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

**อธิบายทีละบรรทัด (Imports):**

- `import 'dart:math'`
  - Library คณิตศาสตร์ (Random, Sin, Cos) ใช้สำหรับการสุ่มตำแหน่งจุด หรือคำนวณกราฟิก

**อธิบาย:**

enum PatternType { dots, lines, cross }

class PatternPainter extends CustomPainter {
  final Color color;
  final PatternType type;

  PatternPainter({
    required this.color, 
    this.type = PatternType.lines
  });

  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()
      ..color = color.withOpacity(0.1)
      ..strokeWidth = 2
      ..style = PaintingStyle.stroke;

    switch (type) {
      case PatternType.lines:
        _drawLines(canvas, size, paint);
        break;
      case PatternType.dots:
        _drawDots(canvas, size, paint);
        break;
      case PatternType.cross:
        _drawCross(canvas, size, paint);
        break;
    }
  }

  void _drawLines(Canvas canvas, Size size, Paint paint) {
    // วาดเส้นทแยงมุมห่างกันทีละ 20px
    for (double i = -size.height; i < size.width; i += 20) {
      canvas.drawLine(
        Offset(i, 0),
        Offset(i + size.height, size.height),
        paint,
      );
    }
  }

  void _drawDots(Canvas canvas, Size size, Paint paint) {
    paint.style = PaintingStyle.fill;
    final step = 30.0;
    for (double x = 0; x < size.width; x += step) {
      for (double y = 0; y < size.height; y += step) {
        canvas.drawCircle(Offset(x, y), 2, paint);
      }
    }
  }

  void _drawCross(Canvas canvas, Size size, Paint paint) {
    // ... logic วาดกากบาท
  }

  @override
  bool shouldRepaint(covariant PatternPainter oldDelegate) {
    // repaint เมื่อสีเปลี่ยน หรือแบบเปลี่ยน
    return color != oldDelegate.color || type != oldDelegate.type;
  }
}

class AspectRatioSelector extends StatelessWidget {
  final Function(double) onSelected;
  final double currentRatio;

  const AspectRatioSelector({
    required this.onSelected, 
    required this.currentRatio
  });

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        _RatioButton(label: "IG Post", ratio: 1.0, current: currentRatio, onTap: onSelected),
        _RatioButton(label: "Portrait", ratio: 4/5, current: currentRatio, onTap: onSelected),
        _RatioButton(label: "Story", ratio: 9/16, current: currentRatio, onTap: onSelected),
      ],
    );
  }
}

class _RatioButton extends StatelessWidget {
  // ... implementation ปุ่มกดง่ายๆ
}

RepaintBoundary(
  key: globalKey,
  child: AspectRatio(
    aspectRatio: currentRatio,
    child: Stack(
      children: [
        // 1. Background (สี/รูป/Pattern)
        Container(color: bgColor),
        CustomPaint(painter: PatternPainter(...)),

        // 2. Quote (ตรงกลาง)
        Center(child: Text(quote)),

        // 3. Watermark (มุมขวาล่าง)
        Positioned(
          bottom: 16,
          right: 16,
          child: Row(
            children: [
              Icon(Icons.auto_awesome, size: 16, color: Colors.white54),
              SizedBox(width: 4),
              Text(
                "Via QUOM App",
                style: TextStyle(
                  color: Colors.white54,
                  fontWeight: FontWeight.bold,
                  fontSize: 12,
                ),
              ),
            ],
          ),
        ),
      ],
    ),
  ),
)

import 'package:flutter/services.dart';

void _copyToClipboard(BuildContext context, String text) {
  // ก๊อปปี้ลง Clipboard
  Clipboard.setData(ClipboardData(text: text));
  
  // แจ้งเตือน
  ScaffoldMessenger.of(context).showSnackBar(
    SnackBar(
      content: Text('คัดลอกข้อความแล้ว'),
      duration: Duration(seconds: 1),
    ),
  );
}