export const DEFAULT_HEADER_LOGO_URL = '/brand/header-logo.png'
export const DEFAULT_LOGIN_LOGO_URL = '/brand/login-logo.png'
export const DEFAULT_FAVICON_URL = '/brand/favicon.png'

export const DEFAULT_SITE_NAME = '由壹点3D素材'
export const BRAND_LOGO_FALLBACK_TEXT = '由壹点'

const LOCAL_BRAND_ASSET_PATTERN = /^\/brand\/[A-Za-z0-9][A-Za-z0-9._/-]*$/

/**
 * 系统设置只保存可长期访问的品牌资源地址。
 * 展示用的 /api/proxy-media 地址是临时派生值，绝不能写回数据库。
 */
export function isAllowedBrandLogoUrl(value: string): boolean {
  const trimmed = value.trim()
  if (!trimmed || trimmed.includes('..') || trimmed.includes('\\')) {
    return false
  }

  if (LOCAL_BRAND_ASSET_PATTERN.test(trimmed)) {
    return true
  }

  try {
    const parsed = new URL(trimmed)
    return (
      parsed.protocol === 'https:' &&
      parsed.hostname === 's3.jiansun.vip' &&
      parsed.port === '' &&
      parsed.username === '' &&
      parsed.password === '' &&
      parsed.pathname.startsWith('/gongxiangpan/') &&
      parsed.search === '' &&
      parsed.hash === ''
    )
  } catch {
    return false
  }
}

export function normalizeBrandLogoUrl(value: unknown): string | null {
  if (typeof value !== 'string') return null
  const trimmed = value.trim()
  return isAllowedBrandLogoUrl(trimmed) ? trimmed : null
}