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

/// 圆形头像组件
class CircleAvatarWidget extends StatelessWidget {
  /// 本地图片
  final ImageProvider? image;

  /// 网络图片URL
  final String? imageUrl;

  /// 加载失败时的占位图
  final ImageProvider? placeholderImage;

  /// 头像大小
  final double size;

  /// 边框颜色
  final Color borderColor;

  /// 边框宽度
  final double borderWidth;

  /// 背景颜色
  final Color backgroundColor;

  /// 加载时的渐变时长
  final Duration fadeInDuration;

  /// 加载中的占位
  final PlaceholderWidgetBuilder? placeholder;

  const CircleAvatarWidget({
    super.key,
    this.image,
    this.imageUrl,
    this.placeholderImage,
    this.size = 40.0,
    this.borderColor = Colors.white,
    this.borderWidth = 2.0,
    this.backgroundColor = const Color(0xFFEEEEEE),
    this.fadeInDuration = const Duration(milliseconds: 500),
    this.placeholder,
  });

  @override
  Widget build(BuildContext context) {
    return Container(
      width: size,
      height: size,
      decoration: BoxDecoration(
        shape: BoxShape.circle,
        border: Border.all(color: borderColor, width: borderWidth),
      ),
      // 裁切圆形
      child: ClipOval(child: _buildContent()),
    );
  }

  /// 构建头像内容
  Widget _buildContent() {
    // 优先使用网络图片
    if (imageUrl != null && imageUrl!.isNotEmpty) {
      return CachedNetworkImage(
        imageUrl: imageUrl!,
        width: size,
        height: size,
        fit: BoxFit.cover,
        fadeInDuration: fadeInDuration,
        placeholder: placeholder ?? _buildLoadingPlaceholder,
        errorWidget: (_, __, ___) => _buildPlaceholder(), // 错误时显示占位
      );
    }
    // 没有，再使用本地图片
    else if (image != null) {
      return Image(
        image: image!,
        width: size,
        height: size,
        fit: BoxFit.cover,
        errorBuilder: (_, __, ___) => _buildPlaceholder(),
      );
    }
    // 无图片状态
    else {
      return _buildPlaceholder();
    }
  }

  /// 加载中占位
  Widget _buildLoadingPlaceholder(BuildContext context, String url) {
    return Container(
      color: Colors.grey[200],
      alignment: Alignment.center,
      child: const CircularProgressIndicator(strokeWidth: 2),
    );
  }

  /// 错误/默认的占位组件
  Widget _buildPlaceholder() {
    // 优先使用自定义占位图
    if (placeholderImage != null) {
      return Image(
        image: placeholderImage!,
        width: size,
        height: size,
        fit: BoxFit.cover,
        // 占位图加载失败时，显示一个纯色背景
        errorBuilder: (_, __, ___) => _buildDefaultPlaceholder(),
      );
    }

    // 默认占位
    return _buildDefaultPlaceholder();
  }

  /// 占位图加载失败时，显示一个纯色背景
  Widget _buildDefaultPlaceholder() {
    return Container(color: backgroundColor, width: size, height: size);
  }
}