namespace Terminal.Gui;

internal class FileDialogTableSource : ITableSource
{
    private readonly int currentSortColumn;
    private readonly bool currentSortIsAsc;
    private readonly FileDialog dlg;
    private readonly FileDialogState state;
    private readonly FileDialogStyle style;

    public FileDialogTableSource (
        FileDialog dlg,
        FileDialogState state,
        FileDialogStyle style,
        int currentSortColumn,
        bool currentSortIsAsc
    )
    {
        this.style = style;
        this.currentSortColumn = currentSortColumn;
        this.currentSortIsAsc = currentSortIsAsc;
        this.dlg = dlg;
        this.state = state;
    }

    public object this [int row, int col] => GetColumnValue (col, state.Children [row]);
    public int Rows => state.Children.Count ();
    public int Columns => 4;

    public string [] ColumnNames => new []
    {
        MaybeAddSortArrows (style.FilenameColumnName, 0),
        MaybeAddSortArrows (style.SizeColumnName, 1),
        MaybeAddSortArrows (style.ModifiedColumnName, 2),
        MaybeAddSortArrows (style.TypeColumnName, 3)
    };

    internal static object GetRawColumnValue (int col, FileSystemInfoStats stats)
    {
        switch (col)
        {
            case 0: return stats.FileSystemInfo.Name;
            case 1: return stats.MachineReadableLength;
            case 2: return stats.LastWriteTime;
            case 3: return stats.Type;
        }

        throw new ArgumentOutOfRangeException (nameof (col));
    }

    private object GetColumnValue (int col, FileSystemInfoStats stats)
    {
        switch (col)
        {
            case 0:
                // do not use icon for ".."
                if (stats?.IsParent ?? false)
                {
                    return stats.Name;
                }

                string icon = dlg.Style.IconProvider.GetIconWithOptionalSpace (stats.FileSystemInfo);

                return (icon + (stats?.Name ?? string.Empty)).Trim ();
            case 1:
                return stats?.HumanReadableLength ?? string.Empty;
            case 2:
                if (stats is null || stats.IsParent || stats.LastWriteTime is null)
                {
                    return string.Empty;
                }

                return stats.LastWriteTime.Value.ToString (style.DateFormat);
            case 3:
                return stats?.Type ?? string.Empty;
            default:
                throw new ArgumentOutOfRangeException (nameof (col));
        }
    }

    private string MaybeAddSortArrows (string name, int idx)
    {
        if (idx == currentSortColumn)
        {
            return name + (currentSortIsAsc ? " (▲)" : " (▼)");
        }

        return name;
    }
}