export interface ApiError {
  message: string;
  code?: string;
  statusCode?: number;
  originalError?: Error;
}

export class ConfigLoadError extends Error {
  code: 'INVALID_URL' | 'STORAGE_ERROR' | 'NETWORK_ERROR' | 'UNKNOWN_ERROR';
  originalError?: Error;

  constructor(message: string, code: ConfigLoadError['code'] = 'UNKNOWN_ERROR', originalError?: Error) {
    super(message);
    this.name = 'ConfigLoadError';
    this.code = code;
    this.originalError = originalError;
  }
}

export const parseApiError = async (response: Response): Promise<string> => {
  try {
    // 优先尝试解析为 JSON
    const errorData = await response.clone().json();
    return errorData.message || JSON.stringify(errorData) || response.statusText;
  } catch (e) {
    try {
      // 如果不是 JSON，尝试解析为文本
      const text = await response.clone().text();
      if (text) {
        // 检查是否为 XML
        if (text.trim().startsWith('<')) {
          // 简单提取 <Message> 或 <Error> 标签内容
          const match = text.match(/<Message>(.*?)<\/Message>/i) || text.match(/<Error>(.*?)<\/Error>/i);
          return match ? match[1] : text;
        }
        return text;
      }
    } catch (e2) {
      // 保持原有 statusText
    }
  }
  return response.statusText;
};

export const handleConfigError = (error: unknown, context: string): ConfigLoadError => {
  if (error instanceof ConfigLoadError) {
    return error;
  }

  if (error instanceof Error) {
    if (error.message.includes('Invalid URL')) {
      return new ConfigLoadError(`Invalid URL in ${context}: ${error.message}`, 'INVALID_URL', error);
    }
    if (error.message.includes('localStorage') || error.message.includes('storage')) {
      return new ConfigLoadError(`Storage error in ${context}: ${error.message}`, 'STORAGE_ERROR', error);
    }
    if (error.message.includes('fetch') || error.message.includes('network')) {
      return new ConfigLoadError(`Network error in ${context}: ${error.message}`, 'NETWORK_ERROR', error);
    }
  }

  return new ConfigLoadError(
    `Unknown error in ${context}: ${error}`,
    'UNKNOWN_ERROR',
    error instanceof Error ? error : new Error(String(error))
  );
};