import 'package:flutter/material.dart';

/// 错误提示组件库 - 提供多种样式的错误状态显示
/// 包括网络错误、服务器错误、权限错误等不同场景的错误提示

/// 基础错误状态组件 - 通用的错误状态显示组件
/// [errorType] 错误类型，决定图标和颜色
/// [title] 错误标题文本
/// [message] 错误描述文本
/// [actionText] 操作按钮文本，null时不显示按钮
/// [onAction] 操作按钮点击回调，null时按钮不可点击
/// [iconSize] 图标大小，null时使用默认大小
/// [showDetails] 是否显示详细错误信息
/// [details] 详细错误信息，用于调试
class ErrorState extends StatelessWidget {
  /// 错误类型，决定图标和颜色
  final ErrorType errorType;

  /// 错误标题文本
  final String title;

  /// 错误描述文本
  final String? message;

  /// 操作按钮文本，null时不显示按钮
  final String? actionText;

  /// 操作按钮点击回调，null时按钮不可点击
  final VoidCallback? onAction;

  /// 图标大小，null时使用默认大小
  final double? iconSize;

  /// 自定义图标组件，优先级高于内置图标
  final Widget? customIcon;

  /// 自定义操作组件，优先级高于actionText参数
  final Widget? customAction;

  /// 主要内容垂直间距
  final double spacing;

  /// 主要内容内边距
  final EdgeInsetsGeometry? padding;

  /// 是否显示边框装饰
  final bool showBorder;

  /// 边框圆角半径
  final double borderRadius;

  /// 背景颜色，null时使用透明背景
  final Color? backgroundColor;

  /// 是否显示详细错误信息
  final bool showDetails;

  /// 详细错误信息，用于调试
  final String? details;

  const ErrorState({
    super.key,
    this.errorType = ErrorType.general,
    required this.title,
    this.message,
    this.actionText,
    this.onAction,
    this.iconSize,
    this.customIcon,
    this.customAction,
    this.spacing = 16,
    this.padding,
    this.showBorder = false,
    this.borderRadius = 12,
    this.backgroundColor,
    this.showDetails = false,
    this.details,
  });

  /// 创建网络错误状态 - 用于网络连接失败场景
  factory ErrorState.networkError({
    VoidCallback? onRetry,
    String? details,
    bool showDetails = false,
  }) {
    return ErrorState(
      errorType: ErrorType.network,
      title: '网络连接失败',
      message: '请检查网络连接后重试',
      actionText: '重新加载',
      onAction: onRetry,
      showDetails: showDetails,
      details: details,
    );
  }

  /// 创建服务器错误状态 - 用于服务器异常场景
  factory ErrorState.serverError({
    VoidCallback? onRetry,
    String? details,
    bool showDetails = false,
  }) {
    return ErrorState(
      errorType: ErrorType.server,
      title: '服务器异常',
      message: '服务器暂时无法访问，请稍后重试',
      actionText: '重新加载',
      onAction: onRetry,
      showDetails: showDetails,
      details: details,
    );
  }

  /// 创建权限错误状态 - 用于无权限访问场景
  factory ErrorState.permissionError({
    VoidCallback? onRequestPermission,
    String? details,
    bool showDetails = false,
  }) {
    return ErrorState(
      errorType: ErrorType.permission,
      title: '权限不足',
      message: '您没有访问此内容的权限',
      actionText: onRequestPermission != null ? '申请权限' : null,
      onAction: onRequestPermission,
      showDetails: showDetails,
      details: details,
    );
  }

  /// 创建数据错误状态 - 用于数据解析失败场景
  factory ErrorState.dataError({
    VoidCallback? onRetry,
    String? details,
    bool showDetails = false,
  }) {
    return ErrorState(
      errorType: ErrorType.data,
      title: '数据解析失败',
      message: '数据格式错误，无法正确解析',
      actionText: '重新加载',
      onAction: onRetry,
      showDetails: showDetails,
      details: details,
    );
  }

