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

import '../../../core/theme/app_colors.dart';

/// Vector shopping-cart illustration drawn in code.
///
/// Painting it avoids shipping a raster asset and keeps it crisp on 4K desktop
/// displays as well as tablet screens.
class WelcomeIllustration extends StatelessWidget {
  const WelcomeIllustration({super.key, this.size = 240});

  final double size;

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      width: size,
      height: size,
      child: CustomPaint(painter: _CartPainter()),
    )
        .animate(onPlay: (c) => c.repeat(reverse: true))
        .moveY(begin: 0, end: -8, duration: 2400.ms, curve: Curves.easeInOut);
  }
}

class _CartPainter extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    final w = size.width;
    final h = size.height;
    final unit = w / 100;

    // Soft backdrop disc.
    canvas.drawCircle(
      Offset(w * 0.5, h * 0.5),
      w * 0.46,
      Paint()..color = AppColors.primarySurface,
    );

    // Decorative arc.
    canvas.drawArc(
      Rect.fromCircle(center: Offset(w * 0.5, h * 0.5), radius: w * 0.46),
      -1.1,
      2.0,
      false,
      Paint()
        ..color = AppColors.primaryBorder
        ..style = PaintingStyle.stroke
        ..strokeWidth = unit * 1.6
        ..strokeCap = StrokeCap.round,
    );

    final stroke = Paint()
      ..color = AppColors.primary
      ..style = PaintingStyle.stroke
      ..strokeWidth = unit * 3
      ..strokeCap = StrokeCap.round
      ..strokeJoin = StrokeJoin.round;

    final fill = Paint()..color = AppColors.primary.withValues(alpha: 0.16);

    // Cart basket.
    final basket = Path()
      ..moveTo(w * 0.30, h * 0.36)
      ..lineTo(w * 0.78, h * 0.36)
      ..lineTo(w * 0.70, h * 0.60)
      ..lineTo(w * 0.37, h * 0.60)
      ..close();
    canvas.drawPath(basket, fill);
    canvas.drawPath(basket, stroke);

    // Handle running to the push bar.
    canvas.drawPath(
      Path()
        ..moveTo(w * 0.16, h * 0.26)
        ..lineTo(w * 0.24, h * 0.26)
        ..lineTo(w * 0.30, h * 0.36),
      stroke,
    );

    // Basket ribs.
    for (var i = 1; i <= 2; i++) {
      final t = i / 3;
      canvas.drawLine(
        Offset(w * (0.30 + 0.48 * t), h * 0.36),
        Offset(w * (0.37 + 0.33 * t), h * 0.60),
        stroke..strokeWidth = unit * 1.6,
      );
    }
    stroke.strokeWidth = unit * 3;

    // Wheels.
    for (final dx in [0.44, 0.66]) {
      canvas.drawCircle(
        Offset(w * dx, h * 0.70),
        unit * 5,
        Paint()..color = AppColors.surface,
      );
      canvas.drawCircle(Offset(w * dx, h * 0.70), unit * 5, stroke);
    }

    // Groceries poking out of the basket.
    _item(canvas, Offset(w * 0.42, h * 0.30), unit * 5.5,
        AppColors.tierGold.withValues(alpha: 0.9));
    _item(canvas, Offset(w * 0.55, h * 0.27), unit * 6.5,
        AppColors.success.withValues(alpha: 0.85));
    _item(canvas, Offset(w * 0.67, h * 0.31), unit * 5,
        AppColors.danger.withValues(alpha: 0.75));

    // Receipt tape drifting away from the terminal.
    final receipt = Path()
      ..moveTo(w * 0.80, h * 0.20)
      ..lineTo(w * 0.94, h * 0.20)
      ..lineTo(w * 0.94, h * 0.44)
      ..lineTo(w * 0.905, h * 0.40)
      ..lineTo(w * 0.87, h * 0.44)
      ..lineTo(w * 0.835, h * 0.40)
      ..lineTo(w * 0.80, h * 0.44)
      ..close();
    canvas.drawPath(receipt, Paint()..color = AppColors.surface);
    canvas.drawPath(
      receipt,
      Paint()
        ..color = AppColors.primaryLight
        ..style = PaintingStyle.stroke
        ..strokeWidth = unit * 1.4
        ..strokeJoin = StrokeJoin.round,
    );

    // Receipt lines.
    final line = Paint()
      ..color = AppColors.primaryBorder
      ..strokeWidth = unit * 1.2
      ..strokeCap = StrokeCap.round;
    for (var i = 0; i < 3; i++) {
      final y = h * (0.25 + i * 0.05);
      canvas.drawLine(Offset(w * 0.835, y), Offset(w * 0.905, y), line);
    }
  }

  void _item(Canvas canvas, Offset center, double radius, Color color) {
    canvas.drawCircle(center, radius, Paint()..color = color);
    canvas.drawCircle(
      center,
      radius,
      Paint()
        ..color = Colors.white.withValues(alpha: 0.5)
        ..style = PaintingStyle.stroke
        ..strokeWidth = 1.5,
    );
  }

  @override
  bool shouldRepaint(covariant CustomPainter oldDelegate) => false;
}