/**
 * 格式化时间
 * @param dateString - ISO 时间字符串
 * @returns 格式化后的时间字符串
 */
export const formatTime = (dateString: string): string => {
  if (!dateString) return '';
  
  const date = new Date(dateString);
  const now = new Date();
  const diffInSeconds = Math.floor((now.getTime() - date.getTime()) / 1000);
  
  if (diffInSeconds < 60) {
    return '刚刚';
  } else if (diffInSeconds < 3600) {
    const minutes = Math.floor(diffInSeconds / 60);
    return `${minutes}分钟前`;
  } else if (diffInSeconds < 86400) {
    const hours = Math.floor(diffInSeconds / 3600);
    return `${hours}小时前`;
  } else if (diffInSeconds < 604800) {
    const days = Math.floor(diffInSeconds / 86400);
    return `${days}天前`;
  } else {
    return date.toLocaleDateString('zh-CN', {
      year: 'numeric',
      month: '2-digit',
      day: '2-digit',
      hour: '2-digit',
      minute: '2-digit'
    });
  }
};

/**
 * 格式化货币
 * @param amount - 金额
 * @returns 格式化后的货币字符串
 */
export const formatCurrency = (amount: number): string => {
  return new Intl.NumberFormat('zh-CN', {
    style: 'currency',
    currency: 'CNY'
  }).format(amount);
};

/**
 * 格式化文件大小
 * @param bytes - 字节数
 * @returns 格式化后的文件大小字符串
 */
export const formatFileSize = (bytes: number): string => {
  if (bytes === 0) return '0 Bytes';
  
  const k = 1024;
  const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
  const i = Math.floor(Math.log(bytes) / Math.log(k));
  
  return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
};

/**
 * 生成随机字符串
 * @param length - 字符串长度
 * @returns 随机字符串
 */
export const generateRandomString = (length: number): string => {
  const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
  let result = '';
  
  for (let i = 0; i < length; i++) {
    result += characters.charAt(Math.floor(Math.random() * characters.length));
  }
  
  return result;
};

/**
 * 防抖函数
 * @param func - 要防抖的函数
 * @param wait - 等待时间（毫秒）
 * @returns 防抖后的函数
 */
export const debounce = <T extends (...args: any[]) => any>(
  func: T,
  wait: number
): ((...args: Parameters<T>) => void) => {
  let timeout: NodeJS.Timeout;
  
  return (...args: Parameters<T>) => {
    clearTimeout(timeout);
    timeout = setTimeout(() => func.apply(null, args), wait);
  };
};

/**
 * 节流函数
 * @param func - 要节流的函数
 * @param limit - 限制时间（毫秒）
 * @returns 节流后的函数
 */
export const throttle = <T extends (...args: any[]) => any>(
  func: T,
  limit: number
): ((...args: Parameters<T>) => void) => {
  let inThrottle: boolean;
  
  return (...args: Parameters<T>) => {
    if (!inThrottle) {
      func.apply(null, args);
      inThrottle = true;
      setTimeout(() => (inThrottle = false), limit);
    }
  };
};

/**
 * 深拷贝对象
 * @param obj - 要拷贝的对象
 * @returns 拷贝后的对象
 */
export const deepClone = <T>(obj: T): T => {
  if (obj === null || typeof obj !== 'object') {
    return obj;
  }
  
  if (obj instanceof Date) {
    return new Date(obj.getTime()) as any;
  }
  
  if (obj instanceof Array) {
    return obj.map(item => deepClone(item)) as any;
  }
  
  if (typeof obj === 'object') {
    const cloned = {} as any;
    Object.keys(obj).forEach(key => {
      cloned[key] = deepClone((obj as any)[key]);
    });
    return cloned;
  }
  
  return obj;
};

/**
 * 获取查询参数
 * @param url - URL 字符串
 * @returns 查询参数对象
 */
export const getQueryParams = (url: string): Record<string, string> => {
  const params: Record<string, string> = {};
  const urlObj = new URL(url);
  
  urlObj.searchParams.forEach((value, key) => {
    params[key] = value;
  });
  
  return params;
};

/**
 * 验证邮箱格式
 * @param email - 邮箱地址
 * @returns 是否为有效邮箱
 */
export const validateEmail = (email: string): boolean => {
  const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
  return emailRegex.test(email);
};

/**
 * 验证手机号格式
 * @param phone - 手机号
 * @returns 是否为有效手机号
 */
export const validatePhone = (phone: string): boolean => {
  const phoneRegex = /^1[3-9]\d{9}$/;
  return phoneRegex.test(phone);
};