  /// 创建超时错误状态 - 用于请求超时场景
  factory ErrorState.timeoutError({
    VoidCallback? onRetry,
    String? details,
    bool showDetails = false,
  }) {
    return ErrorState(
      errorType: ErrorType.timeout,
      title: '请求超时',
      message: '请求时间过长，请重试',
      actionText: '重新加载',
      onAction: onRetry,
      showDetails: showDetails,
      details: details,
    );
  }

  /// 创建未找到错误状态 - 用于资源未找到场景
  factory ErrorState.notFoundError({
    VoidCallback? onGoBack,
    String? details,
    bool showDetails = false,
  }) {
    return ErrorState(
      errorType: ErrorType.notFound,
      title: '页面不存在',
      message: '您访问的内容可能已被删除或移动',
      actionText: onGoBack != null ? '返回' : null,
      onAction: onGoBack,
      showDetails: showDetails,
      details: details,
    );
  }

  /// 创建未知错误状态 - 用于未分类的错误场景
  factory ErrorState.unknownError({
    VoidCallback? onRetry,
    String? details,
    bool showDetails = false,
  }) {
    return ErrorState(
      errorType: ErrorType.unknown,
      title: '发生未知错误',
      message: '抱歉，发生了一些意外情况',
      actionText: '重新加载',
      onAction: onRetry,
      showDetails: showDetails,
      details: details,
    );
  }

  /// 获取错误类型对应的图标
  IconData _getErrorIcon() {
    switch (errorType) {
      case ErrorType.network:
        return Icons.wifi_off_outlined;
      case ErrorType.server:
        return Icons.cloud_off_outlined;
      case ErrorType.permission:
        return Icons.lock_outline;
      case ErrorType.data:
        return Icons.data_array_outlined;
      case ErrorType.timeout:
        return Icons.timer_off_outlined;
      case ErrorType.notFound:
        return Icons.search_off_outlined;
      case ErrorType.unknown:
      default:
        return Icons.error_outline;
    }
  }

  /// 获取错误类型对应的颜色
  Color _getErrorColor(BuildContext context) {
    final theme = Theme.of(context);
    switch (errorType) {
      case ErrorType.network:
        return Colors.orange;
      case ErrorType.server:
        return Colors.red;
      case ErrorType.permission:
        return Colors.orange;
      case ErrorType.data:
        return Colors.red;
      case ErrorType.timeout:
        return Colors.orange;
      case ErrorType.notFound:
        return Colors.grey;
      case ErrorType.unknown:
      default:
        return theme.colorScheme.error;
    }
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final errorColor = _getErrorColor(context);
    final errorIcon = _getErrorIcon();

    Widget content = Column(
      mainAxisSize: MainAxisSize.min,
      mainAxisAlignment: MainAxisAlignment.center,
      crossAxisAlignment: CrossAxisAlignment.center,
      children: [
        // 图标部分
        if (customIcon != null) ...[
          customIcon!,
          SizedBox(height: spacing),
        ] else ...[
          Icon(
            errorIcon,
            size: iconSize ?? 64,
            color: errorColor,
          ),
          SizedBox(height: spacing),
        ],

        // 标题部分
        Text(
          title,
          style: theme.textTheme.titleLarge?.copyWith(
            fontWeight: FontWeight.w600,
            color: errorColor,
          ),
          textAlign: TextAlign.center,
        ),

        // 描述文本部分
        if (message != null) ...[
          SizedBox(height: spacing * 0.5),
          Text(
            message!,
            style: theme.textTheme.bodyMedium?.copyWith(
              color: theme.colorScheme.onSurface.withOpacity(0.6),
            ),
            textAlign: TextAlign.center,
          ),
        ],

