import { joinFileUrl, API_HOST } from '@/config'

const PLACEHOLDER_PATHS = ['/static/logo.png']

/** 是否外链或 data URL */
export function isExternalUrl(url) {
  if (!url) return false
  return /^(https?:|data:|\/\/)/i.test(String(url).trim())
}

/** 去掉 /dev-api 等代理前缀，得到后端真实路径 */
function stripApiProxyPrefix(path) {
  return String(path).replace(/^\/(dev-api|prod-api|shop-api)/, '') || '/'
}

function isPlaceholderPath(path) {
  const raw = String(path || '').trim()
  return PLACEHOLDER_PATHS.includes(raw)
}

/**
 * 是否已是可直接使用的图片地址（避免重复拼接）
 */
export function isResolvedFileUrl(url) {
  if (!url) return false
  const raw = String(url).trim()
  if (isExternalUrl(raw)) return true
  if (raw.startsWith('/static/')) return true
  const apiHost = String(API_HOST).replace(/\/$/, '')
  return !!(apiHost && (raw === apiHost || raw.startsWith(`${apiHost}/`)))
}

/**
 * 将后端返回的图片路径转为可展示的完整 URL（可重复调用）
 * 结果形如：http://192.168.1.6:8020/profile/upload/xxx.jpg
 * @param {string} path bannerImage / categoryPic / mainPic 等
 */
export function resolveFileUrl(path) {
  if (path == null || path === '') {
    return ''
  }
  let raw = String(path).split(',')[0].trim()
  if (!raw || isPlaceholderPath(raw)) {
    return ''
  }
  if (isExternalUrl(raw)) {
    return raw
  }
  if (raw.startsWith('/static/')) {
    return raw
  }
  const apiHost = String(API_HOST).replace(/\/$/, '')
  if (apiHost && (raw === apiHost || raw.startsWith(`${apiHost}/`))) {
    return raw
  }
  if (/^\/(dev-api|prod-api|shop-api)\//i.test(raw)) {
    raw = stripApiProxyPrefix(raw)
  }
  const normalized = raw.startsWith('/') ? raw : `/${raw}`
  return joinFileUrl(normalized)
}

/**
 * 将逗号分隔或数组形式的图片路径转为完整 URL 列表
 * @param {string|string[]|null|undefined} pathOrList
 */
export function resolveFileUrlList(pathOrList) {
  if (pathOrList == null || pathOrList === '') return []
  if (Array.isArray(pathOrList)) {
    return pathOrList.map((item) => resolveFileUrl(item)).filter(Boolean)
  }
  return String(pathOrList)
    .split(',')
    .map((s) => resolveFileUrl(s.trim()))
    .filter(Boolean)
}