monisuo/flutter_monisuo/lib/ui/components/coin_icon.dart

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

/// 数字货币图标组件
///
/// 支持离线 SVG 图标和兜底显示
class CoinIcon extends StatelessWidget {
  final String symbol; // 币种代码，如 'BTC', 'ETH'
  final double size; // 图标大小，默认 40
  final bool isCircle; // 是否圆形背景，默认 false

  const CoinIcon({
    super.key,
    required this.symbol,
    this.size = 40,
    this.isCircle = false,
  });

  // 币种代码到文件名的映射
  static const Map<String, String> _coinFileMap = {
    'BTC': 'btc',
    'ETH': 'eth',
    'USDT': 'usdt',
    'BNB': 'bnb',
    'SOL': 'sol',
    'XRP': 'xrp',
    'ADA': 'ada',
    'DOGE': 'doge',
    'DOT': 'dot',
    'MATIC': 'matic',
    'SHIB': 'shib',
    'LTC': 'ltc',
    'AVAX': 'avax',
    'LINK': 'link',
    'UNI': 'uni',
    'ATOM': 'atom',
  };

  @override
  Widget build(BuildContext context) {
    final normalizedSymbol = symbol.toUpperCase();
    final fileName = _coinFileMap[normalizedSymbol];

    Widget icon;

    if (fileName != null) {
      icon = SvgPicture.asset(
        'assets/icons/crypto/$fileName.svg',
        width: size,
        height: size,
        fit: BoxFit.contain,
        placeholderBuilder: (context) => _buildFallback(context, normalizedSymbol),
      );
    } else {
      icon = _buildFallback(context, normalizedSymbol);
    }

    if (isCircle) {
      return Container(
        width: size,
        height: size,
        decoration: BoxDecoration(
          shape: BoxShape.circle,
          color: Theme.of(context).colorScheme.surfaceContainerHigh,
        ),
        child: Center(child: icon),
      );
    }

    return icon;
  }

  /// 构建兜底UI（显示币种代码）
  Widget _buildFallback(BuildContext context, String symbol) {
    return Container(
      width: size,
      height: size,
      decoration: BoxDecoration(
        shape: BoxShape.circle,
        gradient: LinearGradient(
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
          colors: [
            Theme.of(context).colorScheme.primary,
            Theme.of(context).colorScheme.secondary,
          ],
        ),
      ),
      child: Center(
        child: Text(
          symbol.length > 3 ? symbol.substring(0, 3) : symbol,
          style: TextStyle(
            color: Colors.white,
            fontSize: size * 0.35,
            fontWeight: FontWeight.bold,
          ),
        ),
      ),
    );
  }
}