        // 详细错误信息部分
        if (showDetails && details != null) ...[
          SizedBox(height: spacing * 0.5),
          Container(
            padding: const EdgeInsets.all(12),
            decoration: BoxDecoration(
              color: errorColor.withOpacity(0.1),
              borderRadius: BorderRadius.circular(8),
              border: Border.all(
                color: errorColor.withOpacity(0.3),
                width: 1,
              ),
            ),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  '详细信息：',
                  style: theme.textTheme.bodySmall?.copyWith(
                    color: errorColor,
                    fontWeight: FontWeight.w600,
                  ),
                ),
                const SizedBox(height: 4),
                Text(
                  details!,
                  style: theme.textTheme.bodySmall?.copyWith(
                    color: theme.colorScheme.onSurface.withOpacity(0.7),
                  ),
                ),
              ],
            ),
          ),
        ],

        // 操作按钮部分
        if (customAction != null) ...[
          SizedBox(height: spacing * 1.5),
          customAction!,
        ] else if (actionText != null) ...[
          SizedBox(height: spacing * 1.5),
          ElevatedButton.icon(
            onPressed: onAction,
            icon: const Icon(Icons.refresh, size: 18),
            label: Text(actionText!),
            style: ElevatedButton.styleFrom(
              backgroundColor: errorColor,
              foregroundColor: Colors.white,
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(8),
              ),
            ),
          ),
        ],
      ],
    );

    // 添加内边距
    content = Padding(
      padding: padding ?? const EdgeInsets.all(24),
      child: content,
    );

    // 添加边框装饰
    if (showBorder) {
      content = Container(
        decoration: BoxDecoration(
          color: backgroundColor ?? errorColor.withOpacity(0.05),
          border: Border.all(
            color: errorColor.withOpacity(0.3),
            width: 1,
          ),
          borderRadius: BorderRadius.circular(borderRadius),
        ),
        child: content,
      );
    } else if (backgroundColor != null) {
      content = Container(
        decoration: BoxDecoration(
          color: backgroundColor,
          borderRadius: BorderRadius.circular(borderRadius),
        ),
        child: content,
      );
    }

    return content;
  }
}

/// 错误状态枚举 - 定义不同类型的错误
enum ErrorType {
  /// 一般错误 - 通用错误类型
  general,

  /// 网络错误 - 网络连接问题
  network,

  /// 服务器错误 - 服务端异常
  server,

  /// 权限错误 - 权限不足
  permission,

  /// 数据错误 - 数据解析或格式错误
  data,

  /// 超时错误 - 请求超时
  timeout,

  /// 未找到错误 - 资源不存在
  notFound,

  /// 未知错误 - 未分类的错误
  unknown,
}

/// 错误状态页面 - 全屏错误状态显示，包含图标、文本和操作按钮
/// [errorType] 错误类型
/// [title] 错误标题
/// [message] 错误描述
/// [actionText] 操作按钮文本
/// [onAction] 操作按钮点击回调
/// [showAppBar] 是否显示应用栏
/// [appBarTitle] 应用栏标题
/// [showDetails] 是否显示详细错误信息
/// [details] 详细错误信息
class ErrorStatePage extends StatelessWidget {
  /// 错误类型
  final ErrorType errorType;

  /// 错误标题
  final String title;

  /// 错误描述
  final String? message;

  /// 操作按钮文本
  final String? actionText;

  /// 操作按钮点击回调
  final VoidCallback? onAction;

  /// 是否显示应用栏
  final bool showAppBar;

  /// 应用栏标题
  final String? appBarTitle;

  /// 自定义错误状态组件，优先级高于其他参数
  final Widget? customErrorState;

  /// 背景颜色，null时使用主题背景色
  final Color? backgroundColor;

  /// 是否显示详细错误信息
  final bool showDetails;

  /// 详细错误信息，用于调试
  final String? details;

  const ErrorStatePage({
    super.key,
    this.errorType = ErrorType.general,
    required this.title,
    this.message,
    this.actionText,
    this.onAction,
    this.showAppBar = false,
    this.appBarTitle,
    this.customErrorState,
    this.backgroundColor,
    this.showDetails = false,
    this.details,
  });

