlasMemoryData;
  Grid: TAtlasVirtualGrid;
  Csv, Html, Svg: string;
  Line: string;
begin
  Orders := TAtlasMemoryData.Create(nil);
  Grid := TAtlasVirtualGrid.Create(nil);
  try
    Writeln('1. Columns and rows');
    Orders.AddColumn('Order', ckNumber, True);       // read-only key
    Orders.AddColumn('Customer');                    // ckText by default
    Orders.AddColumn('Shipped', ckDateTime);
    Orders.AddColumn('Quantity', ckNumber);
    Orders.AddColumn('Unit price', ckNumber);
    Orders.AddColumn('Paid', ckBoolean);
    Orders.BeginUpdate;                              // one change notification for the batch
    try
      // One invariant text per column: '.' decimals, ISO dates, yes/no. Empty text is null.
      Orders.AddRow(['1001', 'Contoso', '2026-01-05', '4', '125.50', 'yes']);
      Orders.AddRow(['1002', 'Fabrikam', '2026-01-06', '12', '40', 'no']);
      Orders.AddRow(['1003', 'Northwind', '2026-01-09', '1', '980', 'yes']);
      Orders.AddRow(['1004', 'Contoso', '2026-01-12', '', '125.50', 'no']);
      Orders.AddRow(['1005', 'Tailspin, Ltd', '2026-01-15', '7', '64.25', 'yes']);
      Orders.AddRow(['1006', 'Fabrikam', '', '3', '40', 'yes']);
    finally
      Orders.EndUpdate;
    end;
    Verify((Orders.RowCount = 6) and (Orders.ColumnCount = 6), '6 rows, 6 columns');
    Verify(Rejected(procedure begin Orders.AddRow(['1007', 'Adatum', '2026-02-01', 'twelve', '10', 'no']); end)
      and (Orders.RowCount = 6), 'a row with a value that does not fit its column is rejected whole');

    Writeln('2. Bind the grid and describe the columns');
    Grid.Data := Orders;                             // one grid column per data column
    Grid.Columns[0].Format := '0';
    Grid.Columns[0].Total := tkCount;
    Grid.Columns[1].Band := 'Shipment';
    Grid.Columns[2].Band := 'Shipment';
    Grid.Columns[2].Format := 'yyyy-mm-dd';
    Grid.Columns[3].Band := 'Amount';
    Grid.Columns[3].Total := tkSum;
    Grid.Columns[4].Band := 'Amount';
    Grid.Columns[4].Format := '#,##0.00';
    Grid.Columns[4].Total := tkAverage;
    Verify(Grid.Columns.Count = 6, 'columns were created from the source');
    Verify((Grid.CellText(1, 4) = 'Tailspin, Ltd') and (Grid.CellText(4, 0) = '125.50') and
      (Grid.CellText(5, 1) = 'No') and (Grid.CellText(3, 3) = ''), 'cells are formatted per column');
    Verify((Grid.TotalText(0) = '6') and (Grid.TotalText(3) = '27') and (Grid.TotalText(4) = '229.21'),
      'totals: count 6, quantity sum 27, average price 229.21');

    Writeln('3. Sort');
    Grid.Sort(1);                                    // by customer, ascending, ignoring case
    Verify((Grid.CellText(1, 0) = 'Contoso') and (Grid.DataRowOf(0) = 0) and (Grid.DataRowOf(1) = 3) and
      (Grid.CellText(1, 5) = 'Tailspin, Ltd'), 'ascending by customer; equal keys keep source order');
    Grid.Sort(3, True);                              // by quantity, descending
    Verify((Grid.CellText(3, 0) = '12') and (Grid.DataRowOf(5) = 3), 'descending by quantity; the null quantity comes last');

