export function validateEmail(email: string): boolean {
  if (!email || typeof email !== 'string') {
    return false;
  }
  const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
  return emailRegex.test(email);
}

export function validatePhone(phone: string): boolean {
  if (!phone || typeof phone !== 'string') {
    return false;
  }
  const phoneRegex = /^1[3-9]\d{9}$/;
  return phoneRegex.test(phone);
}

export function validatePassword(password: string): boolean {
  if (!password || typeof password !== 'string') {
    return false;
  }
  return password.length >= 8;
}

export function validateUrl(url: string): boolean {
  if (!url || typeof url !== 'string') {
    return false;
  }
  try {
    new URL(url);
    return true;
  } catch {
    return false;
  }
}

export function validateRequired(value: unknown): boolean {
  if (value === null || value === undefined) {
    return false;
  }
  if (typeof value === 'string') {
    return value.trim().length > 0;
  }
  if (typeof value === 'number') {
    return !isNaN(value);
  }
  if (Array.isArray(value)) {
    return value.length > 0;
  }
  return true;
}

export function validateLength(value: string, min: number, max: number): boolean {
  if (typeof value !== 'string') {
    return false;
  }
  return value.length >= min && value.length <= max;
}

export function validateRange(value: number, min: number, max: number): boolean {
  if (typeof value !== 'number' || isNaN(value)) {
    return false;
  }
  return value >= min && value <= max;
}

export function validateChineseId(id: string): boolean {
  if (!id || typeof id !== 'string') {
    return false;
  }
  const idRegex = /^[1-9]\d{5}(18|19|20)\d{2}(0[1-9]|1[0-2])(0[1-9]|[12]\d|3[01])\d{3}[\dXx]$/;
  return idRegex.test(id);
}

export function validateUsername(username: string): boolean {
  if (!username || typeof username !== 'string') {
    return false;
  }
  const usernameRegex = /^[a-zA-Z0-9_]{3,20}$/;
  return usernameRegex.test(username);
}