import { existsSync, createReadStream } from 'node:fs'
import { clipLastFramePath, clipVideoPath, fileEtag, sniffImageType } from '~/server/utils/library'

export default defineEventHandler(async (event) => {
  const { owner } = assertLibraryOwner(event)
  const id = String(getRouterParam(event, 'id') || '')
  const clip = getClip(owner, id)
  assertFolderAccess(event, clip.folderId)
  const videoPath = clipVideoPath(owner, clip.id)
  if (!existsSync(videoPath)) {
    throw createError({ statusCode: 404, statusMessage: 'Video file is missing' })
  }
  const framePath = clipLastFramePath(owner, clip.id)
  if (!existsSync(framePath)) {
    try {
      await extractLastFrame(videoPath, framePath)
    } catch (error) {
      const message = error instanceof Error ? error.message : String(error)
      throw createError({ statusCode: 500, statusMessage: `Could not extract the last frame: ${message}` })
    }
  }
  const etag = fileEtag(framePath)
  setHeader(event, 'ETag', etag)
  setHeader(event, 'Cache-Control', 'private, max-age=86400, stale-while-revalidate=604800')
  if (getHeader(event, 'if-none-match') === etag) {
    setResponseStatus(event, 304)
    return null
  }
  setHeader(event, 'Content-Type', sniffImageType(framePath))
  return sendStream(event, createReadStream(framePath))
})