    Writeln('4. Filter');
    Grid.FilterText := 'fab';                        // any visible column, formatted text, ignoring case
    Verify((Grid.RowCount = 2) and (Grid.DataRowOf(0) = 1) and (Grid.DataRowOf(1) = 5), '2 Fabrikam rows, still sorted');
    Verify((Grid.TotalText(0) = '2') and (Grid.TotalText(3) = '15') and (Grid.TotalText(4) = '40.00'), 'totals follow the filter');
    Grid.FilterText := '2026-01-0';
    Verify(Grid.RowCount = 3, 'the filter reads the formatted date text: 3 rows shipped before 10 January');
    Grid.FilterText := '';
    Grid.Sort(-1);                                   // back to source order
    Verify((Grid.RowCount = 6) and (Grid.SortColumn = -1), 'filter and sort removed');

    Writeln('5. Edit through the data source');
    Orders.SetText(3, 3, '5', TFormatSettings.Invariant);
    Verify((Grid.CellText(3, 3) = '5') and (Grid.TotalText(3) = '32'), 'the grid follows the source: sum is now 32');
    Verify(Rejected(procedure begin Orders.SetText(3, 3, 'five', TFormatSettings.Invariant); end) and
      (Grid.CellText(3, 3) = '5'), 'text that is not a number is refused and the value kept');
    Verify(Rejected(procedure begin Orders.SetCell(0, 0, TAtlasCell.OfNumber(1)); end), 'the read-only key column refuses writes');

    Writeln('6. Selection text');
    Grid.SelectAll;
    Line := Grid.SelectionText;
    Verify((Grid.SelectedCount = 6) and Line.StartsWith('1001'#9'Contoso'#9'2026-01-05'#9'4'#9'125.50'#9'Yes'#13#10),
      'tab-separated formatted rows, ready for the clipboard');

    Writeln('7. Text output');
    Csv := Grid.ToCSV;
    Writeln(Csv);
    Verify(Csv.StartsWith('Order,Customer,Shipped,Quantity,Unit price,Paid'#13#10'1001,Contoso,2026-01-05,4,125.5,true'),
      'CSV carries raw values: invariant numbers, ISO dates, true/false');
    Verify((Pos('"Tailspin, Ltd"', Csv) > 0) and (Pos('1006,Fabrikam,,3,40,true', Csv) > 0), 'commas are quoted; nulls are empty');
    Grid.Columns[5].Visible := False;
    Verify(Grid.ToCSV.StartsWith('Order,Customer,Shipped,Quantity,Unit price'#13#10), 'hidden columns are left out');
    Grid.Columns[5].Visible := True;
    Html := Grid.ToHTML('Orders');
    Verify((Pos('<caption>Orders</caption>', Html) > 0) and (Pos('<th colspan="2">Amount</th>', Html) > 0) and
      (Pos('<tfoot>', Html) > 0) and (Pos('>229.21<', Html) > 0), 'HTML has the caption, bands and totals');

    Writeln('8. Pictures and files');
    Grid.ClearSelection;                             // pictures show the selection too
    Svg := Grid.ToSVG(800, 300);
    Verify((Pos('<svg', Svg) > 0) and (Pos('Northwind', Svg) > 0), 'SVG of the visible part of the grid');
    Grid.SaveToFile('orders.csv');                   // everything
    Grid.SaveToFile('orders.html');                  // everything, formatted, with totals
    Grid.SaveToFile('orders.svg', 800, 300);         // what is on screen
    Grid.SaveToFile('orders.png', 800, 300);
    for Line in ['orders.csv', 'orders.html', 'orders.svg', 'orders.png'] do
      Verify(TFile.Exists(Line) and (TFile.GetSize(Line) > 100), Line + ' written to ' + TDirectory.GetCurrentDirectory);
    Verify(Rejected(procedure begin Grid.SaveToFile('orders.xlsx'); end), 'unknown extensions are refused');
  finally
    Grid.Free;
    Orders.Free;
  end;
end;

begin
  // Formatting follows the global FormatSettings; fix them so the checks hold on every machine.
  FormatSettings := TFormatSettings.Invariant;
  try
    Run;
    Writeln('MemoryGridExport: all checks passed');
  except
    on E: Exception do
    begin
      Writeln('MemoryGridExport failed: ', E.ClassName, ': ', E.Message);
      ExitCode := 1;
    end;
  end;
end.