import { ref } from 'vue'
import { createFileAccess, rewriteFileHtml, rewriteFileNodes } from './file-access-core'
import { isDevEnv } from './app'

export const fileAccessRevision = ref(0)
const client = createFileAccess({
  appId: import.meta.env.VITE_FILE_ACCESS_APP_ID,
  kid: import.meta.env.VITE_FILE_ACCESS_KEY_ID,
  key: import.meta.env.VITE_FILE_ACCESS_KEY,
  baseUrl: () => isDevEnv() ? (import.meta.env.VITE_IMAGE_DEV_PATH || import.meta.env.VITE_APP_DEV_SERVICE) : import.meta.env.VITE_APP_PROD_IMAGE,
  allowedOrigins: [import.meta.env.VITE_IMAGE_DEV_PATH, import.meta.env.VITE_APP_DEV_SERVICE, import.meta.env.VITE_APP_PROD_IMAGE, import.meta.env.VITE_APP_PROD_SERVICE, ...(import.meta.env.VITE_FILE_ACCESS_ALLOWED_ORIGINS || '').split(',')],
})
let timer: ReturnType<typeof setInterval> | undefined
let pending: Promise<void> | undefined
let lastSync = 0
const retried = new Map<string, number>()
export function fileUrl(source?: string | null): string {
  void fileAccessRevision.value
  try { return client.url(source) } catch { return '' }
}
export const accessFileUrl = (source?: string | null) => isProtectedFile(source) ? fileUrl(source) : (source || '')
export const fileUrls = (sources: any) => Array.isArray(sources) ? sources.map(accessFileUrl) : []
export const originalFileUrl = (source?: string | null) => client.strip(source)
export const resolveFileUrl = (source?: string | null) => client.resolve(source)
export const fileUploadHeaders = (source: string) => client.uploadHeaders(source)
export const fileHtml = (html: string) => rewriteFileHtml(html, accessFileUrl)
export const stripFileHtml = (html: string) => rewriteFileHtml(html, originalFileUrl)
export const fileNodes = (nodes: any) => rewriteFileNodes(nodes, accessFileUrl)
export const isProtectedFile = (source?: string | null) => { try { return client.protected(source) } catch { return false } }
export async function refreshFileAccess(force = false): Promise<void> {
  if (pending) return pending
  if (!force && Date.now() - lastSync < 60000) return
  pending = (async () => {
    const started = Date.now()
    try {
      const result: any = await readAccessInfo()
      const info = result?.data || result
      if (info?.serverTime) client.synchronize(Number(info.serverTime), Number(info.ttlSeconds), Date.now() - started)
      lastSync = Date.now()
    } catch { /* Retain the last clock offset and signed access; never fall back to a bare URL. */ }
    finally { fileAccessRevision.value++; pending = undefined }
  })()
  return pending
}
export function startFileAccess() {
  if (!timer) timer = setInterval(() => { fileAccessRevision.value++ }, 60000)
  void refreshFileAccess()
}
export function stopFileAccess() { if (timer) clearInterval(timer); timer = undefined }
export async function retryFileAccess(source?: string | null) {
  if (!isProtectedFile(source)) return false
  const raw = originalFileUrl(source), previous = retried.get(raw) || 0
  if (Date.now() - previous < 30 * 60 * 1000) return false
  if (retried.size >= 2048) retried.clear()
  retried.set(raw, Date.now())
  const previousUrl = fileUrl(source)
  await refreshFileAccess(true)
  client.clear()
  if (fileUrl(source) === previousUrl) {
    await new Promise(resolve => setTimeout(resolve, 1100))
    client.clear()
  }
  fileAccessRevision.value++
  return true
}
export function installFileAccess(app: any) {
  if (typeof uni.addInterceptor === 'function') {
    uni.addInterceptor('uploadFile', {
      invoke(options: any) {
        options.header = { ...(options.header || {}), ...fileUploadHeaders(options.url) }
      },
    })
  }
  Object.assign(app.config.globalProperties, {
    $fileUrl: accessFileUrl, $fileUrls: fileUrls, $fileHtml: fileHtml, $fileNodes: fileNodes, $fileRetry: retryFileAccess,
  })
  if (typeof document !== 'undefined') {
    document.addEventListener('click', event => {
      const anchor = (event.target as Element | null)?.closest?.('a[href]')
      const href = anchor?.getAttribute('href')
      if (event.defaultPrevented || !href || !isProtectedFile(href)) return
      event.preventDefault()
      event.stopImmediatePropagation()
      openFileLink(href)
    }, true)
  }
  app.mixin({
    onShow() { startFileAccess() },
  })
  uni.onNetworkStatusChange(({ isConnected }: any) => {
    if (isConnected) { retried.clear(); void refreshFileAccess(true) }
  })
}

function readAccessInfo(): Promise<any> {
  return new Promise((resolve, reject) => uni.request({
    url: client.resolve('/admin/sys-file/oss/access-info'), method: 'GET', timeout: 5000,
    success: (response: any) => response.statusCode === 200 ? resolve(response.data) : reject(new Error('File clock unavailable')),
    fail: reject,
  }))
}
/** All preview entrypoints sign at the moment of opening, including already-open pages. */
export function previewFiles(options: any) {
  const values = { ...options, urls: fileUrls(options.urls) }
  if (typeof options.current === 'string') values.current = fileUrl(options.current)
  return uni.previewImage(values)
}
/** One clock/signature retry. Only successful downloads are delivered to the caller. */
export function downloadFile(options: any) {
  const run = (retry: boolean) => uni.downloadFile({
    ...options, url: fileUrl(options.url),
    success: async (response: any) => {
      if (response.statusCode === 200) { options.success?.(response); options.complete?.(response); return }
      if (retry && response.statusCode === 403 && isProtectedFile(options.url)) {
        await refreshFileAccess(true); client.clear(); run(false); return
      }
      const error = { errMsg: '文件下载失败', statusCode: response.statusCode }
      options.fail?.(error); options.complete?.(error)
      if (!options.fail) uni.showToast({ title: error.errMsg, icon: 'none' })
    },
    complete: undefined,
    fail: (error: any) => { options.fail?.(error); options.complete?.(error) },
  })
  return run(true)
}

/** Open owned rich-text file links without navigating the browser to the file endpoint. */
export function openFileLink(source: string) {
  const match = /[?&]fileName=([^&#]*)/.exec(resolveFileUrl(source))
  const filename = match ? decodeURIComponent(match[1].replace(/\+/g, ' ')) : '文件'
  if (/\.(?:jpe?g|png|gif|webp|bmp|svg|ico)$/i.test(filename)) {
    return previewFiles({ urls: [source] })
  }
  return downloadFile({
    url: source,
    success: (response: any) => {
      if (typeof document !== 'undefined') {
        const anchor = document.createElement('a')
        anchor.href = response.tempFilePath
        anchor.download = filename
        document.body.appendChild(anchor)
        anchor.click()
        anchor.remove()
      } else {
        uni.openDocument({
          filePath: response.tempFilePath, showMenu: true,
          fail: () => uni.showToast({ title: '无法打开此文件', icon: 'none' }),
        })
      }
    },
  })
}