import 'dart:math' as math;

import 'package:flutter/material.dart';

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

/// انیمیشنِ «پروازِ سکه‌ها به کیف‌پول»: چند سکه از مبدأ (مثلاً کارتِ هدیه) روی یک
/// قوس به سمتِ مقصد (چیپِ سکه) پرواز می‌کنند. با Overlay نمایش داده می‌شود.
class CoinFly {
  static void play(
    BuildContext context, {
    required Offset from,
    required Offset to,
    int count = 9,
  }) {
    final overlay = Overlay.maybeOf(context, rootOverlay: true);
    if (overlay == null) return;
    late OverlayEntry entry;
    entry = OverlayEntry(
      builder: (_) => _CoinFlyOverlay(
        from: from,
        to: to,
        count: count,
        onDone: () => entry.remove(),
      ),
    );
    overlay.insert(entry);
  }
}

class _CoinFlyOverlay extends StatefulWidget {
  final Offset from, to;
  final int count;
  final VoidCallback onDone;
  const _CoinFlyOverlay({
    required this.from,
    required this.to,
    required this.count,
    required this.onDone,
  });

  @override
  State<_CoinFlyOverlay> createState() => _CoinFlyOverlayState();
}

class _CoinFlyOverlayState extends State<_CoinFlyOverlay>
    with SingleTickerProviderStateMixin {
  late final AnimationController _c;
  late final List<_Coin> _coins;

  @override
  void initState() {
    super.initState();
    final r = math.Random();
    _coins = List.generate(widget.count, (_) {
      return _Coin(
        jitter: Offset((r.nextDouble() - 0.5) * 46, (r.nextDouble() - 0.5) * 46),
        delay: r.nextDouble() * 0.28,
        arc: -60 - r.nextDouble() * 90, // ارتفاعِ قوس (به بالا)
        size: 16 + r.nextDouble() * 8,
      );
    });
    _c = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 950),
    )
      ..addStatusListener((s) {
        if (s == AnimationStatus.completed) widget.onDone();
      })
      ..forward();
  }

  @override
  void dispose() {
    _c.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return IgnorePointer(
      child: AnimatedBuilder(
        animation: _c,
        builder: (_, __) {
          return Stack(
            children: [
              for (final coin in _coins) _buildCoin(coin),
            ],
          );
        },
      ),
    );
  }

  Widget _buildCoin(_Coin coin) {
    final local = ((_c.value - coin.delay) / (1 - coin.delay)).clamp(0.0, 1.0);
    if (local <= 0) return const SizedBox.shrink();
    final start = widget.from + coin.jitter;
    final end = widget.to;
    // قوسِ درجه‌دو: نقطه‌ی کنترل بالای میانه.
    final mid = Offset((start.dx + end.dx) / 2, (start.dy + end.dy) / 2 + coin.arc);
    final t = Curves.easeInCubic.transform(local);
    final p = _quad(start, mid, end, t);
    final opacity = local < 0.85 ? 1.0 : (1 - (local - 0.85) / 0.15);
    final scale = 1.0 - 0.35 * local;
    return Positioned(
      left: p.dx - coin.size / 2,
      top: p.dy - coin.size / 2,
      child: Opacity(
        opacity: opacity.clamp(0.0, 1.0),
        child: Transform.scale(
          scale: scale,
          child: Icon(Icons.monetization_on,
              color: AppColors.gold, size: coin.size),
        ),
      ),
    );
  }

  Offset _quad(Offset a, Offset b, Offset c, double t) {
    final u = 1 - t;
    return a * (u * u) + b * (2 * u * t) + c * (t * t);
  }
}

class _Coin {
  final Offset jitter;
  final double delay, arc, size;
  _Coin({
    required this.jitter,
    required this.delay,
    required this.arc,
    required this.size,
  });
}