import { existsSync, createReadStream } from 'node:fs'
import { fileEtag, stillPath, existingStillThumbPath, stillThumbPath, sniffImageType } from '~/server/utils/library'

export default defineEventHandler((event) => {
  const { owner } = assertLibraryOwner(event)
  const id = String(getRouterParam(event, 'id') || '')
  const still = getStill(owner, id)
  assertFolderAccess(event, still.folderId)
  const wantThumb = String(getQuery(event).thumb || '') === '1'
  const original = stillPath(owner, still.id)

  if (wantThumb) {
    const path = existingStillThumbPath(owner, id)
    if (path && path !== original && existsSync(path)) {
      const etag = fileEtag(path)
      setHeader(event, 'ETag', etag)
      setHeader(event, 'Cache-Control', 'public, max-age=86400')
      if (getHeader(event, 'if-none-match') === etag) {
        setResponseStatus(event, 304)
        return null
      }
      setHeader(event, 'Content-Type', 'image/jpeg')
      return sendStream(event, createReadStream(path))
    }
    void stillThumbPath(owner, id).catch(() => null)
    setHeader(event, 'Cache-Control', 'no-store')
    setResponseStatus(event, 204)
    return null
  }

  if (!existsSync(original)) {
    throw createError({ statusCode: 404, statusMessage: 'Image file is missing' })
  }

  const etag = fileEtag(original)
  setHeader(event, 'ETag', etag)
  setHeader(event, 'Cache-Control', 'private, max-age=3600')
  if (getHeader(event, 'if-none-match') === etag) {
    setResponseStatus(event, 304)
    return null
  }
  setHeader(event, 'Content-Type', sniffImageType(original))
  return sendStream(event, createReadStream(original))
})