export async function getFileById(fileId: string): Promise<Blob> {
  const res = await fetch(`/api/v1/files?key=${encodeURIComponent(fileId)}`)

  if (res.ok) return await res.blob()

  const text = await res.text()
  let json: unknown = null
  if (text) {
    try {
      json = JSON.parse(text) as unknown
    } catch {
      json = null
    }
  }

  const maybeObj = (typeof json === "object" && json !== null ? json : null) as {
    code?: unknown
    message?: unknown
    msg?: unknown
  } | null

  const code = (typeof maybeObj?.code === "number" ? maybeObj.code : res.status) as number
  const msg =
    typeof maybeObj?.message === "string"
      ? maybeObj.message
      : typeof maybeObj?.msg === "string"
        ? maybeObj.msg
        : text || res.statusText || "Request failed"

  if (res.status === 401 || code === 401) throw new Error("UNAUTHORIZED")

  throw { code, msg }
}