import 'package:flutter/material.dart';
import 'package:flutter_drawing_board/flutter_drawing_board.dart';

import 'pdf_page_display.dart';

/// Drawing overlay for annotating PDF pages.
///
/// Uses flutter_drawing_board to provide a paint canvas over the PDF.
/// Only working in single-page mode.
class PaintModeLayer extends StatelessWidget {
  final PdfPageDisplay pageDisplay;
  final DrawingController drawingController;

  const PaintModeLayer({
    super.key,
    required this.pageDisplay,
    required this.drawingController,
  });

  @override
  Widget build(BuildContext context) {
    return SizedBox.expand(
      child: LayoutBuilder(
        builder: (context, constraints) {
          final maxSize = Size(constraints.maxWidth, constraints.maxHeight);
          final (pageSize, _) = pageDisplay.calculateScaledPageSizes(maxSize);

          return DrawingBoard(
            controller: drawingController,
            background: SizedBox(
              width: pageSize.width,
              height: pageSize.height,
              child: pageDisplay,
            ),
            boardConstrained: true,
            minScale: 1,
            maxScale: 3,
            alignment: Alignment.topRight,
            boardBoundaryMargin: EdgeInsets.zero,
          );
        },
      ),
    );
  }
}