rwadurian/frontend/mining-app/lib/presentation/widgets/shimmer_loading.dart

import 'package:flutter/material.dart';

/// 闪烁文字占位符 - 数据加载时显示闪烁的占位文字
class ShimmerText extends StatefulWidget {
  final String placeholder;
  final TextStyle? style;
  final TextAlign? textAlign;

  const ShimmerText({
    super.key,
    this.placeholder = '--',
    this.style,
    this.textAlign,
  });

  @override
  State<ShimmerText> createState() => _ShimmerTextState();
}

class _ShimmerTextState extends State<ShimmerText>
    with SingleTickerProviderStateMixin {
  late AnimationController _controller;
  late Animation<double> _animation;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      duration: const Duration(milliseconds: 800),
      vsync: this,
    )..repeat(reverse: true);
    _animation = Tween<double>(begin: 0.3, end: 1.0).animate(
      CurvedAnimation(parent: _controller, curve: Curves.easeInOut),
    );
  }

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

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _animation,
      builder: (context, child) {
        return Opacity(
          opacity: _animation.value,
          child: Text(
            widget.placeholder,
            style: widget.style,
            textAlign: widget.textAlign,
          ),
        );
      },
    );
  }
}

/// 数据文字组件 - 加载中显示闪烁占位符，加载完成显示真实数据
class DataText extends StatelessWidget {
  final String? data;
  final bool isLoading;
  final String placeholder;
  final TextStyle? style;
  final TextAlign? textAlign;
  final String Function(String)? formatter;

  const DataText({
    super.key,
    this.data,
    this.isLoading = false,
    this.placeholder = '--',
    this.style,
    this.textAlign,
    this.formatter,
  });

  @override
  Widget build(BuildContext context) {
    if (isLoading || data == null) {
      return ShimmerText(
        placeholder: placeholder,
        style: style,
        textAlign: textAlign,
      );
    }

    final displayText = formatter != null ? formatter!(data!) : data!;
    return Text(
      displayText,
      style: style,
      textAlign: textAlign,
    );
  }
}

/// 金额文字组件 - 专门用于显示金额
class AmountText extends StatelessWidget {
  final String? amount;
  final bool isLoading;
  final String prefix;
  final String suffix;
  final TextStyle? style;
  final TextAlign? textAlign;

  const AmountText({
    super.key,
    this.amount,
    this.isLoading = false,
    this.prefix = '',
    this.suffix = '',
    this.style,
    this.textAlign,
  });

  @override
  Widget build(BuildContext context) {
    if (isLoading || amount == null) {
      return ShimmerText(
        placeholder: '$prefix--$suffix',
        style: style,
        textAlign: textAlign,
      );
    }

    return Text(
      '$prefix$amount$suffix',
      style: style,
      textAlign: textAlign,
    );
  }
}

// ============================================================================
// 向后兼容的组件 - 用于尚未迁移的页面
// ============================================================================

/// 闪烁加载效果容器（向后兼容）
class ShimmerLoading extends StatefulWidget {
  final Widget child;

  const ShimmerLoading({super.key, required this.child});

  @override
  State<ShimmerLoading> createState() => _ShimmerLoadingState();
}

class _ShimmerLoadingState extends State<ShimmerLoading>
    with SingleTickerProviderStateMixin {
  late AnimationController _controller;
  late Animation<double> _animation;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      duration: const Duration(milliseconds: 1000),
      vsync: this,
    )..repeat(reverse: true);
    _animation = Tween<double>(begin: 0.4, end: 1.0).animate(
      CurvedAnimation(parent: _controller, curve: Curves.easeInOut),
    );
  }

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

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _animation,
      builder: (context, child) {
        return Opacity(
          opacity: _animation.value,
          child: widget.child,
        );
      },
    );
  }
}

/// 闪烁占位块（向后兼容）
class ShimmerBox extends StatelessWidget {
  final double? width;
  final double height;
  final BorderRadius? borderRadius;

  const ShimmerBox({
    super.key,
    this.width,
    this.height = 16,
    this.borderRadius,
  });

  @override
  Widget build(BuildContext context) {
    return Container(
      width: width,
      height: height,
      decoration: BoxDecoration(
        color: const Color(0xFFE5E7EB),
        borderRadius: borderRadius ?? BorderRadius.circular(4),
      ),
    );
  }
}

/// 页面骨架屏（向后兼容）
class PageSkeleton extends StatelessWidget {
  const PageSkeleton({super.key});

  @override
  Widget build(BuildContext context) {
    return ShimmerLoading(
      child: SingleChildScrollView(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const SizedBox(height: 60),
            const ShimmerBox(width: 120, height: 20),
            const SizedBox(height: 16),
            const ShimmerBox(height: 100),
            const SizedBox(height: 24),
            const ShimmerBox(height: 80),
            const SizedBox(height: 24),
            const ShimmerBox(height: 120),
            const SizedBox(height: 24),
            const ShimmerBox(height: 80),
          ],
        ),
      ),
    );
  }
}