tatlock-ui/lib/shared/components/data_grid/widgets/data_grid_header.dart

import 'package:flutter/material.dart';
import 'package:tatlock_ui/shared/components/data_grid/data_grid_column.dart';
import 'package:tatlock_ui/shared/components/data_grid/data_grid_config.dart';

/// Header row for DataGrid.
class DataGridHeader<T> extends StatelessWidget {
  const DataGridHeader({
    super.key,
    required this.config,
    required this.sortColumnIndex,
    required this.sortDescending,
    required this.onSort,
    this.showCheckbox = false,
    this.allSelected = false,
    this.someSelected = false,
    this.onSelectAll,
  });

  final DataGridConfig<T> config;
  final int? sortColumnIndex;
  final bool sortDescending;
  final void Function(int columnIndex) onSort;
  final bool showCheckbox;
  final bool allSelected;
  final bool someSelected;
  final VoidCallback? onSelectAll;

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;
    final columns = config.visibleColumns;

    return Container(
      height: config.headerHeight,
      decoration: BoxDecoration(
        color: colorScheme.surfaceContainerHighest,
        border: Border(
          bottom: BorderSide(color: colorScheme.outlineVariant),
        ),
      ),
      child: Row(
        children: [
          if (showCheckbox)
            SizedBox(
              width: 56,
              child: Center(
                child: Checkbox(
                  value: allSelected ? true : (someSelected ? null : false),
                  tristate: true,
                  onChanged: (_) => onSelectAll?.call(),
                ),
              ),
            ),
          ...columns.asMap().entries.map((entry) {
            final index = entry.key;
            final column = entry.value;
            final isSorted = sortColumnIndex == index;

            return _buildHeaderCell(
              context,
              column,
              index,
              isSorted,
              isSorted && sortDescending,
            );
          }),
          if (config.actions.isNotEmpty)
            const SizedBox(width: 56), // Space for actions column
        ],
      ),
    );
  }

  Widget _buildHeaderCell(
    BuildContext context,
    DataGridColumn<T> column,
    int index,
    bool isSorted,
    bool isDescending,
  ) {
    final colorScheme = Theme.of(context).colorScheme;
    final textStyle = Theme.of(context).textTheme.labelLarge?.copyWith(
          fontWeight: FontWeight.w600,
          color: colorScheme.onSurfaceVariant,
        );

    Widget content = Row(
      mainAxisSize: MainAxisSize.min,
      children: [
        Flexible(
          child: Text(
            column.header,
            style: textStyle,
            overflow: TextOverflow.ellipsis,
            textAlign: column.textAlign,
          ),
        ),
        if (column.sortable) ...[
          const SizedBox(width: 4),
          AnimatedRotation(
            turns: isDescending ? 0.5 : 0,
            duration: const Duration(milliseconds: 200),
            child: Icon(
              isSorted ? Icons.arrow_upward : Icons.unfold_more,
              size: 16,
              color: isSorted
                  ? colorScheme.primary
                  : colorScheme.onSurfaceVariant.withValues(alpha: 0.5),
            ),
          ),
        ],
      ],
    );

    if (column.sortable) {
      content = InkWell(
        onTap: () => onSort(index),
        child: Padding(
          padding: config.cellPadding,
          child: content,
        ),
      );
    } else {
      content = Padding(
        padding: config.cellPadding,
        child: content,
      );
    }

    return _wrapWithWidth(column.width, content);
  }

  Widget _wrapWithWidth(DataGridColumnWidth width, Widget child) {
    return switch (width) {
      GridFixedWidth(:final width) => SizedBox(width: width, child: child),
      GridFlexWidth(:final flex) => Expanded(flex: flex, child: child),
      GridFractionWidth(:final fraction) => FractionallySizedBox(
          widthFactor: fraction,
          child: child,
        ),
    };
  }
}