  /// 创建网络错误状态页面
  factory ErrorStatePage.networkError({
    VoidCallback? onRetry,
    bool showAppBar = false,
    String? appBarTitle,
    String? details,
    bool showDetails = false,
  }) {
    return ErrorStatePage(
      errorType: ErrorType.network,
      title: '网络连接失败',
      message: '请检查网络连接后重试',
      actionText: '重新加载',
      onAction: onRetry,
      showAppBar: showAppBar,
      appBarTitle: appBarTitle ?? '网络错误',
      showDetails: showDetails,
      details: details,
    );
  }

  /// 创建服务器错误状态页面
  factory ErrorStatePage.serverError({
    VoidCallback? onRetry,
    bool showAppBar = false,
    String? appBarTitle,
    String? details,
    bool showDetails = false,
  }) {
    return ErrorStatePage(
      errorType: ErrorType.server,
      title: '服务器异常',
      message: '服务器暂时无法访问，请稍后重试',
      actionText: '重新加载',
      onAction: onRetry,
      showAppBar: showAppBar,
      appBarTitle: appBarTitle ?? '服务器错误',
      showDetails: showDetails,
      details: details,
    );
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    return Scaffold(
      backgroundColor: backgroundColor ?? theme.colorScheme.background,
      appBar: showAppBar
          ? AppBar(
              title: Text(appBarTitle ?? title),
              centerTitle: true,
            )
          : null,
      body: Center(
        child: SingleChildScrollView(
          padding: const EdgeInsets.all(24),
          child: customErrorState ?? ErrorState(
            errorType: errorType,
            title: title,
            message: message,
            actionText: actionText,
            onAction: onAction,
            showBorder: false,
            showDetails: showDetails,
            details: details,
          ),
        ),
      ),
    );
  }
}

/// 错误状态构建器 - 根据错误状态显示不同内容
/// [hasError] 是否有错误
/// [errorState] 错误状态组件
/// [child] 正常内容组件
class ErrorStateBuilder extends StatelessWidget {
  /// 是否有错误
  final bool hasError;

  /// 错误状态组件
  final Widget errorState;

  /// 正常内容组件
  final Widget child;

  const ErrorStateBuilder({
    super.key,
    required this.hasError,
    required this.errorState,
    required this.child,
  });

  @override
  Widget build(BuildContext context) {
    if (hasError) {
      return errorState;
    }
    return child;
  }
}

/// 错误状态包装器 - 简化版本，自动构建错误状态
/// [hasError] 是否有错误
/// [errorType] 错误类型
/// [title] 错误标题
/// [message] 错误描述
/// [actionText] 操作按钮文本
/// [onAction] 操作按钮点击回调
/// [child] 正常内容组件
/// [showDetails] 是否显示详细错误信息
/// [details] 详细错误信息
class ErrorStateWrapper extends StatelessWidget {
  /// 是否有错误
  final bool hasError;

  /// 错误类型
  final ErrorType errorType;

  /// 错误标题
  final String title;

  /// 错误描述
  final String? message;

  /// 操作按钮文本
  final String? actionText;

  /// 操作按钮点击回调
  final VoidCallback? onAction;

  /// 正常内容组件
  final Widget child;

  /// 自定义错误状态组件，优先级高于其他参数
  final Widget? customErrorState;

  /// 是否显示详细错误信息
  final bool showDetails;

  /// 详细错误信息
  final String? details;

  const ErrorStateWrapper({
    super.key,
    required this.hasError,
    this.errorType = ErrorType.general,
    required this.title,
    required this.child,
    this.message,
    this.actionText,
    this.onAction,
    this.customErrorState,
    this.showDetails = false,
    this.details,
  });

  @override
  Widget build(BuildContext context) {
    if (hasError) {
      return customErrorState ?? ErrorState(
        errorType: errorType,
        title: title,
        message: message,
        actionText: actionText,
        onAction: onAction,
        showDetails: showDetails,
        details: details,
      );
    }
    return child;
  }
}