impact/lib/features/crop/widgets/crop_overlay.dart

/// Overlay visuel pour le recadrage d'image.
///
/// Affiche un masque semi-transparent avec une zone carrée transparente
/// au centre pour indiquer la zone de recadrage.
library;

import 'package:flutter/material.dart';

class CropOverlay extends StatelessWidget {
  /// Taille du carré de recadrage (côté en pixels)
  final double cropSize;

  /// Afficher la grille des tiers
  final bool showGrid;

  const CropOverlay({
    super.key,
    required this.cropSize,
    this.showGrid = true,
  });

  @override
  Widget build(BuildContext context) {
    return CustomPaint(
      size: Size.infinite,
      painter: _CropOverlayPainter(
        cropSize: cropSize,
        showGrid: showGrid,
      ),
    );
  }
}

class _CropOverlayPainter extends CustomPainter {
  final double cropSize;
  final bool showGrid;

  _CropOverlayPainter({
    required this.cropSize,
    required this.showGrid,
  });

  @override
  void paint(Canvas canvas, Size size) {
    // Calculer la position du carré centré
    final cropRect = Rect.fromCenter(
      center: Offset(size.width / 2, size.height / 2),
      width: cropSize,
      height: cropSize,
    );

    // Dessiner le masque semi-transparent
    final maskPaint = Paint()
      ..color = Colors.black.withValues(alpha: 0.6)
      ..style = PaintingStyle.fill;

    // Créer un path pour le masque (tout sauf le carré central)
    final maskPath = Path()
      ..addRect(Rect.fromLTWH(0, 0, size.width, size.height))
      ..addRect(cropRect)
      ..fillType = PathFillType.evenOdd;

    canvas.drawPath(maskPath, maskPaint);

    // Dessiner la bordure du carré de recadrage
    final borderPaint = Paint()
      ..color = Colors.white
      ..style = PaintingStyle.stroke
      ..strokeWidth = 2;

    canvas.drawRect(cropRect, borderPaint);

    // Dessiner les coins accentués
    _drawCorners(canvas, cropRect);

    // Dessiner la grille des tiers si activée
    if (showGrid) {
      _drawGrid(canvas, cropRect);
    }
  }

  void _drawCorners(Canvas canvas, Rect rect) {
    final cornerPaint = Paint()
      ..color = Colors.white
      ..style = PaintingStyle.stroke
      ..strokeWidth = 4
      ..strokeCap = StrokeCap.round;

    const cornerLength = 20.0;

    // Coin supérieur gauche
    canvas.drawLine(
      Offset(rect.left, rect.top + cornerLength),
      Offset(rect.left, rect.top),
      cornerPaint,
    );
    canvas.drawLine(
      Offset(rect.left, rect.top),
      Offset(rect.left + cornerLength, rect.top),
      cornerPaint,
    );

    // Coin supérieur droit
    canvas.drawLine(
      Offset(rect.right - cornerLength, rect.top),
      Offset(rect.right, rect.top),
      cornerPaint,
    );
    canvas.drawLine(
      Offset(rect.right, rect.top),
      Offset(rect.right, rect.top + cornerLength),
      cornerPaint,
    );

    // Coin inférieur gauche
    canvas.drawLine(
      Offset(rect.left, rect.bottom - cornerLength),
      Offset(rect.left, rect.bottom),
      cornerPaint,
    );
    canvas.drawLine(
      Offset(rect.left, rect.bottom),
      Offset(rect.left + cornerLength, rect.bottom),
      cornerPaint,
    );

    // Coin inférieur droit
    canvas.drawLine(
      Offset(rect.right - cornerLength, rect.bottom),
      Offset(rect.right, rect.bottom),
      cornerPaint,
    );
    canvas.drawLine(
      Offset(rect.right, rect.bottom),
      Offset(rect.right, rect.bottom - cornerLength),
      cornerPaint,
    );
  }

  void _drawGrid(Canvas canvas, Rect rect) {
    final gridPaint = Paint()
      ..color = Colors.white.withValues(alpha: 0.4)
      ..style = PaintingStyle.stroke
      ..strokeWidth = 1;

    final thirdWidth = rect.width / 3;
    final thirdHeight = rect.height / 3;

    // Lignes verticales
    canvas.drawLine(
      Offset(rect.left + thirdWidth, rect.top),
      Offset(rect.left + thirdWidth, rect.bottom),
      gridPaint,
    );
    canvas.drawLine(
      Offset(rect.left + thirdWidth * 2, rect.top),
      Offset(rect.left + thirdWidth * 2, rect.bottom),
      gridPaint,
    );

    // Lignes horizontales
    canvas.drawLine(
      Offset(rect.left, rect.top + thirdHeight),
      Offset(rect.right, rect.top + thirdHeight),
      gridPaint,
    );
    canvas.drawLine(
      Offset(rect.left, rect.top + thirdHeight * 2),
      Offset(rect.right, rect.top + thirdHeight * 2),
      gridPaint,
    );
  }

  @override
  bool shouldRepaint(covariant _CropOverlayPainter oldDelegate) {
    return cropSize != oldDelegate.cropSize || showGrid != oldDelegate.showGrid;
  }
}