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

/// 全局 iOS 风格顶部浮动 Toast
/// 用法: AppToast.show(context, '提示内容');
///       AppToast.show(context, '出错了', isError: true);
class AppToast {
  static OverlayEntry? _currentEntry;

  /// 显示 toast，自动消失
  static void show(
    BuildContext context,
    String message, {
    bool isError = false,
  }) {
    // 如果已有 toast，先移除
    _currentEntry?.remove();
    _currentEntry = null;

    final overlay = Overlay.of(context);
    late OverlayEntry entry;

    entry = OverlayEntry(
      builder: (context) => _IOSToastWidget(
        message: message,
        isError: isError,
        onDismiss: () {
          entry.remove();
          if (_currentEntry == entry) _currentEntry = null;
        },
      ),
    );

    _currentEntry = entry;
    overlay.insert(entry);
  }
}

class _IOSToastWidget extends StatefulWidget {
  final String message;
  final bool isError;
  final VoidCallback onDismiss;

  const _IOSToastWidget({
    required this.message,
    required this.isError,
    required this.onDismiss,
  });

  @override
  State<_IOSToastWidget> createState() => _IOSToastWidgetState();
}

class _IOSToastWidgetState extends State<_IOSToastWidget>
    with SingleTickerProviderStateMixin {
  late AnimationController _controller;
  late Animation<double> _slideAnimation;
  late Animation<double> _fadeAnimation;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      duration: const Duration(milliseconds: 350),
      reverseDuration: const Duration(milliseconds: 250),
      vsync: this,
    );

    _slideAnimation = Tween<double>(begin: -1.0, end: 0.0).animate(
      CurvedAnimation(parent: _controller, curve: Curves.easeOutCubic),
    );
    _fadeAnimation = Tween<double>(begin: 0.0, end: 1.0).animate(
      CurvedAnimation(parent: _controller, curve: Curves.easeOut),
    );

    _controller.forward();

    // Auto dismiss after 2.5s
    Future.delayed(const Duration(milliseconds: 2500), () {
      if (mounted) {
        _controller.reverse().then((_) {
          if (mounted) widget.onDismiss();
        });
      }
    });
  }

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

  @override
  Widget build(BuildContext context) {
    final topPadding = MediaQuery.of(context).padding.top;

    return Positioned(
      top: topPadding + 12,
      left: 24,
      right: 24,
      child: AnimatedBuilder(
        animation: _controller,
        builder: (context, child) {
          return Transform.translate(
            offset: Offset(0, _slideAnimation.value * 60),
            child: Opacity(
              opacity: _fadeAnimation.value,
              child: child,
            ),
          );
        },
        child: Center(
          child: ClipRRect(
            borderRadius: BorderRadius.circular(16),
            child: BackdropFilter(
              filter: ImageFilter.blur(sigmaX: 20, sigmaY: 20),
              child: Container(
                padding:
                    const EdgeInsets.symmetric(horizontal: 20, vertical: 14),
                decoration: BoxDecoration(
                  color: widget.isError
                      ? const Color(0xFFFEF2F2).withOpacity(0.85)
                      : Colors.white.withOpacity(0.85),
                  borderRadius: BorderRadius.circular(16),
                  border: Border.all(
                    color: widget.isError
                        ? const Color(0xFFFCA5A5).withOpacity(0.4)
                        : Colors.white.withOpacity(0.6),
                  ),
                  boxShadow: [
                    BoxShadow(
                      color: Colors.black.withOpacity(0.08),
                      offset: const Offset(0, 4),
                      blurRadius: 20,
                    ),
                  ],
                ),
                child: DefaultTextStyle(
                  style: const TextStyle(decoration: TextDecoration.none),
                  child: Row(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      Icon(
                        widget.isError
                            ? Icons.info_outline_rounded
                            : Icons.check_circle_outline_rounded,
                        size: 20,
                        color: widget.isError
                            ? const Color(0xFFEF4444)
                            : const Color(0xFF22C55E),
                      ),
                      const SizedBox(width: 10),
                      Flexible(
                        child: Text(
                          widget.message,
                          style: TextStyle(
                            fontSize: 14,
                            fontWeight: FontWeight.w500,
                            color: widget.isError
                                ? const Color(0xFFDC2626)
                                : const Color(0xFF374151),
                          ),
                        ),
                      ),
                    ],
                  ),
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}