import { Bytes, write } from '@fuman/io'
import { $ } from 'zx'

export async function generateOpusImageBlob(image: Uint8Array) {
  // todo we should probably not use ffprobe here but whatever lol
  const proc = $`ffprobe -of json -v error -show_entries stream=codec_name,width,height pipe:0`
  proc.stdin.write(image)
  proc.stdin.end()
  const json = await proc.json()

  const img = json.streams[0]
  // https://www.rfc-editor.org/rfc/rfc9639.html#section-8.8
  const mime = img.codec_name === 'mjpeg' ? 'image/jpeg' : 'image/png'
  const description = 'Cover Artwork'

  const res = Bytes.alloc(image.length + 128)
  write.uint32be(res, 3) // picture type = album cover
  write.uint32be(res, mime.length)
  write.rawString(res, mime)
  write.uint32be(res, description.length)
  write.rawString(res, description)
  write.uint32be(res, img.width)
  write.uint32be(res, img.height)
  write.uint32be(res, 0) // color depth
  write.uint32be(res, 0) // color index (unused, for gifs)
  write.uint32be(res, image.length)
  write.bytes(res, image)

  return res.result()
}